SC Receiver Research Articles

On the ASER performance of SC receiver with RQAM and HQAM over [formula omitted]-[formula omitted] fading

In this paper, we consider a multi-branch selection combining receiver over independent and non-identically distributed κ-μ fading channels. We derive new exact expressions for moment generating function of output signal-to-noise-ratio (SNR), average symbol error rate (ASER) of coherent rectangular and hexagonal quadrature amplitude modulations, and ASER of non-coherent frequency shift-keying modulation schemes. Further, an asymptotic ASER expression is also derived to determine the diversity order of the system. The analytical results are validated using Monte-Carlo simulations for a wide range of SNRs and fading parameters. Finally, the impact of channel parameters and the number of branches on the ASER performance is also studied.

New Results and Applications about the Level Crossing Rate of SC Receiver output Signal in the Presence of Gamma Shadowing and k-μ or Rician Multipath Fading

In this paper,the wireless communication system with dual SC receiver operating over shadowed multipath fading channel is considered. The multipath fadingis k-μor Rician.The received signal experiences the short term fading which is resulting in SC receiver envelope variation and Gamma long term fading resulting in SC receiver envelope power variation. The closed form expressions for joint probability density functions of SC receiver output signal envelope and their first derivative of SC receiver output signal envelope are calculated for both, k-μand Rician fading. These expressions are used for evaluation of average level crossing rate of SC receiver output signal envelopes. The numerical expressions are plotted to show the effect of Rician fading severity parameter and Gamma shadowing severity parameter on the average level crossing rate of SC receiver output signal envelope.

Unsteady thermotechnical model of a closed flat plate solar collector–storage tank system

The main provisions of the developed numerical unsteady model of the flat plate solar collector–storage tank (SC–ST) system are given. The model takes into account all of the main parameters of the SC (receiver parameters, radiative properties of the transparent fence for solar radiation, and thermophysical properties of the thermal insulation of the bottom) and the ST (thermophysical parameters of thermal insulation). An algorithm and a program for calculating the thermal properties of a closed SC–ST system have been developed based on this model in the Delphi language. The results of the calculated estimates of the time variation of water heating temperatures in the ST and the efficiency of the closed SC–ST system as a function of the ST volume are given for the case where the water temperature at the SC inlet is equal to the mean water temperature in the ST. The model and the program also make it possible to determine the time variation of temperatures of SC elements and water in individual sections along the length of the SC as well as the thermal losses of the SC sections. The model makes it possible to estimate the effect of the thermal properties of SC elements and the water velocity on the thermal properties of the SC–ST system. The program can be modified for the case of the open SC–ST system, i.e., where the water temperature at the SC inlet does not depend on the water temperature in the ST.

Level crossing rate of SC receiver over gamma shadowed Weibull multipath fading channel

Level crossing rate of SC receiver over gamma shadowed Weibull multipath fading channel

On the Effects of Correlation on Outage Performance of FSO-Unbalanced Multibranch SC Receiver

In this letter, we study the outage performance of unbalanced multibranch selection combining receiver operating over free-space optical gamma–gamma turbulence link. The analysis is performed in the case when the position of closely placed photodiodes corresponds to the constant correlation model. Novel analytical expressions for the probability density function and cumulative distribution function of receiver signal-to-noise ratio (SNR) are derived in the infinite series form whose convergence is numerically determined. Based on these analytical results, we examine the simultaneous effects of the spatial correlation, diversity order, photodiode’s diameter, and turbulence strength on outage performance. The results illustrate that spatial correlation has a strong effect on SNR gain decreasing, especially for the higher values of diversity order.

First-Order Statistical Characteristics of Macrodiversity System with Three Microdiversity MRC Receivers in the Presence of k-µ Short-Term Fading and Gamma Long-Term Fading

Macrodiversity system with macrodiversity SC receiver and three microdiversity MRC (maximum ratio combining) receivers is considered. Independent k-μ short-term fading and correlated Gamma long-term fading are present at the inputs of microdiversity MRC receivers. For this model, the probability density function and the cumulative density function of microdiversity MRC receivers and macrodiversity SC receiver output signal envelopes are calculated. Influences of Gamma shadowing severity, k-μ multipath fading severity, Rician factor and correlation coefficient at probability density function, and cumulative density function of macrodiversity SC receiver output signal envelopes are graphically presented.

