Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
DETAILED OFFICE ACTION
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 2024-10-03 in compliance with the provisions of 37 CFR 1.97 has been considered by the examiner and made of record in the application file.
Claim Status
Claims 1-15 are pending in this application and are under examination in this Office Action. No claims have been allowed.
Priority
Applicant's claim for foreign priority under 35 U.S.C. 119(a)-(d) to European Patent Application No. 22166772.8, filed April 5, 2022, is acknowledged. The present application is the U.S. national stage under 35 U.S.C. 371 of International Application No. PCT/EP2023/058119, filed March 29, 2023.
Drawings
The drawings are objected to under 37 CFR 1.83(a). The drawings must show every feature of the invention specified in the claims. Therefore, the claimed limitation within claim 9 is not shown within the drawings, namely a distance detector configured to estimate a communication distance from a remote device intended to establish optical wireless communication with the device. Figures 1-7 do not identify or illustrate any distance detector as a component of the optical wireless communication device 200. Nor are the additional limitations recited in claims 10 and 11 shown, namely that the distance detector is a Time-of-
Flight (ToF) sensor or that the distance detector estimates the communication distance based on Time-of-Arrival, signal strength, or phase difference information of one or more received signals from the remote device. Further, the claimed limitation within claim 12 is not shown within the drawings, namely that the optical wireless communication device further comprises an optical data receiver configured to receive optical data signals. Figures 5 and 6 depict remote receivers 300 and 400 physically separate from the optical wireless communication device 200, and Figure 6 depicts optical data receiver 401 and auxiliary receivers 402 and 403 as components of the remote receiver 400, not as components of the optical wireless communication device 200. No figure shows an optical data receiver incorporated within the optical wireless communication device 200. These feature(s) must be shown or the feature(s) canceled from the claim(s). No new matter should be entered.
Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet
should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. The figure or figure number of an amended drawing should not be labeled as "amended." If a drawing figure is to be canceled, the appropriate figure must be removed from the replacement sheet, and where necessary, the remaining figures must be renumbered and appropriate changes made to the brief description of the several views of the drawings for consistency. Additional replacement sheets may be necessary to show the renumbering of the remaining figures. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either "Replacement Sheet" or "New Sheet" pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
Applicant's invention as claimed:
Double Patenting
The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the "right to exclude" granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the claims at issue are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See,
e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Langi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); and In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969).
A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome a rejection based on a nonstatutory double patenting ground provided the reference application or patent either is shown to be commonly owned with this application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b).
Guidance and examples of acceptable terminal-disclaimer language are provided in MPEP § 1490. Any terminal disclaimer filed to obviate this rejection must comply with 37 CFR 1.321(c), disclaim the terminal portion of any patent granted on this application that would extend beyond U.S. Patent No. 12,627,375 B2, and include the required agreement that any patent granted on this application will be enforceable only for and during the period that it and the reference patent are commonly owned.
The instant application and U.S. Patent No. 12,627,375 B2 are commonly owned by Signify Holding B.V. The instant application identifies Signify Holding B.V. as applicant, and U.S. Patent No. 12,627,375 B2 identifies Signify Holding B.V. as assignee. Accordingly, the common-ownership requirement for consideration of nonstatutory double patenting is satisfied.
Claims 6 and 7 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 5 and 6 of U.S. Patent No. 12,627,375 B2 in view of Ding et al. (AU2021103975A4), Lee et al. (US20110092152A1), and Cho et al. (“Securing Visible Light Communications with Spatial Jamming,” IEEE ICC 2019).
Although the claims at issue are not identical, they are not patentably distinct from each other because of the following:
With respect to claim 6, claim 5 of U.S. Patent No. 12,627,375 B2 has the similar limitations as underlined below:
Instant application
U.S. Patent No. 12,627,375 B2
As per claim 6, The device of claim 4, wherein the masking transmitter and the further masking transmitter are further configured to send alignment information to assist a beam alignment between the data transmitter and a remote receiver.
As per claim 5, The OWC transceiver of claim 4, wherein the controller is arranged to perform an alignment operation with the further OWC transceiver system, wherein the controller is configured to:generate unique orientation beacons comprising identifying information for each one of the plurality of optical transmitters;control each of the plurality of transmitters to transmit their respective orientation beacon;receive, in the output of the TIA, feedback transmitted by the communication partner on a detection from a communication partner on a unique attribute of an optical transmitter of the OWC transceiver system in a beacon from the OWC transceiver system; andselect a proper subset from the plurality of optical transmitters for transmitting the outgoing data to the further OWC transceiver system based on the feedback.
Claim 6 depends from claim 4, which depends from claim 1. Therefore, claim 6 incorporates every limitation of claims 1 and 4, and the complete subject matter of claim 6 not merely its final alignment information limitation is evaluated. The features of claim 6 that are not expressly present in claim 5 of U.S. Patent No. 12,627,375 B2 are: “a data transmitter configured to transmit an optical data signal; a masking transmitter configured to transmit an optical masking signal; wherein the optical masking signal comprising a wavelength component substantially identical to a wavelength component of the optical data signal; the device configured to set a certain distance by controlling at least one of the data transmitter and the masking transmitter, such that a coverage area of the optical data signal is overlapped with a coverage area of the optical masking signal to a certain extent at the certain distance, keeping a signal to noise ratio of the optical data signal below a threshold and complicating a recovery of the optical data signal by another device located at and beyond that certain distance,” and “at least one further masking transmitter ... configured to transmit a further optical masking signal ... such that the coverage area of the optical data signal is overlapped by a combined coverage area of the optical masking signal and the at least one further optical masking signal at the certain distance from the device.”
However, in an analogous art, Ding teaches a secure visible-light wireless system using optical data and artificial-noise sources: “Under the configuration of spatial distributed or centralized visible light wireless transmitters, the receiving signal-to-noise ratio of potential eavesdropper Eve is degraded by means of heterogeneous artificial noise sources, and meanwhile, the receiving signal-to-noise ratio of target user Bob is ensured without being negatively interfered by artificial noise.” [Ding, AU 2021103975 A4, Abstract, p. 2].
Ding further teaches a centralized optical transmitter having multiple optical source sub-arrays: “only a single visible light wireless transmitter is placed on the ceiling ... which is composed of Nsub-array small-sized solid-state light source (such as LED) sub-arrays, and the light source sub-arrays are used as visible light signal transmitters, and each light source sub-array has differentiated radiation characteristics.” [Ding, p. 9; see also pp. 7-10 and Figs. 2, 4, and 6].
Ding additionally teaches simultaneous data and masking/artificial-noise transmission: “part of the transmission power is used for transmitting data symbols, while the rest is used for transmitting artificial noise,” and “the data symbols and artificial noise mixed signals ... are simultaneously loaded on the corresponding distributed light source array or centralized light source sub-array.” [Ding, pp. 11-13 and 21-23].
Ding expressly teaches overlapping optical coverage and the resulting SNR effect: “overlapping coverage of differentiated multi-channel optical signals at the same user position” provides “the necessary link configuration basis for artificial noise scrambling,” while the disclosed method “degrades the receiving signal-to-noise ratio of potential eavesdropping user Eve” and protects Bob from the artificial noise. [Ding, pp. 23-25; Figs. 2-7].
Cho further provides a direct optical teaching that the same VLC LED transmitter architecture may carry either the data signal or the jamming signal: “all of the LED transmitters can share the data and jamming signals by wire cables and are capable of selectively transmitting either a data or jamming signal,” and “the modulated signal s(t) can be described as s(t) = αIDC x(t) or s(t) = αIDC j(t) ... [and] the emitted optical power of each LED can be PTX(t) = η(IDC + s(t)).” [Cho, pp. 1-3, Abstract, Section II-C, Eqs. (5a)-(5b), Figs. 1-2].
