This paper addresses subspace-based direction of arrival (DOA) estimation and its purpose is to complement previously available theoretical results generally obtained for specific algorithms. We focus on asymptotically (in the number of measurements) minimum variance (AMV) estimators based on estimates of orthogonal projectors obtained from singular value decompositions of sample covariance mat...

In this paper, we derive the exact Cramer-Rao bounds (CRBs) for semi-blind channel estimation in amplifyand-forward two-way relay networks employing square QAM modulation. The derived bounds are used to show that the semiblind approach, which exploits both the transmitted pilots and transmitted data symbols, can provide substantial improvements in estimation accuracy over the training-based app...

We consider the problem of time-frequency waveform design for an OFDM dual-functional radar-communications (DFRC) system that communicates with receiver while simultaneously estimating target parameters using backscattered signals. In particular, goal is to achieve a favorable performance trade-off between radar and communications by optimizing subcarrier powers in region interest. First, we fo...

The effect of sampling and quantization on frequency estimation for a single sinusoid is investigated. Asymptotic Cramér-Rao bounds (CRB) for 1-bit quantization and for non-ideal filters are derived, which are simpler to calculate than the exact CRB while still relatively accurate. It is further investigated how many bits should be used in quantization to avoid the problems of 1-bit quantizatio...

One of the important issues in many of array systems such as Radar, Sonar, Mobile, and satellite telecommunications is the estimation of DOA of narrowband received signal. CRB is very important in evaluation of parameter estimation. CRB is the lower bound estimation error variance for any unbiased estimation. In this paper, the array antenna with equal distance arrays is extended in two separat...

In order to resolve direction finding problems in the impulse noise, a of arrival (DOA) estimation method is proposed. The proposed DOA can restrain noise by using infinite norm exponential kernel co-variance matrix and obtain excellent performance via maximum-likelihood (ML) algorithm. global optimal solutions this method, quantum electromagnetic field optimization (QEFO) algorithm designed. v...

In this paper, a reduced-rank angular parameters estimation algorithm is proposed for incoherently distributed (ID) noncircular sources based on uniform linear array (ULA), which addresses the problems of central direction-of-arrival (DOA) and spread estimation. Firstly, noncircularity property signals utilized to establish an extended generalized manifold (GAM) model first-order Taylor series ...

The area of sensor array processing has attracted considerable interest in the signal processing community. The focus of this work has been on high resolution Direction Of Arrival (DOA) estimation algorithms that detect and locate aircrafts using radar systems. These algorithms exploit the fact that an electromagnetic wave that is received by an array of antenna elements reaches each element at...

In a companion paper [1], we studied amplitude estimation of one-dimensional (1-D) sinusoidal signals from measurements corrupted by possibly colored observation noise. We herein extend the results for twodimensional (2-D) amplitude estimation, which is of interest in various applications, including medical imaging, synthetic aperture radar (SAR), seismology, and many others. In particular, we ...

Joint carrier frequency offset (CFO) and channel estimation is considered for two-way relay networks (TWRNs). Existing estimators provide only the convolved channel parameters and themixed CFO values. In contrast, estimators using a superimposed training strategy are developed for the individual frequency and channel parameters. Depending on the number of pilots, three different estimators are ...