Fading distribution

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

The fading of radio waves of medium and high frequencies

Abstract: The fading of radio waves of medium and high frequencies returned from the ionosphere is analysed. The experimental data on high frequencies were recorded by the author at normal incidence using a pulse transmitter, and, when necessary, a circularly polarized receiving aerial. The medium-frequency records were made by the B.B.C. using continuous-wave transmissions from broadcasting stations at different distances up to 1 500 kilometres.A review is given of some theories suggested to explain the production of fading in terms of an ionosphere with varying irregularities in the horizontal plane. The theoretical nature of the fading curve, both with regard to the distribution of amplitude and the variation with time, is indicated, and is compared with experimental results.It is shown that all fading curves can be explained in terms of a wave which is the sum of a steady, specularly reflected component, and a random component with a Rayleigh distribution of amplitude. The relative magnitudes of these two components have been determined for a series of different conditions, and the results are summarized. It is also shown that the rate of variation of the amplitude of the received signal is approximately, but not exactly, in accord with the theories, and from this rate of change it is possible to calculate the “effective velocity” of the irregularities in the ionosphere. If the fading is caused by irregular “turbulent” motions of the irregularities, the “effective velocity” is the r.m.s. velocity of these motions; if it is due to a steady drift of the irregular ionosphere as a whole with a velocity vw, then the “effective velocity” is approximately equal to vw/14. The “effective velocities” deduced from 122 records made at vertical incidence, and 55 made at oblique incidence, lie between 0.3 and 8.0 m/sec and have an average value of 1.9 m/sec.

The performance of reference-based M-ary PSK with trellis coded modulation in Rayleigh fading

Abstract: The performance of trellis-coded M-ary phase shift keying (MPSK) is analyzed for three types of phase detection system; differential detection, pilot-symbol-aided detection and pilot-tone-aided detection. A near-exact solution to the probability of event error in Rayleigh fading is derived, and two extremely tight upper bounds generated. They improve the Chernoff upper bound by at least a factor of four at medium and high signal-to-noise ratios (SNR). >

Performance analysis of system with L-branch selection combining over correlated Weibull fading channels in the presence of cochannel interference

Abstract: In this paper, the performance of L-branch selection combining receiver over correlated Weibull fading channels in the presence of correlated Weibull-distributed cochannel interference is analyzed. Closed-form expressions for probability density function and cumulative distribution function of the signal-to-interference ratio at the output of the selection combining receiver present main contribution of this paper. Numerical results are also presented to show the effects of various parameters as the fading severity, correlation and number of branches on outage probability. Copyright © 2009 John Wiley & Sons, Ltd. This paper analyzes the outage performance of L-branch SC receiver over correlated Weibull fading channels in the presence of correlated Weibull-distributed co-channel interference. In order to carry out this analysis, closed-form expression for the outage probability of considered system is derived. Presented numerical results show the effects of various parameters as the fading severity, correlation and number of branch on the outage probability. Copyright © 2009 John Wiley & Sons, Ltd.

Effect of fading correlation on capacity of distributed MIMO

Abstract: Distributed multiple-input multiple-output (MIMO) system combines the advantages of point-to-point MIMO systems and distributed antenna systems, and improves link quality and coverage. A distributed MIMO channel model which comprises relative path loss, correlated shadow fading and correlated small scale fading is proposed. The impact of two kinds of fading correlation on capacity of distributed MIMO channel is investigated and compared carefully by Monte Carlo simulations, and the characteristics of capacity space distribution of distributed MIMO channel with spatial shadowing correlation are also obtained.