Interference suppression based on beamformer for sensor communications

The interference suppression technique is one of core techniques for the wireless sensor communications. In this paper, we focus on the Tire Pressure Monitoring System (TPMS) interference suppression among the wireless sensor communication techniques. The TPMS is an auxiliary safety device for measuring pressure and temperature, wirelessly transmitting the data to the central processing unit (CPU) of a vehicle and displaying the state of a tire on a display to inform a driver of the relevant information, by means of a sensor installed on the tire of the vehicle. When the data measured from the tire are wirelessly transmitted to a receiving antenna located in the center of the vehicle, exact transmission of data is affected by the interference from various external electronic and electrical devices. In this paper we suggest a minimum-variance distortionless-response (MVDR) beamformer based on the angle-of-arrival (AOA) vector for suppressing external interference and receiving accurate data. Although the MVDR beamformer effectively suppresses the interference, it has high computational complexity because of calculation of an auto-correlation matrix. In order to address this issue, we also suggest a generalized sidelobe canceler (GSC) beamformer which does not have the similar performance of the interference suppression to MVDR, but also has low computational complexity. Since the signal from each tire can cause interference to others, we consider utilizing a unique Gold Code to each tire to minimize inter-tire interference and reduce power consumption of a battery installed in each tire. The performance of the proposed interference suppression technique is verified through computer simulation.