Abstract: A wireless communication base station including a transceiver coupled to a controller configured to cause the base station to serve a plurality of user terminals in a series of downlink radio frames each having a first temporal region and a second temporal region. The controller is configured to assign the plurality of user terminals to first and second groups, wherein the user terminals in the first group are served in the first temporal region of the downlink radio frame and the user terminals in the second group are served in the second temporal region of the downlink radio frame. The controller is also configured to change a duration of either of the first and second temporal regions of at least one downlink radio frame in the series of downlink radio frames, wherein a downlink radio frame contains an indicator signaling a change of duration of either of the first or second temporal regions of at least one downlink radio frame in the series of downlink radio frames.

Abstract: A datastream of bits (which may itself be comprised of a plurality of datastreams as derived from a plurality of sources) are coded (21) and then interleaved (12) across a plurality of transmitters (25 and 26) and a plurality of subcarriers (27) as supported and shared by the transmitters. If desired, the bits can be mapped to corresponding symbols prior to transmission. The resultant information is transmitted simultaneously by the transmitters using the shared channel of subcarriers. Upon reception, the received signals are de-interleaved and decoded to recover the original datastream for each sources.

Abstract: In a wireless communication system, a method and apparatus for closed loop transmission is disclosed. In accordance with the preferred embodiment of the present invention, a time frequency portion of an uplink frame is dynamically reserved as a sounding zone for uplink channel sounding. A first message is transmitted to a first subscriber station in a downlink frame assigning a time-frequency resource within the sounding zone, and a sounding waveform. Furthermore, a signal is received from the subscriber station within the assigned time-frequency resource, a partial channel response is determined from the received sounding signal, and the subsequent transmission to the subscriber station is tailored based on the at least partial channel response.

Abstract: A method in an OFDM wireless user terminal that communicates with a base unit is disclosed. The method comprises computing a transmit spatial covariance matrix, transforming the spatial covariance matrix, and transmitting the transformed spatial covariance matrix to a base unit.

Abstract: The disclosure relates to a frame structure that can be flexibly configured to serve to half-duplex users or a mixture of half- and full-duplex users based upon the grouping of user terminals according to one or more criteria. The disclosure also relates to the switching of users from one group to another. The signaling mechanisms to reconfigure a frame and to switch users are provided.

Abstract: A technique for determining a received signal strength indicator of a target base station at a subscriber station includes performing a discrete Fourier transform on a received signal to provide a transformed signal. In this case, the transformed signal occupies one or more segments of a channel and the one or more segments each include multiple subcarriers. A shift-n cross-correlation is calculated based on the transformed signal and a preamble sequence of the target base station to provide a coarse received signal strength indicator for the target base station.

Abstract: A wireless communication infrastructure entity configured to allocate radio resources, in a radio frame, to a wireless terminal compliant with a first protocol and to a wireless terminal compliant with a second protocol. The radio frame including a first protocol resource region and a second protocol resource region. The radio frame including a first protocol allocation control message that allocates resources within the first protocol resource region to the wireless terminal compliant with the first protocol, and a second protocol allocation control message that allocates resources within the second protocol resource region to the wireless terminal compliant with the second protocol.

Abstract: A wireless communications system base station (101), upon receiving (202) from a mobile station (102) a wireless transmission that comprises a suggested transmitter-receiver configuration, can respond (in appropriate instances) by automatically transmitting (203) to the mobile station a wireless transmission comprising an indication to use instead a default transmitter-receiver configuration. By one approach, the latter action can be based, at least in part, upon a determination regarding reliability (301) of that suggested transmitter-receiver configuration (which might comprise, for example, a direct or indirect measure of quality of the channel by the default transmitter-receiver configuration was received) to provide a corresponding reliability assessment. The latter can then be used (302) to determine whether to use this suggested transmitter-receiver configuration for a subsequent communication with the mobile station.

Abstract: A method and apparatus for performing spatial-division multiple access within a communication system is provided herein. During operation, nodes will return null subspace information along with their channel subspace information. The null subspace is similar to the channel subspace except that the null subspace information directs a base station to the matrix in a predefined codebook that results in minimum power being received at the node. The null subspace for each node is taken into consideration when communicating with a particular node.

Abstract: In a wireless communication system, a method and apparatus for closed loop transmission is disclosed. In accordance with the preferred embodiment of the present invention, a time frequency portion of an uplink frame is dynamically reserved as a sounding zone for uplink channel sounding. A first message is transmitted to a first subscriber station in a downlink frame assigning a time-frequency resource within the sounding zone, and a sounding waveform. Furthermore, a signal is received from the subscriber station within the assigned time-frequency resource, a partial channel response is determined from the received sounding signal, and the subsequent transmission to the subscriber station is tailored based on the at least partial channel response.

