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 § 102
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 person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claim(s) 1-3 and 9-15 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Elsherif et al. (US 2017/0064566 A1), hereinafter referred to as D1.
Regarding claims 1 and 13, D1 discloses MU-MIMO grouping metrics, which comprises:
transmitting a training frame; receiving a plurality of feedback frames from a plurality of stations in response to the training frame, wherein each of the plurality of feedback frames is associated with a respective one of the plurality of stations and includes channel quality information for an associated station (Referring to Figures 1 and 2, AP 105 also transmits a beamforming report poll frame (training frame). Each of the STAs 110 responds in turn with a compressed beamforming action frame (e.g., a VHT CBF frame) for transmitting VHT CBF feedback to AP 105 (receiving a plurality of feedback frames from a plurality of stations in response to the training frame, associated with a respective one of the plurality of stations and includes a channel quality information for an associated station). See paragraph 0039 and 0040.);
determining a plurality of groups based on the channel quality information in the plurality of feedback frames, wherein each of the plurality of groups is associated with a respective one of the plurality of stations and includes an associated station as a primary station and at least one secondary station (Referring to Figures 1 and 2, AP 105-a has received VHT CBF report information from each STA 110, STA-1 (depicted as STA 110-a in FIG. 2), STA-2, STA-3, STA-4, STA-5, and STA-6, as described with respect to FIG. 1. AP 105-a has determined to analyze a candidate MU-MIMO group consisting of STA-1, STA-2, and STA-3. See paragraph 0042. In one example, AP 105-a determines MU SINR metrics and analyzes candidate MU-MIMO groups comprised of STA-2 and STA-3 as a possible MU-2 group, STA-1, STA-5, and STA-6 as a possible MU-3 group, and STA-3, STA-4, STA-5, and STA-6 as a possible MU-4 group. See paragraph 0052.);
determining channel capacities of the plurality of groups; selecting a group of the plurality of groups based on the channel capacities of the plurality of groups; determining users of the selected group as MU-MIMO users; and transmitting a MU PPDU in MU-MIMO for the users of the selected group (Referring to Figures 1 and 5, When AP 105-c determines an MU-MIMO transmission group, comprising the identified stations, (selecting group of the plurality of groups based on channel capacities, determining users of the selected group as MU-MIMO users) based at least in part on the determined or identified MU SINR metrics (channel capacities of the plurality of groups as the SINR metrics are indicative of channel capacity as consistent with instant disclosure), grouping metrics, optimal MU-MIMO groups, optimal sets of spatial streams, or STA traffic indicators 570-a, a beamforming steering matrix W is determined by beamforming steering matrix determiner 550-a, and the MU-MIMO transmission is performed by transmitter 560-a (transmitting a MU PPDU in MU-MIMO for the users of the selected group, note in the context of MU-MIMO the PPDU is the fundamental component that encapsulates the data to be transmitted to multiple users and is such taught by the prior art’s MU-MIMO data transmission according to the standard). See paragraphs 0123 and 0126.)
