The Research Of Network Coding And Resource Allocation Of Wireless Cooperative Communication

The multi-path fading of wireless channel is the main factor that influences the hightransmission rate and high quality of service of the next generation wireless communication system.Multiple Input Multiple Output technology, as one of the key technologies of the next generationwireless communication system, has a great effect to overcome the radio channel multipath fading.However, it is difficult to realize Multiple Input Multiple Output in the uplink, which is due to theconstraints of the mobile station’s power consumption, size and so on. Therefore, one called as"virtual" Multiple Input Multiple Output cooperative communication technology has been proposed.This technology allows multiple single-antenna terminals to share the antennas with each other toacquire spatial diversity gain, which effectively improves the system capacity and transmissionperformance. Network coding, which is first used in cable network, and later is also graduallyapplied in wireless communication system due to its advantages of improving system throughput ,balancing network load and so on. The combination of network coding and cooperative diversitytechnology has become a hotspot of current research. Wireless communication system is a systemwith limited resources, so the question that should be considered is how to further improve theperformance of the system with the limited resources. In order to improve the utilization rate ofresources, this paper mainly studies network coding cooperative communication system, and themain contents and the innovations of this paper are as follows:Firstly, this paper researches the basic network model and the forwarding protocol ofcooperative communication system, analyzes the performance of the forwarding protocol andsimulates the performance, and introduces the network coding. The simulation performance of theforwarding protocol shows that, incremental amplification relay protocol has the best performance,while decoding forwarding protocol has the worst performance.Secondly, this paper also researches the principle of the linear network coding, analyzesperformance of linear network coding cooperative communication system and simulates theperformance. The simulation results show that network coding not only improves systemthroughput, but also improves reliability of the system. Although network coding cooperativecommunication system has the advantages of improving system availability and reliability, the relaynodes of the current network coding cooperative communication are based on a fixed forwarding,that is, all relay nodes will be involved in forwarding. For the two-source network codingcooperative communication systems, if both of the direct passing pathes or neither of them aresuccessful, it is no longer necessary for the relay node to forward the data through network coding. Based on this, a new cooperative mechanism, while is Network coding - incremental relaying, isproposed. This paper explains the principle and process of the algorithm, analyzes the performancefrom the standpoint of the outage probability and resource consumption, and simulates itsperformance. Simulation results show that, the algorithm saves system resources and improvesresource utilization without affecting system performance.Finally, aiming to the problem of that network coding cooperative communications system forresource optimization are based on one-dimensional resource optimization, this paper carries ontwo-dimensional resource optimization for cooperative communication system of two sources-onerelay-one target, including the traditional two-source cooperative communication system andnetwork coding cooperative communication system. Two system models of cooperativecommunication systems are presented and channel capacity is derived. This paper also makes theoptimal allocation of resources and simulation analysis respectively from the power optimization,bandwidth optimization, joint power and bandwidth optimization. The simulation results show thatthe optimization for resources can further improve the system performance, and joint power andbandwidth optimization can make the performance of the system to achieve the optimal.