An Enhanced Opportunity Relay Cooperative Scheme Which Is Improved Based On Decoding Forward

In recent decades, the collaborative communication technology has been widelyapplied in the field of wireless communications. In essence, cooperative communicationcan be viewed as a generalized MIMO concept. it is a collaboration technology whichmade the end user obtain spatial diversity by constituting a virtual antenna array. Since theconcept of cooperative communication, relay cooperation schemes have been the hotspot,which includes the selection of the relay nodes, the timing and selection of thecollaboration agreement and cooperation. This paper studies the relay cooperative protocoland relay collaboration solutions, The work done in this paper is as follows.This paper presents an enhanced opportunity relay cooperative scheme which isimproved based on decoding forward. Firstly, it introduced five common relaying protocolwhich have been compared and analysis. The analysts reveal that comparing to otherprotocols the AF and DF protocols are simple and easy to implement，and comparing toAF,DF has the advantage of decrease relay for additive. In order to verify the DF canmake the performance of the system better, a simulation had been done about thetheoretical bit error rate and actual error rate on two ways. Finally, the simulation resultsshow that DF cooperation model has lower error rate than the AF collaboration model.Secondly, it studied several relay selection program based on DF cooperative mode,these programs focus on opportunistic relaying based on instantaneous channel stateinformation. But the opportunistic relay may conflict and cause the relay selection failedduring optimal relay node selection. And opportunistic relaying with fixed retransmissionstrategy reduces the spectral efficiency and data rate system. In order to solve these twoproblems, it presents an enhanced opportunity relay cooperative scheme which isimproved based on decoding forward. This scheme which reduces the collision probabilityduring relay selecting combines the improved opportunistic relay with the enhanced relay. Through the simulation, the new scheme reduced the outage probability and improved thespectrum efficiency and data rate of the system.