Weighted Space-Time Bit Trellis Coded Modulation for Quasi-Static Rayleigh Fading Channel

Abstract: The data rate of wireless communication system can be increased by MIMO system. The BICM and Space time trellis codes are transmission schemes but their decoding complexity grows exponentially as the number of antenna increases.We used the space-time bit trellis codes instead which are a concatenation of a bit convolutional code, modulator and spatial multiplexing without interleaving. In this paper we present the concept of weighted space-time bit trellis codes. These codes are a combination of space-time bit trellis codes and ideal beamforming. It has been shown that if perfect channel state information is available at the transmitter, the performance of a space-time bit trellis coded system can be further improved by weighting the transmitted signals. In this paper, we evaluate the performance of space-time bit trellis codes combined with ideal beamforming over slow fading channels. Simulation results show that the proposed scheme considerably outperforms the conventional space-time bit trellis codes without weighting. We show simulation results for 4-QAM up to 4x4 transmit/receive antennas with a data rate of 2 bits per channel use.

Keywords: Weighted space time bit trellis codes, channel state information, beamforming, Rayleigh fading channel, MIMO.