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 .
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.
Claim(s) 1-3, 14, 16, 17, 19, 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Shin et al. – US 2015/0280951 (hereinafter Shin) in view of Ahmed et al. – US 2013/0287134 (hereinafter Ahmed) and CN 112688894 – Viterbi Demodulation Algorithm Applied to GFSK System and Device Thereof (herein Ref-1).
Re claim 1, Shin discloses:
“A method of tuning a Viterbi detector at a receiver of a wireless communications system, the method comprising:
receiving a transmitted bit stream at the receiver” (para. 0003, 0016, 0017; wherein receiver perform GFSK-MLSE using a Viterbi trellis);
“detecting a frequency mismatch” between a carrier frequency and a local oscillator frequency at the receiver to derive a carrier frequency offset error (para. 0013, 0090, 0093, 0094, 0096, 0106, wherein Shin estimates frequency offset);
“determining a tuning parameter based on the carrier frequency offset error, the tuning parameter being a value between 0 and 1” (Shin dynamically estimates the frequency offset utilizing a convergence factor β, which has magnitude less than one, then utilizes the frequency offset in calculating the Viterbi branch metric, and ultimately improving the “Viterbi detector” performance (para. 0051, 0110-0114, 0126); and
“applying the tuning parameter to a Viterbi detuning algorithm in order to reduce an effect of the carrier frequency offset error on performance of the Viterbi detector” (para. 0015, 0051, 0072, 0125, 0126; wherein Shin discloses compensating for the frequency offset in GFSK-MLSE/Viterbi detection and reports improved performance).
Shin differs from the claimed invention in that it does not explicitly disclose the above underlined claimed subject matter.
While Shin discloses estimating the frequency offset, it does not explicitly disclose “between a carrier frequency and a local oscillator frequency at the receiver”. Ahmed, in similar field of endeavor, discloses such particular claimed subject matter as known in the art for generating frequency offset at the reciever (para. 0003, 0010, 0017).
Further, in Shin, convergence factor β is used for calculating the frequency offset estimate, then uses the estimated frequency offset in calculating the Viterbi branch metric (claims 10). That is, Shin does not explicitly disclose a “tuning parameter” is used to change/tune the Viterbi detector.
Ref-1, in similar field of endeavor, discloses measuring frequency offset in a GFSK receiver and adapt processing feeding the Viterbi detector according to that frequency offset (para. 0043, 0045, 0047, 0059, 0065, 0066, 0069).
Therefore, it would have been obvious to a person of ordinary skill in the art at the time of the filing in have incorporated the commonly knowledge of the frequency offset in Ahmed as the frequency offset for Shin, and to dynamically select or adjust a parameter controlling the degree of Viterbi frequency offset compensation according to the determined magnitude of frequency offset, because both Shin and Ref-1 recognize frequency offset as the condition producing Viterbi performance degradation and teach modifying the Viterbi detection processing to compensate for that condition.
Re claims 17, 20, see corresponding claim 1 above for similar claimed subject matter and Fig. 17, para. 0150-0152.
Re claim 2, Ahmed further suggests the claimed subject matter “wherein both the carrier frequency and the local oscillator frequency at the receiver comprise errors” in para. 0086, 0109; wherein the frequency offset may be caused by doppler or oscillator difference, either at the transmitter or receiver or both.
Re claim 3, the further claimed subject matter “wherein the carrier frequency is a center frequency of a transmitted carrier signal and the local oscillator frequency is a center frequency of the local oscillator” would have been within the knowledge of one skilled in the art at the time of the filing since the center frequency of a carrier is the carrier frequency for symmetrically spreading the energy and the center frequency of the local oscillator is the local oscillator frequency so it can be mixed with the incoming carrier frequency to provide down-converted signal.
Re claim 14, the above combination of Shin, Ahmed and Ref-1 suggests the claimed subject matter “automatically adjusting the tuning parameter based on the carrier frequency offset error” in Ref-1, para. 0061-0069 where it continuously modifying the Viterbi branch metric calculation on the basis of the frequency offset.
Re claim 19, see corresponding claim 14 for similar claimed subject matter.
Re claim 16, the above combination of Shin, Ahmed and Ref-1 suggests the claimed subject matter “outputting a detected bit stream from the receiver” in Fig. 15, para. 0141.
Claim(s) 15 is/are rejected under 35 U.S.C. 103 as being unpatentable over Shin, Ahmed and Ref-1 as applied to claim 1 above, and further in view of Takeuchi – US 6,408,038.
Re claim 15, the above combination of Shin, Ahmed and Ref-1 discloses almost all claimed subject matter in claim 15 as stated above, except for “wherein detecting a frequency mismatch comprises performing a Fast Fourier Transform on the transmitted bit stream at the receiver or measuring a frequency error using a feedforward or feedback automatic frequency control loop.”
Takeuchi discloses such claimed subject matter is known in the art in col. 3, lines 41-45.
Since the above combination does not restrict to any particular method for detecting the mismatch, it would have been obvious to a person of ordinary skill in the art at the time of the filing to have optionally incorporated the known AFC of Takeuchi for the frequency offset in the aforementioned combination and the same result would have been expected.
Claim(s) 5, 18 is/are rejected under 35 U.S.C. 103 as being unpatentable over Shin, Ahmed and Ref-1 as applied to claim 17 above, and further in view of Yamazaki – US 2010/0103561.
Re claim 18, the above combination of Shin, Ahmed and Ref-1 discloses almost all claimed subject matter in claim 18 as stated above, except for “wherein the Viterbi detector comprises a low pass filter, preferably a first order low pass filter.”
Yamazaki discloses such claimed subject matter in Fig. 2, para. 0046, 0047 (Note: the element 58 as a whole can be considered as the claimed “Viterbi detector”).
Therefore, it would have been obvious to a person or ordinary skill in the art at the time of the filing to have optionally included a LPF, as that in Yamazaki, for smoothing the signal for the Viterbi detector/demodulator.
Re claim 5, the above combination of Shin, Ahmed and Ref-1 discloses almost all claimed subject matter in claim 15 as stated above, except for “wherein applying the tuning parameter to the Viterbi detuning algorithm comprises low pass filtering.” However, since the specification does not disclose any particular method as how a low pass filtering would have been implemented, it would have been obvious to a person or ordinary skill in the art at the time of the filing to have optionally included low pass filtering, as that in Yamazaki, for smoothing the signal for the Viterbi detector/demodulator.
Allowable Subject Matter
Claims 4, 6-13, objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Arslan – US 11,736,322
Kenawy – US 10/924,311
Chen et al. – US 2014/0219397
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/DAC V HA/ Primary Examiner, Art Unit 2633
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