Energy-Efficient Cooperative MIMO-Based Random Walk Routing for Wireless Sensor Networks

To improve energy efficiency of wireless sensor networks, this letter proposes a novel random walk routing algorithm based on the cooperative multi-input multi-output (MIMO) mechanism. For each hop of each walk, we investigate the adaption of communication modes [i.e., single-input single-output, virtual single-input multi-output, virtual multi-input single-output (vMISO), and virtual MIMO]. The parameters are jointly optimized for determining minimum energy consuming communication mode, including the number of transmitters and receivers, the set of cooperation nodes. Additionally, we consider only vMISO mode and derive the approximate optimal number of transmitters by exploiting the relationship with the transmission distances. The simulation results show that the proposed scheme can improve energy efficiency.