Abstract: Disclosed is method of computing a round trip delay between a pair of nodes, the method comprising transmitting at least one beacon at a known transmit time from each of the nodes; measuring the times-of-arrival of the beacons at other of the nodes; and estimating a round trip delay between the nodes from the measured times-of-arrival and the transmit times; and correcting the round trip delay for either or both of a frequency offset between the nodes and relative motion between the nodes.

Abstract: Disclosed is a method, receiver, multi-receiver device, system and computer readable medium for configuring a receiver to perform multi-transmitter channel estimation for a time-varying channel. In one aspect, the method includes: wirelessly receiving at least two frames, each frame including a block of training symbols received at different points in time for a time-varying channel; estimating, for each block at a block location, a first channel coefficient of the time-varying channel, wherein the block location is the same for each block; and interpolating or extrapolating a plurality of second channel coefficients for the respective training symbols of each block based on the respective first channel coefficient.

Abstract: The present invention discloses various improvements to multi-user multiple-input multiple-output orthogonal frequency division multiplexing (MU-MIMO-OFDM) wireless communication systems. In one aspect there is disclosed an efficient and accurate channel estimation method and system using locally consecutive pilot sub-carriers. In another aspect there is disclosed an efficient channel feedback method and system by applying a discrete cosine transform to channel coefficients. In another aspect there is disclosed an efficient method and system to calculate a part of the channel inverse by interpolation. These aspects can be used in combination to improve the MU-MIMO-OFDM system.

Abstract: Disclosed is method of computing a round trip delay between a pair of nodes, the method comprising transmitting at least one beacon at a known transmit time from each of the nodes; measuring the times-of-arrival of the beacons at other of the nodes; and estimating a round trip delay between the nodes from the measured times-of-arrival and the transmit times; and correcting the round trip delay for either or both of a frequency offset between the nodes and relative motion between the nodes.

Abstract: Disclosed is method of computing a round trip delay between a pair of nodes, the method comprising transmitting at least one beacon at a known transmit time from each of the nodes; measuring the times-of-arrival of the beacons at other of the nodes; and estimating a round trip delay between the nodes from the measured times-of-arrival and the transmit times; and correcting the round trip delay for either or both of a frequency offset between the nodes and relative motion between the nodes.

Abstract: Disclosed is a method, receiver, multi-receiver device, system and computer readable medium for configuring a receiver to perform multi-transmitter channel estimation for a time-varying channel. In one aspect, the method includes: wirelessly receiving at least two frames, each frame including a block of training symbols received at different points in time for a time-varying channel; estimating, for each block at a block location, a first channel coefficient of the time-varying channel, wherein the block location is the same for each block; and interpolating or extrapolating a plurality of second channel coefficients for the respective training symbols of each block based on the respective first channel coefficient.

Abstract: The present invention discloses various improvements to multi-user multiple-input multiple-output orthogonal frequency division multiplexing (MU-MIMO-OFDM) wireless communication systems. In one aspect there is disclosed an efficient and accurate channel estimation method and system using locally consecutive pilot sub-carriers. In another aspect there is disclosed an efficient channel feedback method and system by applying a discrete cosine transform to channel coefficients. In another aspect there is disclosed an efficient method and system to calculate a part of the channel inverse by interpolation. These aspects can be used in combination to improve the MU-MIMO-OFDM system.

Abstract: Disclosed is method of computing a round trip delay between a pair of nodes, the method comprising transmitting at least one beacon at a known transmit time from each of the nodes; measuring the times-of-arrival of the beacons at other of the nodes; and estimating a round trip delay between the nodes from the measured times-of-arrival and the transmit times; and correcting the round trip delay for either or both of a frequency offset between the nodes and relative motion between the nodes.

Abstract: Disclosed is method of computing a round trip delay between a pair of nodes, the method comprising transmitting at least one beacon at a known transmit time from each of the nodes; measuring the times-of-arrival of the beacons at other of the nodes; and estimating a round trip delay between the nodes from the measured times-of-arrival and the transmit times; and correcting the round trip delay for either or both of a frequency offset between the nodes and relative motion between the nodes.