动态优化速率和帧长的超宽带链路自适应算法

Link adaptation algorithm for UWB systems with dynamic rate and payload size optimization

超宽带系统因发射功率受限,其传输速率对通信距离和信道衰落十分敏感。针对这一特性,以提高媒体访问控制(M AC)层吞吐量为目的,提出了一种基于接收端估计的链路自适应算法。该算法由接收端通过在线动态优化得出实际信道中给定信噪比估值下最佳的传输速率和M AC净荷长度,并通过应答帧附带的方式通知发送端。仿真结果表明,该算法较已有算法提高了吞吐量近30%。该算法复杂度低,对信噪比估计误差不敏感,具有一定的应用潜力。

The data rates of Ultra wide-band （UWB） systems are quite sensitive to communication range and channel fading due to limited transmission power. A good link adaptation algorithm is urgently needed to counteract this sensitivity to improve medium access （MAC） layer throughput. A receiver based link adaptation algorithm was developed where the receiver dynamically optimizes the transmission rate and MAC packet payload size according to the estimated signal to noise ratio （SNR） and notifies the receiver using the acknowledge packet＇s piggyback. Simulation results show that the algorithm improves MAC layer throughput by about 30% over previous algorithms. Additionally, the algorithm is simple and insensitive to SNR estimation deviations, thus it has many potential applications.