Fading distribution

About: Fading distribution is a research topic. Over the lifetime, 5732 publications have been published within this topic receiving 114193 citations.

The Fluctuating Two-Ray Fading Model for mmWave Communications

Abstract: We introduce the Fluctuating Two-Ray (FTR) fading model, a new statistical channel model that consists of two fluctuating specular components with random phases plus a diffuse component. The FTR model arises as a natural generalization of the two-wave with diffuse power (TWDP) fading model proposed by Durgin, Rappaport and de Wolf; in this extended model, the two specular components exhibit a random amplitude fluctuation. Unlike in the TWDP model, we show that all the chief probability functions of the FTR fading model (PDF, CDF and MGF) can be expressed in closed-form. We also show that the FTR fading model provides a much better fit than the Rician fading model for recent small-scale fading measurements of the 28 GHz outdoor millimeter-wave channels.

Non-Coherent Amplify-and-Forward Generalized Likelihood Ratio Test Receiver

Abstract: This paper proposes a simple non-coherent amplify-and-forward receiver for the relay channel and evaluates its diversity performance for Rayleigh fading channels. We use the generalized likelihood ratio test to obtain the decision rule in closed form, independent of the fading distribution. The receiver is developed for M-ary orthogonal signals and multiple relays. The only side information required at the destination is the average noise energy at the receiver; no statistical knowledge of the channel gains is needed. We develop closed-form upper and lower bounds on the probability of error of this receiver for the case of binary signaling with a single relay and show that this receiver achieves near full diversity, with the probability of error decreasing with increasing signal-to-noise ratio (SNR) as log2(SNR)/ SNR2 for large SNR. Additional results obtained by simulation demonstrate increasing diversity gain with additional relays.

Unified error analysis of DQPSK in fading channels

Abstract: A general result is derived for the bit error rate (BER) of differential quadrature phase shift keying (DQPSK) for reception in slow fading and additive white Gaussian noise (AWGN). Fading models include Rayleigh, Rician, Nakagami and shadowed Rician, which describe a wide range of fading conditions encountered in mobile communications. Easily computable, the result is potentially useful in evaluating the BER of such systems.

BER analysis of optical wireless signals through lognormal fading channels with perfect CSI

Abstract: Due to inconsistent atmospheric conditions, scattering and scintillation of free space optical (FSO) signal can occur, thus negatively influencing the received signal intensity. The channel is usually modeled as a normalized fading coefficient with additive Gaussian noise. Optimal detection of the received signal is designed based on a decision rule, e.g., Maximum Likelihood (ML), assuming the receiver knows the noise statistics and fading correlation of the channel. This paper briefly deals with analysis on bit error rate (BER) of a wireless optical signal passing through a lognormally distributed fading channel, when perfect knowledge of channel state information (CSI) at the receiver side is available. Two approaches will be presented to provide closed-form expressions for BER. One uses Gauss-Hermite quadrature approximation and the other one is based on power series. While numerical analysis shows a very small approximation error when the Gauss-Hermite approach is considered, the power series approach does not uses any approximation.

Joint Data and Kalman Estimation for Rayleigh Fading Channels

Abstract: Channel estimation is an essential part of many detection techniques proposed for data transmission over fading channels. For the frequency selective Rayleigh fading channel an autoregressive moving average representation is proposed based on the fading model parameters. The parameters of this representation are determined based on the fading channel characteristics, making it possible to employ the Kalman filter as the best estimator for the channel impulse response. For IS-136 formatted data transmission the Kalman filter is employed with the Viterbi algorithm in a Per-Survivor Processing (PSP) fashion and the ove rall bit error rate performance is shown to be superior to that of detection techniques using the RLS and LMS estimators. To allow more than one channel estimation per symbol interval, Per-Branch Processing (PBP) method is introduced as a general case of PSP and its effect on performance is evaluated. The sensitivity of performance to parameters such as fading model order and vehicle speed is also studied.