Rate matching and channel interleaving for a communications system

A method of and apparatus for matching a rate of data bits, in a matrix of data bits interleaved by a predetermined interleaving process (50, 53, 62), to a desired rate by deletion of redundant data bits or repetition of data bits derived from the matrix, includes steps of determining (70) in a non-interleaved matrix of the data bits a pattern of bits to be deleted or repeated to provide the desired data rate, decoding (72) an address of each bit in said pattern in a manner inverse to the interleaving process to produce a respective address of the bit in the matrix of interleaved data bits, and deleting or repeating (76) the respective bit in the interleaved data bits in dependence upon the respective address. The address decoding is performed in the same manner as a coding (53) of addresses for producing the interleaved data bits from the non-interleaved matrix of the data bits. Also disclosed is an advantageous interleaving process for channel interleaving in a 3rd generation CDMA wireless communications system, a shuffling method for a second stage of interleaving in such a system, and how the rate matching can be conveniently applied to turbo-coded data coded.