A New Multi-dimensional Mapping of QPSK Constellation for BICM-ID Systems

In this paper, a new multi-dimensional mapping of QPSK constellation is proposed to improve the performance for bit interleaved coded modulation with iteratively decoding (BICM-ID) systems. Based on analyzing the relationship between Hamming distance and Euclidean distance of QPSK symbols, we find that the Euclidean distance between that pair of signals whose labels differ only in one bit is obtained from Hamming distance, and it takes the Hamming distance as rule of designing and optimizing multi-dimensional mapping of QPSK constellation and gives the search steps and result of multidimensional mapping. Analysis and simulation results show that the new scheme achieves the better performance than the conventional two-dimensional and multi-dimensional mapping of QPSK constellation at high SNR in BICM-ID systems.