DETAILED ACTION
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 .
Status of the Application
This Office action is in response to the amendment and remarks filed July 16, 2026. Claims 1, 6, 8, 9, 14, 15, 16, 19 and 20 have been amended; no claims have been added or cancelled. Claims 1-20 are pending and are examined herein.
Applicant’s amendment necessitated the new grounds of rejection of claims 1-19 presented in this Office action, and the rejection of claim 20 is maintained. THIS ACTION IS MADE FINAL.
Response to Arguments
Applicant’s arguments filed July 16, 2026 have been fully considered but they are not persuasive. The answers to each argument follow.
With respect to Applicant’s argument that “Applicant submits that the Non-Final Office Action’s interpretation improperly strips the term ‘FMCW’ of its term-of-art meaning by reducing it to nothing more than a chirp signal with a linearly varying frequency.” (Remarks, page 9), the Examiner respectfully disagrees.
Under the broadest reasonable interpretation, the claims are read in light of the specification, and the specification defines the term by the signal itself: an FMCW signal is one whose frequency sweeps linearly in time (Specification, para [0031] “FMCW generally refers to a signal where the frequency increases linearly with time (referred to as an up-chirp) or decreases linearly with time (referred to as a down-chirp).”). The paragraph numbers of the specification cited in this action are those of the published application, US 2025/0379773 A1. Claims 1, 15 and 20 track that definition, reciting a first FMCW signal whose frequency increases in time according to a first slope and an overlapping second FMCW signal whose frequency decreases in time according to the negative of that slope.
The sentence of the same paragraph on the beat frequency names a quantity observed when a received FMCW signal is compared with the transmitted one (Specification, para [0031] “In FMCW, a difference between the transmitted signal carrier frequency and the received signal carrier frequency is referred to as a beat frequency.”); it describes how the signal may be processed and does not narrow what signal the claims recite. Read that way, Vishwanath’s synchronization burst carries two FMCW signals of opposite slope (Vishwanath, col. 9, lines 56-59 “illustrates the two component waveforms, i.e. the up-chirp waveform 60, wherein frequency increases linearly with time, and a simultaneously transmitted down-chirp waveform 62, wherein frequency decreases linearly with time”; Vishwanath, col. 10, lines 22-24 “As shown in FIG. 4, K is the slope of the up-chirp waveform 60 and -K is the slope of the down-chirp waveform 62.”). See MPEP § 2111; In re Am. Acad. of Sci. Tech. Ctr., 367 F.3d 1359, 1364, 70 USPQ2d 1827, 1830 (Fed. Cir. 2004) (claims are given their broadest reasonable interpretation consistent with the specification); In re Morris, 127 F.3d 1048, 1054, 44 USPQ2d 1023, 1027 (Fed. Cir. 1997).
In regard to Applicant’s argument that “In Vishwanath, there is no VCO-based mixing to produce beat frequencies, or any beat frequency processing of FMCW waveforms.” (Remarks, page 8), the argument is not commensurate with the scope of claims 1, 15 and 20, which recite no oscillator, no mixing and no beat frequency.
In response to applicant’s argument that the references fail to show certain features of the invention, it is noted that the features upon which applicant relies (i.e., mixing the received signal with a local FMCW generated by a voltage controlled oscillator, low pass filtering the mixer output, and estimating a beat frequency from it) are not recited in the rejected claim(s). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993); MPEP § 2111.01(II) and § 2145(VI).
Where the claims do recite beat frequencies (claims 3-5 and 10), Vishwanath supplies them. The specification’s receiver mixes the received signal with a local copy of the transmitted sweep (Specification, para [0097] “at a receiver-side, the received signal is mixed with a local version of the transmitted FMCW (generated via a voltage controlled oscillator-VCO 610) and passed to a low pass filter (LPF 620).”).
Vishwanath’s receiver does the same thing: it multiplies the received signal by a locally generated desweeping chirp (Vishwanath, col. 17, lines 1-4 “the signal output from the matched filter 106 is ‘deswept’ at the first phase shifter 108, which is typically a multiplier, by multiplying the signal r(t) by a first desweeping waveform”), a chirp that hypothesizes the received sweep (Vishwanath, col. 17, lines 13-16 “The first desweeping waveform 130 may also be referred to as a first hypothesizing waveform since it is being used to ‘hypothesize’ an up-chirp waveform in the received waveform.”), and the product levels the received sweep into a narrowband tone (Vishwanath, col. 17, lines 18-22 “the result of such desweeping at the first phase shifter 108 is shown as the frequency vs. time plot 132 in which the frequency of the received up-chirp waveform 134 is now simply leveled out or ‘deswept’ into a ‘tone’ that includes noise”). The frequency of that tone is the difference between the received sweep and the local sweep, which is what the specification calls a beat frequency (Specification, para [0031] “In FMCW, a difference between the transmitted signal carrier frequency and the received signal carrier frequency is referred to as a beat frequency.”), and Vishwanath estimates one such tone for each of its two sweeps (Vishwanath, col. 21, lines 8-13 “once deswept into tones, the detection and estimation processor 116 estimates the frequency of the tone at the peak 140. Similarly, the frequency of the frequency representation of the deswept down-chirp waveform or peak 160 is estimated at the detection and estimation processor 116”). That Vishwanath locates the tone with an FFT is a choice of estimator, and none of the claims excludes it.
