Abstract: Angle estimation for modulated signal. A novel compensation technique is presented by which angle estimation may be performed for a modulated signal. More specifically, the angle between a constellation corresponding to a received signal and a constellation corresponding to a received signal may be very efficiently estimated using any one of the possible embodiments corresponding to various aspects of the invention. After this angle has been estimated, the received signal or the expected constellation may be rotated (or de-rotated) to compensate for this angular difference. In doing so, better estimates of the information bits that are demodulated and decoded from the received signal may be made.

Abstract: Certain embodiments of the invention may be found in a method and system for antenna selection diversity with prediction. An antenna diversity system may use information that it has stored on the antenna selection process in previous frames to predict the starting receiving antenna and the starting transmission antenna for the next frame. The prediction may be based on which antennas were selected in previous frames or may be based metrics associated with performance of the antennas. Prediction may be based on a majority polling scheme of previously selected antennas in a determined number of previous frames. Prediction may also be based on a weighted sum of at least one selection metric for all antennas in a determined number of previous frames. Antenna prediction provides a significant performance improvement by reducing the processing and operational overhead in cases where a transmit or a receive antenna dominates.

Abstract: Certain embodiments of the invention may be found in a method and system for antenna selection diversity with prediction. An antenna diversity system may use information that it has stored on the antenna selection process in previous frames to predict the starting receiving antenna and the starting transmission antenna for the next frame. The prediction may be based on which antennas were selected in previous frames or may be based metrics associated with performance of the antennas. Prediction may be based on a majority polling scheme of previously selected antennas in a determined number of previous frames. Prediction may also be based on a weighted sum of at least one selection metric for all antennas in a determined number of previous frames. Antenna prediction provides a significant performance improvement by reducing the processing and operational overhead in cases where a transmit or a receive antenna dominates.

Abstract: A reduced-complexity maximum-likelihood detector is disclosed that provides a high degree of signal detection accuracy while maintaining high processing speeds. The detector processes the received symbols to obtain initial estimates of the transmitted symbols and then uses the initial estimates to generate a plurality of reduced search sets. The reduced search sets are then used to generate decisions for detecting the transmitted symbols.

Abstract: A method and system for antenna selection diversity with dynamic gain control. A receiver selects a starting antenna and dwells on it until an incoming signal is detected. An AGC is applied on the received signal and an estimate of the received power is determined for the starting antenna. The receiver may dwell on other antennas if the signal in the first antenna is not strong enough for signal processing. The gain of an antenna may be set by the gain and power levels of the previously dwelled-on antennas and/or by a power coupling factor that exists between the antennas in an antenna switch. The receiver switches through the remaining antennas as long as necessary to select at least one of the antennas for signal processing. Dynamically adjusting the gain of antennas in a diversity system provides a more accurate and efficient antenna selection scheme.

Abstract: An adaptive, reduced-complexity soft-output maximum-likelihood detector that is operable to process data by adaptively selecting a processing scheme based on a determination of signal quality. The signal quality is derived as a function of the noise, the modulation format, the channel (the communication environment), the transmit signal power and the receive signal power. If the signal quality is low, the signal is processed using a maximum likelihood detector. If, however, the signal quality is high, a simpler sub-optimal detector is used. By estimating the signal quality and choosing an appropriate detection method, the present invention ensures accurate detection of incoming data signals in a MIMO communication system while maintaining the highest possible processing speed.

Abstract: Angle estimation for modulated signal. A novel compensation technique is presented by which angle estimation may be performed for a modulated signal. More specifically, the angle between a constellation corresponding to a received signal and a constellation corresponding to a received signal may be very efficiently estimated using any one of the possible embodiments corresponding to various aspects of the invention. After this angle has been estimated, the received signal or the expected constellation may be rotated (or de-rotated) to compensate for this angular difference. In doing so, better estimates of the information bits that are demodulated and decoded from the received signal may be made.

Abstract: A reduced-complexity maximum-likelihood detector that provides a high degree of signal detection accuracy while maintaining high processing speeds. A communication system implementing the present invention comprises a plurality of transmit sources operable to transmit a plurality of symbols over a plurality of channels, wherein the detector is operable to receive symbols corresponding to the transmitted symbols. The detector processes the received symbols to obtain initial estimates of the transmitted symbols and then uses the initial estimates to generate a plurality of reduced search sets. The reduced search sets are then used to generate decisions for detecting the transmitted symbols. In various embodiments of the invention, the decisions for detecting the symbols can be hard decisions or soft decisions.

Abstract: An adaptive, reduced-complexity soft-output maximum-likelihood detector that is operable to process data by adaptively selecting a processing scheme based on a determination of signal quality. The signal quality is derived as a function of the noise, the modulation format, the channel (the communication environment), the transmit signal power and the receive signal power. If the signal quality is low, the signal is processed using a maximum likelihood detector. If, however, the signal quality is high, a simpler sub-optimal detector is used. By estimating the signal quality and choosing an appropriate detection method, the present invention ensures accurate detection of incoming data signals in a MIMO communication system while maintaining the highest possible processing speed.

Abstract: Methods and devices for adaptively changing a parameter (such as sub-carrier bit allocation and/or gain) in a multi-carrier communication signal are described. In a method aspect, a unit that determines a need for a change sends an express change request to a second unit. The change request identifies one or more specific sub-carrier carrier to be altered and a desired value for the parameter to be changed for each identified sub-carrier. The requesting unit then monitors the communication signal it receives to determine whether the requested change has been implemented. The determination of whether the requested change has been implemented is based at least in part upon an analysis of a portion of the received communication signal that was intended to be changed. In another aspect of the invention, the change request command includes a header, a control field, at least one sub-carrier identifier, at least one desired parameter value indicator, and an error field.