Wireless MIMO/CDMA receiver generates soft bits for plural candidate vectors derived from an initial candidate determined using lattice reduction

The invention is used in wireless system such as MIMO and CDMA with a lattice reduction aided receiver. The system derives an estimate of the channel response matrix, this is then translated into a reduced lattice matrix which is applied to the received signal to equalise it. An initial candidate vector for the transmitted signal is determined in this reduced basis. A group of candidate transmitted signal vectors is then derived by applying multiple mappings to this initial vector. A soft bit LLR value is then derived for the initial candidate vector using the Euclidean distance between the candidate and the received signal vector. The LLRs of the group of candidate vectors is then derived using the Euclidean distance of the initial candidate vector, the norms of column of the reduced lattice matrix and the vector product of the Euclidean distance and columns of the reduced lattice matrix.