Prosecution Insights
Last updated: April 19, 2026
Application No. 18/235,544

DIGITAL CHIRP OFDM RADAR AND RADAR SENSING METHODS

Non-Final OA §103
Filed
Aug 18, 2023
Examiner
MAKHDOOM, SAMARINA
Art Unit
3648
Tech Center
3600 — Transportation & Electronic Commerce
Assignee
Nxp B V
OA Round
3 (Non-Final)
70%
Grant Probability
Favorable
3-4
OA Rounds
3y 1m
To Grant
97%
With Interview

Examiner Intelligence

Grants 70% — above average
70%
Career Allow Rate
71 granted / 101 resolved
+18.3% vs TC avg
Strong +27% interview lift
Without
With
+26.6%
Interview Lift
resolved cases with interview
Typical timeline
3y 1m
Avg Prosecution
77 currently pending
Career history
178
Total Applications
across all art units

Statute-Specific Performance

§101
2.7%
-37.3% vs TC avg
§103
75.1%
+35.1% vs TC avg
§102
21.4%
-18.6% vs TC avg
§112
0.8%
-39.2% vs TC avg
Black line = Tech Center average estimate • Based on career data from 101 resolved cases

Office Action

§103
DETAILED ACTION Continued Examination Under 37 CFR 1.114 A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Response to Amendment The amendment filed February 9, 2026 has been entered. Claims 1, 11, and 19 are amended. Claim 2 is cancelled. Claims 1 and 3-20 are pending this application. 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 1 and 3-20 are rejected under 35 U.S.C. 103 as being unpatentable over Markish et al (US 2022/0214423 A1) in view of Gupta et al (US 2017/0285140 A1) and Strum et al (US 2012/0076190 A1). Regarding Claim 1, Markish teaches a radar transceiver comprising [0065, 0154]: a radar transmitter configured to selectively transmit digital orthogonal frequency division multiplexing (OFDM) wireless communication signals and radar signals, the radar transmitter comprising [0142, 0149-0150 for a radar transmit signal 0168]: generation circuitry to generate a digital radar chirp sequence [0149-0150]; one or more digital-to-analog converters to convert the digital radar chirp sequence into a radar signal to be transmitted via one or more transmit antennas [0131, 0150-0151 figure 4 element 404]; and a radar receiver configured to perform radar signal sensing and to enable OFDM-based wireless communication, the radar receiver comprising [0152 for receiving radar signals, and 0185-0191 for receiving a plurality of receive signals based on transmitted chirps]: an adder configured to combine the digital I component and the digital Q component to produce a received digital signal [0152-0154 and figure 4 with 0153-0155 for getting range and velocity of objects via radar]. Markish fails to explicitly teach first and second mixers configured to mix a received reflection of the radar signal with a carrier signal from the radar transmitter to generate in-phase (I) and quadrature (Q) analog components of the received reflection of the radar signal, first and second analog-to-digital converters to convert the I and Q analog components of the received reflection of the radar signal to a digital domain to produce a digital I component and a digital Q component. Gupta has a FMCW radar receiver includes a LO providing a chirped LO signal, an in-phase (I) channel (abstract) and teaches first and second mixers configured to mix a received reflection of the radar signal with a carrier signal from the radar transmitter to generate in-phase (I) and quadrature (Q) analog components of the received reflection of the radar signal [0010 for a first and second mixer for an IQ signal with 0040 step 601], first and second analog-to-digital converters to convert the I and Q analog components of the received reflection of the radar signal to a digital domain to produce a digital I component and a digital Q component [0040 for using an first A/D converter for outputting I data and second A/D for Q data]. It would have been obvious to a person of ordinary skill in the art before the effective filling date of the applicant’s invention for modifying the signal propagation techniques, as disclosed by Markish, further including the mixer component calculations as taught by Gupta for the purpose of generating different values during a plurality of intervals for each chirp of the chirped LO signal (Gupta, 0040). Markish fails to explicitly teach and a mixer to mix the received digital signal with the digital radar chirp sequence to generate a digital de-chirped signal for velocity processing followed by range processing. Sturm has a method and also a device for digitally processing OFDM signals which are emitted by a transmission apparatus (abstract) and teaches a mixer to mix the received digital signal with the digital radar chirp sequence to generate a digital de-chirped signal for velocity processing followed by range processing [claim 7 for getting velocity before range and Figure 7 element 19 for de-chirping by complex division]. It would have been obvious to a person of ordinary skill in the art before the effective filling date of the applicant’s invention for modifying the signal propagation techniques, as disclosed by Markish, further including the signal processing calculations as taught by Strum for the purpose of calculating speeds and/or distances of the objects or the corresponding radar images on the basis of the normalised modulation symbols (Strum, 0042). Regarding Claim 3, Markish fails to explicitly teach the radar receiver comprising a serial-to-parallel converter to parallelize the digital de-chirped