Random Switched Beamforming for Uplink Wireless Sensor Networks

Integration of beamforming to sensors is very beneficial for a reduction of transmission power consumption and for improvement of the overall system performance. Unfortunately, the beamforming brings up usually two serious problems. Firstly, the beamforming adaptation needs a lot of processing and hence the power consumption is increased, which is not desirable in the energy constrained devices such as wireless sensors. Secondly, there is not always a feedback channel available to inform the transmitter about the channel to adapt the antennas´ weights. This paper proposes a random beam-switching which relaxes the above two problems and yet achieves important benefits such as fairness and performance. A detailed mathematical analysis of the proposed algorithm is given. The simulations show the improved performance of the suggested beam-switching algorithm compared to the conventional omni-directional antennas.