Abstract :
In this paper, Cramer-Rao lower bounds (CRLBs) for estimation of signal parameters related to periodically moving objects in pulse-based ultra-wideband (UWB) systems are presented. The results also apply to estimation of vital parameters, such as respiration rate, using UWB signals. In addition to obtaining the CRLBs, suboptimal estimation algorithms are also presented. First, a single-path channel with additive white Gaussian noise is considered, and closed-form CRLB expressions are obtained for sinusoidal object movements. Also, a two-step suboptimal algorithm is proposed, which is based on time delay estimation via matched filtering followed by least-squares estimation, and its asymptotic optimality property is shown in the limit of certain system parameters. Then, a multipath environment is considered, and exact and approximate CRLB expressions are derived. Moreover, suboptimal schemes for parameter estimation are studied. Simulation studies are performed for the estimation of respiration rates in order to evaluate the lower bounds and performance of the suboptimal algorithms for realistic system parameters.
Keywords :
AWGN channels; channel estimation; delay estimation; filtering theory; least squares approximations; ultra wideband communication; Cramer-Rao lower bounds; additive white Gaussian noise; asymptotic optimality property; least-squares estimation; matched filtering; multipath environment; periodic movements estimation; periodically moving objects; pulse-based UWB systems; signal parameters estimation; single-path channel; sinusoidal object movements; suboptimal estimation algorithms; time delay estimation; Bandwidth; Biomedical monitoring; Delay effects; Delay estimation; Estimation theory; Parameter estimation; Pulse modulation; Signal processing algorithms; Ultra wideband radar; Ultra wideband technology; Cramer-Rao lower bound (CRLB); estimation theory; impulse radio (IR); least-squares (LS) estimation; matched filtering; ultra-wideband (UWB);
