DETAILED ACTION
This action is in response to the amendment filed on April 20, 2026. Claims 1-20 have been canceled and claims 21-40 are new. Claims 21-40 are pending. Of such, Claims 21-29 represent a device and Claims 30-38 represent a non-transitory computer-readable medium and claims 39-40 represent a method directed to reduction of time-domain correlation for secure sounding signal.
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 .
Claim Objections
The objection to claim 20 is withdrawn in view of the cancellation of the claim.
Claim Rejections - 35 USC § 112
The rejection to claim 10 is withdrawn in view of the cancellation of the claim.
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.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
The term “about” in claims 27 and 36 is a relative term which renders the claim indefinite. The term “about” is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention.
Response to Arguments
Applicant's arguments filed April 20, 2026 have been fully considered but they are not persuasive.
On page 6 of the Remarks, the applicant argues that the cited art Mcelroy does not disclose or suggest a secure high-efficiency long training field (HE-LTF) sounding signal. This argument is not persuasive because the HE-LTF sounding signal is not disclosed in the claims. The previous and new independent claims recite only “a sounding signal” and “a secure sounding signal”. Therefore arguments associated with HE-LTF sounding signals have no merit on the independent claim. The limitations of the newly added HT-LTF sounding signal found in the dependent claims have been addressed in the USC 103 rejection below. However, upon the amendments to the dependent claims, a new ground(s) of rejection is made in view of Mcelroy, He, Sahin, and Seok.
Claim Rejections - 35 USC § 102
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claim(s) 21, 25, 28, 30, 34, 37, and 39 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Mcelroy et al. (WO 2017134310), hereinafter referred to as Mcelroy.
Regarding Claim 21, Mcelroy discloses:
A device comprising processing circuitry coupled to storage (In ¶ 20, Mcelroy discloses “In accordance with a preferred embodiment of our invention, we provide a method for use in a wireless communication system comprising a transmitter and a receiver.”), the processing circuitry configured to: generate a sequence of pseudo-random symbols associated with a sounding signal to be transmitted to a first station device (In ¶ 54, Mcelroy discloses “CLASS_1. Generate a base code-set, C™, of m pseudo-random binary codes each having a predetermined length, n, with exactly one code for each symbol in the transmitted sequence”); modify the sequence of pseudo-random symbols using a modifier (In ¶ 54, Mcelroy discloses “Create a trial code-set, C™, by reversing the sign of bit Cy ;” and further “CLASS 5.1.3. If SSSA trial is smaller than SSSA.sub.base , then replace the base code-set C™ with the trial code-set C™; then, in the transmitter:”); generate a secure sounding signal from the modified sequence of pseudo-random symbols (In ¶ 54, Mcelroy discloses “Transmit as the CLASS the final code-set, C™; and, finally, in the receiver:” and in ¶ 58 further discloses “An attacker might be able to exploit this property of the modified code-set to guess some of the bits, and thus successfully pretend he is nearer than he actually is by transmitting these guessed bits so that they arrive earlier than the real bits.” ); and cause to send the secure sounding signal to the first station device (In ¶ 54, Mcelroy discloses “The final code-set, C™, comprises the CLASS code-set that the transmitter will transmit to the receiver.”).
Regarding Claim 25, Mcelroy discloses:
The device of claim 21, wherein the modifier is a time-domain filter. (In ¶ 54, Mcelroy discloses “CLASS_5.1.1. Create a trial code-set, C™, by reversing the sign of bit Cy ;”)
Regarding Claim 28, Mcelroy discloses:
The device of claim 21, wherein the processing circuitry is further configured to remove a plurality of pulses from the secure sounding signal (In ¶ 54, Mcelroy discloses “by minimizing SSSA, our method ensures that the power in the sum of the sidelobes of the auto-correlation functions of the generated code-set is low, thereby tending to minimize sidelobe distortion.”).
Claim 30, 34, 37 are directed to a non-transitory computer-readable medium having functionality corresponding to the device of Claims 21, 25, 28, respectively and are rejected by a similar rationale, mutatis mutandis.
