Showing papers on "Fading distribution published in 1969"
TL;DR: This paper evaluates the error probabilities due to both additive noise and frequency selective fading for predetection diversity combining FDM-FM systems using the troposcatter channel.
Abstract: This paper evaluates the error probabilities due to both additive noise and frequency selective fading for predetection diversity combining FDM-FM systems using the troposcatter channel. Graphical results are presented for channel and modulation parameters of typical links.
3 citations
TL;DR: In this paper, it was shown that, for a carrier spread Bn ≥ 0.9 f2c (fc, being the mean carrier frequency in megahertz), the system performs better than a 4-fold equal-gain diversity system.
Abstract: Possibilities of efficient digital communication through a fading channel, using a narrowband noise carrier, have been investigated both theoretically and experimentally. It is shown that, for a carrier spread Bn ≥ 0.9 f2c (fc, being the mean carrier frequency in megahertz), the system performs better than a 4-fold equal-gain diversity system. Error rates against the channel carrier/noise ratio (c.n.r.) and channel separation (for multiplexed systems) are also shown.
2 citations
TL;DR: In this paper, a preliminary analysis suggests that the VLF signal strength minima observed during transition fading can be described by the First Asymptotic Distribution of the statistical theory of extreme values.
Abstract: A preliminary analysis suggests that the VLF signal strength minima (in decibels) observed during transition fading can be described by the First Asymptotic Distribution of the statistical theory of extreme values. In addition, the distribution of outage time relative to a fixed threshold level during transition fading seems to follow the Third Asymptotic Distribution.
2 citations
TL;DR: In this paper, two methods are proposed for obtaining the rms value of a fading signal directly and quickly from its decibel values: the direct method shows that the difference between the average of a decibel-scale fading-signal data set and the RMS value of the signal is within 2.5 dB.
Abstract: Two methods are proposed for obtaining the rms value of a fading signal directly and quickly from its decibel values. The level-crossing-rate method shows that the rms values of most kinds of signals are within 3 dB above the signal levels at which their maximum level crossing rates occur. The direct method shows that the difference between the average of a decibel-scale fading-signal datum and the rms value of the signal is within 2.5 dB for most of the fading signals.
1 citations
TL;DR: In this article, the results of an experimental investigation of binary error rates in an FSK channel experiencing nonselective fading are presented, and the theoretical examination and the data obtained demonstrate that fast fading and/or differential Doppler generally improve the link error rate performance with respect to the nonfading case.
Abstract: The results of an experimental investigation of binary error rates in an FSK channel experiencing nonselective fading are presented. For all cases considered, the received frequency uncertainty is large compareded to the bit rate, requiring the use of an envelope detector rather than a matched filter. Both slow and fast fading rates are considered and include the effects of differential Doppler shift between the direct and reflected energy. A simplified mathematical analysis is presented to support the observed results. Both the theoretical examination and the data obtained demonstrate that fast fading and/or differential Doppler generally improve the link error rate performance with respect to the nonfading case.
1 citations
01 Dec 1969