A new non-orthogonal space-time code with low decoding complexity

A full diversity block space-time code over two transmit antennas and two symbol periods is introduced. In this method, each code is equal to the addition of two matrices; A^m and DAⁿ, where A and D are the two constant matrices and m and n are the two data symbols. A is selected such that the set A^m, 0 ≤ m ≤ 2^b - 1 is closed under the matrix multiplication. This structure allows a simple maximum likelihood (ML) decoding method, and at the same time, simplifies the optimization of the coding advantage. Simulations show that the performance of the new code is very close to that of the Damen code (M. O. Damen et al., 2002) which is the best known block space-time code in terms of the coding advantage. Moreover, the decoding complexity of the proposed method is significantly lower than that of the Damen code.