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 .
Priority
Acknowledgment is made of applicant’s claim for foreign priority under 35 U.S.C. 119 (a)-(d). The certified copy has been filed in parent Application No. IN 202041042792, filed on October 1, 2020.
Status of Claims
Amendments to claims 1 and 10 – 19 have been entered.
Response to Remarks
In view of the amendments, the 101 rejection has been withdrawn.
New prior art is found necessitated by amendment.
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 – 6 and 10 – 17 are rejected under 35 U.S.C. 103 as being obvious over Nagaishi (US 20200358178 A1) in view of Rao (US 20180172813 A1).
As to claims 1, 10 – 11 and 15, Nagaishi in view of Rao teach a radar transceiver comprising:
radar system comprising:
transmit circuitry including a phase shifter and configurable to:
transmit a first set of chirp signals in which each chirp signal of the first set of chirp signals has an induced phase shift applied by the phase shifter, and transmit a second set of chirp signals without an induced phase shift being applied by the phase shifter;
receive circuitry configurable to receive reflected signals based on the transmitted first and second sets of chirp signals, and generate a first set of digital signals corresponding to the first set of chirp signals and a second set of digital signals corresponding to the second set of chirp signals (Nagaishi teaches the required circuitry as shown in Fig. 1); and
processing circuitry configurable to:
perform Fourier Transform (FT) operations on the first set of digital signals to generate a first array, and perform FT operations on the second set of digital signals to generate a second array, identify a first peak in the first array and a second peak in the second array representing an object in a field of view of the transmit circuitry, the first and second peaks being at corresponding positions in the first and second arrays, respectively, compare a phase of the first peak with a phase of the second peak, determine an actual phase shift for the induced phase shift based on the comparison (Rao teaches the required signal processing, e.g., Fig. 11 step 1110 and claim 19) and
calibrate the phase shifter based on the actual phase shift (Nagaishi Fig. 1 items 40, 50, 30 and 21 – 22).
In view of the teachings of Rao, it would have obvious to apply the signal processing as taught and cited by Rao because range-Doppler maps provide for better resolution thereby improving accurate phase results resulting in better phase calibration. Chirps are also known for improved resolution resulting in better detection meaning that the peaks are more accurate resulting in better phase calibration. Rao also teaches the storage of phase offsets. See Rao Paras. 70 and 78. The motivation to store phase offsets is to prevent unnecessary calculation thus reducing redundancy resulting in improved computer efficiency.
As to claim 2, Nagaishi in view of Rao teaches a radar system of claim 1, wherein each chirp signal of the second set of chirp signals has a phase of approximately zero (Nagaishi Fig. 1 item 21).
As to claims 3 and 12, Nagaishi in view of Rao teaches the radar system of claim 1, wherein the FT operations performed on each of the first and second sets of chirp signals includes a range FT and a Doppler FT, and each of the first and second arrays is a range-Doppler array (as cited by Rao in claim 1 wherein range-Doppler map requires a fast-time FFT and slow-time FFT.).
As to claim 4, Nagaishi in view of Rao teaches the radar system of claim 1, wherein the chirp signals of the first set of chirp signals are interleaved with the chirp signals of the second set of chirp signals (Rao Figs. 1 – 2. It would have been obvious to one having ordinary skill in the art before filing to interleave the signals in order to reduce ambiguities thereby improving doppler and velocity resolution.)
In the same field, Millar teaches “receive interleaved chirp return signals from the receive antennas and to determine an azimuth angle to the target and a Doppler velocity of the target using the interleaved chirp return signals (Para. 14).”
In view of the teachings of Millar, it would have been obvious to one having ordinary skill in the art before filing to interleave the signals in order to reduce ambiguities thereby improving doppler and velocity resolution.
As to claim 5, Nagaishi in view of Rao teaches the radar system of claim 1, wherein the first and second sets of chirp signals constitute a frame of chirp signals (Rao Abstract. A frame allows for integration thus improved SNR.).
