Adaptive Modulation And Coding Technology Based On RC-LDPC Codes

Many new wireless link transmission technologies have been adopt, which not only meet the needs for high-speed and better QoS of users, but also satisfy the requirements for high-capacity and seamless transmission of operators in the fourth generation mobile communication systems. The new wireless link technologies consist of OFDM, MIMO, FEC, AMC, HARQ, spectrum aggregation based on cognitive radio, etc. Reliability and efficiency are two permanent problems in wireless communication systems. So how to enhance the efficiency is research topic concerned in the growing shortage of band resources based on reliability of the wireless communication system.In reliability, channel coding is an effective way to improve system performance. LDPC codes have been studied extensively in field of channel coding because of its excellent performance, simple form and low implementation complexity in recent years. In efficiency, AMC is one of link adaptive technologies which can improve the spectrum efficiency and has presently become one of the preferred technologies for mobile communication systems.In this paper, LDPC codes and AMC technologies have been studied in the 4G mobile communication systems, which have been supported for research project of "IMT-Advanced Modulation and Coding Technology". The paper is organized as follows.Chapter 1 introduces the background of study about mobile communication technology and the structure of this dissertation.Chapter 2 mainly summarizes the related research about LDPC codes and AMC technologies. Then the target of research is submitted for study about RC-LDPC (Rate Compatible-LDPC) codes and MCS (Modulation and Code Scheme) selection technologies.Chapter 3 studies the RC-LDPC codes structure. According to the inadequacy of the existing algorithms, the chapter proposes an incremental RC-LDPC code and carries out theoretical analysis and simulation.Chapter 4 studies the MCS selection algorithm. By analyzing and summarizing the MCS selection technology in existing mobile communication system, the chapter proposes a new MCS selection algorithm based on RC-LDPC codes. What is more, simulation results validate the feasibility and effectivity of the proposed algorithm.Finally, summarizes the dissertation and points out the directions for further study.