Towards Fully Optimized BICM Transceivers

TL;DR

This paper introduces a novel BICM transceiver design utilizing hierarchical constellations and multiple interleavers, resulting in significant performance improvements over traditional schemes in AWGN and fading channels.

Contribution

The paper proposes a new BICM design with hierarchical constellations and multiple interleavers, providing analytical bounds and demonstrating substantial performance gains.

Findings

Up to 3 dB gain in AWGN channel at BER of 10^{-6}

Up to 2 dB gain in Nakagami-m fading channels at BER of 10^{-7} with m=5

Analytical bounds guide the optimized transceiver design

Abstract

Bit-interleaved coded modulation (BICM) transceivers often use equally spaced constellations and a random interleaver. In this paper, we propose a new BICM design, which considers hierarchical (nonequally spaced) constellations, a bit-level multiplexer, and multiple interleavers. It is shown that this new scheme increases the degrees of freedom that can be exploited in order to improve its performance. Analytical bounds on the bit error rate (BER) of the system in terms of the constellation parameters and the multiplexing rules are developed for the additive white Gaussian Noise (AWGN) and Nakagami-$m$ fading channels. These bounds are then used to design the BICM transceiver. Numerical results show that, compared to conventional BICM designs, and for a target BER of $10^{-6}$, gains up to 3 dB in the AWGN channel are obtained. For fading channels, the gains depend on the fading parameter, and reach 2 dB for a target BER of $10^{-7}$ and $m=5$.