Claim 39 is directed to a method having functionality corresponding to the device of Claim 21 and is rejected by a similar rationale, mutatis mutandis.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all 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.
Claims 22-24, 25, 31-33, 35, and 40 are rejected under 35 U.S.C. 103 as being unpatentable over Mcelroy et al. (WO 2017134310), hereinafter referred to as Mcelroy, in view of Sahin et al. (US 9319253), hereinafter referred to as Sahin.
Regarding Claim 22, Mcelroy discloses the limitations of claim 21.
However, Mcelroy does not explicitly disclose a frequency domain mask.
Sahin discloses:
wherein the modifier is a frequency-domain mask applied to subcarriers modulated with the sequence of pseudo-random symbols (In Col 2, Lines 5-8, Sahin discloses “Adaptive windowing of the orthogonal frequency division multiplexing (OFDM) signals may be used to shape the spectrum of the transmitted signal, thereby limiting interference of adjacent bands.” And further discloses in Col 4, Lines 1-6 “The edge subcarriers 115 and inner subcarriers 118 may be grouped (or divided up) in a variety of ways. For example, the subcarriers of the OFDM symbol 103 may be equally divided between inner subcarriers 118 and edge subcarriers 115 (e.g., 256 subcarriers with 128 edge carriers and 128 inner carriers) on the right and left sides of the inner subcarriers 118.”).
One in ordinary skill in the art of cryptography would have been motivated, before the effective filing date of the claimed invention to modify Mcelroy’s approach by utilizing Sahin’s approach of using a frequency mask as the motivation would be to utilize the frequency mask as edge windowing provides the advantage of maintaining the spectrum efficiency of OFDM while achieving side lobe suppresion (see Sahin, Col 3, Lines 22-25).
Regarding Claim 23, the combination of Mcelroy and Sahin disclose the limitations of Claim 22.
However, Mcelroy does not explicitly disclose a frequency domain mask.
Sahin discloses:
The device of claim 22, wherein the frequency-domain mask comprises a flat top window characterized by a time-domain impulse response. (In Col 3, Lines 48-52, Sahin discloses “Numerous windowing functions that may be used to suppress the side lobes include, e.g., raised-cosine, trapezoidal, cosine, Tukey windowing functions, etc. Edge windowing may be applied not only to OFDM based systems (e.g., OFDM and OFDMA) but also to other OFDM-like systems such as, e.g., single carrier frequency division multiple accessing.”)
One in ordinary skill in the art of cryptography would have been motivated, before the effective filing date of the claimed invention to modify Mcelroy’s approach by utilizing Sahin’s approach of using a frequency mask as the motivation would be to utilize the frequency mask as edge windowing provides the advantage of maintaining the spectrum efficiency of OFDM while achieving side lobe suppresion (see Sahin, Col 3, Lines 22-25).
Regarding Claim 24, the combination of Mcelroy and Sahin disclose the limitations of Claim 23.
However, Mcelroy does not explicitly disclose a frequency domain mask.
Sahin discloses:
The device of claim 23, wherein the time-domain impulse response comprises a plurality of time-domain samples of a pulse shaping window. (In Col 2, Lines 27-33, Sahin discloses “The smooth transition can be provided with point-to-point multiplication of the windowing function and the OFDM symbol extended with a postfix (e.g., adding N.sub.W samples from the beginning of the OFDM symbol 103 to the end of the OFDM symbol 103) and/or a prefix (e.g., adding N.sub.CP+N.sub.W samples from the last of the OFDM symbol 103 to the beginning of the OFDM symbol 103).”)
One in ordinary skill in the art of cryptography would have been motivated, before the effective filing date of the claimed invention to modify Mcelroy’s approach by utilizing Sahin’s approach of using a frequency mask as the motivation would be to utilize the frequency mask as edge windowing provides the advantage of maintaining the spectrum efficiency of OFDM while achieving side lobe suppresion (see Sahin, Col 3, Lines 22-25).
Regarding Claim 26, Mcelroy discloses the limitations of claim 21.
However, Mcelroy does not explicitly disclose the concept of linear filtering.