As to claims 6 and 16, Nagaishi in view of Rao teaches the radar system of claim 1, wherein the processing circuitry is further configurable to: identify additional peaks in the first array, and identify additional peaks in the second array positionally-corresponding to the additional peaks in the first array; compare a phase of each additional peak in the first array with a phase of the corresponding additional peak in the second array; determine a difference between the phase of the first peak and the phase of the second peak, and determine a difference in phase between each additional peak in the first array and the positionally-corresponding additional peak in the second array; and calculating an average phase shift based on the determined differences; wherein the actual phase shift for the induced phase shift is determined based on the average phase shift (Rao Para. 71 “average of the four phase difference.” It would have been obvious to one having ordinary skill in the art before filing to apply averaging in order to reduce noise thus improving accuracy.)
As to claim 13, Nagaishi in view of Rao teaches the processor-readable medium of claim 11, wherein the instructions for identifying an object in a bin of the array, and identifying the object in a corresponding bin of the second array further comprises: identifying a peak in the bin of the first array, identifying a peak in the corresponding bin of the second array, the peaks representing the object (as modified by Rao.).
As to claim 14, Nagaishi in view of Rao teaches the processor-readable medium of claim 13, wherein the instructions for comparing the phase of the object in the bin of the first array to the phase of the object in the corresponding bin of the second array further comprises: comparing the phase of the peak in the bin of the first array to the phase of the peak in the corresponding bin of the second array (as modified by Rao).
As to claim 17, Nagaishi in view of Rao teaches the processor-readable medium of claim 16, wherein the processing instructions further comprise instructions for determining a phase shift offset based on the average phase shift and the induced phase shift (Nagaishi as modified by Rao’s averaging in claim 16.)
Claims 7 – 9 and 18 – 19 are rejected under 35 U.S.C. 103 as being obvious over Nagaishi in view of Rao and in further view of Wan (US 7915942 B2).
As to claims 7 and 18, Nagaishi in view of Rao do not teach the radar system of claim 6, wherein the processing circuitry is further configurable to determine whether a difference between the actual phase shift and the induced phase shift is within a tolerance value.
In the same field, Wan teaches “In the alignment steps (c) and (f), the variable phase shifters are aligned so that the output of the phase comparator is zero, or below a predetermined threshold or within a predetermined range. That is the output of the phase comparator indicates that the phase difference is zero, below a certain threshold, or within a certain range. When the first and second phases are the same, the phase difference should be zero, or below a predetermined threshold. The aligning may be achieved, for example, by adjusting the calibration of one or both variable phase shifters. The aligning in steps (c) and (f) and/or the delaying in step (d) may be carried out automatically by a controller, e.g. a computer, MCU, processor or other similar device (col. 2 ll. 7 – 19).”
In view of the teachings of Wan, it would be obvious to apply a tolerance range to acceptable phase differences so that the calibration does not require unnecessary phase calibration thereby improving efficiency. Also note that the alignment itself could be outside of tolerance and possibly induce an error.
As to claims 8 and 19, Nagaishi in view of Rao and Wan teaches the radar system of claim 7, wherein the processing circuitry includes storage, the processing circuitry further configurable to store the actual phase shift in association with the induced phase shift in the storage.
Wan teaches “The controller 40 controls one, or both, of the variable phase shifters 10, 20 to align their output phases, until there is no output from the phase comparator, (i.e. no phase difference), or until the output is below a predetermined threshold. This control is carried out automatically by the controller 40 which adjusts the calibration of the variable phase shifters. For example, the variable phase shifter may have a table which stores the appropriate response to a control signal and this table may be updated with new values, which give the appropriate phase shift in response to a given control signal (col. 4 ll. 56 – 66).”
In view of Wan, it would be obvious to store calibration values so that the calibration does not need to be repeated unnecessarily thus improving efficiency.
As to claim 9, Nagaishi in view of Rao and Wan teaches the radar system of claim 8, wherein the storage includes a lookup table in which the actual phase shift is stored in association with the induced phase shift (Wan’s new values indicate a table).
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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MICHAEL W JUSTICE whose telephone number is (571)270-7029. The examiner can normally be reached 7:30 - 5:30 M-F.
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/MICHAEL W JUSTICE/Examiner, Art Unit 3648
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