Transmit Antenna Selection for Linear Dispersion Codes Based on Linear Receiver

In an effort to utilize the advantage of using multiple antennas, transmit antenna selection for linear dispersion codes (LDC-TAS) is proposed in this paper. We present three criteria: maximum channel gain, maximum capacity and max-min post-SNR, for selecting the optimal transmit antennas when linear, coherent receiver is used over a slowly varying channel. Simulation results suggest that the max-min post-SNR criterion outperforms the other selection methods in a variety of modulation modes, such as QPSK, 8PSK and 16QAM. Compared with BLAST-TAS, under the same spectral efficiency, LDC-TAS shows significant diversity advantage. In low SNR environment, LDC-TAS is still better than STBC-TAS

I. Introduction

Multiple-input multiple-output (MIMO) systems can offer significant capacity gains over traditional single-input single-output (SISO) systems [1]. Practical modulation schemes for MIMO systems with receive-only channel knowledge fall principally into two areas known as diversity and multiplexing [2]. Space-time coding, such as the space-time trellis codes [3] and space-time block codes [4], uses specially designed codeword that maximize the diversity advantage or reliability of the transmitted information. Recognizing that orthogonal space-time block codes [3], designed to maximize diversity advantage do not achieve full channel capacity in MIMO channels, Hassibi and Hochwald [5] proposed the revolutionary linear dispersion codes (LDCs). And Robert W. Heath [6] introduced a family of LDCs designs based on frame theory, which guarantees good performance in terms of diversity advantage.