Regarding claims 2 and 14, D1 discloses determining initial effective SNR values for the plurality of modulation schemes based on the channel quality information in the plurality of feedback frames, wherein each of the initial effective SNR values is for a modulation scheme of a station considering interference from another station of the plurality of stations; determining recommended modulation and coding scheme (MCS) values and final effective SNR values for the recommended MCS values based on the initial effective SNR values, wherein each of the recommended MCS values is recommended for a station considering interference from another station of the plurality of stations, each of the final effective SNR values is associated with a respective one of the recommended MCS values and an effective SNR for an associated recommended MCS value of a station considering interference from another station of the plurality of stations; determining channel capacities of the plurality of groups based on the final effective SNR values; and determining a plurality of groups based on the channel capacities of the plurality of groups (Referring to Figures 1, 2, and 5, claim interpreted as the prior art’s MU SINR metrics for the STAs provide the AP with estimations of the different levels of channel correlation and associated inter-user interference that a particular STA (final effective SNR values) may experience if that particular STA were to be included in various possible MIMO transmission groupings. As such, the AP forms efficient MU groups of STAs for MIMO transmissions as well as accurately determines a proper modulation and coding scheme (MCS) (determining recommended MCS) for each STA in the corresponding MU transmission group. The MCS for each STA is based at least in part on the MU SINR metrics. For example, the AP may determine MU SINR metrics for the STAs in an MU group and map the MU SINR metric of a particular STA to a MCS (e.g., selecting from predefined MCSs corresponding to a value or range of values associated with the MU SINR metrics). An AP in accordance with aspects of the present disclosure sets the MCS of a particular STA based at least in part on the MU SINR metrics associated with candidate MU-MIMO group(s) (final effective SNR values). Moreover, the AP determines a correlation metric based at least in part on, or independent of, the MU SINR metrics. For example, the correlation metric can be an average, median, or mean distribution of the MU SINR metrics of the STAs for a candidate MU-MIMO group. As such, the AP uses the correlation metric to determine whether the candidate MU-MIMO group is an efficient MU-MIMO transmission and whether to remove one or more STAs from the candidate MU-MIMO group. Correlation metrics relating to multiple candidate transmission groups are analyzed by the AP to detect changes and patterns associated with channel correlations among the STAs and form efficient MU transmission groups. In this regard, the AP uses the MU SINR metrics and correlation metrics to optimize MCS rate adaptation, MU grouping of STAs, MU transmission group ranking and scheduling, etc. See paragraphs 0029-0031. SNR utilized in paragraphs 0040-0042. When AP 105-c determines an MU-MIMO transmission group based at least in part on the determined or identified MU SINR metrics, grouping metrics, optimal MU-MIMO groups, optimal sets of spatial streams, or STA traffic indicators 570-a, a beamforming steering matrix W is determined by beamforming steering matrix determiner 550-a, and the MU-MIMO transmission is performed by transmitter 560-a. See paragraphs 0123 and 0126. Broadly speaking, the method 800 illustrates a procedure by which the AP 105-e receives compressed or non-compressed beamforming information from multiple stations, the beamforming information containing a feedback SNR value and compressed or non-compressed beamforming feedback matrices, and determines a multi-user SINR metric for each station based at least in part on the received SNR values (initial) and the beamforming feedback matrices. See paragraphs 0145-0147.)
Regarding claims 3 and 15, D1 discloses wherein the at least one secondary station is determined to be included in a group based on channel capacity between a previous station in a group and the at least one secondary station, and the channel capacity between a previous station in a group and the at least one secondary station is determined based on the final effective SNR values (Referring to Figures 1-3, wireless communications scenario 200 represents one of many combinations of STAs 110 the AP 105-a may analyze for determining effective MU-MIMO transmission groups with which to transmit data to the number of STAs 110. In one example, AP 105-a determines MU SINR metrics and analyzes candidate MU-MIMO groups comprised of STA-2 and STA-3 as a possible MU-2 group, STA-1, STA-5, and STA-6 as a possible MU-3 group, and STA-3, STA-4, STA-5, and STA-6 as a possible MU-4 group (at least one secondary station is determined to be included in a group based on channel capacity between a previous station in a group and the at least one secondary station, as multiple stations are considered against multiple groups). In this example, AP 105-a determines a correlation metric among the MU SINR metrics of STA-3, STA-4, STA-5, and STA-6 as the candidate MU-4 group, and determines the MU SINR metric of STA-5 is significantly lower (e.g., by one or two standard deviations from the median of all SINR metrics of the candidate MU-4 group). As such, AP 105-a removes STA-5 from the candidate MU-4 group thereby reducing the size of the candidate MU-MIMO group to a new candidate MU-3 group. AP 105-a now determines MU SINR metrics of STA-3, STA-4, and STA-6 as the new candidate MU-3 group, and determines the MU SINR metrics of each of STA-3, STA-4, and STA-6 have increased over their respective MU SINR metrics in the former candidate MU-4 group that included STA-5. AP 110-a then blacklists STA-5 from MU-MIMO transmission groupings with any of STA-3, STA-4, and STA-6 for a predetermined period of time (e.g., 500 ms, 5 second, 30 seconds, 2 minutes, 5 minutes, etc.). In this regard, a goal of analyzing various candidate MU-MIMO groups is to determine channel correlation patterns among the STAs 110 and identity groups of STAs 110 that exhibit good uncorrelated channel characteristics so as to form efficient MU-MIMO transmission groups. In this instance, each STA 110 in an efficient MU-MIMO transmission group exhibits a high MU SINR metric. The high MU SINR metrics of the STAs in such an efficient MU-MIMO transmission group are also correlated to high achievable high MCS rates (channel capacity between a previous station in a group and the at least one secondary station is determined based on the final effective SNR values). See paragraphs 0052-0054.)
