Fading distribution

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

On the Multivariate Weibull Fading Model With Arbitrary Correlation Matrix

Abstract: An efficient approximation for the multivariate Weibull distribution with arbitrary correlations is presented. By approximating the Gaussian correlation matrix with a Green's matrix, a useful analytical expression for the joint distribution of the fading envelopes is derived. As an application, the outage performance of multibranch receivers operating over arbitrarily correlated Weibull fading channels is studied. Numerical and computer simulation results are presented and compared to illustrate the accuracy of the proposed approximation

Secret Key Generation Using Chaotic Signals Over Frequency Selective Fading Channels

Abstract: This paper presents a practical key generation algorithm based on the reciprocity of wireless fading channels. A broadband chaotic signal is employed for transmission so that the fading is frequency selective. In this case, signal components in the frequency domain spaced greater than the coherence bandwidth of the channel can be considered uncorrelated. The proposed algorithm exploits this property to generate a unique shared key between two parties. The nonperiodicity of the chaotic signal provides a unique signal for key generation, which can be used even with static fading channels. The proposed approach is robust to timing differences between the parties because the frequency spectrum of the signals is employed. A technique for information reconciliation is presented which does not reveal any information about the values used to generate the key. The randomness of the key is confirmed, and the effects of additive white Gaussian noise and timing differences on the performance of the algorithm are examined.

Characteristics of a simulated fast fading indoor radio channel

Abstract: The channel characteristics of an indoor radio channel vary very slowly. A simple technique that introduces a fast fading effect on the channel is presented. This scheme requires two or more antennas at the transmitter and has to be used with a suitable channel code. Slow time varying phase offsets are provided to each transmit antenna. Because of the resulting fast fading effect, with this scheme, time diversity can be employed usefully in a coded system. The indoor radio channel is represented by a slow fading Rayleigh channel model, and analytical expressions are provided for the correlation of the received signal in the presence of this simulated fast fading scheme. Expressions are derived for the level crossing rate and the average fade duration of the envelope of the received signal.

On the Secrecy Capacity of Fading Cognitive Wireless Networks

Abstract: In this paper, we compute the primary exclusive region (PER) and the secrecy capacity at a primary receiver in a fading cognitive radio network. We consider Rayleigh fading and log-normal shadowing. We also study the effect of secrecy capacity on the PER. We show that log-normal shadowing and Rayleigh fading can degrade the PER by about 40% and the secrecy capacity by about 70%.

Signal-strength based localization in wireless fading channels

Abstract: We develop maximum likelihood (ML) methods for location estimation using spatio-temporal received-signal-strength (RSS) measurements in wireless fading channels. Fading and composite fading-shadowing scenarios with completely unknown and partially known source signals are considered. We adopt gamma (Nakagami-m) and lognormal models to describe fading and shadowing effects, respectively. We also derive Cramer-Rao bounds (CRBs) for the location parameters and discuss initialization of the proposed algorithms. Numerical simulations demonstrate the performance of our estimators.