一种适用于WMSNs传输机制的信道盲估计方法

虚拟MIMO是一种克服无线多媒体传感器网络信道多径衰落和降低节点能耗的有效方法,但现有文献均假设信道状态信息未知或仅知道信道的统计特性,源节点则无法根据信道的实时信息动态调整传输策略。针对WMSNs信道特点,提出一种适用于WMSNs传输机制的信道盲估计方法以获得节点间信道信息进而确定传输策略,通过构造权值衰减联合决策函数,将节点间的信道盲估计问题转化为一个无约束优化问题,在此基础上设计了一种快速收敛的迭代算法以降低运算代价。该方法仅依赖小数据量就可正确估计出节点间信道,具有对抗信道时变特性的能力;理论推导与仿真表明该算法的收敛速度和运算量均能符合降低节点能耗的要求。

A Blind Channel Estimation Method of WMSNs Transmission Scheme

Virtual MIMO is an effective technology to overcome the multi-path fading and reduce energy consumption in Wireless Multimedia Sensor Networks(WMSNs).However,most of existing literatures assume that the wireless channel state information(CSI)is unavailable,or only the statistical characteristics of the channel is available,which disenable the source node to select transmission schemes dynamically according to real-time CSI.To obtain the CSI between the nodes which is used to determine the transmission schemes,a novel blind channel estimation method is proposed according to the channel characteristics in WMSNs.By constructing a joint decision function for weights attenuation,issue of blind channel estimation is converted to an unconstrained optimization problem.Furthermore,an iterative algorithm with fast convergence rate is presented to reduce the computational cost.The proposed method can overcome the time-varying and multi-path fading characteristics of the wireless channel only depending on a small amount of received data.Theoretical derivation and simulation results show that our method decreases energy consumption for its low overhead and fast convergence rate.