Abstract: In a wireless communication network that operates according to a communication protocol that permits transmissions via multiple channels corresponding to multiple different frequency bandwidths, a communication device receives a packet via a first communication channel that spans a first frequency bandwidth. The communication device determines a second communication channel for transmitting an acknowledgment packet, the second communication channel spanning a second frequency bandwidth that is less than the first frequency bandwidth, the acknowledgment packet responsive to receiving the packet. The communication device transmits the acknowledgment packet via the second communication channel.

Abstract: In a method for wireless communication, a communication device selects a downclocking ratio for generating a physical layer (PHY) protocol data unit (PPDU) to be transmitted in a vehicular communication network. The communication device generates the PPDU i) according to the selected downclocking ratio, and ii) as a downclocked version of a PPDU format defined by one of a) the IEEE 802.11n Standard, b) the IEEE 802.11ac Standard, and c) the IEEE 802.11ax Standard. The communication device transmits the PPDU in the vehicular communication network.

Abstract: A method for communicating in a wireless local area network is disclosed herein. The AP sets an uplink target received signal strength information (RSSI) for all participating stations (STAs) and transmits the information to the STAs in a trigger frame. Specifically, the AP sets the uplink target RSSIs for each STA to be within a predetermined range of each other so that when the STAs transmit respective uplink frames, those frames are received at the AP at the set uplink target RSSI.

Abstract: A physical layer (PHY) preamble of a PHY data unit is generated, including generating one or more short orthogonal frequency division multiplexing (OFDM) symbols for one or more long training fields of the PHY preamble. Each of the one or more short OFDM symbols corresponds to a frequency domain sequence having a number of tones. Every N-th tone is modulated and tones between modulated tones are zero tones, where N is a positive integer greater than one. A time duration of each short OFDM symbol is 1/N of a time duration of a full inverse discrete Fourier transform (IDFT) of the frequency domain sequence. A data portion of the PHY data unit is generated, including generating one or more long OFDM symbols. A time duration of each long OFDM symbol is greater than a time duration of each of the one or more short OFDM symbols.

Abstract: A method for rate adaptation in a communication device includes, during a time interval, transmitting over a wireless channel to a peer communication device both (i) communication packets that carry user data, at a communication data rate, and (ii) channel-probing packets for probing channel conditions, at a channel-probing data rate that is derived from the communication data rate. A first statistical performance of the communication packets, and a second statistical performance of the channel-probing packets, are estimated over the time interval. The communication data rate is set for a subsequent time interval based on at least one of the first statistical performance and the second statistical performance.

Abstract: A boundary within a last orthogonal frequency division multiplexing (OFDM) symbol of a PHY data unit is determined. Pre-encoder padding bits are added to a set of information bits to generate a set of padded information bits such that the set of padded information bits, after being encoded, fill one or more OFDM symbols up to the boundary within the last OFDM symbol. The set of padded information bits are encoded to generate a set of coded bits. A PHY preamble is generated to include a subfield that indicates the boundary. The one or more OFDM symbols are generated to include (i) the set of coded information bits in the one or more OFDM symbols up to the boundary to allow a receiving device to stop decoding the one or more OFDM symbols at the boundary, and (ii) post-encoder padding bits in the last OFDM symbol following the boundary.

Abstract: Embodiments described herein provide a method for performing beamforming in a multiple-user-multiple-input-multiple-output (MUMIMO) system. At a MUMIMO access point, MUMIMO data may be received from a station of a plurality of stations. Uplink channel state information may be obtained, from the MUMIMO data, representing an uplink channel between the station and the MUMIMO access point. The uplink channel includes signals transmitted from the station using the second number of antennas. Downlink channel state information may be computed, based on the uplink channel state information, representing a downlink channel between the MUMIMO access point and the station.