Cho therefore teaches data and random jamming as alternative modulation signals applied to the same type of visible-light LED transmitter and combined at a photodetector as optical data and optical interference.
Lee additionally teaches that effective spatial jamming uses the same frequency as the communication source.
A person of ordinary skill in the optical wireless art would consequently have found it obvious to operate the optical masking signal with a wavelength component common to the optical data signal so that the masking energy occupies the same optical reception band and cannot be removed merely by wavelength filtering. This supplies the claimed substantially identical wavelength component in the optical domain while retaining the established data and jamming functions.
Ding does not expressly define the claimed adjustable distance boundary. However, in an analogous secure-communication art, Lee teaches a jamming boundary formed in the overlap of communication and jamming coverage: “a jamming boundary (b) is formed in the common area of the area C in which the terminal 200 can communicate with the access point 100 and the area (Cj) in which the terminal 200 receives noise from the jammer 300.” [Lee, ¶ [0037], Fig. 2].
Lee teaches the communication consequence at opposite sides of that boundary: “when the terminal 200 is provided on the side of the access point 100 with reference to the jamming boundary (b) ... the terminal 200 can receive a signal ... and when the terminal 200 is provided on the side of the jammer 300 ... the terminal 200 cannot receive the signal ... because of noise of the jammer 300.” [Lee, ¶ [0038]].
Lee further teaches the same-frequency relationship and adjustable location of the boundary: “assuming that the access point 100 and the jammer 300 use the same antenna and frequency,” the boundary depends on signal powers and distances; “as power ... of the jammer 300 is increased ... the jamming boundary (b) approaches the access point 100.” [Lee, ¶ [0041]-[0048], Fig. 4; see also claims 1-7].
Lee also teaches using multiple jammers surrounding the communication source to create a secure region: “The case in which an access point 100 is surrounded by a plurality of jammers” is described, including secure wireless zones formed by two and four jammers. [Lee, ¶ [0052]-[0067], Figs. 5-6].
One of ordinary skill in the art would have been motivated to modify the multi-transmitter optical alignment system of issued claim 5 in three predictable steps.
First, Ding and Cho would have led the skilled artisan to use individually controllable optical transmitters as a data-transmitter path and as artificial-noise or masking-transmitter paths, because both references address physical-layer security in optical wireless communication and teach that optical jamming degrades an eavesdropper while preserving the intended optical link. Second, Lee would have led the artisan to control the relative coverage, power, and placement of the data and masking paths to establish a selected boundary at which the received data-to-noise relationship falls below a usable level.
Third, Cho’s use of the same VLC LED architecture for either data or jamming, together with Lee’s same-frequency operation, would have led the artisan to provide a common optical wavelength component.
These modifications use the issued patent’s existing individually driven optical transmitters, orientation beacons, feedback, and beam selection for their established alignment functions while adding known optical security functions to establish a secure spatial boundary.
Accordingly, issued claim 5 together with Ding, Lee, and Cho teaches or would have suggested every limitation of the complete claim 6 dependency chain.
Each component continues to perform its known function: the issued optical transmitters transmit orientation information and support beam alignment; the Ding/Cho optical paths transmit data and artificial noise; and the Lee control relationship sets the spatial signal/noise boundary through overlap, power, and spacing.
The combination therefore would have produced the predictable result of an aligned optical data link that remains usable within a selected distance and is masked at and beyond that distance. Claim 6 is thus not patentably distinct from claim 5 of U.S. Patent No. 12,627,375 B2 in view of Ding, Lee, and Cho, because the difference is no more than the predictable use of prior-art elements according to their established functions.
With respect to claim 7, claim 6 of U.S. Patent No. 12,627,375 B2 has the similar limitations as underlined below:
Instant application
U.S. Patent No. 12,627,375 B2
As per claim 7, The device of claim 6, wherein the masking transmitter and the further masking transmitter are further configured to use Code-Division Multiple Access, CDMA, to send the alignment information, respectively; wherein the alignment information is transmitted at a frequency range different from either the optical masking signals or the optical data signal.
As per claim 6, The OWC transceiver of claim 5, wherein the orientation beacons are low frequency, CDMA beacons that are transmitted out-of-band from the output data, thereby allowing optical transmitters to transmit orientation beacons and output data simultaneously; and wherein the feedback on the detection from the communication partner is a beacon transmitted by the communication partner with an inverted version of the CDMA sequence as was transmitted by a respective one of the optical transmitters received by the communication partner.
Claim 7 depends from claim 6 and therefore incorporates the complete limitations of claims 1, 4, and 6. Issued claim 6 expressly recites the closest additional subject matter: low-frequency CDMA optical orientation beacons, transmission out-of-band from optical output data, transmitter-specific CDMA signaling, and simultaneous transmission of auxiliary beacons and data. Present claim 7 additionally identifies the beacon-transmitting optical paths as the masking transmitter and further masking transmitter and requires the alignment-information frequency range to be different from the optical masking signals as well as the optical data signal.
Ding supplies those inherited optical masking features by teaching visible-light transmitters that simultaneously carry data symbols and artificial noise, including a centralized transmitter formed from multiple light-source sub-arrays, with the artificial noise degrading Eve’s SNR while not negatively interfering with Bob. The artificial-noise power is distributed among multiple optical source directions, and the data and artificial-noise signals are simultaneously loaded on the optical source array. [Ding, Abstract, pp. 7-13 and 20-25, Figs. 2-7].
Lee supplies the inherited adjustable secure-distance boundary by teaching a same-frequency jammer and communication source having overlapping coverage, an SNR-defined boundary separating a receivable side from a non-receivable side, movement of the boundary through relative power control, and secure zones produced by multiple jammers. These teachings establish a known mechanism for spatially confining a communication area through signal/noise coverage and power control. [Lee, ¶ [0033]-[0048] and [0052]-[0067], Figs. 2-6, claims 1-7].
U.S. Patent No. 12,627,375 B2 further explains the practical separation represented by issued claim 6: “The out-of-band (OOB) emitted beacons preferably use the same optical transmitters and receiver as the main optical signal,” while the high-speed main signal is routed to the baseband and the OOB signal is separated by a low-pass filter and processed through a low-bandwidth path. [U.S. Patent No. 12,627,375 B2, pp. 7-8, Fig. 6].
Ding teaches that the data symbols and artificial-noise signals are mixed and simultaneously loaded on the same optical source array.
Thus, in the modified optical-security system, the data and masking signals form the main optical transmission path, while the low-frequency CDMA alignment beacons occupy the separate out-of-band path.
The beacon frequency range is therefore different from both the optical data signal and the optical masking/artificial-noise signal carried by the main path.
One of ordinary skill in the art would have been motivated to apply the issued claim 6 low-frequency, out-of-band CDMA orientation-beacon technique to the individually controllable masking-transmitter paths of the Ding-Lee-Cho secure optical system.
The issued claim itself identifies the benefit: simultaneous beacon and data transmission and reliable identification of the transmitter path detected by the remote communication partner. Applying that known signaling technique to the masking transmitters would permit the remote receiver to distinguish and align the data and masking paths while the data and artificial-noise signals remain on the main optical channel. Because the issued patent already uses the same optical transmitter for the high-speed path and a separate low-frequency OOB beacon path, and Ding already mixes the data and artificial-noise signals on the main source array, the resulting frequency separation from both data and masking signals would have been predictable.
Accordingly, issued claim 6 together with Ding, Lee, and Cho teaches or would have suggested every limitation of the complete claim 7 dependency chain.
The difference between claim 7 and issued claim 6 is the predictable application of the issued patent’s low-frequency, out-of-band CDMA orientation-beacon arrangement to known optical masking transmitters in a known spatial-jamming system. Each element continues to perform its established function, and the combination predictably provides simultaneous optical data, masking, and separately identifiable alignment signaling. Claim 7 is therefore not patentably distinct from claim 6 of U.S. Patent No. 12,627,375 B2 in view of Ding, Lee, and Cho.
