Bit-Wise Detection Algorithms for V-BLAST Systems

The Vertical Bell Laboratories Layered Space-Time (V-BLAST) scheme achieves very high spectral efficiency while maintaining low implementation complexity. There have been great efforts focusing on the V-BLAST detection algorithms. However, all these algorithms concentrate on the symbol-wise detection. In this paper, a bit-wise V-BLAST detection algorithm is proposed based on the fact that the bits in one modulation symbol may have different reliabilities depending on their mapping methods. This new algorithm regards bit, rather than symbol in traditional algorithms, as the minimum process unit to do the interference nulling, canceling and ordering. Considerable performance gains are achieved over the symbol-wise detection algorithms, which are demonstrated by simulations. Also, two simplified algorithms are proposed to reduce the computation complexity.