Abstract: Decoding CFC codewords in the form of sums of QPSK-modulated spread symbols in a spread spectrum communications systems using comma-free codes with elements made of sums of QPSK-modulated secondary synchronization codes.

Abstract: Automatic repeat request (ARQ) operations can be implemented in wireless communications by sending (2401) a plurality of data packets in a superpacket, and responding (2430) with an acknowledgement packet that indicates which packets of the superpacket require retransmission.

Abstract: Space time transmit diversity (9, 14, 17, 19) is applied at the block level to an original block of bits (12) in order to reduce the effects of fading in wireless communication systems that use nonlinear modulation schemes (13, 33). At the receiving end, fading parameters (?1, ?2) are estimated (?E1, ?E2) and the properties of complex conjugates are utilized (28, 29, 201, 202) to produce a result (r1, r2) that is representative of the original block of bits.

Abstract: System and method for determining a separation between communicating devices. A preferred embodiment comprises a first device transmitting a signal over multiple subbands to a second device, the second device determining a timing for the signal by processing the signal in each subband separately. The second device then transmits a signal back to the first device along with timing information (again, over multiple subbands). The first device then determines a timing for the signal and by determining a difference in the timing information provided by the second device and timing information it determines, the first device can compute the separation between it and the second device. The use of multiple subbands can dedicate more bandwidth to the transmission of the signal, permitting greater resolution.

Abstract: A wireless communication system (10). The system comprises a user station (12). The user station comprises despreading circuitry (22) for receiving and despreading a plurality of slots received from at least a first transmit antenna (A121) and a second transmit antenna (A122) at a transmitting station (14). Each of the plurality of slots comprises a first channel (DPCH) comprising a first set of pilot symbols and a second channel (PCCPCH) comprising a second set of pilot symbols. The user station further comprises circuitry (50) for measuring a first channel measurement (?1,n) for each given slot in the plurality of slots from the first transmit antenna and in response to the first set of pilot symbols in the given slot. The user station further comprises circuitry (50) for measuring a second channel measurement (?2,n) for each given slot in the plurality of slots from the second transmit antenna and in response to the first set of pilot symbols in the given slot.

Abstract: A wireless communication system (10). The system comprises a user station (12). The user station comprises despreading circuitry (22) for receiving and despreading a plurality of slots received from at least a first transmit antenna (A121) and a second transmit antenna (A122) at a transmitting station (14). Each of the plurality of slots comprises a first channel (DPCH) comprising a first set of pilot symbols and a second channel (PCCPCH) comprising a second set of pilot symbols. The user station further comprises circuitry (50) for measuring a first channel measurement (?1,n) for each given slot in the plurality of slots from the first transmit antenna and in response to the first set of pilot symbols in the given slot. The user station further comprises circuitry (50) for measuring a second channel measurement (?2,n) for each given slot in the plurality of slots from the second transmit antenna and in response to the first set of pilot symbols in the given slot.

Abstract: A method described evaluates the pilot-to-data power ratio based on the values of the demodulated data at the output of a receiver such as a conventional maximal ratio combiner or an equalizer receiver. Since the data are not scaled to their particular decision grid, their distribution and statistics deviate from the ones defined by the known decision grid. Measuring these deviations of the statistics, the pilot-to-data power ratio and the appropriate demodulated data scaling can be accurately determined. Subsequent data processing may then commence.

Abstract: Quasi-parallel read/write interleaver architecture for data blocks by sequential spreading of variable size data subblocks into memory banks with bank address contention initiating the next data subblock. Iterative Turbo decoders with MAP decoders use such quasi-parallel interleavers and deinterleavers.

Abstract: Quasi-parallel read/write interleaver architecture for data blocks by sequential spreading of variable size data subblocks into memory banks with bank address contention initiating the next data subblock. Iterative Turbo decoders with MAP decoders use such quasi-parallel interleavers and deinterleavers.

Abstract: Interference rejection (85) can be applied to a wireless communication signal with reduced computational complexity by producing from a sample vector (y) a plurality of vectors (w) that are smaller than the sample vector. The interference rejection operation can then be applied to each of the smaller vectors individually to decide communication symbols represented by the sample vector.

Abstract: A method for reducing multiple access interference (MAI) in a code division multiple access (CDMA) spread spectrum receiver assigned a number of codes which also despreads the received signal with the remaining codes of the same spreading factor. For forward link transmission with orthogonal codes, as in 3GPP and 3GPP2, interferers using larger spreading factors than the one used by the referenced mobile will have codes that are formed from the orthogonal codes of the same spreading factor as the multicodes corresponding to the referenced mobile. As a consequence, in a multipath environment, the output of a despreader using any of these remaining orthogonal codes will provide an estimate of the composite interference attributed to signals, if any, using codes that partly comprise the corresponding orthogonal code. No decisions are made for the previous despreader's output because it corresponds to a sum of interferers with unknown powers.

Abstract: The present invention provides an apparatus, system and method for removal of interference due to multi-path for multiple transmit antennas (hereinafter referred to as MTA-MPIC) for High Speed Downlink Packet Access (HSDPA) encoded for transmit diversity, such as Space-Time Transmit Diversity (STTD). For a single receive antenna, the signal is received (25) and each multi-path delayed signal is demodulated (21). The demodulation can include long code removal and despreading. Subsequently, each demodulated signal is received by the RAKE receiver (22) for determining the channel estimate and channel normalization for the total HSDPA signal, and for computing space-time decoding for the HSDPA signal. Following the space-time decoding, a data decision is made (23). Next, reconstructed interference signals are generated (24) and combined with the received signal (25). For other user signals, an interference estimate is made from the despreader (322) outputs without applying the RAKE/space-time coding operations.

Abstract: Turbo encoder with even-odd bit interleaving for upper and lower component convolutional encoders and symbol-level interleaving after mapping to modulation symbols plus symbol-level buffer for both ARQ and Turbo decoding.

Abstract: Spread spectrum rake receiver estimates number of paths within a chip interval and assigns corresponding fingers. Cross-correlation matrix eigenvalues or direct BER estimates for differing numbers of fingers determine whether one or two fingers assigned to the group of paths within a chip.

Abstract: A wireless communication transmission channel estimation by initial data exchange to determine calibration factors to apply to tracked channel estimations from received transmissions.