signal into a plurality of digital data streams. Sturm has a method and also a device for digitally processing OFDM signals which are emitted by a transmission apparatus (abstract) and teaches the radar receiver comprising a serial-to-parallel converter to parallelize the digital de-chirped signal into a plurality of digital data streams [figure 7 element 16 for a parallel to serial converter and 0041]. It would have been obvious to a person of ordinary skill in the art before the effective filling date of the applicant’s invention for modifying the signal propagation techniques, as disclosed by Markish, further including the signal processing calculations as taught by Strum for the purpose of calculating speeds and/or distances of the objects or the corresponding radar images on the basis of the normalised modulation symbols (Strum, 0042). Regarding Claim 4, Markish teaches the radar receiver comprising a first fast Fourier transform (FFT) component to apply a first FFT to data in the digital de-chirped signal in a first dimension corresponding to a slow time to generate velocity information associated with the received reflection [0165-0167]. Regarding Claim 5, Markish teaches the radar receiver comprising a second FFT component after the first FFT component to apply a second FFT to data in the digital de-chirped signal in a second dimension corresponding to a fast time to generate range information associated with the received reflection [0164-0167]. Regarding Claim 6, Markish fails to explicitly teach the generation circuitry comprises a serial-to-parallel converter to convert a signal representative of a radar waveform into a plurality of radar symbols over different frequency carriers. Sturm has a method and also a device for digitally processing OFDM signals which are emitted by a transmission apparatus (abstract) and teaches the generation circuitry comprises a serial-to-parallel converter to convert a signal representative of a radar waveform into a plurality of radar symbols over different frequency carriers [0039-0040 for using serial/parallel converter for N parallel data sequences]. It would have been obvious to a person of ordinary skill in the art before the effective filling date of the applicant’s invention for modifying the signal propagation techniques, as disclosed by Markish, further including the signal processing calculations as taught by Strum for the purpose of calculating speeds and/or distances of the objects or the corresponding radar images on the basis of the normalised modulation symbols (Strum, 0042). Regarding Claim 7, Markish teaches the generation circuitry comprises an inverse fast Fourier transform (FFT) component [0696]. Markish fails to explicitly teach and a parallel-to-serial converter to receive the plurality of radar symbols and generate the digital radar chirp sequence. Sturm has a method and also a device for digitally processing OFDM signals which are emitted by a transmission apparatus (abstract) and teaches and a parallel-to-serial converter to receive the plurality of radar symbols and generate the digital radar chirp sequence [figure 6 element 4, 5 and 0039-0040]. It would have been obvious to a person of ordinary skill in the art before the effective filling date of the applicant’s invention for modifying the signal propagation techniques, as disclosed by Markish, further including the signal processing calculations as taught by Strum for the purpose of calculating speeds and/or distances of the objects or the corresponding radar images on the basis of the normalised modulation symbols (Strum, 0042). Regarding Claim 8, Markish fails to explicitly teach a cyclic prefix is absent from the digital radar chirp sequence. Sturm has a method and also a device for digitally processing OFDM signals which are emitted by a transmission apparatus (abstract) and teaches and a parallel-to-serial converter to receive the plurality of a cyclic prefix is absent from the digital radar chirp sequence [0040-0041]. It would have been obvious to a person of ordinary skill in the art before the effective filling date of the applicant’s invention for modifying the signal propagation techniques, as disclosed by Markish, further including the signal processing calculations as taught by Strum for the purpose of calculating speeds and/or distances of the objects or the corresponding radar images on the basis of the normalised modulation symbols (Strum, 0042). Regarding Claim 9, Markish teaches the radar transmitter comprises one or more transmit antennas to transmit the radar signal [0160-0164]. Regarding Claim 10, Markish teaches the radar receiver comprises one or more receive antennas to receive the received reflection of the radar signal [0160-0164]. Regarding Claim 11, Markish teaches method comprising [0154]: generating, at a transmitter of a radar transceiver [0065, 0154], a radar signal for transmission based on a digital radar chirp sequence generated using orthogonal frequency digital multiplexing (OFDM) [0150-0151 and 0168]; transmitting the radar signal via one or more transmit antennas of the transmitter [0131, 0150-0151 figure 4 element 404]; receiving a reflection of the radar signal at one or more receive antennas coupled to a receiver of the radar transceiver [0152-0154 and figure 4]; converting, at one or more analog-to-digital converters, the I and Q analog components of the received reflection to a received