As demand for the high rate in the next generation mobile communication system is higherand higher. How to reach the maximum network coverage and higher transmission rate under thelimited bandwidth resources has been the hot topic of research in recent years. Cooperativenetwork coding is expected to become a key technology to solve this problem. Joint channelcoding and network coding design can effectively improve the performance of cooperativecommunication system..The paper first introduces the coding and decoding principle of the low density parity checkcode (LDPC codes), and focuses on the implementing steps of two decoding algorithms andtheir performance comparison, simulation results show that the performance of soft decisiondecoding algorithm is better than hard decision decoding algorithm. The third chapter presentsthe basic principle and application of network coding and three kinds of cooperation way incooperative communication system, and probes into the performance of three kinds oftransmission mode in wireless relay channel, then gives the simulation results of bit error rateperformance under the different transmission mode.In the fourth chapter of the joint design of channel coding and network coding scheme, weput forward a network coding of the maximum likelihood decoding algorithm, the receiver usesthis algorithm to compensate and correct the received signal’soft informations so that it canobtain maximum likelihood. The chapter first introduces two existing joint design of channelcoding and network coding schemes, in view of the shortcomings for the existing schemes, thepaper introduces one joint design of channel coding and network coding scheme based on softdecision. Due to the high complexity of data processing, we proposes a new decoding algorithm,the relay node uses directly hard decision to realize the network coding, without consideringnetwork coding coding errors, but at the destination,we compensate and correct the signal.Finally through the simulation analysis and comparison show the performance of the fourschemes in cooperative relay system. |