Abstract: A method and apparatus is described for modifying a smart antenna processing strategy determined from a set of signals received at an array of antenna elements of a wireless station, such as a set of weights for processing received antenna signals or forming a set of antenna signals for transmission. The method and apparatus uses the signatures of one or more interferers to produce a modified processing strategy that improves the nulling to the one or more interferers in that, when the modified strategy is applied on the downlink, the transmit signal strength in the direction of the one or more interferers is decreased, and, when the modified strategy is applied on the uplink, the sensitivity to signals from the direction of the one or more interferers is decreased.

Abstract: According to an embodiment of the invention, a method and apparatus are described for producing an error word for a data stream. According to an embodiment of the invention, a method includes receiving a plurality of data elements of a data stream; and updating an error word for the data stream by processing the plurality of data elements in a single iteration.

Abstract: A method, device, and machine readable medium to communicate from a base station having a smart antenna system to a user terminal. The method includes providing a downlink channel for transmitting downlink data from the base station to the user terminal, providing an associated channel for the base station to receive an uplink response signal from the user terminal in response to the downlink data. The associated channel is associated, and has a predefined relationship, with the downlink channel. The method further includes providing an uplink data channel, distinct from the associated uplink channel, for the base station to receive uplink data from the user terminal.

Abstract: The present invention allows many of the benefits of spatial diversity to be realized in a hopping radio communications system. One embodiment of the invention includes transmitting signals from a first radio using a first hopping sequence and transmitting signals from a second radio using spatial processing and a second hopping sequence. The second hopping sequence is coordinated with the first hopping sequence. In another embodiment, the invention includes selecting a set of spatial processing parameters based, at least in part, on a determination whether a third radio using a first frequency resource during a first time interval uses a second frequency resource during a second time interval and transmitting a signal from a first radio to a second radio during the second time interval using the second frequency resource and the selected set of spatial processing parameters.

Abstract: A method and apparatus are provided that measures received radio communications signals to determine whether or what degree to use transmit diversity and beam forming. In one embodiment, the invention includes receiving a radio signal from a remote terminal at a plurality of antennas, comparing characteristics of the received signal as received at the plurality of antennas, determining whether reception of radio signals transmitted to the remote terminal is likely to be improved by diversity transmission based on the comparisons and transmitting radio signals to the remote terminal using diversity if the reception is likely to be improved.

Abstract: Spatial and temporal characteristics of received radio signals in a multiple user radio system can be estimated based on signals received from the users. In one embodiment, the invention includes collecting measurements of radio frequency signals received at different elements of an antenna system over time, the received signals corresponding at least in part to transmissions received from a system user, collecting representations of the transmissions of the system user, cross-correlating the collected measurements and the collected representations, and comparing the cross-correlation to the collected measurements to form a characterization of the radio channel traversed by transmissions of the system user.

Abstract: Methods and apparatus for calculating spatial processing strategies in adaptive antenna array processing systems. Reference signal quality, intersymbol interference, data processed and received signal quality can be determined by burst type or remote device type and used to determine a synthetic signal level for use in developing a spatial processing strategy. A synthetic signal have an isotropically distributed component can be added to the antennas in the array or the diagonal elements of the received signal covariance matrix to develop uplink and downlink spatial processing strategies. Different synthetic signals at different signal levels can be used to develop different uplink and downlink spatial processing strategies. The downlink signal level can be larger than the uplink signal level. Uplink and downlink processing strategies can be developed in substantially the same way.

Abstract: A method and apparatus are provided that calibrate a wideband radio communications system without causing significant interference with simultaneous users of the system. In one embodiment, the invention includes an antenna array adapted to transmit and receive radio communications signals with a plurality of other terminals the communications signals each using a particular minimum bandwidth. A transmit chain transmits a calibration signal through the antenna array to a transponder, and a receive chain receives through the antenna array a transponder signal from the transponder, the transponder signal being based on the calibration signal and having a bandwidth narrower than the minimum bandwidth. A signal processor measures characteristics of the transponder signal as received through the receive chain. These can be used to determine spatial signatures and to calibrate the transmit chain and the receive chain.

Abstract: A method for ongoing power control for a communication station with a multiple antenna array, the power control using a method for signal quality estimation applicable for angle modulated signals. One aspect of the ongoing power control method is applicable for the uplink and includes separating the joint determination of a receive weight vector and ongoing power control into a receive weight vector determining part and a separate transmit power adjustment part. In one embodiment, the ongoing power control method for the downlink includes separating the joint determination of a receive weight vector and ongoing power control into a receive weight vector determining part and a separate transmit power adjustment part. The method starts with one part, for example transmit power assignment. Receive weight vector determination is carried out with this assigned transmit power, and the new weights used. An estimate of the resulting received signal quality is obtained and used for new ongoing power adjustment.

