Quasi-orthogonal Space-Time Block Codes for Four Antenna

This paper analyzes the structure and characteristics of several types of quasi-orthogonal space-time block codes (QSTBC), and proposes two novel methods of QSTBC for four antennas to enrich the family of QSTBC. Experiment results indicate that, while the decoding complexity is the same as other quasi-orthogonal codes, the two new QSTBC approaches achieve good performance as TBH and Jafarkhani cases. This paper proposes a zero forcing (ZF) decoding algorithm for new QSTBC. Simulation results indicate that ZF algorithm possesses good performance and can reduce the complexity of decoding.