Wireless MIMO Sensor Network with Power Constraint WLS/BLUE Estimators

摘要

Sensor networks are used in various applications. Sensors acquire samples of physical data and send them to a central node in different topologies to process the data and makes decisions. Multiple Input Multiple Output (MIMO) systems showed good utilization of channel characteristics. In MIMO Sensor Network, multiple signals are transmitted from the sensors and multiple antennas are used at the control node. This provides each receiver the whole combined signal and hence, array processing techniques helps in reducing the effects of noise. In this paper we devise the use of MIMO sensor network and array decision techniques to reduce the noise effect. The proposed Constrained Best Linear Unbiased Estimator (CBLUE) and Constrained Weighted Least Square (CWLS) estimators showed good performance BER when used with MIMO Sensor Network. Most importantly these estimates showed good perturbation results when the estimated channel matrix is not accurate. The condition for good performance was to have the number of receiving antennas at the central node to be equal to the number of transmitting sensors and no significant improve was seen if the number of antennas is greater than the number of transmitting sensors. If the number of sensors is greater than the number of receiving antennas, time or frequency multiplexing is possible to keep good performance for the devised system. Enhancing the BER results in longer battery life at sensor nodes.