digital signal [0152-0154 and figure 4 with 0153-0155 for getting range and velocity of objects via radar]. Markish fails to explicitly teach mixing the received reflection with a carrier signal of the radar signal for transmission to produce in-phase (I) and quadrature (Q) analog components of the received reflection. Gupta has a FMCW radar receiver includes a LO providing a chirped LO signal, an in-phase (I) channel (abstract) and teaches mixing the received reflection with a carrier signal of the radar signal for transmission to produce in-phase (I) and quadrature (Q) analog components of the received reflection [0010 for a first and second mixer for an IQ signal with 0040 step 601]. It would have been obvious to a person of ordinary skill in the art before the effective filling date of the applicant’s invention for modifying the signal propagation techniques, as disclosed by Markish, further including the mixer component calculations as taught by Gupta for the purpose of generating different values during a plurality of intervals for each chirp of the chirped LO signal (Gupta, 0040). Markish fails to explicitly teach and mixing the received digital signal with the digital radar chirp sequence to generate a digital signal for velocity processing followed by range processing. Sturm has a method and also a device for digitally processing OFDM signals which are emitted by a transmission apparatus (abstract) teaches and mixing the received digital signal with the digital radar chirp sequence to generate a digital signal for velocity processing followed by range processing [claim 7 for getting velocity before range and Figure 7 element 19 for de-chirping by complex division]. It would have been obvious to a person of ordinary skill in the art before the effective filling date of the applicant’s invention for modifying the signal propagation techniques, as disclosed by Markish, further including the signal processing calculations as taught by Strum for the purpose of calculating speeds and/or distances of the objects or the corresponding radar images on the basis of the normalised modulation symbols (Strum, 0042). Regarding Claim 12, Markish teaches converting the digital radar chirp sequence into the radar signal via one or more digital-to-analog converters [0131, 0148 and figure 4 element 404]. Regarding Claim 13, Markish teaches parallelizing the digital de-chirped signal into a plurality of digital data streams prior to the velocity processing and the range processing [0053, 0155-0156]. Regarding Claim 14, Markish teaches performing the velocity processing of the received reflection based on the plurality of digital data streams [0155-0156]. Regarding Claim 15, Markish teaches performing the range processing based on a result of the velocity processing [0202-0205]. Regarding Claim 16, Markish teaches converting a signal representative of a radar waveform into a plurality of radar symbols over different frequency carriers. Sturm has a method and also a device for digitally processing OFDM signals which are emitted by a transmission apparatus (abstract) and teaches converting a signal representative of a radar waveform into a plurality of radar symbols over different frequency carriers [figure 6 element 3 and 0039-0040]. It would have been obvious to a person of ordinary skill in the art before the effective filling date of the applicant’s invention for modifying the signal propagation techniques, as disclosed by Markish, further including the signal processing calculations as taught by Strum for the purpose of calculating speeds and/or distances of the objects or the corresponding radar images on the basis of the normalised modulation symbols (Strum, 0042). Regarding Claim 17, Markish teaches generating the digital radar chirp sequence based on the plurality of radar symbols [0598-0601]. Regarding Claim 18, Markish fails to explicitly teach generating the digital radar chirp sequence without inserting a cyclic prefix in the digital radar chirp sequence. Sturm has a method and also a device for digitally processing OFDM signals which are emitted by a transmission apparatus (abstract) and teaches generating the digital radar chirp sequence without inserting a cyclic prefix in the digital radar chirp sequence [0040-0041]. It would have been obvious to a person of ordinary skill in the art before the effective filling date of the applicant’s invention for modifying the signal propagation techniques, as disclosed by Markish, further including the signal processing calculations as taught by Strum for the purpose of calculating speeds and/or distances of the objects or the corresponding radar images on the basis of the normalised modulation symbols (Strum, 0042). Regarding Claim 19, Markish teaches radar processing device comprising [0065, 0154]: one or more transmit antennas for transmitting a radar signal based on a digital radar chirp sequence [0149-0150]; one or more receive antennas for receiving a reflection of the radar signal [0131, 0150-0151 figure 4 element 404]; and signal processing circuitry to: convert the I and Q analog components of received reflection of the radar signal to a received digital signal [0152-0154 and figure 4 with 0153-0155 for getting range and velocity of objects via radar]. Markish fails to explicitly teach mix the received reflection with a carrier signal of the radar signal for transmission to produce in-phase (I) and