This paper investigated a Subsample Time delay Estimation (STE) algorithm based on the amplitude of cross-correlation function to improve estimation accuracy. In this paper, rough time is applied traditional cross correlator, and fine achieved by approximating sampled sequence theoretical for linear frequency modulation (LFM) signal. Simulation results show that proposed outperforms existing me...

• (z)r and (z)i denote the real and imaginary part of z. II. CONSTRAINED CRAMER-RAO BOUND A. Problem Statement Problem statement and notation are based on [1]. • a: a K × 1 non-random vector which are to be estimated. • r: an observation of a random vector . • â (R): an estimate of a basing on the observed vector r . It is required that â (R) satisfies M nonlinear equality constraints (M < K), ...

A closed-form expanded autocorrelation method for real single-tone frequency estimation is proposed. Firstly, the modified covariance (MC) method based on multiple autocorrelation lags is applied to provide a coarse frequency estimate. Then, a closedform adjustment term based on a least square cost function is derived to get the fine frequency estimate. Simulation results show that the performa...

This paper is concerned with DOA estimation using a single-electromagnetic vector sensor in the presence of mutual coupling. Firstly, we apply the temporally smoothing technique to improve the identifiability limit of a single-vector sensor. In particular, we establish sufficient conditions for constructing temporally smoothed matrices to resolve K > 2 incompletely polarized (IP) monochromatic ...

This paper examines the problem of complex amplitude estimation of a multichannel signal in the presence of colored noise with unknown spatial and temporal correlation. A number of amplitude estimators are developed, including the optimum maximum likelihood (ML) estimator, which involves nonlinear optimization, and several suboptimal but computationally more efficient estimators based on least-...

We present maximum likelihood (ML) methods for space–time fading channel estimation with an antenna array in spatially correlated noise having unknown covariance; the results are applied to symbol detection. The received signal is modeled as a linear combination of multipath-delayed and Doppler-shifted copies of the transmitted waveform. We consider structured and unstructured array response mo...

In wireless networks, an essential step for precise range-based localization is the high-resolution estimation of multipath channel delays. The resolution traditional delay algorithms inversely proportional to bandwidth training signals used probing. Considering that typical have limited bandwidth, using these often leads poor performance. To mitigate constraints, we exploit multiband and carri...

A computationally e cient method for structured covariance matrix estimation is presented. The proposed method provides an Asymptotic (for large samples) Maximum Likelihood estimate of a structured covariance matrix and is referred to as AML. A closed-form formula for estimating Hermitian Toeplitz covariance matrices is derived which makes AML computationally much simpler than most existing Her...

We consider array geometries whose direction-of-arrival (DOA) estimation performance is isotropic. An isotropic array is one whose Cramér–Rao bound (CRB) on the DOA of a single source is uniform for all angles. For both planar arrays and volume arrays we derive necessary and sufficient conditions on array element locations so that the array is isotropic. We also present several designs of isotr...

Several current ultra-wide band applications, such as millimeter wave radar and communication systems, require high sampling rates therefore expensive energy-hungry analogto-digital converters (ADCs). In applications where cost power constraints exist, the use of high-precision ADCs is not feasible designer must resort to with coarse quantization. Consequently interest in topic signal parameter...