Transmit Antenna Selection for Space–Time Line Code Systems
Seung-Chan Lim, Jingon Joung
Abstract
In this study, we consider a space-time line code (STLC) system with N transmit antennas and two receive antennas. Although the STLC system is scalable to an arbitrary number of transmit antennas, a large number of them will increase the hardware cost and complicate the implementation of the system. To resolve this practical limitation, we propose a transmit antenna selection (TAS) scheme for the N-by-2 STLC system. If S ≤ N antennas are used for the transmission, the STLC transmitter selects the S antennas such that the instantaneous signal-to-noise ratio (SNR) is maximized. For a comprehensive performance analysis, the instantaneous SNR of the proposed TAS is characterized in terms of the statistical mean and moment-generating function (MGF). To investigate the performance of the proposed TAS approach, the approximated expression of error rate is derived based on the MGF method. Moreover, using asymptotic analysis, we show that the proposed TAS-STLC system achieves full spatial diversity of 2N, while the coding gain is affected by N, S, and the modulation order. As a special case, we also provide a mathematical analysis of the error rate of the conventional STLC system when N = S.