Abstract: The present disclosure describes apparatuses and methods of interference cancellation for receivers with multiple antennas. In some aspects, an interference packet transmitted by an interfering device of a wireless environment is received via multiple antennas of a device. Based on the interference packet, an interference channel that describes interference in the wireless environment is estimated. The device then receives an intended packet through the wireless environment in which the interfering device is operating. At least a portion of interference received with the intended packet, such as interference caused by other interfering packets, is cancelled using the interference channel By so doing, a receiver may reduce effects of interfering packets or signals of the wireless environment to improve receive performance (e.g., bit-error rate) for packets that are intended for reception by the device.

Abstract: Some embodiments described herein provide a method for transmitting a preamble in accordance with a wireless local area network communication protocol. In some embodiments, a data frame may be obtained for transmission including a preamble compliant with the wireless local area network communication protocol. It may be determined that the preamble includes a first preamble portion that spans multiple symbol durations and a second preamble portion that spans a single symbol duration. The first preamble portion via beamforming may be transmitted based on a first beamforming matrix. When a transmission mode of the second preamble portion is beamforming, a second beamforming matrix may be generated based on the first beamforming matrix, each tone for the second preamble portion may be calculated based on the second beamforming matrix. Each calculated tone may be transmitted in accordance with the wireless local area network communication protocol.

Abstract: A method for communication over a wireless interface between transceivers that are moving with respect to each other. The method includes transmitting, by a communication station (STA) in a moving vehicle over a wireless channel to a receiver outside the vehicle, a sequence of data symbols encoded in accordance with a frequency-domain multiplexing scheme extending over a range of sub-carrier tones. A condition affecting the wireless channel is evaluated. Responsively to the evaluated condition, a pilot scheme is selected from among a plurality of available pilot schemes, for interleaving of pilot signals in specified sub-carrier tones of the data symbols. An indication of the selected pilot scheme is exchanged between the STA and the receiver. The pilot signals are interleaved in the transmitted data symbols in accordance with the selected pilot scheme.

Abstract: A first communication device generates a first portion and a second portion of a wakeup radio (WUR) wakeup packet. The first portion of the WUR wakeup packet corresponds to a wireless local area network (WLAN) legacy preamble, and spans a first frequency bandwidth. The second portion of the WUR wakeup packet spans a second bandwidth that is less than the first bandwidth, and is configured to cause a WUR of a second communication device to cause a WLAN network interface device of the second communication device to transition from a low power state to the active state. Generating the second portion of the WUR wakeup packet includes i) generating a sync portion having a plurality of sync symbols, and ii) generating a wakeup packet body. The first communication device transmits the WUR wakeup packet.

Abstract: Embodiments described herein methods and systems for channel correlation based user detection in an uplink multiuser transmission of a multiple-input multiple-output (MIMIO) network. In some embodiments, the channel correlation based user detection may be used in 802.11 UL MUMIMO systems. For example, an access point may detect whether a client station responds to a trigger frame and then adjust a channel matrix accordingly to reflect whether the client station is responsive. The access point may then decode received data signals based on the adjusted channel matrix that reflects whether a client station has transmitted.

Abstract: The present disclosure includes systems and techniques relating to multi-antenna coherent combining (MACC) for carrier sensing (CS) and symbol timing (ST) in a wireless communication system. In some implementations, a device includes a receiver and processor electronics. The receiver is configured to receive two or more signals from two or more antennas, each of the two or more signals including a known, periodic reference signal that has gone through a respective wireless channel via one of the two or more antennas. The processor electronics are configured to obtain estimated phases of the two or more signals from the two or more antennas; obtain a combined signal by combining the two or more signals with coherent estimated phases of the two or more signals; and perform carrier sensing and symbol timing of the two or more signals based on the combined signal.

Abstract: A first set of orthogonal frequency domain multiplexing (OFDM) symbols for a first portion of a PHY data unit and a second set of OFDM symbols for a second portion of the PHY data unit are generated. OFDM symbols of the first set are generated with a first OFDM tone spacing. At least some OFDM symbols of the second set are generated with a second tone spacing different from the first tone spacing. A value for a length indicator indicative of a duration of the PHY data unit is determined based on the first tone spacing and the second tone spacing. The first portion of the PHY data unit is generated to include (i) the first set of OFDM symbols and (ii) the length indicator set to the determined value. The second portion of the PHY data unit is generated to include the second set of OFDM symbols.

