Abstract: A vehicle or other mobile communication entity (102) locates objects using received (typically radio frequency) signals (104, 106). These received signals included multi-path versions of the transmitted signals (104). The received signals may include packets having location information of the transmission source. The receiving vehicle may track, or know, its own position. The receiving entity may determine properties for a multi-path version of the signal (208, 210). These properties may include a delay, a Doppler and an angle of reception (122, 124) for one or more multi-path versions of the received signal. The receiving entity may also measure an imbalance (504) induced between a pair (or more) of antenna elements (302) for a particular multi-path version of the signal received. This imbalance may be dependent on the angle of arrival of the particular signal being received.

Abstract: A vehicle or other mobile communication entity (102) locates objects using received (typically radio frequency) signals (104, 106). These received signals included multi-path versions of the transmitted signals (104). The received signals may include packets having location information of the transmission source. The receiving vehicle may track, or know, its own position. The receiving entity may determine properties for a multi-path version of the signal (208, 210). These properties may include a delay, a Doppler and an angle of reception (122, 124) for one or more multi-path versions of the received signal. The receiving entity may also measure an imbalance (504) induced between a pair (or more) of antenna elements (302) for a particular multi-path version of the signal received. This imbalance may be dependent on the angle of arrival of the particular signal being received.

Abstract: In one embodiment, the present invention is a method for reducing the peak-to-average power ratio (PAPR) of a multi-carrier modulated symbol, such as an orthogonal frequency division multiplexed (OFDM) symbol. The method first transforms a set of data symbols into a multi-carrier modulated symbol. The method then uses the multi-carrier modulated symbol and a gradient-descent algorithm to generate a set of symbols for PAPR-reduction tones. The data symbols and the PAPR-reduction symbols are then transformed to generate an updated multi-carrier modulated symbol. The PAPR-reduction symbols are iteratively updated until a terminating condition occurs (e.g., an acceptable PAPR is achieved for the multi-carrier modulated symbol).

Abstract: Methods and apparatus are described for processing data in a wireless communication network. Iterative estimation techniques are used to enable tracking of time-varying communication channels. A signal is transmitted over a channel in the network, the signal comprising a sequence of symbols carried on a plurality of sub-carriers. Boot-up estimator (304) estimates, in a time domain, parameters of a model of the channel based on the received signal. A domain converter (206) transforms at least one of the estimated parameters from the time domain to provide at least one transformed parameter in a second domain. An equalizer (210) and decoder (212) determine estimates of symbols from the received signal using the at least one transformed parameter, and tracking estimator (314) updates the estimated model parameters during reception of the signal using at least one estimated symbol.

Abstract: In one embodiment, the present invention is a method for reducing the peak-to-average power ratio (PAPR) of a multi-carrier modulated symbol, such as an orthogonal frequency division multiplexed (OFDM) symbol. The method first transforms a set of data symbols into a multi-carrier modulated symbol. The method then uses the multi-carrier modulated symbol and a gradient-descent algorithm to generate a set of symbols for PAPR-reduction tones. The data symbols and the PAPR-reduction symbols are then transformed to generate an updated multi-carrier modulated symbol. The PAPR-reduction symbols are iteratively updated until a terminating condition occurs (e.g., an acceptable PAPR is achieved for the multi-carrier modulated symbol).

Abstract: Methods and apparatus are described for improving receiver performance in a multicarrier communication network in which an encoded symbol (250) is transmitted over a transmission channel (20) in the communications system. A model of the transmission channel (20) is estimated (718, 760), said model characterising an effect of intercarrier interference on at least one carrier in the multicarrier system. The received symbol (250) is decoded (720, 762) using the estimated model to remove a predicted effect of intercarrier interference. A pre-processor (40) is also described for operation in conjunction with a communications receiver (30) in the network. The pre-processor (40) includes a channel estimator (42) operable to estimate at least one feature of the communication channel based on a received signal. The pre-processor (40) modifies the received signal dependent on the at least one estimated feature and provides the modified signal to the communications receiver (30).

Abstract: A data processing device (100, 300) is described forming part of a receiver for a multicarrier communications system. The data processing device is configured to process at least one observed symbol to generate an information bit estimate for the symbol, and includes a channel prediction stage configured to receive an observed symbol and at least one feedback signal representing an estimate of a transmitted symbol and to generate a channel prediction. At least one initial processing stream (104) is configured to process the observed symbol on the basis of a channel prediction calculated at a respective time by the channel prediction stage and to output a signal representing an estimate of a transmitted symbol corresponding to the observed symbol for feed back into the channel prediction stage.