Claim Rejections - 35 USC § 112(b)
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION. —The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
Claims 2, 9, 10 and 11 are rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor, or for pre-AIA the applicant regards as the invention.
Regarding claim 2,
Claim 2 recites that the device is configured to change the certain distance by at least one of: "adjusting a beam angle of at least one of the data transmitter and the masking transmitter tilting at least one of the data transmitter and the masking transmitter to make the coverage areas of the optical masking signal and the optical data signal move towards or away from each other."
As presently written, there is no punctuation, conjunction, or other delimiter separating "the masking transmitter" from "tilting." It is therefore unclear whether "adjusting a beam angle" and "tilting" are intended to define two separate alternatives within the recited "at least one of" arrangement, or whether "tilting" is intended to modify the immediately preceding recitation as part of a single combined limitation. Because the claim does not clearly delineate the alternatives by which the certain distance is changed, the metes and bounds of claim 2 are not reasonably certain, and claim 2 is indefinite.
Regarding claim 9,
Claim 9 depends from claim 1 and recites that the device is "further configured to control the masking transmitter and the further masking transmitter such that the communication distance is within the certain distance."
There is a lack of antecedent basis for "the further masking transmitter" because claim 1 introduces a data transmitter and a masking transmitter, but does not introduce a further masking transmitter. A further masking transmitter is separately introduced in claim 4, from which claim 9 does not depend. As written, it is unclear whether "the further masking transmitter" in claim 9 is intended to refer to the additional masking transmitter recited in claim 4, an additional transmitter that has not been affirmatively introduced in claim 9, or some other component. Accordingly, the identity of the claimed further masking transmitter and the structural scope of the device of claim 9 are unclear, and claim 9 is indefinite.
Regarding claim 10,
Claim 10 recites ("wherein the distance detector is a Time-of-Flight, ToF, sensor.")
Claim 10 depends from claim 9 and incorporates all limitations of claim 9, including the indefinite recitation of "the further masking transmitter" identified above. Although claim 10 further limits the type of distance detector to a Time-of-Flight (ToF) sensor, this additional limitation does not introduce, identify, or otherwise clarify "the further masking transmitter" incorporated from claim 9. Accordingly, the identity of the further masking transmitter remains unclear in claim 10, and the metes and bounds of claim 10 are not reasonably certain. Therefore, claim 10 is indefinite under 35 U.S.C. 112(b).
Regarding claim 11,
Claim 11 recites ("wherein the distance detector is configured to estimate the communication distance based on one of Time-of-Arrival, signal strength, or phase difference information of one or more received signals from the remote device.")
Claim 11 depends from claim 9 and incorporates all limitations of claim 9, including the indefinite recitation of "the further masking transmitter" identified above. Although claim 11 further limits the manner in which the distance detector estimates the communication distance, this additional limitation does not introduce, identify, or otherwise clarify "the further masking transmitter" incorporated from claim 9. Accordingly, the identity of the further masking transmitter remains unclear in claim 11, and the metes and bounds of claim 11 are not reasonably certain. Therefore, claim 11 is indefinite under 35 U.S.C. 112(b).
Accordingly, claims 2, 9, 10 and 11 are indefinite under 35 U.S.C. 112(b).
Claim Rejections – 35 U.S.C. § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for the obviousness rejections set forth in this Office Action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
As reiterated by the Supreme Court in KSR, and as set forth in MPEP 2141 (R-01.2024), II, the factual inquiries of Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), applied for establishing a background for determining obviousness under 35 U.S.C. §103, are summarized as follows:
Determining the scope and content of the prior art;
Ascertaining the differences between the prior art and the claims at issue;
Resolving the level of ordinary skill in the pertinent art; and
Considering objective evidence indicative of obviousness or non-obviousness, if present.
This application currently names joint inventors. In considering patentability of the claims, the examiner presumes that the subject matter disclosed in the prior art was created by another (i.e., not by the inventive entity) unless proven otherwise. Applicant is advised of the obligation under 37 C.F.R. § 1.56 to point out the inventor and effective filing dates of each claim, and any evidence of common ownership/assignment as of the effective filing date, so that the examiner may properly consider the applicability of 35 U.S.C. § 102(b)(2)(C) for any potential 35 U.S.C. § 102(a)(2) prior art against the claimed invention(s).
Claims 1, 3, 4, 13, and 15 are rejected under 35 U.S.C. § 103 as being unpatentable over Ding et al. (AU2021103975A4) in view of Lee et al. (US20110092152A1), further in view of Cho et al. (“Securing Visible Light Communications with Spatial Jamming,” IEEE ICC 2019), and further in view of Mostafa et al. (“Securing Visible Light Communications via Friendly Jamming,” IEEE GLOBECOM Workshops 2014).
Claim 1
For clarity and completeness, claim 1 is addressed limitation-by-limitation. The claimed subject matter requires: (i) an optical wireless communication device having a data transmitter and a masking transmitter; (ii) an optical masking signal having a wavelength component substantially identical to a wavelength component of the optical data signal; (iii) control of at least one transmitter to set a certain distance at which the data and masking coverage areas overlap; and (iv) the overlap to keep the optical-data SNR below a threshold and complicate recovery by a receiver at and beyond the certain distance.
Ding expressly teaches a secure optical wireless communication environment using spatially distributed or spatially centralized visible-light transmitters, useful data, and artificial-noise optical signals.
Ding states in the Abstract: “Under the configuration of spatial distributed or centralized visible light wireless transmitters, the receiving signal-to-noise ratio of potential eavesdropper Eve is degraded by means of heterogeneous artificial noise sources, and meanwhile, the receiving signal-to-noise ratio of target user Bob is ensured without being negatively interfered by artificial noise.” [Ding, p. 2, Abstract; FIGS. 1-7].
Ding further teaches an integrated or centralized optical transmitter formed from multiple optical source sub-arrays: “the configuration of the spatial centralized visible light wireless transmitter is that only a single visible light wireless transmitter is placed on the ceiling ... which is composed of Nsub-array small-sized solid-state light source (such as LED) sub-arrays, and the light source sub-arrays are used as visible light signal transmitters, and each light source sub-array has differentiated radiation characteristics” [Ding, p. 15; FIGS. 2, 4, and 6].
Ding expressly allocates optical transmission power between useful data and masking/artificial noise: “part of the transmission power is used for transmitting data symbols, while the rest is used for transmitting artificial noise, wherein the proportion of the transmission power of useful data symbols is p, and the proportion of the transmission power of artificial noise is (1-p)” [Ding, p. 18, Step 3].
Ding then teaches simultaneous optical emission of the useful data and artificial-noise components: “the data symbols and artificial noise mixed signals ... are simultaneously loaded on the corresponding distributed light source array or centralized light source sub-array” [Ding, p. 19, Step 4].
Ding identifies the different effects at the intended receiver and eavesdropper: “target user Bob will not be affected by artificial noise ... [and] eavesdropper Eve will be significantly influenced by artificial noise” [Ding, p. 20].
Ding further expressly teaches overlapping optical coverage as the basis for secure artificial-noise scrambling: “it is necessary to provide overlapping coverage of differentiated multi-channel optical signals at the same user location ... thus providing the necessary link configuration basis for artificial noise scrambling for secure visible light communication” [Ding, p. 22; FIGS. 2-7].
Cho confirms that distinct LEDs in the same VLC installation may serve as data transmitters or masking transmitters. Cho states: “an LED transmitter can choose to convey data or a jamming signal.” [Cho, p. 1, Abstract].
Cho further teaches that the data and jamming paths are implemented with the same optical transmitter technology and therefore occupy the same visible-light communication medium: “capable of selectively transmitting either a data or jamming signal.” [Cho, p. 2, Section II-A; FIG. 2].
