Fast Relay-node Selection And Optimal Power Algorithm In MSMR Communications System

Multipath fading and noise are the key factor which cause the low QoS of communication.Cooperative communication can build a virtual MIMO system to get diversity gain.Cooperative communication with distributed transmission can transmit far,extend coverage range,improve capacity and spectrum utilization ratio.Due to high complexity of the relay node selection and optimal power algorithm in MSMR system,we have proposed the fast relay-node assignment(FRA)and Optimal Capacity Algorithm(OCA)to reduce the system complexity,and we also designed optimal power assignment(OPA)algorithm to improve system capacity.The main research contents of this paper are as follows:(1)For the higher complexity,the lower spectrum utilization ratio and longer timedelay in relay-node selection algorithm,we proposed FRA algorithm to reduce the complexity and improve spectrum utilization ratio.Then,we gave OCA scheme to improve system capacity.The simulation results are shown that the FRA can reduce complexity compare with ORA algorithm and the OCA scheme can improve system capacity.(2)In MSMR system,if there are many source nodes or a small amount of relay nodes or the poor ICSI of part relay nodes,it will lead to bigger capacity range.We designed OPA algorithm to maximize the minimum system capacity.The simulation results are shown that the OPA algorithm can reduce the capacity range for each SSMR compare with the EPA algorithm,and the effectivelyis more obvious with the increase of the number of relay nodes.