Abstract: According to an embodiment of the invention, a method and apparatus are described for error detection for multi-stream communication. Under an embodiment of the invention, a method for producing an error word for a data stream comprises computing an intermediate error word for each of a plurality of data sub-streams, the data stream being equivalent to a concatenation of the plurality of data sub-streams; and combining the intermediate error words to produce the error word for the data stream.

Abstract: The power of a signal received on a spatial channel in a wireless radio communications system can be estimated. One embodiment of the invention includes receiving a signal at a plurality of antenna elements, the received signal including a first component from a first radio and a second component from a second radio. Then the contribution of the first component to the received signal may be estimated by calculating a first power estimate for the first radio using the received signal, calculating a second power estimate for the second radio using the received signal, and estimating the contribution of the first component to the received signal, the estimation using the first power estimate and the second power estimate. In one embodiment the first power estimate is an SINR of the first component.

Abstract: A system and method for communicating information between two locations via a wireless microwave link is provided. The system includes at least two antennas, each to transmit information as a narrow beam signal to be directed toward a focal point at a remote location. The antennas include at least one antenna to transmit a narrow beam signal toward a redirection point different from the focal point. A redirection device is located at the redirection point to receive the narrow beam signal from the at least one antenna element and to redirect the received narrow beam signal toward the receiver. The redirection point is located such that the narrow beam signals from the at least two antenna elements converge and overlap to form proximate to the receiver, an interference pattern that includes peaks and nulls having a peak-to-peak spacing narrower than the width of each received narrow beam signal.

Abstract: Methods and apparatus implementing spatial processing in a remote unit. In general, in one aspect, the present invention provides a remote unit, that includes a plurality of antennas and a spatial processing unit coupled to the plurality of antennas. The remote unit also includes a performance determination unit to determine a performance of the remote unit and a feedback adjustment unit to adjust feedback transmitted from the remote unit to a device, wherein the adjusted feedback accounts for performance associated with the spatial processing unit.

Abstract: An embodiment of the invention provides a method for effecting switchback on a spatial division multiple access (SDMA) PHS channel. A communication signal is broadcast over each of one or more SDMA channels of a multi-access channel to one or more corresponding user terminals. A set of transmit spatial weights is determined for a synchronization burst to a user terminal attempting to reestablish communication over an SDMA channel of the multi-access channel. The set of transmit spatial weights is determined such that interference caused by one or more communication signals to the synchronization burst is reduced.

Abstract: A method and apparatus are provided that generate, transmit, or receive a training sequence in a communications system, where the training sequence exhibits certain desirable characteristics when used by a peak to average power constrained modulation formal. In one embodiment, the invention includes selecting an original training sequence from a set of possible original training sequences having at least one desired property, forming a modified training sequence by modifying the original training sequence based on a corresponding modifying sequence, such that the modified training sequence exhibits the desired property of the original training sequence when used in a peak to average power constrained modulation format that would otherwise impair the desired property of the original training sequence.

Abstract: A wireless communication system includes base stations with adaptive antenna arrays that communicate with remote communication devices. The base stations monitor the power of uplink signals received from user terminals, and generate a downlink array pattern that directs signals toward desired users and directs nulls toward undesired users. A base station will increase the strength of the downlink signals directed to a desired user from which it senses an increasing uplink signal power and will deepen the null directed to an undesired user from which it senses an increasing uplink signal power. The remote devices monitor the quality of downlink signals they receive and increase the power of the uplink signal they transmit in order to improve received downlink signal quality.

Abstract: A method and apparatus are provided that allows beamforming to be used on a user-specific signal together with a sector-wide pilot signal in a communication system, such as a CDMA system. In one embodiment, the invention includes a plurality of elements in a defined order to transmit spatially directed signals to specific receiving radio terminals, and a single element, substantially in the center of the ordering to transmit a single pilot signal simultaneously to a plurality of receiving radio terminals.

Abstract: Methods and systems are provided for assigning channels in a spatial division multiple access communication network. The network includes a plurality of conventional channels some of which are configurable to be shared concurrently by plural subscribers. The method includes determining combinations of subscribers from the existing subscribers. Existing subscribers are reassigned to share channels thereby freeing resources for new subscribers.

Abstract: A system and related methods for clustering multi-point communication targets is presented. According to one aspect of the invention, a method comprising measuring one or more performance characteristics associated for each of at least a subset of a plurality of targets in a wireless communication system, and selectively building one or more clusters, each cluster including one or more target(s) and sharing a wireless communication channel, based at least in part on the performance characteristics.

Abstract: The present invention provides method and apparatus for facilitating base station selection/handover by a user terminal in a distributed (e.g., cellular-type) wireless communication system. In accordance with one aspect, hysteresis is adaptively determined as a function of the variance of receive signal strength fluctuations. In turn, an adaptive hysteresis factor can be obtained and used for a subsequent handover decision, for example, based on a cost function that takes into account the hysteresis. In accordance with another aspect, base station selection depends on a number of criteria, such as received signal strength, base station load, and estimated distance between a receiving user terminal and one or more base stations.