We construct a finite-state Markov chain model for a Rayleigh fading channel by partitioning the range of the received signal envelope into K intervals. From a simulation of the classic two-way Rayleigh fading model, a Markov transition probability matrix is obtained. Based on this matrix, we introduce an adaptive forward error correction (FEC) coding scheme. Simulation results show that the adaptive FEC coding scheme significantly improves the performance of a wireless communication system.

In most current implementations of CT2 telepoint systems, only handset initiated calls are allowed. This paper describes a design to allow two-way calling for the CT2 public telepoint system with minimal modifications to the current CT2 infrastructure and the public switched telephone network (PSTN). The design makes use of centralized databases in the home location register (HLR) and visitor location registers (VLR) to track the location of handsets. This location information is stored in the VLR and HLR, and is used by the PSTN to route incoming calls destined for CT2 handsets to the appropriate CT2 telepoint base station (TBS). The TBS connect to the PSTN local exchanges (LE) through the integrated services digital network (ISDN) basic rate interfaces (BRI) for fast out-of-band signaling. We present simulation results of the system with the objective of determining where congestion might occur within the system and to understand the impact of the new implementation on the PSTN. The results indicate that the performance of the system will be limited by the VLR processing speed and the number of ISDN BRI's connecting the ISDN front end (IFE) to the PSTN.>

The probability of an SCM (subcarrier multiplexed) signal falling outside the linear region of a laser diode is calculated in order to determine the overmodulation that may be practically employed for multichannel video distribution in single-octave SCM networks. The overmodulation is predicted as a function of the number of subcarriers in single-octave SCM systems supporting up to about 70 FM video channels, for SNRs (signal-to-noise ratios) of 47 dB (I/PAL), and 56 dB (M/NTSC). The RMS optical modulation index (OMI) is demonstrated to be a more useful performance parameter than the linear OMI in SCM systems carrying a large number of channels. A 47 dB weighted SNR (with 4 dB margin) is deemed sufficient for acceptable picture quality in cable distribution systems, whereas a 56 dB value would be required for long-distance point-to-point optical links. RMS OMI values of around 70 and 50, respectively, can be employed.>

An algorithm that can minimize the effects of a tone interference in a Fourier transform data transmission (FTDT) system is derived. The algorithm works well even in the presence of additive white Gaussian noise. The error performance of the FTDT system with this tone removal method is discussed. A simulation study shows that this algorithm limits the system error performance deterioration due to a large tone interference to about 0.3 dB. The implementation of this algorithm requires three complex words at the transmitter transform input to be filled with zeros. The observed values at the corresponding location at the receiver transform output are used to evaluate the characteristics of the interfering tone. The effects of the tone interference can then be eliminated.>

Two new series representations for the Rice functionIe (k, x)are presented. One of the series involves the modified Struve functions and the other involves the modified Bessel functions. These two series complement each other in their convergence speeds as functions of the values ofkandx. The truncation error bounds are derived for both series. Therefore, they can be used alternatively with high efficiency and known precision.

This paper presents a new series for evaluating the conditional bit error rate (BER) of a given transmitted data sequence in a band-limited binary differential-phase-shift-keyed system. This series involves modified Struve functions and it was found to have converged quickly. The conditional BER can then be averaged over all possible bit sequences to yield the system BER. The results obtained are close to those reported by G. J. Marshall. In our analysis the noise samples a bit period apart were assumed to be uncorrelated.