Accordingly, the combination of Ding and Cho teaches an optical wireless communication device having at least one optical source path operated as a data transmitter and at least one optical source path operated as a masking transmitter. Ding’s centralized light-source sub-array provides the claimed single-device implementation, while Cho confirms that optical emitters within the VLC device may be selectively assigned to data and jamming functions.
Mostafa independently and expressly teaches the claimed separate optical data-transmitter and masking-transmitter architecture. “The sender transmits data via a single light source ... [and] the jammer is equipped with multiple light sources, without having access to the transmitted data. A jamming signal is transmitted to increase the interference seen by the eavesdropper.” [Mostafa, p. 1, Abstract and Introduction; FIG. 1].
Mostafa further explains that the data transmitter and jammer use the same optical-fixture technology and are received in the same VLC channel: “The room is illuminated by NJ + 1 identical light fixtures. Each fixture consists of a group of LEDs modulated by the same current signal. Alice, the transmitter, sends her data via a single fixture. On the other hand, the jammer is equipped with NJ fixtures.” [Mostafa, p. 2, Section II-B; FIG. 1].
Mostafa maps the optical superposition at both receivers as “y = hABx + hJBᵀs + wB” and “z = hAEx + hJEᵀs + wE,” where x is the data signal and s is the jamming signal. [Mostafa, p. 2, Eqs. (4a)-(4b)]. These equations expressly show that the data and jamming components are incident together on the same optical receiver and that the masking component degrades the eavesdropper’s received SINR.
Ding and Cho do not expressly state the claimed radial boundary as a selected distance from the device at which recovery crosses a defined SNR threshold. However, within analogous physical-layer security art, Lee expressly teaches that precise missing relationship.
Lee states in the Abstract: “A jamming boundary for dividing an area in which the terminal can communicate with the access point and an area in which the terminal cannot communicate with the access point in an area in which the first area and the second area are overlapped is formed, and the jamming boundary is formed by a ratio between power of a signal transmitted to the terminal by the access point and power of a signal of the noise” [Lee, Abstract; FIGS. 1-6].
Lee expressly teaches movement and control of that boundary by adjusting relative signal power: “as power of the jammer 300 is increased compared to power of the access point 100, the center of the circle forming the jamming boundary moves towards the access point 100, and the radius of the circle forming the jamming boundary is reduced” [Lee, ¶¶ [0047]-[0049]; FIG. 4].
Lee further teaches multiple masking sources operating co-channel with the data source: “When K jammers 300_1, 300_2, ... 300_k using the same frequency are provided near the access point 100 ... a plurality of jammers ... obstruct the terminal 200 in receipt of a signal from the access point 100” [Lee, ¶¶ [0052]-[0054]].
Lee defines communication according to a received signal-to-noise ratio: “the SNR at the point (x,y) is expressed in Equation 5 ... and [the terminal] can communicate with the access point 100 in the area having the value of Equation 5 that is greater than 1” [Lee, ¶¶ [0055]-[0056]].
Lee teaches that the inside of the boundary is the protected useful region: “the inner part of the jamming boundary with respect to the access point 100 is a ‘secure wireless zone’” [Lee, ¶ [0064]; FIGS. 5-6].
Lee expressly states the generality of its spatial-control technique: “the current invention is applicable to the general communication system since it does not depend on a special protocol but uses power of the jammer and a relative position of the terminal” [Lee, ¶ [0071]].
Ding provides the optical propagation facts that make Lee’s boundary control directly applicable. Ding states that differences in received visible-light channel gain are affected by “(1) The link length difference between each spatially distributed visible light wireless transmitter and different receiving positions [and] (2) The intensity difference from each spatial distributed visible light wireless transmitter to different receiving positions.” [Ding, p. 5].
Ding’s LOS channel-gain expression further contains the inverse-square distance factor 1/d² together with beam-radiation intensity and transmitter/receiver angles.
Mostafa similarly models the VLC channel gain with an inverse-square distance term and the LED irradiance and receiver-incidence angles. [Mostafa, p. 2, Eq. (2)].
Lee is analogous art under both recognized inquiries.
First, Lee is in the same field of wireless physical-layer security using a desired transmitter and one or more intentional jammers to create a spatially protected communication region.
Second, Lee is at least reasonably pertinent to the precise problem faced by the inventors controlling where a desired wireless signal remains recoverable as a function of transmitter/jammer power, spacing, propagation distance, and receiver position.
The fact that Lee illustrates RF radiation does not remove its pertinence because Ding and Mostafa expressly show that the corresponding optical received powers depend on the same controllable quantities of path length, transmitter power, beam pattern, and spatial position.
A person of ordinary skill would have had a reasonable expectation of success. Both Lee and the optical references determine receiver usability from the ratio of desired received power to intentional interference/noise. Both superpose desired and jamming energy at the receiver. Both vary received power predictably with transmitter power and spatial separation. Implementing Lee’s boundary calculation with the optical channel-gain equations of Ding or Mostafa therefore requires only substituting measured or modeled optical received powers for the corresponding wireless received powers, not redesigning the communication principle. The expected result is a calculable locus at which the optical data-to-masking ratio crosses the receiver’s demodulation threshold.
The rejection does not require bodily incorporation of Lee’s RF antenna hardware into the optical apparatus. The relied-upon teaching is the known control relationship among desired-signal power, jammer power, separation, receiver position, and a decoding threshold.
Ding, Mostafa, and Cho supply the optical emitters, optical propagation, optical receiver, and optical artificial-noise implementation; Lee supplies the known spatial-boundary control rule. The combined teachings, rather than the physical structures of any single embodiment, are what render the claimed subject matter obvious.
With respect to the limitation “wherein the optical masking signal comprising a wavelength component substantially identical to a wavelength component of the optical data signal,” Ding and Mostafa provide a direct optical basis, while Cho and Lee provide corroborating design incentives. Ding’s transmitted vector contains both the useful-data term and the artificial-noise term and is then simultaneously loaded on the same distributed or centralized LED source array. Thus, within each selected LED/sub-array path, the data and artificial-noise modulation components necessarily ride on the optical carrier emitted by that LED and necessarily share at least one emitted wavelength component. Mostafa likewise uses NJ + 1 identical light fixtures for the data and jammer paths and models the data and jamming components as additive optical contributions at the same photodetector. Cho teaches that the same population of VLC LEDs may be selectively assigned to data or jamming, and Lee teaches that effective spatial jamming is intentionally co-channel with the desired signal.
A person of ordinary skill therefore would have used a common optical detection band—and at least one substantially identical wavelength component so that the artificial-noise energy directly interferes with demodulation of the data component rather than being rejected by wavelength filtering. This is not a conclusory substitution of RF frequency for optical wavelength; it is the ordinary optical implementation expressly suggested by the same-LED, same-fixture, additive-photodetector teachings of Ding, Mostafa, and Cho.
One of ordinary skill in the art would have been motivated to combine Lee’s spatial-boundary control with the optical artificial-noise architectures of Ding, Cho, and Mostafa for several independent, technically grounded reasons.
First, Ding and Mostafa already seek to preserve the intended optical receiver while reducing the eavesdropper’s SINR, but their null-space/beamforming approaches require control of the spatial distribution of optical data and noise.
Lee provides a known way to translate those received-power distributions into an explicit secure boundary.
Second, Cho teaches choosing which LEDs transmit data and which transmit jamming based on expected user and eavesdropper locations; Lee’s boundary calculation provides a predictable quantitative criterion for making that spatial assignment.
Third, Lee expressly teaches changing jammer power and relative placement to move the boundary, while Ding and Mostafa expressly teach that optical channel gain changes with optical power, distance, beam angle, and receiver location. The references therefore invite the same control variables.