Abstract: Some embodiments described herein provide a method for transmitting a preamble in accordance with a wireless local area network communication protocol. In some embodiments, a data frame may be obtained for transmission including a preamble compliant with the wireless local area network communication protocol. It may be determined that the preamble includes a first preamble portion that spans multiple symbol durations and a second preamble portion that spans a single symbol duration. The first preamble portion via beamforming may be transmitted based on a first beamforming matrix. When a transmission mode of the second preamble portion is beamforming, a second beamforming matrix may be generated based on the first beamforming matrix, each tone for the second preamble portion may be calculated based on the second beamforming matrix. Each calculated tone may be transmitted in accordance with the wireless local area network communication protocol.

Abstract: A first communication device generates and transmits a wakeup packet configured to cause a wakeup radio of a second communication device to prompt a wireless local area network (WLAN) network interface device of the second communication device to transition from a low power state to an active state. The wakeup packet is generated to include i) a WLAN legacy preamble, ii) a wakeup radio (WUR) preamble, and iii) a data portion. The data portion comprises a plurality of time segments, each time segment corresponds to a respective information bit. The data portion is generated to include a respective prefix inserted prior to each time segment corresponding to the respective bit to mitigate intersymbol interference at a receiver caused at least by multipath effects.

Abstract: This disclosure describes systems and methods for detecting motion based on channel correlation in wireless communication signals. A receiver at a first wireless communication device is capable of wirelessly communicating with a second wireless communication device. The first wireless communication device is configured to receive from the second wireless communication device via two or more subcarriers a first packet and a channel correlation for the first packet across the two or more subcarriers. Control circuitry is configured to estimate a channel energy difference for the receiver based on the channel correlation for the first packet. A motion detection decision is then made based on the estimated channel energy difference.

Abstract: A method for identifying active resource units in a high-efficiency wireless system includes quantizing phase angles of samples received in a high-efficiency short training field of a transmission, performing a transform operation on quantized phase angle samples to derive transmitted power, comparing transmitted power of an individual resource unit as determined from transformed quantized phase angle samples to transmitted power of other resource units as determined from transformed quantized phase angle samples, and identifying, as active, resource units whose transmitted power, as determined from transformed quantized phase angle samples, bears a first predetermined relationship to transmitted power of the other resource units. Transmitted power of a resource unit may be compared to the total transmitted power of all resource units, or to the transmitted power of one of the other resource units whose transmitted power is a maximum transmitted power of all resource units.

Abstract: Systems and methods for carrier sensing and symbol timing in a multiple-antenna communication system are provided. A wireless receiver receives two or more signals from two or more antennas, respectively. A set of column vectors comprising time samples obtained from each of the received signals at the two or more antennas are generated. A multiple-antenna eigen-combining (MAEC) vector is computed based on the set of column vectors. The respective received signals are multiplied with a corresponding combining coefficient of the MAEC vector to obtain a respective weighted signal. A combined signal is generated by adding the respective weighted signals and carrier sensing and symbol timing is performed on the two or more received signals based on the combined signal.

Abstract: A boundary within a last orthogonal frequency division multiplexing (OFDM) symbol of a PHY data unit is determined. Pre-encoder padding bits are added to a set of information bits to generate a set of padded information bits such that the set of padded information bits, after being encoded, fill one or more OFDM symbols up to the boundary within the last OFDM symbol. The set of padded information bits are encoded to generate a set of coded bits. A PHY preamble is generated to include a subfield that indicates the boundary. The one or more OFDM symbols are generated to include (i) the set of coded information bits in the one or more OFDM symbols up to the boundary to allow a receiving device to stop decoding the one or more OFDM symbols at the boundary, and (ii) post-encoder padding bits in the last OFDM symbol following the boundary.