基于信道感知与监测的传感器网络传输参数自适应调整方法

Adaptively Adjusting Method of Transmission Parameters in Sensor Networks Based On Channel Sensing and Monitoring

针对预警系统中广域部署在偏远地区的传感器利用现有话音通信线路传输感知信息时,信道具有时变的特征,提出了一种基于信道感知与监测的传输参数自适应调整方法。该方法解决了连接线路在低信噪比下频繁掉线导致的传感器网络采集数据缺失与延时的问题。首先,在数据包传输期间,引入盲信噪比估计方法对信道质量进行感知,通过加权滑窗平均估计结果得到信道质量周期监测的观测值。然后根据卡尔曼滤波原理建立离散化的传输参数自适应调整模型,在保持链路连通状态下,根据信道质量优劣变化自适应地调整传输速率与功率。最后,实验表明,对于野外布设传感器网络的时变信道,该方法能有效保证信息传输的实时性与可靠性。

According to the time-varying characteristic of information transmission channel between sensors distributed on remote and wild regions,which transmit data by existing speech channel in Early Warning System,a new method is proposed for adaptively adjusting transmission parameters in sensor networks based on channel sensing and monitoring.The method solves the problems of the sensing data loss and delay caused by connecting lines frequently dropped in low SNR（Signal to Noise Ratio）.Firstly,we adopt a blind SNR estimation algorithm to sensing the current channel quality during the packets transmission period and obtain the observed values by integrating the estimation results with weighted sliding-window.Then,we establish a discrete adjusting transmission parameter model based on Kalman Filtering principle,which can adaptively adjust the transmission rate and power according to the changes in the channel quality while maintaining the link.Finally,experiments results show,in condition of wild field emplaced sensor network＇s time-varying channel,this method can guarantee the information transmission＇ s instantaneity and reliability.