Fourth, the modification improves the known optical systems by allowing the unobstructed communication range to be selected for a particular room, receiver location, mobility condition, or security requirement rather than merely maximizing an abstract secrecy-rate objective. Each component continues to perform its established function: the data LEDs transmit the desired optical signal, the jammer LEDs transmit artificial noise in the same optical receiver band, and the controller adjusts relative optical powers and spatial coverage until the modeled or measured data-to-noise ratio crosses the selected decoding threshold at the desired distance. The combination is therefore a predictable use of known elements, supported by a reasonable expectation of success, and does not depend on impermissible hindsight.
Accordingly, Ding in view of Lee, Cho, and Mostafa teaches or would have suggested every limitation of claim 1.
The optical wireless communication device is taught by Ding’s centralized transmitter and the integrated VLC arrangements of Cho and Mostafa. The data transmitter and masking transmitter are expressly taught by Mostafa’s separate Alice and multi-light-source jammer and by Cho’s selectable data/jamming LEDs. The substantially identical wavelength component is taught or at least necessarily suggested by Ding’s composite data/artificial-noise modulation on the same LED source array, Mostafa’s identical LED fixtures and additive optical channel, and Lee’s co-channel jamming requirement. Setting the certain distance by controlling the transmitters and overlapping their coverage areas is taught by Lee’s movable jamming boundary together with the distance-, angle-, and intensity-dependent optical channel gains of Ding and Mostafa. Keeping the optical-data SNR below a threshold and complicating recovery at and beyond the certain distance is expressly taught by Lee’s SNR-defined secure zone and by Ding, Cho, and Mostafa’s degradation of the eavesdropper’s optical SINR.
Claim 1 as a whole would therefore have been obvious before the effective filing date.
Claim 3
With respect to claim 3, Ding, Lee, Cho, and Mostafa teach all limitations of claim 1. Claim 3 further requires the masking transmitter to transmit the optical masking signal at an output power level at least equal to the output power level of the data transmitter.
However, within analogous art, Ding expressly teaches allocating the fixed total optical power between data and artificial noise: “part of the transmission power is used for transmitting data symbols, while the rest is used for transmitting artificial noise” [Ding, p. 18, Step 3].
Lee expressly evaluates equal and greater jammer-power conditions and states: “when power of the access point 100 and the jammer 300 have the same power, the jamming boundary is formed by the straight line” [Lee, ¶ [0046]; FIG. 4].
Lee further teaches: “when power of the jammer 300 becomes greater than power of the access point 100 ... the jamming boundary ... moves toward the access point 100” [Lee, ¶¶ [0048]-[0049]].
One of ordinary skill would have been motivated to select masking power equal to or greater than data-transmitter power because Lee expressly identifies that relationship as controlling the location and strength of the jamming boundary, while Ding requires allocation of optical power to artificial noise sufficient to significantly influence the eavesdropper. Using an equal masking/data power relationship provides a predictable baseline boundary, and increasing the masking power moves the boundary toward the data source and increases the protected effect. This is a routine selection of a disclosed operating range to obtain the known result of stronger masking and a more restrictive communication region. Therefore, claim 3 would have been obvious.
Claim 4
With respect to claim 4, Ding, Lee, Cho, and Mostafa teach all limitations of claim 1. Claim 4 further requires at least one further masking transmitter configured to transmit a further optical masking signal, with the data-signal coverage overlapped by the combined coverage of the masking signals at the certain distance.
However, within analogous art, Ding teaches a plurality of artificial-noise directions or optical source sub-arrays: “the emission power of artificial noise with the proportion of (1-p) is equally distributed in Nsub-array-1 null space directions ... under the configuration of spatial centralized visible light wireless transmitter” [Ding, p. 18].
Ding further teaches that the multiple data/noise components provide: “overlapping coverage of differentiated multi-channel optical signals at the same user position” [Ding, p. 22; FIGS. 2-7].
Lee expressly teaches an access point surrounded by multiple co-channel jammers: “The case in which an access point 100 is surrounded by a plurality of jammers 300_1, 300_2, ... 300_m will now be described” [Lee, ¶ [0052]].
Lee further states: “the area that can be communicated with the access point 100 is included in the area where the areas available for communication with the access point 100 for a plurality of respective jammers ... are overlapped” [Lee, ¶ [0057]].
One of ordinary skill would have been motivated to provide an additional optical masking transmitter because both Ding and Lee teach that multiple independently directed noise sources provide broader and more controllable spatial protection than a single noise source. Ding’s multiple light-source sub-arrays and null-space artificial-noise directions are expressly intended to cover potential eavesdropper locations while preserving the legitimate receiver. Lee teaches that the combined received power of multiple jammers defines a secure zone and that their individual communication areas overlap. Implementing a further masking transmitter in the Ding/Cho/Mostafa optical device would therefore predictably enlarge or shape the combined masking coverage and allow the boundary distance to be set more accurately. Each added transmitter performs the same established masking function, and the combined coverage is the expected superposition of the individual optical fields. Claim 4 would have been obvious.
Claim 13
With respect to claim 13, Ding, Lee, Cho, and Mostafa teach all limitations of claim 1. Claim 13 further recites a system containing the claim-1 optical wireless communication device and a remote optical data receiver located within the certain distance.
However, within analogous art, Ding expressly distinguishes an intended optical receiver from an eavesdropper: “target user Bob will not be affected by artificial noise ... [while] eavesdropper Eve will be significantly influenced by artificial noise” [Ding, p. 20].
Lee places a communicating terminal inside the protected boundary and states: “the inner part of the jamming boundary with respect to the access point 100 is a ‘secure wireless zone’” [Lee, ¶ [0064]; FIGS. 5-6].
The remote optical receiver limitation is also inherent in and expressly contemplated by Ding and Cho because their VLC security systems evaluate received optical data at a legitimate user photodetector. The location requirement would have been obvious from Lee’s boundary definition: the intended receiver must be within the region where the data-to-jamming ratio exceeds the communication threshold, whereas a receiver at or outside the boundary is unable to recover the data.
One of ordinary skill would have placed the intended remote photodetector within that secure region to achieve the stated purpose of useful optical communication. The resulting system merely combines the known secure optical transmitter and intended VLC receiver at their disclosed operative locations. Claim 13 would have been obvious.
Claim 15
For claim 15, the same prior-art facts are applied to the recited method acts rather than merely referring to the apparatus conclusion.
The method requires: transmitting the optical data signal; transmitting the optical masking signal having the common wavelength component; and actively setting the certain distance by controlling at least one transmitter so the optical coverage areas overlap and the data SNR crosses the recovery threshold at and beyond that distance.
Claim 15 recites the method operations corresponding to the claim-1 apparatus.
Ding and Mostafa expressly perform optical data transmission and artificial-noise transmission, Cho selects optical emitters to transmit data or random jamming signals, and Lee controls the resulting communication boundary by relative power and position.
Ding states: “part of the transmission power is used for transmitting data symbols, while the rest is used for transmitting artificial noise” [Ding, p. 18, Step 3].
Mostafa expressly performs the corresponding optical method with separate light-source paths: “Alice, the transmitter, sends her data via a single fixture. On the other hand, the jammer is equipped with NJ fixtures,” and the received signals contain both the data term and the jammer term. [Mostafa, p. 2, Section II-B, Eqs. (4a)-(4b), FIG. 1].
Ding further states: “the data symbols and artificial noise mixed signals ... are simultaneously loaded on the corresponding distributed light source array or centralized light source sub-array” [Ding, p. 19, Step 4].
Lee teaches the boundary-setting operation: “the jamming boundary is formed by a ratio between power of a signal transmitted to the terminal by the access point and power of a signal of the noise” [Lee, Abstract].
One of ordinary skill would have been motivated to operate the combined Ding/Lee/Cho/Mostafa apparatus according to the method of claim 15 because the recited steps are the necessary and direct operation of the device rendered obvious for claim 1. Transmitting the optical data and masking signals activates the respective known source paths; controlling their power and coverage applies Lee’s known boundary-setting rule; and using overlapping optical wavelength content places the noise in the data-receiver band so that the received SNR falls below a usable level outside the selected region. Performing these known functions in their ordinary sequence would predictably create the near usable region and the distant masked region. Claim 15 would have been obvious.