As to Applicant’s argument that “Vishwanath, by contrast, never uses the term ‘FMCW’ anywhere in its disclosure, never characterizes its waveform as FMCW” (Remarks, page 8), anticipation does not turn on the label a reference gives its subject matter. The elements must be arranged as the claim requires, but identity of terminology is not required. See In re Bond, 910 F.2d 831, 832, 15 USPQ2d 1566, 1567 (Fed. Cir. 1990); MPEP § 2131. Vishwanath’s up-chirp and down-chirp are linear frequency sweeps (Vishwanath, col. 9, lines 56-59 “illustrates the two component waveforms, i.e. the up-chirp waveform 60, wherein frequency increases linearly with time, and a simultaneously transmitted down-chirp waveform 62, wherein frequency decreases linearly with time”), which is the very signal the specification calls FMCW (Specification, para [0031] “FMCW generally refers to a signal where the frequency increases linearly with time (referred to as an up-chirp) or decreases linearly with time (referred to as a down-chirp).”).
Turning to Applicant’s argument that “Ko does not teach or suggest FMCW signals of any kind.” (Remarks, page 11), in response to applicant’s arguments against the references individually, one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986). Ko is not relied upon for the FMCW signals. Vishwanath supplies the first and second FMCW signals, their overlap and opposite slopes, and the frequency offset estimation; Ko supplies the transceiver, the memory holding instructions and the processor that executes them (Ko, para [0096], “The UE can include a processor 810, a memory 820, and a transceiver 830 and the eNB 850 can include a processor 860, a memory 870, and a transceiver 880.”). See MPEP § 2145(IV).
With respect to Applicant’s argument that “Claim 4 depends from independent claim 1 (via claim 3), which Applicant submits is allowable over Vishwanath in view of Ko for at least the reasons discussed above.” (Remarks, page 11), claims 4 and 11 are argued only through their dependence on claim 1 (see also Remarks, page 11), and claim 1 remains rejected for the reasons given above. Filipovic and Jung are applied for the limitations that claims 4 and 11 add, as set forth below.
For at least these reasons, the rejections are maintained and are restated below to address the amended claim language. The amendment added at least one transceiver, and receiving or transmitting via that transceiver, to claims 1 and 15, and moved the transceiver out of claims 14 and 19; the rejections of claims 1-19 set forth below are therefore new grounds of rejection necessitated by the amendment. The rejection of claim 20 is maintained.
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)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claim 20 is rejected under 35 U.S.C. 102(a)(2) as being anticipated by Vishwanath (US 6,418,158 B1).
Regarding claim 20, (Currently Amended) Vishwanath discloses: A method for wireless communication by a wireless node, comprising: receiving a synchronization signal (SS) comprising a first frequency modulated continuous waveform (FMCW) signal associated with a frequency that increases in time for a duration according to a first slope, given that Vishwanath sets out the mobile terminal 12, a wireless transceiver, finding the synchronization waveform sent from the gateway station, a burst of duration T whose up-chirp waveform 60 (i.e., “first frequency modulated continuous waveform (FMCW) signal” as claimed) rises linearly in frequency at slope K, so that the wireless node receives a synchronization signal whose first FMCW signal increases in frequency for a duration according to a first slope: (Vishwanath, col. 6, lines 35-37 “second communications terminal or mobile terminal 12 (also referred to as a wireless terminal or wireless transceiver)”; Vishwanath, col. 6, lines 60-64 “the mobile terminal 12 must be able to find the waveform (also referred to as a synchronization signal) sent from the gateway station 24 via the satellite 26 to synchronize with the timing and frequency of the communications link 30”; Vishwanath, col. 10, lines 1-2 “continuous time t, wherein t is defined with respect to a start of a burst of duration T, (i.e. t=0 at the start of the burst)”; Vishwanath, col. 9, lines 56-59 “illustrates the two component waveforms, i.e. the up-chirp waveform 60, wherein frequency increases linearly with time, and a simultaneously transmitted down-chirp waveform 62, wherein frequency decreases linearly with time”).
Furthermore, Vishwanath discloses: a second FMCW signal that overlaps with the first FMCW signal, because Vishwanath teaches the down-chirp waveform 62 transmitted simultaneously with the up-chirp waveform 60 as the second component of the one composite waveform, which means that the second FMCW signal overlaps with the first FMCW signal: (Vishwanath, col. 9, lines 42-45 “dual-chirp waveform is one example of a composite waveform of two simultaneously transmitted waveforms having a known frequency variation, i.e. the frequency varies linearly with time”).
Moreover, Vishwanath discloses: wherein the second FMCW signal is associated with a frequency that decreases in time for the duration according to a second slope that corresponds to a negative of the first slope, as Vishwanath describes the down-chirp waveform 62 falling linearly in frequency over the same burst at slope -K, the negative of the up-chirp slope K, such that the second FMCW signal decreases in frequency for the duration according to a second slope that corresponds to a negative of the first slope: (Vishwanath, col. 10, lines 22-24 “As shown in FIG. 4, K is the slope of the up-chirp waveform 60 and -K is the slope of the down-chirp waveform 62.”).
In addition, Vishwanath discloses: performing frequency offset estimation based on the first and second FMCW signals, since Vishwanath explains the receiver identifying the frequencies of both the deswept up-chirp and the deswept down-chirp (i.e., “first and second FMCW signals” as claimed) and using them to estimate the frequency offset, whereby the frequency offset estimation is performed based on the first and second FMCW signals: (Vishwanath, col. 10, lines 43-47 “acquisition systems at the receiver 44 of FIG. 2 (e.g. mobile terminal 12) employing an FFT can identify the dominant frequency components of both the deswept up-chirp waveform 60 and down-chirp waveform 62, which is then used to estimate the frequency offset”).
