Flexible optical network is a promising technology to accommodate high-capacity demands in next-generation networks. To ensure uninterrupted communication, existing lightpath provisioning schemes are mainly done with the assumption of worst-case resource under-provisioning and fixed channel spacing, which preserves an excessive signal-to-noise ratio (SNR) margin. However, under over-provisionin...

In this paper, power allocation is distributed within each Base Station. Two cases are considered: CSIT, and iterative water filling. In both cases, a distributed convergence criterion for power control is determined and included within iterative power allocation. In the past margin Adaptive (MA) problem in MIMO OFDMA multi-cell networks. The CSIT is avoiding the margin adaptive and are consequ...

In this paper, we introduce an improved image transmission scheme over wireless channels with flat Rayleigh fading. The proposed scheme jointly optimizes bit power and modulation level to maximize the peak signal-tonoise ratio (PSNR) of the reconstructed image and hence improves the perceptual quality of the received image. In this optimization process, the significance of bits with regard to t...

In this paper, we introduce a new algorithm for estimating the signal-to-noise ratio (SNR) of speech signals, called WADASNR (Waveform Amplitude Distribution Analysis). In this algorithm we assume that the amplitude distribution of clean speech can be approximated by the Gamma distribution with a shaping parameter of 0.4, and that an additive noise signal is Gaussian. Based on this assumption, ...

Introduction: In this study the evaluation of a Platelet-based Maximum Penalized Likelihood Estimation (MPLE) for denoising SPECT images was performed and compared with other denoising methods such as Wavelets or Butterworth filtration. Platelet-based MPLE factorization as a multiscale decomposition approach has been already proposed for better edges and surfaces representation due to Poi...

background: in this study, quantitative 32p bremsstrahlung planar and spect imaging and consequent dose assessment were carried out as a comprehensive phantom study to define an appropriate method for accurate dosimetry in clinical practice. materials and methods: ct, planar and spect bremsstrahlung images of jaszczak phantom containing a known activity of 32p were acquired. in addition, phanto...