In this paper, we consider wireless powered sensor networks. In these networks, the energy access point (EAP) transmits the energy packets to the sensor nodes and then, the sensor nodes send their sensing data to the information access point (IAP) by exploiting the harvested energy. Because the sensor nodes have a limited information queue (data storage) and energy queue (battery), energy packet/data packet scheduling is important. Accordingly, to reduce the total energy required to support the associated sensor network and simultaneously avoid sensing data loss, the energy packet/data packet transmission periods are jointly optimized. Furthermore, analyses identify the optimal location of EAP which will yield energy-efficient wireless powered sensor networks. Through the computer simulations, the performance of the proposed packet scheduling and deployment policy is demonstrated.

To estimate angle, velocity, and range information of multiple targets jointly in FMCW MIMO radar, two-dimensional (2D) MUSIC with matched filtering and FFT algorithm is proposed. By reformulating the received FMCW signal of the colocated MIMO radar, we exploit 2D MUSIC to estimate the angle and Doppler frequency of multiple targets. Then by using a matched filter together with the estimated angle and Doppler frequency and FFT operation, the range of the target is estimated. To effectively estimate the parameters of multiple targets with large distance differences, we also propose a successive interference cancellation method that uses the orthogonal projection. That is, rather than estimating the multiple target parameters simultaneously using 2D MUSIC, we estimate the target parameters sequentially, in which the parameters of the target having strongest reflected power are estimated first and then, their effect on the received signal is canceled out by using the orthogonal projection. Simulations verify the performance of the proposed algorithm.