Xidian University

About: Xidian University is a education organization based out in Xi'an, China. It is known for research contribution in the topics: Antenna (radio) & Computer science. The organization has 32099 authors who have published 38961 publications receiving 431820 citations. The organization is also known as: University of Electronic Science and Technology at Xi'an & Xīān Diànzǐ Kējì Dàxué.

Joint Beam Selection and Power Allocation for Multiple Target Tracking in Netted Colocated MIMO Radar System

Abstract: In this paper, a joint beam selection and power allocation (JBSPA) strategy is developed for multiple target tracking in netted colocated multiple-input multiple-output radar system. Each radar in this network adopts a multibeam working mode, in which multiple simultaneous transmit beams are synthesized. The basis of the JBSPA strategy is to use the optimization technique to control the limited beam and power resource of each radar in order to achieve accurate target state estimation. The Bayesian Cramer–Rao lower bound is derived, normalized, and subsequently utilized, as the optimization criterion for the JBSPA strategy. The resulting optimization problem consists of two adaptable parameters, one for beam selection and the other for power allocation. By introducing an auxiliary vector, a fast two-step solution technique is presented to jointly decide the number of beams generated by each radar, as well as the assignment and transmit power of each beam, subject to some resource constraints. Simulation results verify the superiority of the proposed JBSPA algorithm, in terms of the worst-case tracking accuracy of the multiple targets.

Effects of Reentry Plasma Sheath on the Polarization Properties of Obliquely Incident EM Waves

Abstract: A novel and simple analytical technique referred to as transmission line analogy is developed and modified to study the transmission properties of the perpendicular polarized wave and the parallel polarized wave obliquely incident on the reentry plasma sheath. Based on the transmission coefficients, the effects of the plasma sheath on the polarization property of obliquely incident electromagnetic (EM) waves are studied. Taking the GPS navigation right hand circularly polarized wave as an example, the influences of incident angle and plasma parameters, including the electron density and the collision frequency on the EM wave’s polarization property are studied. Numerical results indicate that the larger the incident angle and the lower the collision frequency is, the worse the deterioration of the polarization property. In addition, the polarization property deteriorates most seriously when the cutoff frequency of the peak electron density is closest to the frequency of the EM waves.