Abstract: Methods and receivers are described for receiving data transmitted over a radio communications channel wherein the data is transmitted as a plurality of sequential symbols wherein each sequential symbol is determined as a function of a previous symbol and a respective differential symbol corresponding to a portion of the data being transmitted. In particular, a plurality of received segments are sampled wherein the received segments correspond to respective ones of the transmitted symbols, and an initial differential MAP symbol estimation is performed for estimated received symbols corresponding to the sampled received segments to provide initial estimates of the differential symbols. New received symbol estimates are calculated using the initial estimates of the differential symbols, and a subsequent differential MAP symbol estimation is performed using the new received symbol estimates to provide improved estimates of the differential symbols.

Abstract: Methods and systems are provided for processing a received signal including receiving the signal to provide a sequence of symbols associated with the received signal in respective ones of a plurality of symbol positions. A known block of the sequence of symbols containing known symbol values and an unknown block of the sequence of symbols containing unknown symbol values are identified. A desired demodulation type is determined for use in demodulating the unknown block based on the known symbol values. An interferer signal characteristic discontinuity location in the unknown block is detected.

Abstract: A pulse-shape estimator calculates an impulse response for the transmit and receive pulse-shaping filters in a mobile wireless terminal. The pulse-shape estimator receives a training signal that has passed through the pulse-shaping filters and known training symbols. Based on the actual received signal containing the training symbols and the expected received signal, the pulse-shape estimator estimates the impulse response of the pulse-shaping filters. The calculated impulse response may be used to improve signal demodulation or to calculate the coefficients for a digital filter applied before demodulation to compensate for pulse-shape distortion.

Abstract: Methods of demodulating a received signal are disclosed in which an interference map containing information regarding a plurality of candidate co-channel interference sources is provided. The information in the interference map regarding the plurality of candidate interference sources may be used to identify any of the candidate co-channel interference sources that comprise a dominant interference source. The received signal may then be demodulated in a manner that cancels at least part of the contribution of any identified dominant interference source by using the information regarding any such interference source contained in the interference map.

Abstract: A digital radio communication system includes processing to jointly mitigate the deleterious effects of fading, time dispersion and interference using interference rejection and diversity combining. The system employs a selection processor for preliminarily reducing the number of signals for interference rejection and diversity combining based on one or more criterion. The system accommodates signals from dual polarized antennas. In one particular embodiment, the system performs interference rejection and diversity combining by separating a received signal into its in-phase and quadrature components.

Abstract: In a communications system wherein a broadcast signal is received by a plurality of antennas each connected to a receiver, the resulting plurality of received signals are jointly subjected to automatic frequency correction (AFC) before interference rejection combining (IRC) or maximal ratio combining (MRC) processing to output an estimate of the broadcast signal. The joint automatic frequency correction processing involves computing and applying a frequency offset on a sample by sample basis to each of the received signals to output corresponding frequency corrected received signals for IRC or MRC processing.