Abstract: A first communication device prompts a plurality of second communication devices to transmit, during a contiguous time period reserved for a range measurement exchange, respective first null data packets (NDPs) at respective times. The first communication device receives first NDPs from at least some of the second communication devices during the contiguous time period, and transmits one or more second NDPs to the plurality of second communication devices. The first communication device uses reception of the first NDPs and transmission of the one or more second NDPs to determine respective ranges between the first communication device and respective second communication devices.

Abstract: A first client station receives from an access point an indication of whether angular information is to be included in feedback information in a range measurement session. The first client station transmits a null data packet (NDP) as part of an uplink multi-user (MU) PHY transmission that also includes simultaneous transmissions by one or more second client stations of one or more other respective NDPs to the access point as part of the range measurement session. The first client station receives a downlink physical layer (PHY) data unit from the access point that includes respective downlink feedback frames for the first client station and the one or more second client stations. When angular information is to be included in the feedback, a downlink feedback frame for the first client station includes angular information.

Abstract: A first communication device determines which one or more types of feedback information, from among a plurality of types of feedback information associated with a range measurement exchange session, a second communication device is to provide to the first communication device in a feedback packet transmitted as part of the range measurement exchange session. The first communication device transmits to the second communication device one or more indications of the determined one or more types of feedback information that the second communication device is to provide to the first communication device in the feedback packet. The first communication device performs the range measurement exchange, including receiving the feedback packet from the second communication device, wherein the feedback packet includes the determined one or more types of feedback information.

Abstract: A first communication device generates a frame that includes an indication of a transmit power corresponding to one or more null data packets (NDPs) separate from the frame to permit a second communication device to determine a pathloss between the first communication device and the second communication device based on a received power of the one or more NDPs at the second communication device. The first communication device transmits the frame as part of a ranging measurement exchange. As part of one or more ranging measurement exchanges, the first communication device transmits the one or more NDPs in accordance with the transmit power indicated in the frame.

Abstract: A first communication device determines which one or more types of feedback information, from among a plurality of types of feedback information associated with a range measurement exchange session, a second communication device is to provide to the first communication device in a feedback packet transmitted as part of the range measurement exchange session. The first communication device transmits to the second communication device one or more indications of the determined one or more types of feedback information that the second communication device is to provide to the first communication device in the feedback packet. The first communication device performs the range measurement exchange, including receiving the feedback packet from the second communication device, wherein the feedback packet includes the determined one or more types of feedback information.

Abstract: A first communication device generates and transmits a first trigger frame. One or more trigger type information fields of the first trigger frame are set to a first one or more respective values that indicates the first trigger frame is for: i) a multi-user (MU) ranging measurement procedure, and ii) causing multiple second communication devices to simultaneously transmit first null data packets (NDPs) as part of a first MU transmission associated with the MU ranging measurement procedure. The first communication device generates and transmits a second trigger frame. One or more trigger type information fields of the second trigger frame are set to a second one or more respective values that indicates the second trigger frame is for i) an MU ranging measurement procedure, and ii) causing the multiple second communication devices to simultaneously transmit feedback packets to the first communication device as part of a second MU transmission associated with the MU ranging measurement procedure.

Abstract: A first communication device prompts a plurality of second communication devices to transmit, during a contiguous time period reserved for a range measurement exchange, respective first null data packets (NDPs) at respective times. The first communication device receives first NDPs from at least some of the second communication devices during the contiguous time period, and transmits one or more second NDPs to the plurality of second communication devices. The first communication device uses reception of the first NDPs and transmission of the one or more second NDPs to determine respective ranges between the first communication device and respective second communication devices.

Abstract: A first communication device generates a null data packet (NDP) announcement (NDPA) frame to announce a subsequent transmission of one or more NDPs to one or more second communication devices as part of a ranging measurement procedure. The NDPA frame is generated to include a training signal repetition field that specifies a number of instances of a training signal to be included in the one or more NDPs. The first communication device transmits the NDPA frame as part of the ranging measurement procedure. The first communication device generates at least one NDP to include a number of instances of the training signal that equals the number of instances of the training signal indicated by the training signal repetition field in the NDPA, and after transmitting the NDPA frame, transmits the at least one NDP as part of the ranging measurement procedure.

Abstract: At a receiver in a short-range wireless system having a plurality of channels and a plurality of receiving antennas, an angle-of-arrival of a signal is determined by receiving, at at least two antennas, the signal on one of the channels, determining a phase difference between the signal as received at those antennas, removing a local oscillator phase from the phase difference to provide an adjusted phase difference, and determining, from the adjusted phase difference, the angle-of-arrival. Removing the local oscillator phase includes estimating a local oscillator phase for each channel to be used for all antennas, or determining an angle using multi-channel combining, and for each channel, using that angle to determine a channel local oscillator phase, or, for a given channel, identifying, as the local oscillator phase, a phase that minimizes the sum, over all antennas, of squares of phase differences between the given channel and a neighboring channel.

