Cooperative Relay Based Resource Allocation for OFDMA Network

Cooperative relaying is a promising technique for Long Term Evolution Advanced (LTE-A) networks to satisfy high throughput demand and support heterogeneous communication services with diverse quality-of-service (QoS) requirements. Optimal relay selection, power allocation and sub carrier assignment scheme under a total power constrain is proposed for a Qos aware resource allocation for multi user cooperative OFDMA network. The relay selection, power allocation and subcarrier assignment problem are formulated as a joint optimization problem with the objective of maximizing system throughput. User at the cell edge and shadowing degrade the signal quality, hence cooperative relaying is very promising solution to provide better throughput and coverage extension. Combining OFDMA and cooperative relaying assures high throughput enhancement for user at cell edge .Throughput enhancement problem is solved by two level dual composition and sub gradient method. To further reduce the computational cost, low complexity suboptimal schemes are also proposed in this work. Simulation result indicates that the proposed scheme will guarantee the users Qos requirement and maximize the system throughput.