Transmitter diversity antenna selection techniques for wireless channels utilizing differential space-time block codes

Abstract

The paper deals with transmitter diversity antenna selection techniques (ASTs) for wireless channels utilizing differential space-time block codes (DSTBCs). The proposed ASTs tend to maximize the signal-to-noise ratio (SNR) of those channels. Particularly, we propose here the so-called general (M,N;K) AST/DSTBC scheme for such channels. Then, based on this AST, we propose two modified ASTs which are more amenable to practical implementation, namely the restricted (M,N;K) AST/DSTBC scheme and the (N + ¯N,N;K) AST/DSTBC scheme. The restricted (M,N;K) AST/DSTBC scheme provides relatively good bit error performance us- ing only one feedback bit for transmission diversity purpose, while the (N+ ¯N,N;K) AST/DSTBC scheme shortens the time required to process feedback information. These techniques remarkably improve bit error rate (BER) performance of wireless channels using DSTBCs with a limited number (typi- cally 1 or 2) of training symbols per each coherent duration of the channel. Simulations show that the proposed AST/DSTBC schemes outperform the DSTBCs without antenna selection even with only 1 training symbol.

Keywords

• differential space-time modulation
• differential space-time block codes
• diversity antenna selection
• MIMO