Abstract: The invention relates to a transmitter comprising: means (304) for arranging information bits in an information matrix; means (304) for encoding rows of the information matrix for generating a base code matrix; means (304) for generating a parity check row for the base code matrix to obtain an extended code matrix; means (304) for shifting predetermined rows of the extended code matrix with respect to a preceding row in a predetermined way and generating a following parity check row for obtaining a following extended code matrix in such a way that there are more than two parity check rows in the following extended code matrix; and means (304) for derotating the rows of the following extended code matrix for generating a multiple parity code matrix.

Abstract: A flexible solution for turbo equalization is provided. According to the solution, the turbo equalization process is divided into an inner loop equalization process and an outer loop decoding process. Consequently, it is not necessary for each equalization process to be followed by a decoding process. Thus, equalization based soft information on the transmitted data symbols may be updated more frequently than decoding based soft information.

Abstract: A method for use by a receiver of a wireless communication system in providing information of use in adapting to changing characteristics of a communication channel (22) over which the receiver (23) receives a signal at an offset from a carrier frequency due to changes in the characteristics of the communication channel characteristics, the changing communication channel characteristics also causing from time to time changes in other characteristics of the communication channel (22), the method characterized by: a step (23b-1a 23b-1b) of providing expectation maximization estimates of autoregressive parameters representing the changing communication channel (22) using received signal samples extracted from the received signal and corresponding to transmitted pilot symbol; and a step (23b-1a 23b-1c) of providing an estimate of the channel impulse response and an estimate of a frequency offset of at least one multipath signal based on the estimated values of the autoregressive parameters.

Abstract: A method for use by a receiver of a wireless communication system in providing information of use in adapting to changing characteristics of a communication channel (22) over which the receiver (23) receives a signal at an offset from a carrier frequency due to changes in the characteristics of the communication channel characteristics, the changing communication channel characteristics also causing from time to time changes in other characteristics of the communication channel (22), the method characterized by: a step (23b-1a 23b-1b) of providing expectation maximization estimates of autoregressive parameters representing the changing communication channel (22) using received signal samples extracted from the received signal and corresponding to transmitted pilot symbol; and a step (23b-1a 23b-1c) of providing an estimate of the channel impulse response and an estimate of a frequency offset of at least one multipath signal based on the estimated values of the autoregressive parameters.