Energy Efficiency of Collaborative Communication with Imperfect Frequency Synchronization in Wireless Sensor Networks

Collaborative communication produces significant (N-2 where N is number of nodes used for collaboration) power gain and overcomes the effect of fading. With imperfect frequency synchronization significant but slightly less than N-2 power can be achieved. As the N increases more power gain can be achieved at the expense of more circuit power. In this paper an energy consumption model for collaborative communication system with imperfect frequency synchronization is proposed. The model to calculate the energy consumed by the sensor network for local communication and communication with base station is presented. Energy efficiency model for collaborative communication for the off-the shell products (CC2420 and AT86RF212) are presented. It is also shown that significant energy can be saved using collaborative communication as compared to traditional SISO (Single input single output) for products. The break-even distance where the energy consumed by SISO and collaborative communication is also calculated. From results it is revealed that collaborative communication using 5 nodes produces efficient energy saving.