The quality of biomedical image is degraded by many sources of noise such as imperfect instruments, interference from natural phenomena and data acquisition errors. In Ultrasound and MRI images, the image quality is degraded mainly by Speckle noise and Rician noise respectively. Removing noise from biomedical image is still a challenging problem for the biomedical researchers and lots of denois...

In this paper, the performdnce of trellis coded M-PSK systems is investigated operating over Rician fading channels with phase jitter. Thus the results reflect not only the degradation due to the effect of fading on the amplitude of the received signal, but also the impairment caused by the noisy carrier reference, which is usually neglected by the assumption of perfect phase tracking at the re...

ABSTRACT In this paper, we investigate the performance of Turbo Trellis Coded Modulation (TTCM) over AWGN, and Rician channels and assume that phase disturbance is available. As we know Turbo Trellis Coded Modulation (TTCM) is similer to binary turbo codes, but employs Trellis Coded Modulation (TCM) codes which include multi-dimensional codes. The combination of turbo codes with trellis codes l...

Timing jitter is a major issue in very high speed OFDM systems, which causes serious impairments that, degrades the performance of overall system. In order to reduce the effect caused by timing jitter, here in this proposal, we introduced a novel scheme that reduces the noise caused by the effect of timing jitter by using integral oversampling under different channel environments such as AWGN, ...

In this paper, we consider the optimization of the performance of QPSK and 16-QAM coded orthogonal frequency division multiplexing (COFDM) signals over the non-linear and mobile satellite channel. A high power amplifier and Rician flat fading channel produces non-linear and linear distortions; an adaptive predistortion technique combined with turbo codes will reduce both types of distortion. Th...

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Spherical deconvolution (SD) methods are widely used to estimate the intra-voxel white-matter fiber orientations from diffusion MRI data. However, while some of these methods assume a zero-mean Gaussian distribution for the underlying noise, its real distribution is known to be non-Gaussian and to depend on many factors such as the number of coils and the methodology used to combine multichanne...

Wavelet packet analysis is a mathematical transformation that can be used to post-process images, for example, to remove image noise ("denoising"). At a very low signal-to-noise ratio (SNR <5), standard magnitude magnetic resonance images have skewed Rician noise statistics that degrade denoising performance. Since the quadrature images have approximately Gaussian noise, it was postulated that ...

The transmission quality in mobile wireless communications is affected by not only the thermal noise but also the multipass fading which changes drastically an amplitude and a phase of received signal. The paper proposes the theoretical and approximate methods for deriving an average bit error rate in DS-CDMA systems under the Rician fading environment on the assumption of the frequency non-sel...

AbstructThis paper studies the coded performance of multichannel MFSK and DPSK signalings in mobile satellite environments characterized by various kinds of multipath fading. Rician, Riciadognormal, and a convex combination of Rician and Riciadognormal or RayleigMognormal distributions are used to model these communication channels. We investigate the minimum average signal-energy-to-noise rati...