Pragmatic Joint Transmit Power and CCA Threshold Adaptation in HD WLAN
Jing Zhu, Xingang Guo, Sumit Roy and Konstantina Papagiannaki
Submitted to IEEE Infocom 2007
Abstract : In this paper, we study spatial reuse in high density WLAN, and the impact of two key network parameters – transmission power and clear channel assessment (CCA) threshold – on throughput and fairness. We designed a self adaptation solution based on local packet error rate (PER), in which a) CCA threshold is adapted to enhance spatial reuse for higher aggregate throughput; while b) transmission power control (TPC) is used to address fairness. The key idea is to classify the interference according to its timing relation with signal, measure PER for each type of interference individually, and adapt CCA threshold and transmission power accordingly. Compared to an end-to-end feedback loop for adaptation, ours has negligible complexity and is thus readily applicable in real systems. Simulation results show that our solution achieves near the ideal throughput predicted by analysis, and higher worst link throughput than the legacy.