Two adaptive diagonalization method for Double STTD system

Abstract

In this paper, we deliver the diagonalization methods for the single user and multi-user D-STTD (Double Space Time Transmission Diversity) system. A single user D-STTD system is that one transmitter sends four streams to one receiver and a multi-user D-STTD system is that one transmitter sends four streams to two receivers. In the two scenarios, we utilize the special structure of HHH of D-STTD system and split the precoding matrix W as W1W2 with known channel knowledge in the transmitter: at first, the anti-diagonal sub-matrix of HHH has been diagonalized by W1; in the second, the leaving element of symmetric structure matrix (HW1)HHW1 has been diagonalized by W2 through SVD or GSVD. Furthermore, the adaptive antenna shuffling has been introduced into multi-user D-STTD system to improve performance. Our methods in two systems all have significant performance gain which are proved by the simulation results: in the single user D-STTD system, our method has the same performance as SVD method and no special operation is needed in receiver; in the multi-user D-STTD system, our method has almost 2.0dB gain than no precoding method.