Claim Rejections - 35 USC § 103
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 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 1-3, 5-10 and 12-19 are rejected under 35 U.S.C. 103 as being unpatentable over Vishwanath (US 6,418,158 B1) in view of Ko (US 2020/0383129 A1).
Regarding claim 1, (Currently Amended) Vishwanath discloses: receive, via the at least one transceiver, a synchronization signal (SS) comprising a first frequency modulated continuous waveform (FMCW) signal associated with a frequency that increases in time for a duration according to a first slope, because Vishwanath teaches the mobile terminal 12, a wireless transceiver, finding the synchronization waveform sent from the gateway station, a burst of duration T whose up-chirp waveform 60 (i.e., “first frequency modulated continuous waveform (FMCW) signal” as claimed) rises linearly in frequency at slope K, which means that the apparatus receives through its transceiver a synchronization signal whose first FMCW signal increases in frequency for a duration according to a first slope: (Vishwanath, col. 6, lines 35-37 “second communications terminal or mobile terminal 12 (also referred to as a wireless terminal or wireless transceiver)”; Vishwanath, col. 6, lines 60-64 “the mobile terminal 12 must be able to find the waveform (also referred to as a synchronization signal) sent from the gateway station 24 via the satellite 26 to synchronize with the timing and frequency of the communications link 30”; Vishwanath, col. 10, lines 1-2 “continuous time t, wherein t is defined with respect to a start of a burst of duration T, (i.e. t=0 at the start of the burst)”; Vishwanath, col. 9, lines 56-59 “illustrates the two component waveforms, i.e. the up-chirp waveform 60, wherein frequency increases linearly with time, and a simultaneously transmitted down-chirp waveform 62, wherein frequency decreases linearly with time”).
Furthermore, Vishwanath discloses: a second FMCW signal that overlaps with the first FMCW signal, as Vishwanath describes the down-chirp waveform 62 transmitted simultaneously with the up-chirp waveform 60 as the second component of the one composite waveform, such that the second FMCW signal overlaps with the first FMCW signal: (Vishwanath, col. 9, lines 42-45 “dual-chirp waveform is one example of a composite waveform of two simultaneously transmitted waveforms having a known frequency variation, i.e. the frequency varies linearly with time”).
Moreover, Vishwanath discloses: wherein the second FMCW signal is associated with a frequency that decreases in time for the duration according to a second slope that corresponds to a negative of the first slope, since Vishwanath explains the down-chirp waveform 62 falling linearly in frequency over the same burst at slope -K, the negative of the up-chirp slope K, whereby the second FMCW signal decreases in frequency for the duration according to a second slope that corresponds to a negative of the first slope: (Vishwanath, col. 10, lines 22-24 “As shown in FIG. 4, K is the slope of the up-chirp waveform 60 and -K is the slope of the down-chirp waveform 62.”).
In addition, Vishwanath discloses: perform frequency offset estimation based on the first and second FMCW signals, in that Vishwanath shows the receiver identifying the frequencies of both the deswept up-chirp and the deswept down-chirp (i.e., “first and second FMCW signals” as claimed) and using them to estimate the frequency offset, with the result that the apparatus performs frequency offset estimation based on the first and second FMCW signals: (Vishwanath, col. 10, lines 43-47 “acquisition systems at the receiver 44 of FIG. 2 (e.g. mobile terminal 12) employing an FFT can identify the dominant frequency components of both the deswept up-chirp waveform 60 and down-chirp waveform 62, which is then used to estimate the frequency offset”).
Although Vishwanath teaches a mobile terminal, itself a wireless transceiver, that acquires the dual-chirp synchronization waveform and estimates the frequency offset from it: (Vishwanath, col. 6, lines 35-37), Vishwanath does not explicitly disclose a memory holding computer-executable instructions and one or more processors that execute those instructions to cause the apparatus to carry out the acquisition.
However, Vishwanath in view of Ko discloses An apparatus for wireless communication, comprising: at least one transceiver; at least one memory comprising computer-executable instructions given that Ko sets out a UE built from a processor 810, a memory 820 and a transceiver 830, so that the apparatus for wireless communication comprises at least one transceiver and at least one memory, the memory holding the instructions the processor runs (Ko, para [0096], “The UE can include a processor 810, a memory 820, and a transceiver 830 and the eNB 850 can include a processor 860, a memory 870, and a transceiver 880.”).
Furthermore, Ko discloses one or more processors configured to execute the computer-executable instructions to cause the apparatus to because Ko teaches the method being carried out by a software module that is stored in the memory 820/870 and executed by the processor 810/860, which means that one or more processors execute the computer-executable instructions to cause the apparatus to perform the recited operations (Ko, para [0097], “The module can be stored in the memory 820/870 and can be executed by the processor 810/860.”).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to implement Vishwanath’s dual-chirp synchronization acquisition and frequency offset estimation in a wireless device having Ko’s transceiver, memory holding instructions, and processor that executes those instructions, and to carry Vishwanath’s dual-chirp waveform as the synchronization signal within the synchronization signal framework Ko describes.
Doing so would have predictably provided a practical hardware and software implementation of Vishwanath’s known receiver functions with conventional wireless device components, and would have let the waveform take the band, numerology and symbol-duration dependent synchronization signal configurations that Ko teaches for such devices.