Regarding claim 9, D1 discloses determining required SNR values for the plurality of modulation schemes, and wherein the recommended modulation and coding scheme (MCS) values and the final effective SNR values for the recommended MCS values are determined based on the initial effective SNR values and the required SNR values (Referring to Figures 1, 2, and 5, claim interpreted as the prior art’s MU SINR metrics for the STAs provide the AP with estimations of the different levels of channel correlation and associated inter-user interference that a particular STA (final effective SNR values) may experience if that particular STA were to be included in various possible MIMO transmission groupings. As such, the AP forms efficient MU groups of STAs for MIMO transmissions as well as accurately determines a proper modulation and coding scheme (MCS) (determining recommended MCS) for each STA in the corresponding MU transmission group. The MCS for each STA is based at least in part on the MU SINR metrics. For example, the AP may determine MU SINR metrics for the STAs in an MU group and map the MU SINR metric of a particular STA to a MCS (e.g., selecting from predefined MCSs corresponding to a value or range of values associated with the MU SINR metrics). An AP in accordance with aspects of the present disclosure sets the MCS of a particular STA based at least in part on the MU SINR metrics associated with candidate MU-MIMO group(s) (final effective SNR values). Moreover, the AP determines a correlation metric based at least in part on, or independent of, the MU SINR metrics. For example, the correlation metric can be an average, median, or mean distribution of the MU SINR metrics of the STAs for a candidate MU-MIMO group. As such, the AP uses the correlation metric to determine whether the candidate MU-MIMO group is an efficient MU-MIMO transmission and whether to remove one or more STAs from the candidate MU-MIMO group. Correlation metrics relating to multiple candidate transmission groups are analyzed by the AP to detect changes and patterns associated with channel correlations among the STAs and form efficient MU transmission groups. In this regard, the AP uses the MU SINR metrics and correlation metrics to optimize MCS rate adaptation, MU grouping of STAs, MU transmission group ranking and scheduling, etc. See paragraphs 0029-0031. SNR utilized in paragraphs 0040-0042. When AP 105-c determines an MU-MIMO transmission group based at least in part on the determined or identified MU SINR metrics, grouping metrics, optimal MU-MIMO groups, optimal sets of spatial streams, or STA traffic indicators 570-a, a beamforming steering matrix W is determined by beamforming steering matrix determiner 550-a, and the MU-MIMO transmission is performed by transmitter 560-a. See paragraphs 0123 and 0126. Broadly speaking, the method 800 illustrates a procedure by which the AP 105-e receives compressed or non-compressed beamforming information from multiple stations, the beamforming information containing a feedback SNR value and compressed or non-compressed beamforming feedback matrices, and determines a multi-user SINR metric for each station based at least in part on the received SNR values and the beamforming feedback matrices. See paragraphs 0145-0147.)
Regarding claim 10, D1 discloses transmitting a null data packet announcement frame; and transmitting a null data packet as the training frame a short interframe space (SIFS) after the null data packet announcement frame (Referring to Figures 1 and 2, AP 105 sounds the channel by transmitting null data packet announcement (NDPA) frames and null data packet (NDP) frames to a number of STAs 110 such as STA-1, STA-2, STA-3, STA-4, STA-5, and STA-6. AP 105 has knowledge that STA-7 does not support MU-MIMO operations, for instance, and does not include STA-7 in the multi-user channel sounding procedure. See paragraphs 0037-0039.)
