Showing papers on "Channel state information published in 1983"
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: 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: The findings show that the worst channel conditions for an optical communication system exist when the turbulence is moderate, and a binary union decoder system consisting of one storage register is used to enhance the reliability of this type of fading channel.
Abstract: Atmospheric turbulence causes random fading in any open-air optical communication channel. When the transmitted message is in the form of a block code, a binary union decoding system consisting of one storage register can be used to enhance the reliability of this type of fading channel. To illustrate the effectiveness of the binary union decoder, we compare probabilities of detecting one word out of N + 1 received words for both a binary union decoder and a simple word recognition decoder system. Finally, the binary union decoder is analyzed for three different fading conditions of the channel corresponding to conditions of atmospheric turbulence typical of weak, moderate, and superstrong scattering. Our findings show that the worst channel conditions for an optical communication system exist when the turbulence is moderate
1 citations