title: Cramer-Rao Lower Bound Evaluation for Linear Frequency Modulation Based Active Radar Networks Operating in a Rice Fading Environment.
abstract: This paper investigates the joint target parameter (delay and Doppler) estimation performance of linear frequency modulation (LFM)-based radar networks in a Rice fading environment. The active radar networks are composed of multiple radar transmitters and multichannel receivers placed on moving platforms. First, the log-likelihood function of the received signal for a Rician target is derived, where the received signal scattered off the target comprises of dominant scatterer (DS) component and weak isotropic scatterers (WIS) components. Then, the analytically closed-form expressions of the Cramer-Rao lower bounds (CRLBs) on the Cartesian coordinates of target position and velocity are calculated, which can be adopted as a performance metric to access the target parameter estimation accuracy for LFM-based radar network systems in a Rice fading environment. It is found that the cumulative Fisher information matrix (FIM) is a linear combination of both DS component and WIS components, and it also demonstrates that the joint CRLB is a function of signal-to-noise ratio (SNR), target's radar cross section (RCS) and transmitted waveform parameters, as well as the relative geometry between the target and the radar network architectures. Finally, numerical results are provided to indicate that the joint target parameter estimation performance of active radar networks can be significantly improved with the exploitation of DS component.
authors.affiliation: Key Laboratory of Radar Imaging and Microwave Photonics, Ministry of Education, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China. scg_space@163.com.|School of Engineering and Computing Sciences, Durham University, Durham DH1 3DE, UK. scg_space@163.com.
authors.forename: Chenguang
authors.initials: C
authors.lastname: Shi
authors.affiliation: School of Engineering and Computing Sciences, Durham University, Durham DH1 3DE, UK. salous.durham@gmail.com.
authors.forename: Sana
authors.initials: S
authors.lastname: Salous
authors.affiliation: Key Laboratory of Radar Imaging and Microwave Photonics, Ministry of Education, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China. wangxiaoxian@nuaa.edu.cn.
authors.forename: Fei
authors.initials: F
authors.lastname: Wang
authors.affiliation: Key Laboratory of Radar Imaging and Microwave Photonics, Ministry of Education, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China. zjjee@nuaa.edu.cn.
authors.forename: Jianjiang
authors.initials: J
authors.lastname: Zhou
keywords: Cramer-Rao lower bound (CRLB); Fisher information matrix (FIM); Rician target; active radar networks; joint parameter estimation; linear frequency modulation (LFM) signal