Pilot‐aided 1 × 2 and 2 × 2 space‐time line code systems with transmit antenna selection

Abstract

SummaryThe space‐time line code (STLC), which has been recently proposed in the literature, assumes fully known channel state information at the transmitter and not the receiver. However, the effective channel gain is still required at the receiver to coherently detect ‐ary quadrature amplitude modulation ( QAM) symbols. In this paper, we propose pilot‐aided STLC systems, which do not require the effective channel gain at the receiver to detect the QAM symbols. In order to further improve the error performance of the proposed schemes, we present the pilot‐aided STLC systems with transmit antenna selection (TAS). Using a more direct and simpler approach, we derive the average symbol error probability (ASEP) of the coherent STLC systems with TAS, which represents the lower bound of the pilot‐aided STLC systems with TAS. For comparison, in a similar manner, we also derive the ASEP of the coherent STLC systems without TAS, which represents the lower bound of the pilot‐aided STLC systems. For pilot‐aided STLC systems with TAS, the gap between the simulated symbol error rate (SER) and the derived theoretical ASEP lower bound is very small. For a given number of transmit antennas, the simulated SER and theoretical ASEP also show that the error performance of the pilot‐aided STLC systems with or without TAS is superior to the pilot‐aided STLC systems with TAS by at least 1.8 dB.