Showing papers on "Fading distribution published in 1983"
TL;DR: The effects of frequency-selective fading in a cellular mobile radio system that uses phase-shift keying with cosine rolloff pulses, and space diversity with maximal-radio combining is analyzed, highlighting the importance of the ratio \tau_{0}/T, where T is the digital symbol period.
Abstract: we analyze the effects of frequency-selective fading in a cellular mobile radio system that uses 1) phase-shift keying (PSK) with cosine rolloff pulses, and 2) space diversity with maximal-radio combining. The distorting phenomena with which we deal are multipath fading (which produces the frequency selectivity), shadow fading, and cochannel interference. The relevant quality measure is defined to be the bit error rate averaged over the multipath fading, denoted by (BER). The relevant system performance characteristic is defined to be the probability distribution for (BER), taken over the ensemble of shadow fadings and locations of the desired and interfering mobiles. To obtain numerical results, we use a combination of analysis and Monte Carlo simulation, invoke widely accepted models for the multipath and shadow fadings, and assume a cellular system with seven channel sets and centrally located base stations. The outcome is a set of performance curves that reveal the influences of various system and channel parameters. These include: the number of modulation levels (two or four), the diversity order, the shape of the multipath delay spectrum, and the standard deviation (or delay spread, τ 0 ) of the multipath delay spectrum. Practical factors accounted for in these assessments include fading- and interference-related timing recovery errors and combiner imperfections. Our results highlight the importance of the ratio \tau_{0}/T , where T is the digital symbol period. They show that the delay spectrum shape is of no importance for \tau_{0}/T \leq 0.2 , but can have a profound influence for \tau_{0}/T \geq 0.3 . We also find that using 4-PSK leads to better detection performance, in certain cases, than using 2-PSK.
199 citations
TL;DR: A new approach to PSK signal detection over a slow nonselective Rayleigh fading channel which does not require a carrier recovery loop is considered and coherent demodulation is achieved by making use of estimates of the quadrature amplitudes of the received PSK signals.
Abstract: We consider here a new approach to PSK signal detection over a slow nonselective Rayleigh fading channel which does not require a carrier recovery loop. The receiver achieves coherent demodulation by making use of estimates of the quadrature amplitudes of the received PSK signals in its likelihood ratio test. The receiver is assumed to have a memory containing information on the past received signals which enables it to generate the estimates. The error rate of the receiver can be evaluated analytically and computer simulation results are presented to verify the predicted performance.
73 citations
TL;DR: In this article, a combined source-channel coding approach is described for the encoding, transmission, and remote reconstruction of image data, where the transmission medium considered is that of a fading dispersive communications channel.
Abstract: A combined source-channel coding approach is described for the encoding, transmission, and remote reconstruction of image data. The transmission medium considered is that of a fading dispersive communications channel. Both the Rician fading and Rayleigh fading channel models are considered. The image source encoder employs two-dimensional (2-D) differential pulse code modulation (DPCM). This is a relatively efficient encoding scheme in the absence of channel errors. In the presence of fading, however, the performance degrades rapidly. By providing error control protection to those encoded bits which contribute most significantly to image reconstruction, it is possible to minimize this degradation without sacrificing transmission bandwidth. Several modulation techniques are employed in evaluation of system performance including noncoherent multiple frequency shift-keyed (MFSK) modulation. Analytical results are provided for assumed 2-D autoregressive image models, while simulation results are described for real-world images.
24 citations
TL;DR: A simplified method based on the correlated Rayleigh probability distribution of in-band radio signals can be efficiently applied to the calculation of the outage for various radio path length, propagation terrain, radio frequency, bandwidth, and digital modulation techniques.
Abstract: We propose a simplified method based on the correlated Rayleigh probability distribution of in-band radio signals. It can be efficiently applied to the calculation of the outage for various radio path length, propagation terrain, radio frequency, bandwidth, and digital modulation techniques. Predicted results are compared to various propagation data.
14 citations
TL;DR: Equalizer circuitry at intermediate frequencies is described, which continuously senses the level as a function of frequency in the transmission band and dynamically corrects the effects of multipath fading.
Abstract: Multipath fading can introduce severe amplitude distortion and level changes in a radio channel. These must be dynamically equalized to meet the toll transmission requirements of AR6A. This article describes equalizer circuitry at intermediate frequencies, which continuously senses the level as a function of frequency in the transmission band and dynamically corrects the effects of multipath fading.
5 citations
TL;DR: Application of the union bound to MFSK signaling on certain channels where probability of bit error varies in an inverse linear fashion with E_{b}/N_{0} can lead to the erroneous conclusion that performance degrades with increasing alphabet size.
Abstract: Application of the union bound to MFSK signaling on certain channels where probability of bit error varies in an inverse linear fashion with E_{b}/N_{0} can lead to the erroneous conclusion that performance degrades with increasing alphabet size. The anomaly is shown for the worst-case partial band Gaussian interference channel and the Rayleigh fading channel.
4 citations
TL;DR: Distributions for the intervals between shallower fades exhibit preferred durations caused by peaks in the Doppler fading spectrum, and for intervals between deep fades, these distributions take on a Poisson form.
Abstract: This paper presents distributions of the intervals between fades measured on a hardware-simulated Rayleigh-fading mobile radio channel. For intervals between deep fades, these distributions take on a Poisson form. Measured results are in good agreement with a simple analytical model. Distributions for the intervals between shallower fades exhibit preferred durations caused by peaks in the Doppler fading spectrum.
2 citations