Regarding claim 2, which depends on claim 1, (Original) Vishwanath discloses The apparatus of claim 1, wherein the second slope corresponds to a negative of the first slope, as Vishwanath further discloses the up-chirp waveform 60 sweeping at slope K and the down-chirp waveform 62 sweeping at slope -K, such that the second slope corresponds to a negative of the first slope (Vishwanath, col. 10, lines 22-24 “As shown in FIG. 4, K is the slope of the up-chirp waveform 60 and -K is the slope of the down-chirp waveform 62.”).
Regarding claim 3, which depends on claim 1, (Original) Vishwanath discloses The apparatus of claim 1, wherein performing the frequency offset estimation involves estimation of a difference between a first beat frequency associated with the first FMCW signal and a second beat frequency associated with the second FMCW signal, as Vishwanath further discloses the received signal being multiplied by a locally generated desweeping chirp so that the received up-chirp is leveled into a tone, the tone frequency of the deswept up-chirp and of the deswept down-chirp each being estimated, and the two equations relating those two frequencies being solved together for the frequency offset and the time offset, the time offset being the difference of the two tone frequencies scaled by the sweep rate (Equation (8)), whereby the frequency offset estimation involves estimating the difference between a first beat frequency of the first FMCW signal and a second beat frequency of the second FMCW signal (Vishwanath, col. 17, lines 1-4 “the signal output from the matched filter 106 is ‘deswept’ at the first phase shifter 108, which is typically a multiplier, by multiplying the signal r(t) by a first desweeping waveform”; Vishwanath, col. 17, lines 13-16 “The first desweeping waveform 130 may also be referred to as a first hypothesizing waveform since it is being used to ‘hypothesize’ an up-chirp waveform in the received waveform.”; Vishwanath, col. 17, lines 18-22 “the result of such desweeping at the first phase shifter 108 is shown as the frequency vs. time plot 132 in which the frequency of the received up-chirp waveform 134 is now simply leveled out or ‘deswept’ into a ‘tone’ that includes noise”; Vishwanath, col. 21, lines 8-13 “once deswept into tones, the detection and estimation processor 116 estimates the frequency of the tone at the peak 140. Similarly, the frequency of the frequency representation of the deswept down-chirp waveform or peak 160 is estimated at the detection and estimation processor 116”; Vishwanath, col. 21, lines 45-48 “Since fup, fdn, K are known, the two Equations (5) and (6) can be solved for the frequency offset fd, and the time offset t0 which are needed for the mobile terminal to synchronize with the gateway station as in Equations (7) and (8).”).
Regarding claim 5, which depends on claim 3, (Original) Vishwanath discloses The apparatus of claim 3, wherein in order to perform the frequency offset estimation, the one or more processors are further configured to cause the apparatus to: process the first FMCW signal via a first signal path that involves estimating the first beat frequency, as Vishwanath further discloses the first path 107 running from the buffer through the first phase shifter and the first FFT processor to the detection and estimation processor, which estimates the tone frequency of the deswept up-chirp at peak 140, so that the first FMCW signal is processed along a first signal path that involves estimating the first beat frequency (Vishwanath, col. 15, lines 40-44 “The first path 107 is represented as the path taken by a sampled signal going from the buffer 120 to the first phase shifter 108, then to the first FFT processor 112, and finally to the detection and estimation processor 116.”).
Vishwanath discloses process the second FMCW signal via a second signal path that involves estimating the second beat frequency, as Vishwanath further discloses the second path 109 running from the buffer through the second phase shifter and the second FFT processor to the detection and estimation processor, which estimates the tone frequency of the deswept down-chirp at peak 160, which means that the second FMCW signal is processed along a second signal path that involves estimating the second beat frequency (Vishwanath, col. 15, lines 44-48 “The second path 109 is represented as the path taken by a sampled signal going from the buffer 120 to the second phase shifter 110, then to the second FFT processor 114, and finally to the detection and estimation processor 116.”; Vishwanath, col. 21, lines 8-13 “once deswept into tones, the detection and estimation processor 116 estimates the frequency of the tone at the peak 140. Similarly, the frequency of the frequency representation of the deswept down-chirp waveform or peak 160 is estimated at the detection and estimation processor 116”).
Vishwanath discloses estimate the difference between the first beat frequency and the second beat frequency based on the estimate of the first beat frequency and the estimate of the second beat frequency, as Vishwanath further discloses the two tone frequency estimates, once known, being used to solve the two equations for the frequency offset and the time offset, the latter from the difference of the two estimates (Equation (8)), such that the difference between the first and second beat frequencies is estimated from the estimate of each (Vishwanath, col. 21, lines 45-48 “Since fup, fdn, K are known, the two Equations (5) and (6) can be solved for the frequency offset fd, and the time offset t0 which are needed for the mobile terminal to synchronize with the gateway station as in Equations (7) and (8).”).
Regarding claim 6, which depends on claim 5, (Currently Amended) Vishwanath discloses The apparatus of claim 5, wherein the first FMCW signal is received via a frequency band B over a period T, wherein the first slope is B/T and the second slope is -B/T, as Vishwanath further discloses the up-chirp sweeping a 15 kHz band over the burst duration T, K being the rate at which the frequency is swept across that duration, and the down-chirp slope being -K, which means that the first FMCW signal is received over a band B during a period T, the first slope is B/T and the second slope is -B/T (Vishwanath, col. 12, lines 9-11 “the range of values of f1(t), which is the up-chirp waveform 60, is from fc-7500 Hz to fc+7500 Hz (total bandwidth 15 kHz of an available bandwidth of 18 kHz)”; Vishwanath, col. 10, lines 18-21 “where K is sweeping rate parameter (i.e. the rate at which the frequency is ‘swept’ across the duration of the burst or the ‘slope’ of the lines presenting the up-chirp waveform and the down-chirp waveform)”; Vishwanath, col. 10, lines 22-24 “As shown in FIG. 4, K is the slope of the up-chirp waveform 60 and -K is the slope of the down-chirp waveform 62.”).