Sahin discloses:
wherein the time-domain filter performs linear filtering (In Col 5, Lines 25-28, Sahin discloses “Since the inverse fast Fourier transformation (IFFT) and windowing are linear operations, edge windowing method can be implemented by employing two branches for edge and inner subcarriers… point-to-point operations such as point-to-point multiplication of windowing function and IFFT results and point-to-point summation of the results of the two branches.”)
One in ordinary skill in the art of cryptography would have been motivated, before the effective filing date of the claimed invention to modify Mcelroy’s approach by utilizing Sahin’s approach of using a frequency mask as the motivation would be to utilize the frequency mask as edge windowing provides the advantage of maintaining the spectrum efficiency of OFDM while achieving side lobe suppresion (see Sahin, Col 3, Lines 22-25).
Claims 31, 32, 33, and 35 are directed to a non-transitory computer-readable medium having functionality corresponding to the device of Claims 22, 23, 24, and 26, respectively, and are rejected by a similar rationale, mutatis mutandis.
Claim 40 is directed to a method having functionality corresponding to the device of Claim 22, and is rejected by a similar rationale, mutatis mutandis.
Claims 27 and 36 are rejected under 35 U.S.C. 103 as being unpatentable over Mcelroy et al. (WO 2017134310), hereinafter referred to as Mcelroy, in view of He et al. (US 20170257250), hereinafter referred to as He.
Regarding Claim 27, Mcelroy discloses the limitations of claim 21.
The device of claim 21, wherein a time-domain impulse response of the modifier comprises two opposite main pulses symmetric about a value of zero. (In ¶ 73, He discloses “FIG. 9 is a time domain response diagram of a pulse shaping function in an embodiment of the present invention”)
One in ordinary skill in the art of cryptography would have been motivated, before the effective filing date of the claimed invention to modify Mcelroy’s approach by utilizing He’s approach of a pulse time domain response as the motivation would be to provide a single-carrier and multi-carrier compatible hybrid carrier mechanism utilizing MIMO communication which reduces interference between the carrier system and increase reliability of the communication system (see He, ¶ 64).
Claim 36 is directed to a non-transitory computer-readable medium having functionality corresponding to the device of Claims 27, and is rejected by a similar rationale, mutatis mutandis.
Claims 29 and 38 are rejected under 35 U.S.C. 103 as being unpatentable over Mcelroy et al. (WO 2017134310), hereinafter referred to as Mcelroy, in view of Soek et al. (US 10694407), hereinafter referred to as Seok.
Regarding Claim 29, Mcelroy discloses the concept of a secure sounding signal as disclosed in claim 21.
However, Mcelroy does not explicitly disclose a High Efficiency Null Data Packet sounding signal.
Soek discloses:
wherein the secure sounding signal is a High Efficiency (HE) null data packet (NDP) sounding signal. (In Col 2, Lines 55-65, Soek discloses “frame includes a first LTF sequence derived from the LTF generation information associated with the LTF generation sequence authentication code, transmitting an NDP announcement frame and a DL-NDP frame from the responding STA, where the DL-NDP frame includes a second LTF sequence derived from the LTF generation information”)
One in ordinary skill in the art of cryptography would have been motivated, before the effective filing date of the claimed invention to modify Mcelroy’s approach by utilizing Seok’s approach of a HE-NDP as the motivation would be to reduce spoofing abilities because the field used to channel/time-of-arrival (TOA) measurement should not include any form of repetition in the time domain, or any structure that is predictable. (see Seok, Background).
Claim 38 is directed to a non-transitory computer-readable medium having functionality corresponding to the device of Claims 29, and is rejected by a similar rationale, mutatis mutandis.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Raissinia et al. (US 11431539) discloses methods, devices and systems for improving the security of secure long training field (LTF) transmissions.
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to SHADI H KOBROSLI whose telephone number is (571)272-1952. The examiner can normally be reached M-F 9am-5pm ET.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Rupal Dharia can be reached at 571-272-3880. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/SHADI H KOBROSLI/Examiner, Art Unit 2492 /RUPAL DHARIA/Supervisory Patent Examiner, Art Unit 2492
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