This paper derives a theoretical limit for image registration and presents an iterative estimator that achieves the limit. The variance of any parametric registration is bounded by the Cramer-Rao bound (CRB). This bound is signal-dependent and is proportional to the variance of input noise. Since most available registration techniques are biased, they are not optimal. The bias, however, can be ...

In the accompanying paper a method for blind (i.e., no calibration needed) estimation and compensation of the time errors in a time interleaved ADC system was presented. In this paper we evaluate this method. The Cramer-Rao bound is calculated, both for additive noise and random clock jitter. Monte-Carlo simulations have also been done to compare to the CRB. Finally, the estimation method is va...

The problem of blind detection in a synchronous code division multiple access (CDMA) system when there is no knowledge of the users’ spreading sequences is considered. An expectation maximization (EM)-based algorithm that exploits the finite alphabet (FA) property of the digital communications source is proposed. Simulations indicate that this approach, which makes use of knowledge of the subsp...

This paper presents a preprocessing technique based on exponential windowing (EW) for parameter estimation of superimposed exponentially damped sinusoids. It is shown that the EW technique significantly improves the robustness to noise over two other commonly used preprocessing techniques: subspace decomposition and higher order statistics. An ad-hoc but efficient approach for the EW parameter ...

This paper contains a review of the issues surrounding sinusoidal parameter estimation which is a vital part of many audio manipulation algorithms. A number of algorithms which use the phase of the Fourier transform for estimation (e.g. [1]) are explored and shown to be identical. Their performance against a classical interpolation estimator [2] and comparison with the Cramer Rao Bound (CRB) is...

We present maximum likelihood (ML) methods for active estimation of range (time delay), velocity (Doppler shift), and direction of a point target with a radar array in spatially correlated noise with unknown covariance. We consider structured and unstructured array response models and compute the Cram er-Rao bound (CRB) for the time delay, Doppler shift, and direction of arrival. We derive ambi...

In the above-mentioned paper a Cramer-Rao bound was derived for the performance of a blind channel estimation algorithm. In this paper an error in the bound is pointed out and corrected. It is observed here that the performance of the said algorithm does not achieve the Cramer-Rao bound. In the above paper [1], important work has been done to analyze the algorithm in [2] which solves a blind ch...

The goal of this paper is to characterize the best achievable performance for the problem of estimating an unknown parameter having a sparse representation. Specifically, we consider the setting in which a sparsely representable deterministic parameter vector is to be estimated from measurements corrupted by Gaussian noise, and derive a lower bound on the mean-squared error (MSE) achievable in ...

The goal of this paper is to characterize the best achievable performance for the problem of estimating an unknown parameter having a sparse representation. Specifically, we consider the setting in which a sparsely representable deterministic parameter vector is to be estimated from measurements corrupted by Gaussian noise, and derive a lower bound on the mean-squared error (MSE) achievable in ...

In this contribution we consider the Cramer-Rao bound (CRB) for the estimation of the synchronization parameters of a noisy linearly modulated signal with random data symbols. We explore three scenarios, i.e., (i) joint estimation of carrier phase, carrier frequency and time delay, irrespective of the data; (ii) joint estimation of carrier frequency and time delay, irrespective of the data and ...