MIMO-Based and SISO Multihop Sensor Networks: Energy Efficiency Evaluation

Low-cost and low-power sensor nodes forming Wireless Sensor Networks have become suitable for a wide range of applications during recent years. These networks demand the implementation of energy-aware techniques and low complexity protocols in all layers. Recently, a MIMO - based structure has been proposed to offer enhanced energy savings in WSNs, compared with simple SISO transmission. In this paper we consider the most common transmission structure for WSNs, using multiple hops. We examine and compare MIMO - based WSN with a multihop transmission in terms of energy efficiency. The results mainly depend on the channel conditions and the distance to the destination node. We reach analytical expressions to calculate threshold values of these parameters, which determine the areas where the MIMO - based structure outperforms multihop transmission.