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 .
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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, 4, 7, and 9 rejected under 35 U.S.C. 103 as being unpatentable over Zuo et al. (US 2021/0168005, “Zuo”) in view of Choi et al. (US 2017/0302343, “Choi”).
Examiner’s note: in what follows, references are drawn to Zuo unless otherwise mentioned.
Zuo comprises the following features:
With respect to independent claims:
Regarding claim 1, a method performed by a first station (STA) in a wireless local area network (WLAN) system, the method comprising:
generating a physical layer protocol data unit (PPDU) including a non-legacy short training field (STF) field ([0145] “Step 210: Determine a short training sequence.”, and [0147] “for differentiation from a legacy-short training field, the short training field corresponding to the bandwidth of the target channel is denoted as an EHT-STF.” “PPDU” will be discussed in view of Choi.); and
transmitting the generated PPDU to at least one second STA ([0146] “Step 220: Send a short training field on a target channel, where the short training field is obtained by performing inverse fast Fourier transformation IFFT on the short training sequence” “A second STA” will be discussed in view of Choi.).
It is noted that while disclosing short training sequence design, Zuo does not specifically teach about an 80 MHz sequence. It, however, had been known in the art before the effective date of the instant application as shown by Choi as follows;
generating a physical layer protocol data unit (PPDU) ([Choi, 0091] “An STF that is generated based on the above-described basic STF sequence may be transmitted through a PPDU.”);
PPDU to at least one second STA ([Choi, 0131] “the AP may transmit a DL MU PPDU to a plurality of STAs based on a transmission based on downlink (DL) multi-user (MU) OFDMA.”);
for a transmission on a 80MHz bandwidth, a first sequence for the non- legacy STF field is based on {-1, -1, -1, 1, 1, 1, -1, 1, 1, 1, -1, 1, 1, -1, 1, 0, 1, 1, 1, -1, -1, -1, 1, -1, -1, -1, 1, -1, -1, 1, -1, 0,1,1,1, -1, -1, -1, 1, -1, -1, -1, 1, -1, -1, 1, -1, 0,1,1,1, -1, -1, -1, 1, -1, -1, -1, 1, -1, -1, 1, -1} ([Choi, 0113 and Eq. 8] “in the 80 MHz bandwidth, the STF sequence may be defined”).
It would have been obvious to a person of ordinary skill in the art to employ Choi’s disclosed 80-MHz STF sequence when configuring Choi’s HE PPDU for an 80 MHz transmission. Choi explains that, in an OFDMA transmission, a legacy STF design may leave a particular STA’s allocated subband without an STF signa, thereby making synchronization, AGC, and channel tracking/estimation difficult. Choi addresses that problem by designing the STF sequence so that non-null tones are present in the subbands allocated to the respective STAs, thereby enabling each STA to perform AGC. [Choi, 0035 and 0039-0040]. Choi expressly specifies the corresponding 80 MHz construction shown in [Choi, 0113 and Eq.8]. A skilled artisan would have had a reasonable expectation that this bandwidth-scaled sequence would preserve the necessary STF tone availability and thereby provide the stated synchronization and AGC benefits in an 80 MHz OFDMA PPDU.
Regarding claim 7, it is a first station claim corresponding to the method claim 1, except the limitations, “at least one transceiver; and at least one processor coupled with the at least one transceiver” (See Fig. 8 for 820 “Transceiver” and 810 “Processor”), and is therefore rejected for the similar reasons set forth in the rejection of claim 1.
Regarding claim 9, it is a second station claim corresponding to the method claim 7 in a reciprocal way, and is therefore rejected for the similar reasons set forth in the rejection of claim 7.
With respect to dependent claims:
Regarding claim 4, the method of Claim 1, wherein: a duration of the non-legacy STF field is determined based on a STF periodicity, the STF periodicity is 0.8us ([0150] “a scenario in which the periodicity is 0.8 μs”).
Allowable Subject Matter
Claim(s) 2-3 and 5-6 objected to as being dependent upon a rejected base claim, but be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The claims contain the following underlined features which, when combined with other features of the claim, prior art of record failed to anticipate or render obvious before the effective filing date of the instant application was filed:
2. The method of Claim 1, wherein: the first sequency is given by S-992:32:992={-1, -1, -1, 1, 1, 1, -1, 1, 1, 1, -1, 1, 1, -1, 1, 0,1,1,1, -1, -1, -1, 1, -1, -1, -1, 1, -1, -1, 1, -1, 0,1,1,1, -1, -1, -1, 1, -1, -1, -1, 1, -1, -1, 1, -1, 0, 1, 1, 1, -1, -1, -1, 1, -1, -1, -1, 1, -1, -1, 1, -1} *(1+j)/sqrt(2), S-x:y:z represents coefficients of the non-legacy STF on every y sub-carrier indices from subcarrier indices x to z, and coefficients on other subcarrier indices are set to 0.
3. The method of Claim 1, wherein: for a transmission on a 40MHz bandwidth, a second sequence for the non-legacy STF field is given by S-480:32:480 = {-1, -1, -1, 1, 1, 1, -1, 1, 1, 1, -1, 1, 1, -1, 1, 0, 1, 1, 1, -1, -1, -1, 1, -1, -1, -1, 1, -1, -1, 1, -1} *(1+j)/sqrt(2).
5. The method of Claim 1, wherein:
based on the PPDU being a 20MHz PPDU, a total number of subcarriers is 512, based on the PPDU being a 40MHz PPDU, the total number of subcarriers is 1024, based on the PPDU being a 80MHz PPDU, the total number of subcarriers is 2048, based on the PPDU being a 160MHz PPDU, the total number of subcarriers is 4096, and based on the PPDU being a 320MHz PPDU, the total number of subcarriers is 8192.
Regarding claim 6, this claim depends from claim 5 and thus is objected for the same reason.
Conclusion
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/HARRY H KIM/ Primary Examiner, Art Unit 2411
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