Abstract: A first network device including a calibration module, a steering module, and a control module. The calibration module is configured to determine whether a second network device is capable of generating steering data for the first network device, wherein the steering data corresponds to data for steering signals in a desired direction. The steering module is configured to, if the second network device is not capable of generating the steering data for the first network device, receive channel state information from the second network device and determine the steering data based on the channel state information. The control module is configured to receive the steering data from the second network device if the second network device is capable of generating the steering data for the first network device.

Abstract: A first network device including a first calibration module to generate training signals for each of a plurality of subcarriers. The training signals are transmitted from the first network device to a second network device via antennas of the first network device using the subcarriers. A first steering module receives a first matrix for each subcarrier, which includes channel state information for each of the training signals received by the second network device, from the second network device according to a transmission schedule and generates a steering matrix based on the first matrix. The transmission schedule is predetermined or is transmitted to the second network device prior to transmitting the training signals. A first control module adjusts, based on the steering matrix, first beamforming weights associated with the antennas to direct first radio frequency signals to be transmitted toward the second network device.

Abstract: A first network device including a first calibration module to generate training signals for each of a plurality of subcarriers. The training signals are transmitted from the first network device to a second network device via antennas of the first network device using the subcarriers. A first steering module receives a first matrix for each subcarrier, which includes channel state information for each of the training signals received by the second network device, from the second network device according to a transmission schedule and generates a steering matrix based on the first matrix. The transmission schedule is predetermined or is transmitted to the second network device prior to transmitting the training signals. A first control module adjusts, based on the steering matrix, first beamforming weights associated with the antennas to direct first radio frequency signals to be transmitted toward the second network device.

Abstract: A beamforming technique used in a MIMO wireless transmission system determines a transmitter beamforming steering matrix using a matrix equalizer of a transmitter or a receiver within the MIMO communication system, to thereby increase the speed and/or to decrease the processing needed to implement effective beamforming within the transmitter of the communication system. While this beamforming technique may not provide the best possible set of steering coefficients that obtain the best possible transmission and reception in the communication system, this technique can provide increased performance over no beamforming without significantly increasing the processing overhead of the transmission system. This beamforming technique can used when a transmitter, with multiple transmitter antennas, is used to communicate with one or with multiple receivers within the communication system.

Abstract: A method and system for improving channel estimation in a wireless device is disclosed. Aspects of the exemplary embodiment include receiving a data packet wirelessly transmitted from a transmitter, the packet including a preamble portion and a data portion containing data, wherein the preamble portion includes at least one training field and a second field; performing a first channel estimation using the training field; and using the second field to refine the first channel estimation.

Abstract: A plurality of diagonal matrices Ci is determined, where the plurality of diagonal matrices Ci is for modifying a plurality of transmit signals to be transmitted via a plurality of transmit antennas, each diagonal matrix Ci for modifying an i-th block of sub-carriers, adjacent in frequency, in the plurality of transmit signals. The plurality of diagonal matrices Ci is used to modify the plurality of transmit signals to implement transmit diversity.

Abstract: A network device includes a first feedback module and a first calibration module. The first feedback module selectively generates a first transmission schedule that is transmitted to a link partner, wherein the first transmission schedule includes a first matrix map. The first calibration module selectively transmits a first set of training signals to the link partner, receives a first set of channel state information (CSI) for the training signals from the link partner according to the first transmission schedule, and generates a first CSI matrix based on the first set of CSI and the first matrix map.

Abstract: A system and method of beamforming may reduce feedback requirements. In some implementations, a beamforming technique may employ a diagonal matrix as a beamforming matrix along with a stream-to-transmit antenna mapping matrix. In some antenna phase beamforming strategies, a diagonal beamforming matrix in which the diagonal elements have a constant magnitude may be employed. Accordingly, a beamforming system may be utilized with few feedback information bits being transmitted from the beamformee; such a system may also minimize or eliminate power fluctuations among multiple transmit antennae.

Abstract: A method and apparatus for estimating a frequency response of a channel. The method includes adjusting phase components of estimates of the frequency response to provide phase-adjusted estimates; performing a smoothing operation on the phase-adjusted estimates to provide smoothed phase-adjusted estimates; and generating an output of a reverse phase adjustment, wherein the reverse phase adjustment is performed on the smoothed phase-adjusted estimates.

