On the Decoding and Optimizing Performance of Four-Group Decodable Space-Time Block Codes

A class of rate-one space-time block codes (STBC) allowing the decoding of transmitted symbols into four groups is recently proposed by Yuen, Guan and Tjhung. This code is called four-group decodable STBC (4Gp-STBC). In this paper, the equivalent channel of 4Gp-STBC is derived and a new method to decode 4Gp-STBC based on sphere decoders is presented. Furthermore, the performance of 4Gp-STBC is analyzed. A New signal rotation method is proposed, which performs better than the existing one.