Abstract: A first communication device determines which one or more types of feedback information, from among a plurality of types of feedback information associated with a range measurement exchange session, a second communication device is to provide to the first communication device in a feedback packet transmitted as part of the range measurement exchange session. The first communication device transmits to the second communication device one or more indications of the determined one or more types of feedback information that the second communication device is to provide to the first communication device in the feedback packet. The first communication device performs the range measurement exchange, including receiving the feedback packet from the second communication device, wherein the feedback packet includes the determined one or more types of feedback information.

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: A first communication device prompts a plurality of second communication devices to transmit, during a contiguous time period reserved for a range measurement exchange, respective first null data packets (NDPs) at respective times. The first communication device receives first NDPs from at least some of the second communication devices during the contiguous time period, and transmits one or more second NDPs to the plurality of second communication devices. The first communication device uses reception of the first NDPs and transmission of the one or more second NDPs to determine respective ranges between the first communication device and respective second communication devices.

Abstract: In a range measurement signal exchange session between a first communication device and a second communication device, the first communication device generates an NDP, which includes: generating a plurality of training fields to be used by the second communication device to determine a time of arrival of the NDP. Each training field corresponds to a respective orthogonal frequency divisional multiplexing (OFDM) symbol. Generating the plurality of training fields includes: i) setting signal samples corresponding to guard intervals between the OFDM symbols to zero, and ii) for each OFDM symbol, setting a plurality of frequency domain values corresponding to OFDM sub carriers of the OFDM symbol to complex number values. The first communication device transmits the NDP as part of the range measurement signal exchange session.

Abstract: A first communication device generates a null data packet (NDP) announcement (NDPA) frame to announce a subsequent transmission of one or more NDPs to one or more second communication devices as part of a ranging measurement procedure. The NDPA frame is generated to include a training signal repetition field that specifies a number of instances of a training signal to be included in the one or more NDPs. The first communication device transmits the NDPA frame as part of the ranging measurement procedure. The first communication device generates at least one NDP to include a number of instances of the training signal that equals the number of instances of the training signal indicated by the training signal repetition field in the NDPA, and after transmitting the NDPA frame, transmits the at least one NDP as part of the ranging measurement procedure.

Abstract: Aspects of the disclosure provide an apparatus that includes a transceiver circuit and a processing circuit. The transceiver circuit is configured to transmit and receive wireless signals. The processing circuit is configured to generate a request frame using an extended control frame format to indicate an enhanced fine timing measurement (EFTM) based range measurement to a second apparatus, cause the transceiver circuit to transmit, when a transmission opportunity (TXOP) is granted to the apparatus, wireless signals carrying the request frame to start the EFTM based range measurement that exchanges null data packets with the second apparatus, and determine a round trip time based on departure and arrival timing information of the null data packets.

Abstract: The present disclosure describes methods and apparatuses for fine timing measurement with frequency domain processing. In some aspects, a first device receives a frame that is transmitted by a second device via a wireless medium. A degree to which the frame is affected by multipath propagation in the wireless medium is determined based on frequency power and linear phase of the frame, which can be calculated using frequency domain processing. Based on the degree to which the frame is affected, a time of arrival calculation for the frame can be compensated for effects related to the multipath propagation. By so doing, the effects of multipath propagation can be addressed without time domain processing, which is typically complex and more expensive to implement.

Abstract: Adjusting automatic gain control of a receiver, in a short-range wireless system having a plurality of channels and a plurality of receiving antennas, includes setting initial gain to be set by receiver AGC based on signals received at a receiver reference antenna, receiving, at each of the receiving antennas, a signal on a current channel, and adjusting gain to be set by AGC for the signal to prevent saturation. Angle-of-arrival estimation may be performed following adjusting of the AGC. Adjusting AGC may include backing off the AGC, changing the reference antenna prior to deriving gain to be set by AGC, or determining gain to be set by AGC at additional receiving antennas, and for each antenna that is not the reference antenna and is not one of the additional antennas, selecting gain to be set by AGC from a closest one of the reference antenna and the additional antennas.

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: In a range measurement signal exchange session between a first communication device and a second communication device, the first communication device generates an NDP, which includes: generating a plurality of training fields to be used by the second communication device to determine a time of arrival of the NDP. Each training field corresponds to a respective orthogonal frequency divisional multiplexing (OFDM) symbol. Generating the plurality of training fields includes: i) setting signal samples corresponding to guard intervals between the OFDM symbols to zero, and ii) for each OFDM symbol, setting a plurality of frequency domain values corresponding to OFDM sub carriers of the OFDM symbol to complex number values. The first communication device transmits the NDP as part of the range measurement signal exchange session.

Abstract: At an antenna array of a first communication device, a wireless signal transmitted by a second communication device is received. The first communication device calculates a plurality of oversampled matched filter values corresponding to the wireless signal, which correspond to i) different values of a signal delay corresponding to the wireless signal, and ii) different values of a phase corresponding to the wireless signal. The first communication device determines a local maximum of the plurality of oversampled matched filter values across different values of the signal delay and different values of the phase, where the local maximum corresponds to a component of the wireless signal that is first to arrive at the antenna array. The first communication device calculates an angle of arrival of the wireless signal at the antenna array using a value of the phase corresponding to the local maximum of the plurality of matched filter values.