%0 Journal Article %T Energy Balance Routing Algorithm Based on Virtual MIMO Scheme for Wireless Sensor Networks %A Jianpo Li %A Xue Jiang %A I-Tai Lu %J Journal of Sensors %D 2014 %I Hindawi Publishing Corporation %R 10.1155/2014/589249 %X Wireless sensor networks are usually energy limited and therefore an energy-efficient routing algorithm is desired for prolonging the network lifetime. In this paper, we propose a new energy balance routing algorithm which has the following three improvements over the conventional LEACH algorithm. Firstly, we propose a new cluster head selection scheme by taking into consideration the remaining energy and the most recent energy consumption of the nodes and the entire network. In this way, the sensor nodes with smaller remaining energy or larger energy consumption will be much less likely to be chosen as cluster heads. Secondly, according to the ratio of remaining energy to distance, cooperative nodes are selected to form virtual MIMO structures. It mitigates the uneven distribution of clusters and the unbalanced energy consumption of the whole network. Thirdly, we construct a comprehensive energy consumption model, which can reflect more realistically the practical energy consumption. Numerical simulations analyze the influences of cooperative node numbers and cluster head node numbers on the network lifetime. It is shown that the energy consumption of the proposed routing algorithm is lower than the conventional LEACH algorithm and for the simulation example the network lifetime is prolonged about 25%. 1. Introduction Wireless sensor networks (WSNs) typically consist of a large number of energy-constrained sensor nodes with limited onboard battery resources which are difficult to recharge or replace. Thus, the reduction of energy consumption for end-to-end transmission and the maximization of network lifetime have become chief research concerns. In recent years, many techniques have been proposed for improving the energy efficiency in energy-constrained and distributed WSNs. Among these techniques, the multiple-input multiple-output (MIMO) technique has been considered as one of the effective ways to save energy. The MIMO technique, including various space-time coding schemes, layered space-time architectures, has the potential to enhance channel capacity and reduce transmission energy consumption particularly in fading channels [1¨C3]. However, constrained by its physical size and limited battery, individual sensor node usually contains only one antenna. The antenna array cannot be implemented in a single sensor node in the radio frequency range. Fortunately, the dense senor nodes can jointly act as a multiantenna array through messages interchange. Numerical results show that if these sensor nodes can be constructed into virtual MIMO systems, in a %U http://www.hindawi.com/journals/js/2014/589249/