The Effects of Signal Mappings to the Performance of a BICM-ID System Based on 8PSK Constellation Operating over a Rayleigh Fading Channel

Abstract

Bit Interleaved Coded Modulation (BICM) was first suggested to improve the performance of Trellis Coded Modulation (TCM) over Rayleigh fading channels. It was shown that BICM with Iterative Decoding (BICM-ID) can be used to provide excellent performance over both gaussian and Rayleigh fading channels. The transmitter of BICM-ID system consists of three serially concatenated blocks which are, a convolutional encoder, a bit interleaver and a binary mapping function which maps blocks of coded bits to signal constellation points. It has been shown that when signal constellation, bit interleaver and convolutional encoder are fixed, signal mapping has a critical influence to the system's error performance. This paper studies the effects of signal mappings to the performance of a BICM-ID system using 8PSK constellation operating over a Rayleigh fading channel. The Bit Error Rate (BER) curves are used to determine the most attractive mapping. Simulation results for different mappings are also provided and discussed.