摘要
This paper proposes a novel mapping scheme for bit-interleaved coded modulation with iterative decoding(BICM-ID).The symbol mapping is composed of two QPSK with different radiuses and phases,called cross equalization-8PSK-quasi-semi set partitioning(CE-8PSK-Quasi-SSP).Providing the same average power,the proposed scheme can increase the minimum squared Euclidean distance(MSED)and then improve the receiving performance of BICM-ID compared with conventional symbol mapping schemes.Simultaneously,a modified iteration decoding algorithm is proposed in this paper.In the process of iteration decoding,different proportion of the extrinsic information to the systematic observations results in distinct decoding performance.At high SNR(4~9dB),the observation information plays a more important role than the extrinsic information.Simulation results show that the proportion set at 1.2 is more suitable for the novel mapping in BICM-ID.When the BER is 10^(-4),more than 0.9dB coding gain over Rayleigh channels can be achieved for the improved mapping and decoding scheme.
This paper proposes a novel mapping scheme for bit-interleaved coded modulation with iterative decoding （BICM-ID）. The symbol mapping is composed of two QPSK with different radiuses and phases, called cross equalization-8PSK-quasi-semi set partitioning （CE-8PSK-Quasi-SSP）. Providing the same average power, the proposed scheme can increase the minimum squared Euclidean distance （MSED） and then improve the receiving performance of BICM-ID compared with conven- tional symbol mapping schemes. Simultaneously, a modified iteration decoding algorithm is proposed in this paper. In the process of iteration decoding, different proportion of the extrinsic information to the systematic observations results in distinct decoding performance. At high SNR （4 -9dB）, the observation information plays a more important role than the extrinsic information. Simulation results show that the proportion set at 1.2 is more suitable for the novel mapping in BICM-ID. When the BER is 10-4, more than 0.9dB coding gain over Rayleigh channels can be achieved for the improved mapping and decoding scheme.
基金
Supported by the Key Project of Chinese Ministry of Education(No.106042)
the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry(2007[24])
