Resource Optimization For Centralized Cooperative Relay Network

Abstract

The wireless radio channel su ers from fading. Time varying nature of the chan- nel imposes restrictions on the achievable data rate. By e ectively transmitting or processing (semi)independently fading copies of the signal, diversity is a method for directly combating the e ects of fading. However, any type of diversity requires extra resources in the form of frequency, time or antenna. Multiple input multiple out- put systems (MIMO) has achieved higher through put suitable to cater the demands of next generation wireless applications. But MIMO requires extra hardware which makes it di cult for handhold or small wireless nodes in terms of cost, size and extra power requirement. Recently, cooperative communications have gained attentions as an emerging transmit strategy for future wireless networks. The basic idea is that the relay nodes can help the source nodes transmission by relaying the replica of the information. The cooperative communications e ciently take advantage of the broadcasting nature of wireless networks, as well as exploit the inherent spatial and multiuser diversities. To taste the avour of cooperation, it is utmost essential to attract the nodes to operate cooperatively and optimize the resources (bandwidth, power) among the sources and relays. Techniques to stimulate the cooperation by op- timizing the resources are discussed in this report. In this thesis, resource allocation is done for di erent situation like e cient allocation, fair allocation and to provide best quality of service(Qos). Simulation result shows cooperative communication provide higher data rate and also shows trade o between e ciency and data rate for di erent type of allocation.