Regarding claim 7, which depends on claim 6, (Original) Vishwanath discloses The apparatus of claim 6, wherein the apparatus searches for the FMCW signal for a duration L across a frequency range of B*L/T, as Vishwanath further discloses the mobile terminal searching for the dual-chirp burst with a sliding search window slid over time and over a variety of frequencies, a sweep of rate K observed over a search time L spanning K times L of frequency, K being the band swept per burst duration, such that the apparatus searches for the FMCW signal for a duration L across a frequency range of B times L divided by T (Vishwanath, col. 16, lines 49-51 “the mobile terminal must ‘search’ for the 5 msec dual-chirp waveform that occurs every 320 msec over a variety of frequencies using the sliding search window”; Vishwanath, col. 10, lines 18-21 “where K is sweeping rate parameter (i.e. the rate at which the frequency is ‘swept’ across the duration of the burst or the ‘slope’ of the lines presenting the up-chirp waveform and the down-chirp waveform)”).
Regarding claim 8, which depends on claim 6, (Currently Amended) Vishwanath discloses The apparatus of claim 6, wherein: the SS is received according to multiple frequency rasters or multiple operating bands, as Vishwanath further discloses the acquisition system searching a defined set of carriers for the burst that carries the dual-chirp waveform, whereby the SS is received according to multiple frequency rasters (Vishwanath, col. 15, lines 59-62 “During acquisition at the mobile terminal, the acquisition system 100 searches a defined set of carriers (e.g. searches 10 channels of approximately 1000 available channels) for the burst containing the dual-chirp waveform.”).
Vishwanath discloses a value of B, T, or B/T is defined for each of the multiple frequency rasters or each of the multiple operating bands, as Vishwanath further discloses the sweep slope K and the swept bandwidth each being set against the available bandwidth of the channel the burst occupies, with the result that a value of B or B/T is defined for each of the frequency rasters on which the SS is carried (Vishwanath, col. 11, lines 8-13 “The sweep parameter or slope K of the up-chirp waveform 60 and down-chirp waveforms 62 controls a trade-off between timing accuracy and signal bandwidth. Higher values of K increase the accuracy of the timing estimate; however, the value of K is limited by the available bandwidth of the channel.”; Vishwanath, col. 12, lines 3-6 “the bandwidth of the component waveforms should be greater than half (50%), or ideally greater than 80%, of the available bandwidth of the channel”).
Regarding claim 9, which depends on claim 6, (Currently Amended) Vishwanath in view of Ko discloses The apparatus of claim 6, wherein: the SS is received according to one of multiple numerologies, as Ko further discloses a synchronization signal transmitted under Numerology type 1 with a long OFDM symbol duration or under Numerology type 2 with a short OFDM symbol duration, with the result that the SS is received according to one of multiple numerologies (Ko, para [0071], “the time position of the synchronization signal in Numerology type 1 having a long OFDM symbol duration and the time position of the synchronization signal in Numerology type 2 having a short OFDM symbol duration may match each other as shown in FIG. 7.”).
Vishwanath in view of Ko discloses a value of B, T, or B/T is defined for each of the multiple numerologies, as Ko further discloses the PSS/SSS taking a long OFDM symbol duration under a 15 kHz subcarrier spacing and a short OFDM symbol duration under a 30 kHz subcarrier spacing, the synchronization signal duration thus being set per numerology, so that a value of T is defined for each of the multiple numerologies (Ko, para [0079], “a PSS/SSS with a long OFDM symbol duration (e.g., based on a 15-kHz subcarrier spacing) may employ the TDM, while a PSS/SSS with a short OFDM symbol duration (e.g., based on 30 kHz subcarrier spacing) may employ the FDM.”).
Consequently, Vishwanath and Ko are combined for the reasons set forth in the rejection of claim 1 above.
Regarding claim 10, which depends on claim 6, (Original) Vishwanath discloses The apparatus of claim 6, wherein the one or more processors are further configured to cause the apparatus to: perform timing offset estimation based on the first beat frequency, the second beat frequency, B, and T, as Vishwanath further discloses the time offset being solved from the two tone frequency estimates and the known sweep rate K (Equation (8)), K being the band swept over the burst duration T, so that the timing offset estimation is based on the first beat frequency, the second beat frequency, B, and T (Vishwanath, col. 21, lines 45-48 “Since fup, fdn, K are known, the two Equations (5) and (6) can be solved for the frequency offset fd, and the time offset t0 which are needed for the mobile terminal to synchronize with the gateway station as in Equations (7) and (8).”; Vishwanath, col. 10, lines 18-21 “where K is sweeping rate parameter (i.e. the rate at which the frequency is ‘swept’ across the duration of the burst or the ‘slope’ of the lines presenting the up-chirp waveform and the down-chirp waveform)”).
Regarding claim 12, which depends on claim 1, (Original) Vishwanath in view of Ko discloses The apparatus of claim 1, wherein the duration corresponds to an orthogonal frequency division multiplexing (OFDM) symbol duration, as Ko further discloses the unit time taken to transmit the PSS/SSS being one OFDM symbol or two OFDM symbols, such that the duration of the synchronization signal corresponds to an OFDM symbol duration (Ko, para [0081], “When there are N beams, N times of a unit time taken to transmit the PSS/SSS may be required (for example, one OFDM symbol or two OFDM symbols may be the unit time according to the multiplexing method as shown in FIG. 9).”).