Claim 5 is rejected under 35 U.S.C. § 103 as being unpatentable over Ding et al. in view of Lee et al., Cho et al., and Mostafa et al., and further in view of Sibilio (US20200314069A1).
Claim 5
With respect to claim 5, Ding, Lee, Cho, and Mostafa teach all limitations of claim 4, including the masking transmitter, the further masking transmitter, and their combined masking coverage. Claim 5 further requires the masking transmitter and the further masking transmitter to be placed on different sides of the data transmitter such that the data-signal coverage is surrounded by the combined masking coverage.
However, within analogous art, Sibilio expressly teaches an optical data-light source surrounded by multiple protective light sources: “The light transmitter may comprise a barrier light source; wherein the barrier light source may substantially surround the one or more light transmitting cells such that a light generated by the barrier light source encapsulates the data light. The barrier light source may comprise a plurality of light emitting sources” [Sibilio, ¶ [0008]].
Sibilio further states: “the protection layer 110 is sent by transmitting cells 140 which form a physical perimeter around the transmitting cells 140 of the communication layer 120. The protection layer 110 thus forms an ‘envelope’ around the information contained within the communication layer 120” [Sibilio, ¶ [0035]; FIGS. 1-2].
Sibilio additionally teaches an array arrangement: “FIG. 2 provides a detailed illustration of the transmission cells 140 and receiving cells 150 arranged in an array, bordered by the protection layer 110” [Sibilio, ¶ [0037]].
One of ordinary skill would have been motivated to arrange the first and further optical masking transmitters on opposite or different sides of the data transmitter because Lee already teaches surrounding an access point with plural jammers, Ding teaches multiple artificial-noise source sub-arrays and differentiated overlapping coverage, and Sibilio expressly teaches the optical implementation in which plural protective light emitters form a perimeter or envelope around the data-light emitters. The known perimeter arrangement protects the data path from interception from multiple approach directions and provides a more symmetric and controllable masking field. Applying Sibilio’s optical perimeter geometry to the masking emitters of the Ding/Lee/Cho/Mostafa system would predictably surround the data coverage with the combined masking coverage while leaving the underlying data and masking functions unchanged. Claim 5 would have been obvious.
Claim 2 is rejected under 35 U.S.C. § 103 as being unpatentable over Ding et al. in view of Lee et al., Cho et al., and Mostafa et al., and further in view of Verbana (US20040120718A1) and Maerki et al. (US6097522).
Claim 2
For purposes of the prior-art rejection only, and without withdrawing the separate rejection under 35 U.S.C. § 112(b), claim 2 is interpreted as separately reciting four alternatives for changing the certain distance: (i) adjusting a beam angle of at least one of the data transmitter and the masking transmitter; (ii) tilting at least one of the data transmitter and the masking transmitter so that the coverage areas move toward or away from each other; (iii) changing an inter-transmitter separation distance; or (iv) changing an output power of at least one transmitter.
With respect to claim 2, Ding, Lee, Cho, and Mostafa teach all limitations of claim 1. Under the prior-art interpretation stated above, claim 2 further recites changing the certain distance through beam-angle adjustment, transmitter tilt, inter-transmitter spacing, or output-power adjustment.
However, within analogous art, Verbana expressly teaches variable divergence of an optical communication beam: “By reducing the source distance (source closest to the lens), the divergence angle of the beam increases (the beam becomes wider and its power density decreases)” [Verbana, ¶ [0034]; FIGS. 1-2].
Verbana further teaches the converse control and the received-power feedback relationship: “Each time the signal received decreases due to atmospheric problems ... the transmission power is increased by reducing the angle of the beam being transmitted” [Verbana, ¶ [0026]].
Verbana states that the source/lens movement provides direct beam-angle adjustment: “the same results can be achieved by keeping the lens fixed and moving the source towards the lens itself (in order to increase the angle) or by bringing the source towards the focal point” [Verbana, ¶ [0030]].
Additionally, Maerki expressly teaches tilting optical steering components: “One of the two mirrors can be tilted in addition in two axes which are located orthogonally in respect to each other and therefore permits the fine adjustment of the light beams” [Maerki, col. 3-4].
Lee teaches boundary control by relative spacing: “when power of the access point corresponds to power of the noise, the jamming boundary is formed at a point having the same distance from the access point and the jammer, respectively” [Lee, claim 2; ¶ [0046]].
Lee also teaches boundary control by power: “as power of the jammer 300 is increased ... the jamming boundary moves towards the access point 100” [Lee, ¶¶ [0047]-[0049]].
One of ordinary skill would have been motivated to provide these adjustment options because the base combination already uses the geometric overlap and relative received powers of optical data and masking fields to define the secure boundary.
Verbana teaches that varying beam divergence predictably changes the area illuminated and optical power density at a given distance.
Maerki teaches tilting an optical element to shift the beam direction.
Lee expressly teaches that changing jammer power or the relative transmitter/jammer geometry moves the jamming boundary. Each claimed adjustment is therefore a known control variable acting on the same underlying quantities that define the boundary: beam footprint, relative overlap, path length, and received power. Incorporating those controls would have allowed a designer to tune the secure distance for room geometry, receiver position, atmospheric loss, and security requirements without changing the basic optical-jamming principle. The result is the predictable movement of the overlap/SNR boundary toward or away from the device. Claim 2 would have been obvious.
Claims 6 and 12 are rejected under 35 U.S.C. § 103 as being unpatentable over Ding et al. in view of Lee et al., Cho et al., and Mostafa et al., and further in view of Jeganathan et al. (WO2002073835A1).
Claim 6
With respect to claim 6, Ding, Lee, Cho, and Mostafa teach all limitations of claim 4. Claim 6 further requires the masking transmitter and further masking transmitter to transmit alignment information that assists alignment of the data-transmitter beam with a remote receiver.
However, within analogous art, Jeganathan teaches a free-space optical transceiver having communication and beacon optical paths: “The optical assembly units transmit and receive optical communication signals such as data, voice, and video information ... The light sources emit beacon signals which are received and detected by the optical assembly units” [Jeganathan, p. 3, lines 1-10; FIG. 1].
Jeganathan expressly states the alignment use of the beacon information: “After demodulation, the received signal can be processed to determine where the transmit communication beam should be pointed and the beam directing mechanism can be adjusted accordingly” [Jeganathan, p. 4, lines 1-4].
Jeganathan further teaches that the beacon has a wider coverage than the data beam: “The light sources ... emit beacon signals ... [and] have a wide enough beam divergence/width such that the receiver sees the beacon despite any nominal transceiver motion or jitter” [Jeganathan, p. 3, lines 14-24].
One of ordinary skill would have been motivated to place alignment information on the masking-transmitter paths because those paths are already optical emitters having broader spatial coverage than the narrow data beam and are already individually controllable. Jeganathan expressly teaches using wide beacon beams to acquire a remote receiver and then processing the beacon to point the narrow communication beam. Using the existing masking emitters for the additional beacon/alignment function avoids a dedicated alignment source, reduces components, and increases the probability that the remote receiver detects an acquisition signal before the narrow data beam is aligned. The masking function and alignment function can coexist through distinct modulation components, and each performs its known function. The combination would predictably assist alignment of the data transmitter with the remote receiver. Claim 6 would have been obvious.
Claim 12
With respect to claim 12, Ding, Lee, Cho, and Mostafa teach all limitations of claim 1. Claim 12 further requires the optical wireless communication device itself to include an optical data receiver configured to receive optical data signals.
However, within analogous art, Jeganathan expressly teaches an optical transceiver that both transmits and receives optical communication signals: “The present invention provides a free-space optical communication system including one or more optical transceivers each having an optical assembly unit ... The optical assembly units transmit and receive optical communication signals” [Jeganathan, p. 3, lines 1-8; FIGS. 1 and 6].
