A Study On Cooperative Relay Technology In Cooperative Communication Networking

In wireless communication systems, the connection reliability and high data-rate communication are important indicators of performance. Due to multipath fading, shadowing and path loss effects, the channel quality in time, frequency and space will generate random variations, leading to the decline in the quality of wireless communications. At present, by sending and receiving of diversity technology, the wireless communication system can achieve spatial diversity gains, and get a reliable high data-rate communication. For example, in a multi-input multi-output (MIMO) systems, the wireless communication terminals are embedded multiple antennas to achieve spatial diversity gain. However, the size and cost of wireless devices limit for many applications, e.g., in sensor networks or for cellular phones, placing multiple antennas on a single terminal may not be practical. In this case, cooperating with other nodes in the network to form a distributed antenna system becomes a desirable and promising alternative, underling the premise of effective cost control to achieve reliable high-speed communications.Cooperative communication networks allow users to cooperate through the different Relay-Cooperation Technology, to relay each other’s messages to the destination. Because users who consume a certain amount of resources, and the size and cost of wireless devices, mobile devices such as energy, bandwidth, processing power and storage capacity resources are limited for many applications in wireless communication systems. Therefore, the users for own interests, tend to broadcast own messages to other users and refuse to relay the messages of other users. As the "free rider", our works focus on how to design a relay protocol to coordinate the cooperative behavior of users who emerging in the system. And in the process of evolution game, we will design a user to learn the update mechanism to ensure the high quality of communications delay and overhead of the relay in the process of cooperation. Our works show that it is a basis of the key indicators of reliability, transmission rate, throughput, communication delay and energy consumption in the future wireless communication networks. It will have the important practical significance.In this paper, we complete the following aspects: First, we analysis the ways of relay technique in the cooperative communication, the network structure of multiuser cooperative system and the current incentive relay cooperation mechanism. Basing on the cooperation and competition for multi-relay users, we put forward the method of evolution game on the networks in this paper.Next, because the role of relay users often as "free-rider" in the cooperative communication, we propose a punishment mechanism on the complex grid networks. In our model, punisher will punish the defector with the fine, and also consume a certain amount of communication resources, that is cost. Monte Carlo simulation experiments show that moderate consumption of resources and beyond a certain threshold of punishment, cooperative behavior of relay emerge and maintain, and the evolution system evolve the three strategies coexisting in the cooperative communication networks.Finally, as the aspiration-based leaning of relay user, we propose an aspiration-based leaning model in the complex network. The model emphasizes the relay user in each round of the evolution game compare with the certainty aspiration value. If the value of practical value beyond the certainty aspiration value, user will remain the original game strategy, in turn, transfer to others strategies with a certain probability of selection neighbors’ strategy. Monte Carlo simulation experiments show, in value of intermediate aspiration value, relay cooperation behavior reinforce in a high frequencies. And in the high aspiration value, cooperation behavior will increse in the cooperative communication networks.