A New Approach for Subsurface Wireless Sensor Networks

Abstract

Subsurface wireless sensor network is a sensor network in which sensors are installed under water or soil. This is to monitor earthquakes or Tsunami, to secure a society against natural disasters. The subsurface wireless communication is not easy since the power mitigation of the signal is severe due to the water and soil. In addition, the battery capacity in the sensor node is very limited. In this paper, based on the spread spectrum (SS) which is robust against low signal-to-noise power ratio (SNR), we propose a new transmitter and receiver configurations achieving code division multiplexing (CDM) for the subsurface wireless sensor networks. The proposed method is advantageous in terms of the following points. First, it realizes CDM by using a single spreading code. Second, the receiver does not need the training sequence to adjust the multiple antenna for the SNR improvement. This is effective to reduce the battery consumption at the sensor node since it does not need to send the training sequence. The performance is verified through computer simulations.