Jeganathan identifies the receiver structure: “the light beams are processed by a beam splitter ... [and] the communication receiver 38 [provides] detection of the received optical signals” [Jeganathan, pp. 5-7; FIG. 6].
One of ordinary skill would have been motivated to add the known optical data receiver because bidirectional free-space optical links conventionally use transceivers at each endpoint, and Jeganathan expressly integrates the optical receiver with the communication transmitter and beacon/alignment optics. Integrating that receiver into the secure Ding /Lee /Cho /Mostafa device permits return-link data, acknowledgments, channel-state information, and mobility/alignment feedback while reusing the same optical aperture and steering mechanism. The receiver performs its ordinary function and does not alter the masking or boundary-setting operation. Claim 12 would have been obvious.
Claim 7 is rejected under 35 U.S.C. § 103 as being unpatentable over Ding et al. in view of Lee et al., Cho et al., and Mostafa et al., further in view of Jeganathan et al., and further in view of Marmet (US20190107628A1).
Claim 7
With respect to claim 7, Ding, Lee, Cho, Mostafa, and Jeganathan teach all limitations of claim 6. Claim 7 further requires the masking transmitter and further masking transmitter to use CDMA to send their respective alignment information and requires the alignment-information frequency range to differ from the optical data and masking-signal frequency ranges.
However, within analogous art, Marmet expressly identifies the transmitter-specific spreading arrangement as CDMA: “The VLC transmitters of a same area use different pseudo random sequences. This CDMA technique (acronym for Code Division Multiple Access) makes the receiver capable of separating the different sources.” [Marmet, ¶ [0085]].
Marmet further teaches simultaneous receiver discrimination by code or frequency: “the receiver discriminates the received signals using the pseudo random code or the transmission frequency that is specific to each of the VLC and GNSS transmitters” [Marmet, ¶ [0175]].
Jeganathan expressly teaches frequency separation between alignment beacons and high-rate optical data: “Because of the substantial difference in the bandwidth of the beacon signals (few kHz) and communication signals (MHz to GHz or higher), the beacon detector can be made much more sensitive” [Jeganathan., p. 4, lines 8-16].
Jeganathan also teaches different transmitter-specific beacon frequencies: “the light sources 16a of transceiver 12a emit beacon signals ... intensity modulated at 8 kHz, and the light sources 16b of transceiver 12b emit beacon signals ... intensity modulated at 5 kHz” [Jeganathan, p. 5, lines 5-13; FIGS. 7-8].
Marmet therefore expressly teaches, rather than merely implying, that different pseudo-random sequences assigned to respective VLC transmitters implement CDMA and permit the receiver to separate the simultaneously received optical sources.
One of ordinary skill would have been motivated to apply that transmitter-specific spreading arrangement to the two masking/alignment emitters because it permits both emitters to transmit alignment information concurrently without time-slot coordination and enables the remote receiver to identify the contribution from each side of the data transmitter. Jeganathan independently teaches that the acquisition/alignment channel should occupy a low-frequency band separated from the MHz-to-GHz communication channel. Ding and Mostafa teach that the data and artificial-noise components are carried in the main optical transmission path. The combined system therefore places the coded alignment information in an auxiliary low-frequency band different from both the high-rate data modulation and the artificial-noise masking modulation. The skilled artisan would have expected success because optical receivers routinely separate such auxiliary and main-channel components by correlation and filtering. The result is the predictable simultaneous transmission and recovery of two separately identifiable alignment signals while the data and masking functions continue uninterrupted. Claim 7 would have been obvious.
Claim 8 is rejected under 35 U.S.C. § 103 as being unpatentable over Ding et al. in view of Lee et al., Cho et al., and Mostafa et al., further in view of Jeganathan et al., and further in view of Basting et al. (US6014206).
Claim 8
With respect to claim 8, Ding, Lee, Cho, Mostafa, and Jeganathan teach all limitations of claim 6. Claim 8 further requires the alignment information to include information regarding the center of gravity of the data transmitter.
For purposes of prior-art examination, the phrase “information regarding center of gravity of the data transmitter” is given its broadest reasonable interpretation consistent with the specification as information regarding the optical center or centroid of the data transmitter's emitted beam used for center-of-gravity alignment. The specification describes using the COG principle to align the devices and places the data transmitter at the center of the surrounding masking transmitters. [Instant specification ¶¶ [0020]-[0021] and [0050]; FIG. 4].
However, within analogous art, Basting expressly teaches center-of-gravity measurement for optical beam alignment: “The beam detection unit 100 preferably effectively measures a center of gravity of a profile of the beam 21 at the two locations, i.e., near- and far-field, along its optical path” [Basting, col. 7, lines 35-55; FIGS. 1-4].
Basting further teaches using the measured information for automatic correction: “The controller 300 can activate a feedback loop for adjustment and stabilization of the laser beam angular and lateral positions” [Basting, col. 7, lines 25-40].
One of ordinary skill would have been motivated to include center-of-gravity/centroid information in the alignment message because Basting identifies the beam-profile center of gravity as the measured parameter used to determine lateral and angular pointing error and then closes a feedback loop to correct the beam.
In the combined claim-6 system, the wider masking/alignment beams provide acquisition information while the narrow data beam must be centered on the remote receiver. Transmitting the measured centroid or the error relative to that centroid gives the remote station an objective, noise-tolerant alignment metric and permits the data beam to be positioned between the flanking masking beams. This modification uses a known optical alignment parameter for its established purpose and would have predictably improved pointing accuracy. It does not require treating the physical mass center of a transmitter as the claimed information; in the optical-alignment context, Basting expressly uses the center of gravity of the beam profile, which is the meaningful transmitter-output centroid presented to the receiver. Claim 8 would have been obvious.
Claims 9 and 11 are rejected under 35 U.S.C. § 103 as being unpatentable over Ding et al. in view of Lee et al., Cho et al., and Mostafa et al., and further in view of Marmet (US20190107628A1).
Claim 9
For purposes of the prior-art rejection only, and without withdrawing the separate rejection under 35 U.S.C. § 112(b), claim 9 is interpreted as requiring control of the masking transmitter and an additional/further masking transmitter of the type expressly taught by claim 4.
With respect to claim 9, Ding, Lee, Cho, and Mostafa teach all limitations of claim 1 and teach plural masking sources. Under the prior-art interpretation stated above, claim 9 further requires estimating the communication distance to the intended remote device and controlling the masking sources so that the intended remote device remains within the certain distance.
However, within analogous art, Marmet teaches optical distance determination by VLC pseudo-ranging: “The receiver is configured to calculate a pseudo range from the calculated reception time and said time information” [Marmet, ¶ [0023]].
Marmet further states: “a pseudo range, relative to a propagation time between the VLC transmitter and the receiver, can be computed” [Marmet, ¶ [0175]].
Marmet then determines position from the optical ranges: “the method comprises a third step 803 of determining a position from said calculated pseudo ranges” [Marmet, ¶ [0177]].
Lee expressly uses terminal relative position and jammer power to control the protected region: “the current invention ... uses power of the jammer and a relative position of the terminal” [Lee, ¶ [0071]].
One of ordinary skill would have been motivated to add Marmet’s optical pseudo-range detector to the secure optical device because Lee’s boundary must be placed relative to the intended terminal, and mobility or installation variation makes a fixed assumed range less reliable. Marmet provides a known VLC-compatible way to estimate transmitter-receiver propagation distance and position from received optical positioning signals. Feeding that measured communication distance to the controller would allow the controller to adjust data/masking power or beam geometry until the intended receiver remains inside the SNR-useful boundary, while the region beyond remains jammed. This closed-loop combination directly improves the stated security objective and uses known sensing and control components for their ordinary functions. Claim 9 would have been obvious.
