Resource Allocation In Wireless Relay System

As one of the key technologies of next generation wireless communication, Relay Technology can effectively expand communication scope and increase the transmission rate of edge users. However, the relay node introduced into the traditional cellular communication systems brings a big challenge for resource allocation. So the research of resource allocation is becoming more and more important. Current researches show that resource allocation could effectively improve the system throughput and reduce the system outage probability and total consumption power. Based on this consideration, we study resource allocation schemes by optimizing the system outage probability and the consumption of total power in different configuration of wireless networks. Then, for multi-user relay network, we propose two new scheduling solutions.In second chapter, under enhanced and selective relay strategy of relay transmission modes, we give the system outage probability expression in single-user single-relay communication systems under enhanced and selective relay strategy of relay transmission. We give the optimal relay node location by optimizing the outage probability. Finally, simulation results match the theoretical one well. Both of them show that when non-coherent ratio combining is used by the target nodes, the optimum relay node should be located in the middle of the path.The third chapter, we study the resource allocation scheme of the target node configured multiple antennas and single antenna, respectively. First for single-antenna target node system, we minimize the total system power consumption by given the goal system outage probability under unknown channel information between relay and destination. We give the resource allocation scheme in two kinds of different relay selection strategies.Then we analyze simulation results in different scenarios. We find that if the relay node is close to the source, multiplerelays cost less power consumption than single relay. By constrasties, single relay costs less power consumption than multiple relays when the relay node is far away from the source. Then, we utilize the power allocation to minimize the outage probability of the dual-hop DF relay system with multiple destination antennas based on the given strategy of relay selection. Then we discuss the relation of the number of destination antennas on the outage probability. We also find that the fraction of the power allocation between source and relay is relevant to the number of the destination antennas.Finally, we study resource scheduling for multi-user Orthogonal Frequency Division Multiplexing (OFDM) relay system. In the wireless communication system, multi-user scheduling is an important problem. Proportional fair resource scheduling algorithm has been widely used in the scheduling for cellular systems. But for the relay system, a new relay scheduling algorithm needs to be considered. In this chapter, we study resource scheduling for the OFDM relay system. We present two different resource scheduling schemes. Both of them consider the transmission efficiencies and the fairness between the relay users and direct users. Then we compare the proposed schemes with the existed scheme and find the proposed performs better than the existed one.