On The Performance Analysis Of Cooperative ARQ Protocols In Relay Communications

The word'cooperate'derives from the Latin words co-and operate (to work), thus it connotes the idea of "working together". Cooperation is the strategy of a group of entities working together to achieve a common or individual goal.Cooperative nature of distributed multi-node communication resource sharing, common way for the use of distributed multi-terminal nodes in a single antenna to form a virtual multi-antenna diversity in cooperation technology solutions. It has increased connectivity and energy efficiency, improved network coverage, increased spectral efficiency and increased network capacity and so on. Cooperative ARQ protocols will extend Cooperative Communication's range from the signal processing of physical layer to the data transmission of data link layer. As the relay node's involvement, the agreement can take full advantage of multi-user cooperative spatial diversity and the time diversity and coding gain from retransmission mechanism. The performance of cooperative ARQ protocols within different communication settings and workplaces are discussed in this thesis. Based on the performance analysis methods, restrictive factors and key techniques are addressed in detail, which may provide some hints on the possible optimized and improved strategies.Firstly, the studies of the status quo at home and abroad, as well as the latest developments are reviewed. On this basis, the typical small-scaled network communications for the G/M/N model are summed up. At last, the design ideas and improved methods are given in cooperation scenarios of single-relay cooperative ARQ protocols, multi-relay cooperative ARQ protocols and cooperative broadcast ARQ protocols. Then, the thesis introduces the principles and analysis methods of C-ARQ protocols to analyze the performance of C-ARQ and H-ARQ protocols. On this basis, the paper discusses several restrictive factors of single-relay cooperative ARQ protocols. It analyzes and compares the performance of C-ARQ protocols without or with error control coding. The technology of frame combining is introduced in multi-relay cooperative communication scenario. Its numerical calculation and performance analysis are given in this thesis. Thereafter, the thesis analyzes the cooperation gain of time-division multi-user C-ARQ protocols. The constraint relationship of retransmission probability, cooperation gain and distance is discussed. It is shown that the location of the relay node will affect the achieved performance significantly. Generally, reasonable retransmission rate gain, the throughput gain together with the delay gain could be realized when the relay nodes is located at the intermediate position between source node and the destination node; however, the relay which is more close to source node will be preferable when the channel quality of the source-destination link is not good enough. Finally, under the guidance of thought in "ARQ error control", the thesis investigate the design of cooperative ARQ design with the buffer and the target frame error rate constraints with the aim of the effective use of the transmitter channel state information. The joint AMC and ARQ design, the signal noise ratio assisited design as well as the buffer-assisted design are discussed and compared as well.The analysis in this thesis is a good reference for the performance analysis and optimized design of cooperative ARQ protocols.