Accordingly, Vishwanath and Ko are combined for the reasons set forth in the rejection of claim 1 above.
Regarding claim 13, which depends on claim 1, (Original) Vishwanath in view of Ko discloses The apparatus of claim 1, wherein the SS comprises a primary synchronization signal (PSS), as Ko further discloses the NR synchronization signal including the Primary Synchronization Signal, whereby the SS comprises a PSS (Ko, para [0076], “The synchronization signal of the NR system may include the Primary Synchronization Signal (PSS) and the Secondary Synchronization Signal (SSS).”).
Thus, Vishwanath and Ko are combined for the reasons set forth in the rejection of claim 1 above.
Regarding claim 14, which depends on claim 1, (Currently Amended) Vishwanath in view of Ko discloses The apparatus of claim 1, wherein the apparatus is configured to operate as a user equipment (UE), as Ko further discloses the wireless device 800 corresponding to a UE, with the result that the apparatus is configured to operate as a user equipment (Ko, para [0095], “In FIG. 14, a wireless device 800 corresponds to a specific UE in the foregoing description and a wireless device 850 may correspond to a base station or an eNB.”).
Consequently, Vishwanath and Ko are combined for the reasons set forth in the rejection of claim 1 above.
Regarding claim 15, (Currently Amended) Vishwanath discloses: transmit, via the at least one transceiver, a first frequency modulated continuous waveform (FMCW) signal associated with a frequency that increases in time for a duration according to a first slope, given that Vishwanath sets out the gateway station 24, a communications terminal and so a transceiver, transmitting the burst that contains the dual-chirp waveform, whose up-chirp waveform 60 (i.e., “first frequency modulated continuous waveform (FMCW) signal” as claimed) rises linearly in frequency over the burst duration T at slope K, so that the apparatus transmits through its transceiver a first FMCW signal whose frequency increases for a duration according to a first slope: (Vishwanath, col. 6, lines 33-35 “a first communications terminal or a gateway station 24 (also referred to as a base station)”; Vishwanath, col. 6, lines 40-42 “It is noted that the terms communications terminal, terminal, and transceiver are used synonymously.”; Vishwanath, col. 9, lines 65-67 “the source signal s(t) that is transmitted, as a burst containing the dual-chirp waveform of FIG. 3, from the gateway station 24 to the mobile terminal 12”; Vishwanath, col. 10, lines 1-2 “continuous time t, wherein t is defined with respect to a start of a burst of duration T, (i.e. t=0 at the start of the burst)”; Vishwanath, col. 9, lines 56-59 “illustrates the two component waveforms, i.e. the up-chirp waveform 60, wherein frequency increases linearly with time, and a simultaneously transmitted down-chirp waveform 62, wherein frequency decreases linearly with time”).
Furthermore, Vishwanath discloses: transmit, via the at least one transceiver, a second FMCW signal that overlaps with the first FMCW signal, because Vishwanath teaches the down-chirp waveform 62 transmitted simultaneously with the up-chirp waveform 60 by the same gateway station as the second component of the one composite waveform, which means that the second FMCW signal is transmitted through the transceiver overlapping the first FMCW signal: (Vishwanath, col. 9, lines 42-45 “dual-chirp waveform is one example of a composite waveform of two simultaneously transmitted waveforms having a known frequency variation, i.e. the frequency varies linearly with time”).
Moreover, Vishwanath discloses: wherein the second FMCW signal is associated with a frequency that decreases in time for the duration according to a second slope that corresponds to a negative of the first slope, as Vishwanath describes the down-chirp waveform 62 falling linearly in frequency over the same burst at slope -K, the negative of the up-chirp slope K, such that the second FMCW signal decreases in frequency for the duration according to a second slope that corresponds to a negative of the first slope: (Vishwanath, col. 10, lines 22-24 “As shown in FIG. 4, K is the slope of the up-chirp waveform 60 and -K is the slope of the down-chirp waveform 62.”).
In addition, Vishwanath discloses: wherein the first FMCW signal and second FMCW signal form a synchronization signal (SS), since Vishwanath explains the up-chirp and down-chirp together forming the composite dual-chirp waveform (i.e., “synchronization signal (SS)” as claimed) that the mobile terminal finds in order to synchronize, whereby the first and second FMCW signals form a synchronization signal: (Vishwanath, col. 9, lines 35-38 “dual-chirp waveform 50, is represented mathematically on a real plane, and may thus be referred to as a ‘real waveform’, as shown in FIG. 3 as a composite of an up-chirp waveform and a down-chirp waveform”; Vishwanath, col. 6, lines 60-64 “the mobile terminal 12 must be able to find the waveform (also referred to as a synchronization signal) sent from the gateway station 24 via the satellite 26 to synchronize with the timing and frequency of the communications link 30”).
Although Vishwanath teaches a gateway station, itself a communications terminal and so a transceiver, that transmits the dual-chirp synchronization waveform: (Vishwanath, col. 6, lines 33-35), Vishwanath stops short of disclosing a memory holding computer-executable instructions and one or more processors that execute those instructions to cause the apparatus to transmit the waveform.
