无线网络中基于信道速率和传输功率的MAC性能优化

目前多种无线传输标准均支持多速率的数据传送，通过对信道状况的估算设置合适的数据传输速率，有利于网络性能的优化。同时，调整无线网络中节点的发射功率可以间接改变物理载波侦听范围，从而提高网络的空间复用。本文提出了一种基于信道速率和传输功率自适应调整的PRA算法（Power and Rate Adaptation），该算法的基本思想是发送节点根据通信距离保守计算起始速率，并根据成功和失败的状况调整传输速率和发送功率，从而有效改善介质访问控制协议的性能。仿真结果表明，该机制可以使节点在通信过程中自动调整到较高的信道速率和合适的发送功率范围，提高了网络吞吐量，降低了功耗，同时改善了公平性。

Improving MAC Performance Based on Transmit Power and Channel Rate in Wireless Networks

Many today’s Wireless Network Standards provide multiple channel rates today so that different rates can be exploited in an adaptive manner depending on the underlying channel conditions in order to optimize the network performance. In the meanwhile, the degree of the spatial reuse can be enhanced by adjusting transmit power to change carrier sensing range. This paper proposes a new algorithm with the joint control of transmit power and channel rate in order to improve the performance of medium access mechanism. In this algorithm, the transmitter first decides to use appropriate channel rate according to communication distance, and then adjusts its rate and transmit power adaptively based on the communication results. Simulation results show that, the proposed rate and power control algorithm yields higher throughout , decreases power consumption, and improves equity effectively.