Research On The System Of Joint Coded Modulation Diversity With Iterative Demodulation/Decoding

In the wireless communication system, the central issue is to use the limited radio spectrum resources to ensure better transmission reliability and effectiveness. For wireless channel, channel coding and modulation techniques have been more and more important. Therefore, efficient coding and modulation scheme, and joint demodulation iterative decoding techniques have the advantages on spectrum efficiency, complexity, and resistance to fading.Bit Interleaved Coded Modulation with Iterative Demodulation/ Decoding is a coded modulation scheme to effectively improve the transmission efficiency of wireless channel. Its low complexity, flexibility, high spectrum efficiency, good performance and other characteristics have drawn widespread attention on the development of next generation of wireless mobile communication.BICM-ID combines coding and modulation techniques to resist to fading by the interweaving technology. While, it can improve the performance of BICM systems by iterative demodulation and decoding. Wireless mobile communications have other factors such as inter-symbol interference, limited bandwidth and power. Meanwhile, it has Doppler shift, which is significant to the reliability of digital communication. Diversity technique is an effective way to against multipath fading, such as the well-known modulation diversity.Based on the above conlustion, this paper researches on the BICM-ID system and the modulation diversity technique. This scheme of Joint Coded Modulation Diversity with Iterative Demodulation/ Decoding (JCMD-ID), can obtain coding and diversity gain. The method utilizes the characteristic of time diversity and modulation diversity, which can resist types of interference in fading channel and improve the performance of communication system. What's more, we introduce OFDM technology to JCMD-ID system, and utilize frequency diversity to meet the needs on high-speed transmission in complex fading channel.