Abstract: An apparatus having: 1) a database for storing R active wireless terminal records, each of the R active wireless terminal records containing: a) an active orthogonal code and b) corresponding downlink beamforming coefficients used to communicate with one of the wireless access terminals; and 2) a controller associated with the database that receives a notification that a new wireless access terminal is accessing the base station and, in response to the notification, compares each of the R active wireless terminal records to new downlink beamforming coefficients associated with the new wireless access terminal. The controller determines at least one active wireless terminal record containing corresponding downlink beamforming coefficients that have the least correlation with the new downlink beamforming coefficients.

Abstract: A system and method is disclosed for improving downlink performance of an adaptive antenna array in a vehicular environment. The system comprises a mobile station that has a first mobile antenna and a second mobile antenna. A spatial signature estimator associated with a base transceiver station obtains spatial signatures from signals from the first mobile antenna and from the second mobile antenna within an uplink interval. Correlation circuitry uses the spatial signatures to identify a least changing spatial signature to obtain an optimal downlink beamforming weight vector to be used in the transmission of a signal to the mobile station in the next downlink interval.

Abstract: A demodulator for demodulating S orthogonal modulation codes, each code comprising M binary bits representing an N-bit data symbol, where M=2N. The demodulator comprises a Logic 00 detector for comparing pairs of binary bits to 00 and outputting [+1,+1] if a match occurs or [?1,?1] otherwise; S accumulators; and a Logic 00 switch array comprising S switches, where a Kth switch couples an output of the Logic 00 detector to a first input of a Kth S accumulator. The demodulator also comprises a storage array for storing S code masks, each code mask comprising M/2 code mask bits and each M/2 code mask bit associated with a corresponding sequential pair of M binary bits; and control circuitry for synchronously applying the M/2 code mask bits in a Kth code mask as a control signal to the Kth switch in the Logic 00 switch array.

Abstract: A demodulator for demodulating S possible orthogonal modulation codes received serially as binary data, wherein each of the S possible orthogonal modulation codes comprises M binary bits representing an N-bit data symbol and wherein M=2N. The demodulator comprises Logic 00, Logic 01, Logic 10, and Logic 11 input detectors, each of which compares M/2 sequential pairs of the M binary bits of the orthogonal modulation codes to a respective one of a Logic 00 value, a Logic 01 value, a Logic 10 value, or a Logic 11 value and outputs a [+1,+1] signal if a match occurs and outputs a [?1,?1] signal if a match does not occur. An input decision circuit detects a [+1,+1] signal output by one of the input detectors after a comparison of a jth sequential pair of the M/2 sequential pairs of the M binary bits.

Abstract: A system and method is disclosed for providing an improved channel encoder in a digital data communication system. In one advantageous embodiment the invention comprises a channel encoder that comprises a first Turbo encoder, an interleaver, and a second Turbo encoder. Data from a source encoder is Turbo encoded in the first Turbo encoder, then interleaved, and then Turbo encoded in the second Turbo encoder. The data is then punctured and repeated in a symbol puncture and repetition unit. In an alternate advantageous embodiment of the invention, the first and second Turbo encoders are coupled in parallel. The data provided to one of the Turbo encoders is interleaved. The outputs of the first and second Turbo encoders are multiplexed and the result is provided to the symbol puncture and repetition unit. The invention provides low packet error rates when higher RF modulation is used.

Abstract: A system and method is disclosed for providing an improved channel encoder in a digital data communication system. In one advantageous embodiment the invention comprises a channel encoder that comprises a first Turbo encoder, an interleaver, and a second Turbo encoder. Data from a source encoder is Turbo encoded in the first Turbo encoder, then interleaved, and then Turbo encoded in the second Turbo encoder. The data is then punctured and repeated in a symbol puncture and repetition unit. In an alternate advantageous embodiment of the invention, the first and second Turbo encoders are coupled in parallel. The data provided to one of the Turbo encoders is interleaved. The outputs of the first and second Turbo encoders are multiplexed and the result is provided to the symbol puncture and repetition unit. The invention provides low packet error rates when higher RF modulation is used.

Abstract: A demodulator for demodulating S possible orthogonal modulation codes received serially as binary data, wherein each of the S possible orthogonal modulation codes comprises M binary bits representing an N-bit data symbol and wherein M=2N. The demodulator comprises Logic 00, Logic 01, Logic 10, and Logic 11 input detectors, each of which compares M/2 sequential pairs of the M binary bits of the orthogonal modulation codes to a respective one of a Logic 00 value, a Logic 01 value, a Logic 10 value, or a Logic 11 value and outputs a [+1,+1] signal if a match occurs and outputs a [−1,−1] signal if a match does not occur. An input decision circuit detects a [+1,+1] signal output by one of the input detectors after a comparison of a jth sequential pair of the M/2 sequential pairs of the M binary bits.

Abstract: A demodulator for demodulating S orthogonal modulation codes, each code comprising M binary bits representing an N-bit data symbol, where M=2N. The demodulator comprises a Logic 00 detector for comparing pairs of binary bits to 00 and outputting [+1,+1] if a match occurs or [−1,−1] otherwise; S accumulators; and a Logic 00 switch array comprising S switches, where a Kth switch couples an output of the Logic 00 detector to a first input of a Kth S accumulator. The demodulator also comprises a storage array for storing S code masks, each code mask comprising M/2 code mask bits and each M/2 code mask bit associated with a corresponding sequential pair of M binary bits; and control circuitry for synchronously applying the M/2 code mask bits in a Kth code mask as a control signal to the Kth switch in the Logic 00 switch array.

Abstract: A system and method is disclosed for improving downlink performance of an adaptive antenna array in a vehicular environment. The system comprises a mobile station that has a first mobile antenna and a second mobile antenna. A spatial signature estimator associated with a base transceiver station obtains spatial signatures from signals from the first mobile antenna and from the second mobile antenna within an uplink interval. Correlation circuitry uses the spatial signatures to identify a least changing spatial signature to obtain an optimal downlink beamforming weight vector to be used in the transmission of a signal to the mobile station in the next downlink interval.

Abstract: An apparatus for allocating orthogonal codes used for downlink transmissions to wireless access terminals for use in a base station of a code division multiple access (CDMA) wireless network. The base station communicates with the wireless access terminals using transmit beams formed by an adaptive antenna array. The apparatus comprises: 1) a database for storing R active wireless terminal records, each of the R active wireless terminal records containing: a) an active orthogonal code and b) corresponding downlink beamforming coefficients used to communicate with one of the wireless access terminals; and 2) a controller associated with the database that receives a notification that a new wireless access terminal is accessing the base station and, in response to the notification, compares each of the R active wireless terminal records to new downlink beamforming coefficients associated with the new wireless access terminal.