4 × 4 Perfect space-time code partition

In this paper, we partition the 4 times 4 perfect code in order to increase the minimum determinant between codewords, and hence improve the performance in slow fading channels. Using construction A at the encoder, we construct the lattices corresponding to perfect code subcodes at different levels of the partition chain, and we find the convenient binary codes. This partition is made in the same manner as for golden code. We propose also a new decoder, based on stack decoder, which is valid for partitioning schemes. It achieves ML performance with significantly reduced complexity. Suboptimal versions are presented to reduce furthermore the complexity.