Performance Analysis and System Design for Hierarchical Modulated BICM-ID

Abstract

Hierarchical modulation (HM) enables unequal priority transmissions using a signal constellation of non-uniformly spaced constellation points, which is an important property for broadcast systems. Using bit interleaved coded modulation (BICM) and iterative decoding (ID), the performance of HM systems can be further improved. In this paper, we study HM system with BICM-ID or HM-BICM-ID. Since the performance of BICM-ID depends on signal mapping rules, we derive a mapping rule based on distance properties to minimize the bit error rate (BER). Furthermore, we perform the BER performance analysis for HM-BICM-ID based on binary erasure channel (BEC) modeling, which provides BER prediction without time-consuming simulations. Based on the derived BER prediction scheme, we can also perform system design and optimization for applications of HM-BICM-ID. For example, we are able to optimize the constellation priority parameter in a broadcast system to maximize the throughput.