Collaborative Communication Relay Node Selection And Ergodic Capacity Study

Relay technology can greatly expand the service area andenhance the system performance since it adds relay nodes at thecellular system. It has become the key technology in LTE-A in recentyears. Different technologies are required in different communicationsituations. In this paper multi-user relay node selection strategy andergodic capacity of multi-antenna (MIMO) relay system have beenstudied. The amplify-and-forward mode, decode-and-forward mode,code-and-forward mode are among the important cooperativestrategies. Because the traditional relay selection methods areaccording to the throughput gain of the system. They cannot balancebetween the throughput gain of the system and the BER of the system.For each mobile user both location information and the throughputgain of the system are taken into account in this paper. The theoreticalanalysis and numerical simulation show that relay selection in this waycan improve both performance of the through-put gain of the systemand BER of the system. In order to improve the throughput, theallocation of power resource which uses convex optimization isresearched in this paper. In order to increase the ergodic capacity ofMIMO relay systems. The closed-form solution of capacity is given in thispaper when the multi-antennas system adopts decode-and-forwardmode. Random matrix theory is used in the theory analysis of ergodiccapacity. Monte Carlo algorithm is used in the numerical simulation formulti-antennas relay system. Compared with the ergodic capacity ofMIMO relay system adopting amplify-and-forward, MIMO relay systemadopting decode-and-forward upgrade ergodic capacity. The model,methods and results provide a reference for the next generation ofmobile communications.