Moments of Macrodiversity SC Receiver with Two Microdiversity EGC Receivers over Gamma Shadowed Rician Multipath Fading Channel

SC macrodiversity system with dual EGC microdiversity receivers operating over shadowed multipath fading environment is considered. Received signal experiences correlated Gamma long term fading and Rician short term fading. SC macrodiversity receiver reduces Gamma large scale fading effects, while EGC microdiversity receivers mitigate short term fading effects on system performance. Closed form expressions for arbitrary order output moments of macrodiversity structure output signal is evaluated. Numerical results, obtained for arbitrary order output moments are presented graphically to show Gamma long term fading severity effect, correlation coefficient effects and Rician factor effect.

Level Crossing Rate of Macrodiversity System in the Presence of Multipath Fading and Shadowing

Macrodiversity system including macrodiversity SC receiver and two microdiversity SC receivers is consid- ered in this paper. Received signal experiences, simultane- ously, both, long term fading and short term fading. Microdiversity SC receivers reduce Rayleigh fading effects on system performance and macrodiversity SC receivers mitigate Gamma shadowing effects on system performance. Closed form expressions for level crossing rate of microdi- versity SC receivers output signals envelopes are calcu- lated. This expression is used for evaluation of level crossing rate of macrodiversity SC receiver output signal envelope. Numerical expressions are illustrated to show the influence of Gamma shadowing severity on level crossing rate.

Outage Probability of L-SC Receiver over Exponentially Correlated η – μ Fading Channels

A mathematical expression for the outage probability of an L branch selection combining diversity receiver is obtained for exponentially correlated η - μ fading channels. A new expression for the joint probability density function of exponentially correlated multivariate η - μ random variable is derived, which is further used to obtain the expression for the outage probability of a SC receiver. Numerical and simulation results are plotted and the effect of fading correlation, L and fading parameter on the outage probability of the receiver are studied. From the obtained result, we observed that it is better to go for lower order diversity with sufficient antenna spacing instead of higher order diversity with less antenna spacing.

Performance of SC Receiver over Generalized K Fading Channel in the Presence of Imperfect Reference Signal Recovery

This paper considers a partially coherent detection of quadrature phase-shift keying (QPSK) signals in a composite generalized K (KG) fading channel. At the reception the selection combining is applied, while the branches of the combiner are not identically distributed. The extraction of the reference carrier from non-modulated pilot signal is performed in a phase-locked loop (PLL) circuit. The difference between received signal phase and extracted reference signal phase is a stochastic variable with Tikhonov probability density function. The influence of the fading parameters, the standard deviation of phase error and the number of diversity branches on the system performance is examined. The bit-error rate is used as a measure of the reception quality. Ill. 6, bibl. 17 (in English; abstracts in English and Lithuanian).http://dx.doi.org/10.5755/j01.eee.115.9.746

Outage probability of SC receiver over exponentially correlated K fading channels

A mathematical expression for the outage probability of a selection combining diversity receiver with an arbitrary number of input branches is presented for exponentially correlated K fading channels. Numerical and simulation results are plotted and the effect of correlation, number of diversity branches and fading parameter on the outage performance of the receiver is studied. Results suggest that a correlation coefficient less than 0.5 may be used in practice.

Performance of S + N Selection Diversity Receivers in Correlated Rician and Rayleigh Fading

The performances of two signal-plus-noise (S + N) selection diversity receivers employing noncoherent M-ary frequency shift keying (MFSK) in slow, flat, correlated Rayleigh and Rician fading channels are examined. The branches are assumed to be equally correlated for Rician fading. The correlation model for Rayleigh fading is more general than the equally correlated scenario and includes it as a special case. Analytical expressions are derived for the average symbol error rate (SER) and the average bit error rate (BER) of each receiver structure. Extensive Monte Carlo simulation results are presented to validate the analytical expressions. The performances of the S + N SC receivers are compared to the performance of the classical SC receiver. The effects of correlation, average fading power imbalance and diversity order on the performances of the S + N SC receivers are examined.