Throughput and QoS improvement via fixed relay station cooperated beam-forming

Throughput and quality-of-service (QoS) over multicell environments are two of the most challenging issues that must be addressed when developing next generation wireless network standards. Currently, multiple-input/multiple-output (MIMO), inter-cell coordination and multi-hop relay technologies are viable options for improving channel capacity or coverage extension. Nevertheless, severe QoS degradation occurs in the outer region of multi-cells due to significant interference from neighboring cells or relay stations, thereby limiting overall performance. This paper describes an effective technique, fixed relay station cooperated beam-forming (FCBF), which combines MIMO, multi-hop relay and multi-cell coordination. Simulated testing of FCBF demonstrates an increase of 10% in the average sum-rate and a decrease of 25% in the outage probability compared with conventional techniques. In particular, throughput at the cell boundary is remarkably increased with FCBF compared with traditional beam-forming technologies.