Abstract: A network device including a first feedback module and a first calibration module. The first feedback module generates a first transmission schedule, which include (i) a first subcarrier schedule to determine an order of transmitting subcarriers and (ii) a first matrix map, and which is transmitted to a link partner. The first calibration module transmits a first set of training signals to the link partner, receives a first set of channel state information (CSI) (i) generated by the link partner based on the training signals and (ii) transmitted by the link partner according to the first transmission schedule, and generates a first CSI matrix based on the first set of CSI and the first matrix map. The first calibration module is configured to (i) generate the same first set of training signals for each of the subcarriers and (ii) receive the first set of CSI for each of the subcarriers.

Abstract: A method and system for improving channel estimation in a wireless device is disclosed. Aspects of the exemplary embodiment include receiving a data packet wirelessly transmitted from a transmitter, the packet including a preamble portion and a data portion containing data, wherein the preamble portion includes at least one training field and a second field; performing a first channel estimation using the training field; and using the second field to refine the first channel estimation.

Abstract: The disclosed technology relates to estimating the frequency response of a frequency division multiplexed (FDM) channel. In accordance with one aspect of the invention, a channel estimation circuit of a receiver can compute initial estimates of the frequency response of sub-channels in the FDM channel. A phase adjustment circuit can adjust the phase components of the initial estimates to provide phase-adjusted estimates. A smoothing circuit can apply a smoothing operation to the phase-adjusted estimates to provide smoothed phase-adjusted estimates. When necessary, a reverse phase adjustment circuit can reverse the phase adjustment by adjusting the phase components of the smoothed phase-adjusted estimates to provide final channel estimates.

Abstract: The disclosed technology relates to a communication system and method in which multiple versions of a signal are processed to detect the signal. The communication system can include transmitters that communicate different versions of a signal to a receiver. The different versions are weighted versions of the signal and are communicated on different channels. The weight for a weighted signal is based on an inverse of an estimate of the phase shift of the particular channel to which the weighted signal will be communicated. The weights are also based on a unity gain such that each weighted signal has the same magnitude as the original signal. A receiver that receives the weighted signals processes the received signals to detect the original signal.

Abstract: A first network device includes a calibration module configured to receive a training signal from a second network device. The training signal indicates the second network device is capable of adjusting beamforming weights associated with the second network device based on a steering matrix received from the first network device. A steering module is configured to determine a first steering matrix for the second network device based on the training signal. The steering module is configured to transmit the first steering matrix to the second network device for adjustment of the beamforming weights associated with the second network device.

Abstract: A beamforming technique used in a MIMO wireless transmission system performs beamforming based on a subset of the receiver antennas within the communication system to increase the speed and/or to decrease the processing needed to implement effective beamforming at the transmitter of the MIMO system. This beamforming technique can provide increased performance over no beamforming without significantly increasing the processing overhead of the transmission system, especially when a large number of receiver antennas are present at a receiver of the MIMO system. This beamforming technique can additionally be used when a transmitter, with multiple transmission antennas, is used to communicate with multiple receivers, each of which includes one or more receiver antennas. In this case, the beamforming technique may select a subset of the receiver antennas that includes, for example, one receiver antenna from each of the receivers, and may then beamform to the selected subset of receiver antennas.

Abstract: A network device includes a calibration module that receives a first channel state information (CSI) matrix from a link partner, that determines CSI based on radio frequency (RF) signals transmitted from the link partner, and that generates a second CSI matrix that includes the CSI for the RF signals. The network device includes a first steering module that determines a first steering matrix based on the first CSI matrix, a control module that adjusts beamforming weights based on the first steering matrix, and a second steering module that determines a second steering matrix based on the second CSI matrix and that transmits the second steering matrix to the link partner.

Abstract: A transmitter beamforming technique for use in a MIMO wireless communication system determines a partial description of a reverse channel without determining a full dimensional description of the reverse channel. A correction matrix is developed from the partial description of the reverse channel and a description of the forward channel. The correction matrix is used to process signals to be transmitted via the forward channel, and a steering matrix is used to perform beamforming in the forward channel.