Conversely, Vishwanath in view of Ko discloses An apparatus for wireless communication, comprising: at least one transceiver; at least one memory comprising computer-executable instructions in that Ko shows an eNB built from a processor 860, a memory 870 and a transceiver 880, with the result that the apparatus for wireless communication comprises at least one transceiver and at least one memory, the memory holding the instructions the processor runs (Ko, para [0096], “The UE can include a processor 810, a memory 820, and a transceiver 830 and the eNB 850 can include a processor 860, a memory 870, and a transceiver 880.”).
Furthermore, Ko discloses one or more processors configured to execute the computer-executable instructions to cause the apparatus to given that Ko sets out the processor 860, connected with the transceiver 880, performing the procedure of transmitting the synchronization signal block, so that one or more processors execute the instructions to cause the apparatus to transmit the recited signals (Ko, para [0096], “The processor 810/860 is executed in a physical layer and/or a MAC layer and is connected with the transceiver 830/880. The processor 810/860 can perform a procedure of transmitting the aforementioned SS block.”).
For these reasons, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to implement Vishwanath’s gateway-side transmission of the dual-chirp synchronization waveform in a network device having Ko’s transceiver, memory holding instructions, and processor that executes those instructions to transmit the synchronization signal, and to carry that waveform within the synchronization signal framework Ko describes. Doing so would have predictably provided a practical hardware and software implementation of Vishwanath’s known transmitter functions with conventional base station components, and would have let the waveform take the band and numerology dependent synchronization signal configurations that Ko teaches.
Regarding claim 16, which depends on claim 15, (Currently Amended) Vishwanath discloses The apparatus of claim 15, wherein the first FMCW signal is transmitted across a frequency band B over a period T, wherein the first slope is B/T and the second slope is -B/T, as Vishwanath further discloses the up-chirp sweeping a 15 kHz band over the burst duration T, K being the rate at which the frequency is swept across that duration, and the down-chirp slope being -K, which means that the first FMCW signal is transmitted across a band B over a period T, the first slope is B/T and the second slope is -B/T (Vishwanath, col. 12, lines 9-11 “the range of values of f1(t), which is the up-chirp waveform 60, is from fc-7500 Hz to fc+7500 Hz (total bandwidth 15 kHz of an available bandwidth of 18 kHz)”; Vishwanath, col. 10, lines 18-21 “where K is sweeping rate parameter (i.e. the rate at which the frequency is ‘swept’ across the duration of the burst or the ‘slope’ of the lines presenting the up-chirp waveform and the down-chirp waveform)”; Vishwanath, col. 10, lines 22-24 “As shown in FIG. 4, K is the slope of the up-chirp waveform 60 and -K is the slope of the down-chirp waveform 62.”).
Regarding claim 17, which depends on claim 16, (Original) Vishwanath discloses The apparatus of claim 16, wherein: the SS is generated according to one of multiple frequency rasters or operating bands, as Vishwanath further discloses the burst carrying the dual-chirp waveform being sent on one of a defined set of carriers that the terminal searches, such that the SS is generated according to one of multiple frequency rasters (Vishwanath, col. 15, lines 59-62 “During acquisition at the mobile terminal, the acquisition system 100 searches a defined set of carriers (e.g. searches 10 channels of approximately 1000 available channels) for the burst containing the dual-chirp waveform.”).
Vishwanath discloses a value of B, T, or B/T is defined for each of the multiple frequency rasters or each of the multiple operating bands, as Vishwanath further discloses the sweep slope K and the swept bandwidth each being set against the available bandwidth of the channel the burst occupies, whereby a value of B or B/T is defined for each of the frequency rasters on which the SS is generated (Vishwanath, col. 11, lines 8-13 “The sweep parameter or slope K of the up-chirp waveform 60 and down-chirp waveforms 62 controls a trade-off between timing accuracy and signal bandwidth. Higher values of K increase the accuracy of the timing estimate; however, the value of K is limited by the available bandwidth of the channel.”; Vishwanath, col. 12, lines 3-6 “the bandwidth of the component waveforms should be greater than half (50%), or ideally greater than 80%, of the available bandwidth of the channel”).
Regarding claim 18, which depends on claim 16, (Original) Vishwanath in view of Ko discloses The apparatus of claim 16, wherein: the SS is generated according to one of multiple numerologies, as Ko further discloses a synchronization signal transmitted under Numerology type 1 with a long OFDM symbol duration or under Numerology type 2 with a short OFDM symbol duration, whereby the SS is generated according to one of multiple numerologies (Ko, para [0071], “the time position of the synchronization signal in Numerology type 1 having a long OFDM symbol duration and the time position of the synchronization signal in Numerology type 2 having a short OFDM symbol duration may match each other as shown in FIG. 7.”).
Vishwanath in view of Ko discloses a value of B, T, or B/T is defined for each of the multiple numerologies, as Ko further discloses the PSS/SSS taking a long OFDM symbol duration under a 15 kHz subcarrier spacing and a short OFDM symbol duration under a 30 kHz subcarrier spacing, the synchronization signal duration thus being set per numerology, with the result that a value of T is defined for each of the multiple numerologies (Ko, para [0079], “a PSS/SSS with a long OFDM symbol duration (e.g., based on a 15-kHz subcarrier spacing) may employ the TDM, while a PSS/SSS with a short OFDM symbol duration (e.g., based on 30 kHz subcarrier spacing) may employ the FDM.”).
Thus, Vishwanath and Ko are combined for the reasons set forth in the rejection of claim 15 above.
Regarding claim 19, which depends on claim 15, (Currently Amended) Vishwanath in view of Ko discloses The apparatus of claim 15, wherein the apparatus is configured to operate as a network entity, as Ko further discloses the wireless device 850 corresponding to a base station or an eNB, with the result that the apparatus is configured to operate as a network entity (Ko, para [0095], “In FIG. 14, a wireless device 800 corresponds to a specific UE in the foregoing description and a wireless device 850 may correspond to a base station or an eNB.”).