Regarding claim 11, D1 discloses determining final MCS levels for the MU-MIMO users based on the recommended MCS values, wherein the final MCS levels are applied to the MU PPDU (Referring to Figures 1, 2, and 5, the AP forms efficient MU groups of STAs for MIMO transmissions as well as accurately determines a proper modulation and coding scheme (MCS) (determining final MCS) for each STA in the corresponding MU transmission group. The MCS for each STA is based at least in part on the MU SINR metrics. For example, the AP may determine MU SINR metrics for the STAs in an MU group and map the MU SINR metric of a particular STA to a MCS (e.g., selecting from predefined MCSs corresponding to a value or range of values associated with the MU SINR metrics). An AP in accordance with aspects of the present disclosure sets the MCS of a particular STA based at least in part on the MU SINR metrics associated with candidate MU-MIMO group(s) (final effective SNR values). Moreover, the AP determines a correlation metric based at least in part on, or independent of, the MU SINR metrics. For example, the correlation metric can be an average, median, or mean distribution of the MU SINR metrics of the STAs for a candidate MU-MIMO group. As such, the AP uses the correlation metric to determine whether the candidate MU-MIMO group is an efficient MU-MIMO transmission and whether to remove one or more STAs from the candidate MU-MIMO group. Correlation metrics relating to multiple candidate transmission groups are analyzed by the AP to detect changes and patterns associated with channel correlations among the STAs and form efficient MU transmission groups. In this regard, the AP uses the MU SINR metrics and correlation metrics to optimize MCS rate adaptation, MU grouping of STAs, MU transmission group ranking and scheduling, etc. See paragraphs 0029-0031. SNR utilized in paragraphs 0040-0042. See paragraphs 0145-0147. Note in the context of MU-MIMO the PPDU is the fundamental component that encapsulates the data to be transmitted to multiple users and is such taught by the prior art’s MU-MIMO data transmission according to the standard). See paragraphs 0123 and 0126.)
Regarding claim 12, D1 discloses determining a plurality of steering matrices, wherein each of the plurality of steering matrices is associated with a respective one of the users of the selected group, wherein the plurality of steering matrices are applied to the MU PPDU (Referring to Figures 1-3, When AP 105-b determines an MU-MIMO transmission group based at least in part on the determined MU SINR metrics, a beamforming steering matrix W is determined by beamforming steering matrix determiner 550, and the MU-MIMO transmission is performed by transmitter 560. See paragraphs 0113-0115. See above in regards to PPDU.)
Allowable Subject Matter
Claims 4-8 and 16-20 are 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.
Yang et al. (US 2024/0080690 A1) - A transmitting device transmits a test packet, over a wireless channel, to a receiving device. The receiving device generates one or more signal-to-interference-plus-noise ratio (SINR) estimates for the wireless channel based on the received sounding packet. In some aspects, each SINR estimate may be associated with a particular modulation order. In some other aspects, each SINR estimate may be generated based on a transmitter configuration or a receiver type to be used for subsequent communications between the transmitting device and the receiving device.
Oteri et al. (US 2024/0405829 A1) - The AP may transmit a null data packet (NDP) for measurement of a channel quality for a resource unit of a bandwidth. The AP may transmit, based on a response, another feedback request for resource units of the bandwidth.
Yun et al. (US 2019/0341975 A1) - The first STA transmits the feedback frame to a second STA. The feedback frame includes information related to a feedback subcarrier for a predetermined frequency band and a beamforming report field for the MU-MIMO beamforming. The feedback subcarrier includes a first subcarrier transmitted first in the feedback subcarrier and a second subcarrier of which a subcarrier index is determined based on a grouping value related to a subcarrier spacing. The beamforming report field includes a first signal to noise ratio (SNR) for the first subcarrier and a first differential SNR for the second subcarrier.
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DONALD L. MILLS
Primary Examiner
Art Unit 2462
/Donald L Mills/ Primary Examiner, Art Unit 2462