Computation of the Cramer-Rao bound (CRB) on estimator variance requires the inverse or the pseudo-inverse Fisher information matrix (FIM). Direct matrix inversion can be computationally intractable when the number of unknown parameters is large. In this correspondence, we compare several iterative methods for approximating the CRB using matrix splitting and preconditioned conjugate gradient al...

In this paper, the Cramér Rao bound (CRB) for range estimate between two underwater nodes is calculated. The nodes are equipped with Conductivity-Temperature-Density (CTD) sensors to measure their depths, and the sound speed at different depths, and an acoustic modem to measure their mutual time of flight. The measurement noise is assumed to be Gaussian distributed. We show how much the CRB get...

Membrane-associated guanylate kinases (MAGUKs) constitute a family of scaffold molecules involved in diverse cellular processes, such as cell–cell communication, cell polarity, and signal transduction (1). MAGUKs are multidomain proteins with a core structure consisting of PSD-95/DLG/ ZO-1 (PDZ), Src homolgy 3 (SH3), and enzymatically inactive guanylate kinase (GK) domains. Although full-length...

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...

In this contribution we point out that the nondecision-aided (NDA) carrier synchronizer, maximizing the low E s / N o limit of the likelihood function averaged over a general 2r/N-rotationally symmetric signal constellation, reduces to the familiar timing-aided Nth power synchronizer; this extends a result from [6] where only M-PSK constellations have been considered. Whereas in the case of M-P...

The use of spectrally e cient continuous phase modulations for mobile communications may lead to a serious performance degradation of the classical frequency error detectors (FEDs) due to the presence of self-noise. This contribution presents a new statistically e cient frequency estimation algorithm for staggered modulations. The cancellation of the self-noise is accomplished by the use of the...

Computation of the Cramer-Rao bound (CRB) on estimator variance requires the inverse or the pseudo-inverse Fisher information matrix (FIM). Direct matrix inversion can be computationally intractable when the number of unknown parameters is large. In this note we compare several iterative methods for approximating the CRB using matrix splitting and preconditioned conjugate gradient algorithms. F...

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...

Computation of the Cramer-Rao bound (CRB) on estimator variance requires the inverse or the pseudo-inverse Fisher information matrix (FIM). Direct matrix inversion can be computationally intractable when the number of unknown parameters is large. In this correspondence, we compare several iterative methods for approximating the CRB using matrix splitting and preconditioned conjugate gradient al...

Predicting CAP-related mortality with CRB-65 Ewig et al are to be commended for their very large study of 388 406 patients admitted with community-acquired pneumonia (CAP) in German hospitals from 2005 to 2006. Using the CRB-65 tool (confusion, respiratory rate $30 min, low blood pressure (either systolic <90 mm Hg or diastolic #60 mm Hg) and age $65 years), the authors found 30-day mortality r...