Claim 11
For purposes of the prior-art rejection only, and without withdrawing the separate rejection under 35 U.S.C. § 112(b), claim 11 is interpreted as incorporating claim 9 under the interpretation stated above and further requiring the distance detector to estimate the communication distance based on at least one of Time-of-Arrival, signal-strength, or phase-difference information of one or more signals received from the remote device.
With respect to claim 11, Ding, Lee, Cho, Mostafa, and Marmet teach all limitations of claim 9 under the stated interpretation. Claim 11 further requires the distance estimate to be based on at least one of Time-of-Arrival, signal-strength, or phase-difference information. Because the limitation is written in the alternative, disclosure of Time-of-Arrival is sufficient.
However, within analogous art, Marmet expressly teaches reception-time/Time-of-Arrival processing: “each of the tracking loops [is] configured to calculate a reception time from a correlation between one of said received positioning signal and a local replica of said positioning signal” [Marmet, ¶ [0023]; claim 12].
Marmet further explains: “From the synchronisation value and the time information ... a pseudo range, relative to a propagation time between the VLC transmitter and the receiver, can be computed” [Marmet, ¶ [0175]].
One of ordinary skill would have been motivated to use Time-of-Arrival/correlation ranging because the same VLC receiver already receives the remote optical signals, and time correlation provides a direct propagation-delay measurement without requiring a separate non-optical ranging channel. Marmet’s method provides transmitter identification, reception time, and pseudo-range in the same received waveform. Applying that method to the claim-9 controller would yield the communication distance needed to keep the intended receiver within the secure boundary. The result is a predictable use of known VLC positioning technology in a secure VLC link. Claim 11 would have been obvious.
Claim 10 is rejected under 35 U.S.C. § 103 as being unpatentable over Ding et al. in view of Lee et al., Cho et al., and Mostafa et al., further in view of Marmet, and further in view of Tien et al. (US20140240692A1).
Claim 10
For purposes of the prior-art rejection only, and without withdrawing the separate rejection under 35 U.S.C. § 112(b), claim 10 is interpreted as incorporating claim 9 under the interpretation stated above and further requiring that the claimed distance detector is implemented as a Time-of-Flight (ToF) sensor.
With respect to claim 10, Ding, Lee, Cho, Mostafa, and Marmet teach all limitations of claim 9 under the stated interpretation. Claim 10 further specifies that the distance detector is a Time-of-Flight sensor.
However, within analogous art, Tien expressly teaches a Time-of-Flight system and the distance relationship: “A time-of-flight (TOF) system, typically, includes a light source and a TOF sensor. The light source emits light pulses towards a target, which reflects the light pulses back towards the TOF sensor. The TOF sensor receives the light pulses after a time of flight, which is proportional to the distance from the TOF system to the target” [Tien, ¶ [0002]].
Tien expressly claims a processor-based distance detector: “a processing system, connected to the light source and the TOF sensor, for determining a distance to the target by using the first-period capacitor voltage” [Tien, claim 4].
Tien further states: “The capacitor voltage is related to the time of flight of the light pulses and may be used to determine a distance to a target” [Tien, Abstract; FIG. 2].
One of ordinary skill would have been motivated to implement the claim-9 distance detector as Tien’s optical ToF sensor because it directly supplies the required communication-distance measurement using compact light-source, photodetector, and processing circuitry compatible with an optical wireless transceiver. ToF measurement is especially useful where received-power ranging may vary with beam divergence, atmospheric attenuation, and receiver orientation. The ToF sensor would provide a direct propagation-distance input to the existing boundary controller, allowing the masking boundary to be adjusted so the intended receiver remains inside the useful region. This is a predictable substitution of one known optical ranging implementation for the generic distance detector. Claim 10 would have been obvious.
Claim 14 is rejected under 35 U.S.C. § 103 as being unpatentable over Ding et al. in view of Lee et al., Cho et al., and Mostafa et al., further in view of Jeganathan et al., and further in view of Maerki et al. (US6097522).
Claim 14
With respect to claim 14, Ding, Lee, Cho, Mostafa, and Jeganathan teach all limitations of claim 6. Claim 14 incorporates the optical wireless communication device of claim 6 and further recites a remote receiver having an optical data receiver and at least two auxiliary receivers, with the remote receiver located within the certain distance.
Under the broadest reasonable interpretation, the recitation that “the auxiliary receivers [are] configured to receive the alignment information sent by the masking transmitter and the further masking transmitter” requires the pair of auxiliary receivers collectively to receive the alignment information from the two masking transmitters; it does not require a one-to-one correspondence between each auxiliary receiver and a particular masking transmitter. In the proposed combination, the two masking transmitters emit distinguishable alignment-bearing optical signals, while the acquisition and tracking receivers receive and process that incoming alignment field at different alignment stages.
Ding, Lee, Cho, Mostafa, and Jeganathan teach the secure claim-6 transmitter and a remote transceiver that receives data and beacon/alignment signals.
However, within analogous art, Jeganathan expressly teaches two remote free-space optical transceivers and separate data/beacon reception: “The system 10 includes at least a pair of optical transceivers, namely a first transceiver 12a and a second transceiver 12b ... [and] optical communication signals and beacon signals” [Jeganathan, p. 3, lines 12-20; FIG. 1].
Jeganathan further teaches a multi-element alignment photodetector and a separate communication receiver: “transceiver 12a further includes a multi-element photodetector 24 to detect the beacon signal and deduce the apparent position of the other transceiver” [Jeganathan, p. 6, lines 6-15; FIG. 6].
Jeganathan separately identifies: “communication receiver 38 for detection of the received optical signals” [Jeganathan, pp. 6-7; FIG. 6].
Maerki expressly teaches at least two alignment receivers: “the received light beam ... is distributed to the sensors required for the individual stages ... these are two separate CCD sensors ... The CCD sensor used for acquisition has a resolution of 288x288 pixels ... [and] the CCD sensor provided for tracking only has 14x14 pixels” [Maerki, col. 1-2].
Maerki also teaches a separate high-speed optical communication receiver: “For tracking, there is on the reception side a four quadrant circuit of high-speed photodiodes, which at the same time deliver the electrical reception signal” [Maerki, col. 3-4].
One of ordinary skill would have been motivated to provide at least two auxiliary alignment receivers because acquisition and precision tracking impose different field-of-view and update-rate requirements. Maerki expressly uses a wide-field acquisition CCD and a separate fast-tracking CCD before delivering the communication signal to high-speed photodiodes. Jeganathan similarly separates beacon-position detection from the data receiver. Applying that known staged alignment receiver architecture to the two separately coded masking/alignment beacons of claim 6 would allow the remote station to detect the transmitters over a wide uncertainty region and then maintain precise alignment during communication. The remote station would be placed inside Lee’s secure boundary for the same reasons discussed for claim 13. Each receiver performs its established function, and the result is the predictable remote system of claim 14. Claim 14 would have been obvious.
Accordingly, Jeganathan supplies the remote optical data receiver and beacon-position receiver, while Maerki supplies two separate auxiliary alignment receivers—an acquisition CCD and a tracking CCD—that receive alignment-bearing optical energy. When used with the claim-6 masking transmitters, the two auxiliary receivers would collectively receive the alignment information emitted by the masking transmitter and the further masking transmitter, and the optical data receiver would receive the optical data signal. Lee's secure-zone teaching places that remote receiver within the certain distance.
It is noted that any citations to specific, pages, columns, lines, or figures in the prior art references and any interpretation of the reference should not be considered to be limiting in any way. A reference is relevant for all it contains and may be relied upon for all that it would have reasonably suggested to one having ordinary skill in the art. See MPEP 2123.
Conclusion
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/MOHAMMED ABDELRAHEEM/Examiner, Art Unit 2635
/DAVID C PAYNE/Supervisory Patent Examiner, Art Unit 2635
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