quadrature (Q) analog components of the received reflection. Gupta has A FMCW radar receiver includes a LO providing a chirped LO signal, an in-phase (I) channel (abstract) and teaches mix the received reflection with a carrier signal of the radar signal for transmission to produce in-phase (I) and quadrature (Q) analog components of the received reflection [0010 for a first and second mixer for an IQ signal with 0040 step 601]. It would have been obvious to a person of ordinary skill in the art before the effective filling date of the applicant’s invention for modifying the signal propagation techniques, as disclosed by Markish, further including the mixer component calculations as taught by Gupta for the purpose of generating different values during a plurality of intervals for each chirp of the chirped LO signal (Gupta, 0040). Markish fails to explicitly teach and a mixer to mix the received digital signal with the digital radar chirp sequence to generate a digital de-chirped signal for velocity processing followed by range processing. Sturm has a method and also a device for digitally processing OFDM signals which are emitted by a transmission apparatus (abstract) and teaches mix the received digital signal with the digital radar chirp sequence to a digital signal for velocity processing followed by range processing [claim 7 for getting velocity before range and Figure 7 element 19 for de-chirping by complex division]. It would have been obvious to a person of ordinary skill in the art before the effective filling date of the applicant’s invention for modifying the signal propagation techniques, as disclosed by Markish, further including the signal processing calculations as taught by Strum for the purpose of calculating speeds and/or distances of the objects or the corresponding radar images on the basis of the normalised modulation symbols (Strum, 0042). Regarding Claim 20, Markish teaches mixing the received digital signal with the digital radar chirp sequence to a digital de-chirped signal comprises [0153-0155 for getting range and velocity of objects via radar]. Markish fails to explicitly teach multiplying the digital radar chirp sequence with a complex conjugate of the received digital signal. Sturm has a method and also a device for digitally processing OFDM signals which are emitted by a transmission apparatus (abstract) and teaches multiplying the digital radar chirp sequence with a complex conjugate of the received digital signal [0027-0028]. It would have been obvious to a person of ordinary skill in the art before the effective filling date of the applicant’s invention for modifying the signal propagation techniques, as disclosed by Markish, further including the signal processing calculations as taught by Strum for the purpose of calculating speeds and/or distances of the objects or the corresponding radar images on the basis of the normalised modulation symbols (Strum, 0042). Response to Arguments Applicant’s arguments with respect to claims 1 and 3-20 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument. Applicant’s arguments page 6 last paragraph, the applicant states that Markish and Seller fails to teach first and second mixers configured to mix the reflection of the radar signal. The examiner explicitly disagrees: new reference Gupta explicitly teaches a first and second mixer for both I and Q signals [Gupta, 0040]. Applicant’s arguments page 7 last paragraph, the applicant states that Markish fails to teach a first and second Mixer. The examiner explicitly disagrees: new reference Gupta explicitly teaches a first and second mixer for both I and Q signals [Gupta, 0040]. Applicant’s arguments page 8 last paragraph, the applicant states that Seller fails to teach a transceiver with a first and second mixer. The examiner explicitly disagrees: see previous response. Applicant’s arguments page 9 last paragraph, the applicant states that Kumar fail to teach receiving the reflected signal, mixing the signal and de-chirping the signal. The examiner explicitly disagrees: Kumar is no longer part of the prior art in this response. Applicant’s arguments page 11 second paragraph, the applicant states that Yang fail to teach a first and second mixer. The examiner explicitly disagrees: Yang is no longer part of the prior art in this response. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to SAMARINA MAKHDOOM whose telephone number is (703)756-1044. The examiner can normally be reached Monday – Thursdays from 8:30 to 5:30 pm eastern time. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, William Kelleher can be reached on 571-272-7753 The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /SAMARINA MAKHDOOM/ Examiner, Art Unit 3648
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Prosecution Timeline

Aug 18, 2023
Application Filed
Aug 07, 2025
Non-Final Rejection — §103
Nov 11, 2025
Response Filed
Dec 09, 2025
Final Rejection — §103
Feb 09, 2026
Response after Non-Final Action
Feb 13, 2026
Request for Continued Examination
Mar 11, 2026
Response after Non-Final Action
Mar 17, 2026
Non-Final Rejection — §103 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

3-4
Expected OA Rounds
70%
Grant Probability
97%
With Interview (+26.6%)
3y 1m
Median Time to Grant
High
PTA Risk
Based on 101 resolved cases by this examiner. Grant probability derived from career allow rate.

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