Consequently, Vishwanath and Ko are combined for the reasons set forth in the rejection of claim 15 above.
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Vishwanath (US 6,418,158 B1) in view of Ko (US 2020/0383129 A1) and further in view of Filipovic (US 2007/0189419 A1).
Regarding claim 4, which depends on claim 3, (Original) Vishwanath discloses The apparatus of claim 3, wherein in order to perform the frequency offset estimation, the one or more processors are further configured to cause the apparatus to: process the first FMCW signal via a first signal path, as Vishwanath further discloses the first path 107 running from the buffer through the first phase shifter and the first FFT processor to the detection and estimation processor, with the result that the first FMCW signal is processed along a first signal path (Vishwanath, col. 15, lines 40-44 “The first path 107 is represented as the path taken by a sampled signal going from the buffer 120 to the first phase shifter 108, then to the first FFT processor 112, and finally to the detection and estimation processor 116.”).
Vishwanath discloses estimate the difference between the first beat frequency and the second beat frequency, as Vishwanath further discloses the two tone frequency estimates being used to solve the two equations for the frequency offset and the time offset, the latter from the difference of the two estimates (Equation (8)), so that the difference between the first and second beat frequencies is estimated (Vishwanath, col. 21, lines 45-48 “Since fup, fdn, K are known, the two Equations (5) and (6) can be solved for the frequency offset fd, and the time offset t0 which are needed for the mobile terminal to synchronize with the gateway station as in Equations (7) and (8).”).
Even though Vishwanath in view of Ko teaches first and second signal paths that each isolate one sweep of the dual-chirp waveform for frequency estimation by a processor executing stored instructions: (Vishwanath, col. 15, lines 40-48, Ko, para [0097]), Vishwanath in view of Ko does not expressly teach merging the second path with the first path ahead of an analog to digital conversion and estimating from the output of that conversion.
Conversely, Vishwanath in view of Ko and further in view of Filipovic discloses process the second FMCW signal via a second signal path that merges with the first signal path prior to performing an analog to digital signal conversion because Filipovic teaches a signal adder 124 combining two analog signal paths into one input of the analog to digital converter 102, which means that the second signal path merges with the first signal path before the analog to digital conversion (Filipovic, para [0019], “After the RF signals 118, 122 are frequency shifted and filtered, a signal adder 124 combines the analog signals 104,106 to be fed into the ADC 102.”).
Furthermore, Filipovic discloses based on an output of the analog to digital signal conversion as Filipovic describes the second signal being recovered digitally from the composite digital signal 110 that the converter outputs, such that the component signals from which the difference is estimated are taken from the output of the analog to digital conversion (Filipovic, para [0019], “An inverse offset frequency shifter 128 frequency shifts the composite digital signal 110 in the digital domain to recover the second digital signal 114 at baseband.”).
For these reasons, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to carry Vishwanath’s first and second component paths as analog paths that Filipovic’s adder merges ahead of a single analog to digital converter, and to recover each component from the composite converter output before Vishwanath’s tone frequency estimation, because Filipovic teaches that a single converter can simultaneously convert multiple analog signals that are then separated in the digital domain. Doing so would have predictably reduced the number of converters in the receiver front end while keeping the separate estimates of the two component frequencies.
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Vishwanath (US 6,418,158 B1) in view of Ko (US 2020/0383129 A1) and further in view of Jung (US 2020/0280942 A1).
Regarding claim 11, which depends on claim 1, (Original) Vishwanath discloses The apparatus of claim 1, wherein the frequency associated with the first FMCW signal and the frequency associated with the second FMCW signal are the same at a time, as Vishwanath further discloses the difference between the up-chirp frequency f1(t) and the down-chirp frequency f2(t) shrinking through the burst to about 0 kHz at point E, where the two sweeps cross, which means that the frequencies of the first and second FMCW signals are the same at a time within the burst (Vishwanath, col. 12, lines 29-31 “And at point ‘D’, the difference between f1(t) and f2(t) is about -4 kHz. At point ‘E’, the difference between f1(t) and f2(t) is about 0 kHz.”).
Even though Vishwanath in view of Ko teaches a dual-chirp synchronization signal whose two sweeps reach the same frequency within the burst, received by a device with Ko’s transceiver: (Vishwanath, col. 12, lines 29-31, Ko, para [0096]), Vishwanath in view of Ko stops short of disclosing that the crossing time corresponds to a raster point of the synchronization signal.
Nevertheless, Vishwanath in view of Ko and further in view of Jung discloses corresponding to a raster point of the SS as Jung describes the synchronization raster being placed at the center of the SS block, such that the time at which the two sweeps share one frequency corresponds to the raster point of the SS (Jung, para [0208], “The synchronization raster needs to be located at the center of the SS block.”).
Accordingly, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to center Vishwanath’s dual-chirp synchronization signal on the synchronization raster, so that the point at which the up-chirp and down-chirp share one frequency falls at the raster point, because Jung teaches that the synchronization raster is located at the center of the synchronization signal block that a user equipment detects during initial cell search. Doing so would have predictably given the receiver a known frequency location at which to tune while searching for the synchronization signal.
Conclusion
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.
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/CHONGSUH PARK/Examiner, Art Unit 2478
/JOSEPH E AVELLINO/Supervisory Patent Examiner, Art Unit 2478