Abstract: A method for link adaptation at a base station using metric feedback is disclosed. The method can include the steps of communicating with a mobile station over a communication link having one or more sub-channels and during the communication, receiving from the mobile station information relating to one or more mutual information per coded bit metrics for one or more candidate modulation types. The mutual information per coded bit metrics can be based on channel state knowledge of the sub-channels. Also, based on the received information, the operational performance of the mobile station can be predicted in view of one or more transmission parameters and performance factors and one or more of the transmission parameters can be selected based on a transmission condition of the communication link.

Abstract: In a wireless communication system, a method and apparatus for closed loop transmission is disclosed. In accordance with the preferred embodiment of the present invention, a time frequency portion of an uplink frame is dynamically reserved as a sounding zone for uplink channel sounding. A first message is transmitted to a first subscriber station in a downlink frame assigning a time-frequency resource within the sounding zone, and a sounding waveform. Furthermore, a signal is received from the subscriber station within the assigned time-frequency resource, a partial channel response is determined from the received sounding signal, and the subsequent transmission to the subscriber station is tailored based on the at least partial channel response.

Abstract: Pilot sequences are constructed from distinct “classes” of chirp sequences that have an optimal cross correlation property. Utilization of chirp sequences for pilot sequences results in pilot sequences that have optimal or nearly-optimal cross correlation and auto-correlation properties.

Abstract: A method and apparatus for performing spatial-division multiple access within a communication system is provided herein. During operation, nodes will return null subspace information along with their channel subspace information. The null subspace is similar to the channel subspace except that the null subspace information directs a base station to the matrix in a predefined codebook that results in minimum power being received at the node. The null subspace for each node is taken into consideration when communicating with a particular node.

Abstract: A method for communicating channel estimates on a plurality of subcarriers between a transmitting device and a receiving device. The transmitting device determines a channel estimates on a plurality of subcarriers and then encodes the channel estimates into at least one encoded channel waveform. Then the transmitting device transmits the at least one encoded channel waveform to the receiving device.

Abstract: Cyclic-shift diversity transmission and optional per-subcarrier transmit beamforming within a same time interval (e.g., OFDM symbol interval) takes place. The CSD transmission technique circularly shifts the IFFT output prior to any cyclic prefix insertion and has the effect of putting a subcarrier and antenna dependent phase shift in the effective channel response from each transmit antenna. To properly perform transmit adaptive array (TXAA) transmission within an OFDM symbol interval that is being circularly shifted by the CSD transmission technique, the TXAA weights will account for the frequency domain phase shift created by the CSD circular shift operation.

Abstract: A method and apparatus for performing spatial-division multiple access within a communication system is provided herein. During operation, nodes will return null subspace information along with their channel subspace information. The null subspace is similar to the channel subspace except that the null subspace information directs a base station to the matrix in a predefined codebook that results in minimum power being received at the node. The null subspace for each node is taken into consideration when communicating with a particular node.

Abstract: A method for communicating channel estimates on a plurality of subcarriers between a transmitting device and a receiving device. The transmitting device determines a channel estimates on a plurality of subcarriers and then encodes the channel estimates into at least one encoded channel waveform. Then the transmitting device transmits the at least one encoded channel waveform to the receiving device.

Abstract: A system (10) and method (50) of operating a wireless communication system between a transmit device (12) employing an array of transmit antennas and a receiver (15) can include transmitting (52) a beamformed signal with antenna weights computed based on knowledge of a plurality of channels forming an aggregate channel and computing (54) a set of characteristics for the aggregate channel such as a power delay profile, a frequency correlation, or an expected beamforming gain of the aggregate channel. Characteristics can also be based on factors among a number of transmit antennas, a beamforming weight application delay value, an expected Doppler profile, or an expected delay profile of the propagation channel. The method can further determine (58) a channel estimator based on the computed set of characteristics, receive (62) the beamformed signal, and compute (64) an aggregate channel estimate as a function of the channel estimator and the beamformed signal.

Abstract: A method for communicating a plurality of data streams between a transmitting device with multiple transmit antennas and a receiving device, is disclosed. The method comprises determining a set of power weightings, efficiently quantizing the power weightings, and providing the set of power weightings the transmitting device. Another aspect of the invention comprises the transmitter implicitly signaling the number of data streams which the receiver should feedback information for through the amount of feedback requested. An additional aspect of the invention is a means of determining the best codebook weights by combining the maximum power and maximum capacity criteria.