A Novel Method of Feedback Reducing and Cross-layer Scheduling Based on Traffic Rate for Relay System

Considering Traffic Rate Feedback (CTRF) is proposed for Orthogonal Frequency Division Multiple (OFDM) relay system with different user traffic rate. According to user traffic rate and channel gain, CTRF adjusts dynamically the value of feedback utility function and then compares it with feedback threshold to decide feedback, which can reduce the feedback quality of the system. Meanwhile, a cross-layer scheduling criterion based on user Traffic Queue Proportional Fair (TQPF) is proposed. Finally, a feedback reducing and scheduling algorithm combining CTRF and TQPF (CTRF-TQPF) is proposed to support different traffic rate. Theoretical and simulation results show that CTRF can reduce feedback and CTRF-TQPF can meet user traffic need and reduce packet loss rate of the system.