On the Performance of the Layered-Division-Multiplexing using Maximal-Ratio Combining

2012 ◽  
Vol 16 (2) ◽  
pp. 52-62
Author(s):  
Tanapong Khumyat
Keyword(s):  
Fading Channels ◽  
Signal To Noise Ratio ◽  
Moment Generating Function ◽  
Symbol Error Rate ◽  
Maximal Ratio Combining ◽  
Gain Enhancement ◽  
Significant Performance ◽  
Average Symbol Error Rate ◽  
The Moment ◽  
Systems Simulation

This article proposes the diversity gain enhancement in layered division multiplexing (LDM) systems by applying maximal-ratio combining (MRC) technique. LDM systems is adopted as a baseline technology of the ATSC 3.0 systems which the two transmission layers are simultaneously transmitted over two different types of fading channels for fixed and mobile services. Hence, the performance analysis of each layer need to be evaluated on different type of fading channel. Starting with the moment generating function (MGF) of the MRC output signal-to-noise ratio (SNR), we propose the new method to derive closed-form expressions for average symbol-error rate (SER) of the proposed systems over Rayleigh and Nakagami-m fading channels in the presence of error propagation (EP) that is generated from the first layer detection. Analytical results show that the specific value of injection level at the transmitter need to be precisely defined to obtain the best mutual benefit for both LDM layers, and the proposed technique has significant performance advantage over conventional LDM systems. Simulation results demonstrate the tightness of the author’s analysis.

Dual-Hop Amplify-and-Forward Variable Gain Relaying over Mixture Gamma Fading Channels

2015 ◽  
Vol 719-720 ◽  
pp. 767-772
Author(s):  
Wei Jun Cheng
Keyword(s):  
Fading Channels ◽  
Signal To Noise Ratio ◽  
Symbol Error Rate ◽  
Amplify And Forward ◽  
Variable Gain ◽  
Average Symbol Error Rate ◽  
Simulation Results ◽  
End To End ◽  
The Moment ◽  
Relaying System

In this paper, we present the end-to-end performance of a dual-hop amplify-and-forward variablegain relaying system over Mixture Gamma distribution. Novel closed-form expressions for the probability density function and the moment-generation function of the end-to-end Signal-to-noise ratio (SNR) are derived. Moreover, the average symbol error rate, the average SNR and the average capacity are found based on the above new expressions, respectively. These expressions are more simple and accuracy than the previous ones obtained by using generalized-K (KG) distribution. Finally, numerical and simulation results are shown to verify the accuracy of the analytical results.

Dual-Hop Fixed Gain Relaying Transmissions with Semi-Blind in Asymmetric Multipath/Shadowing Fading Channels

2015 ◽  
Vol 9 (1) ◽  
pp. 82-90
Author(s):  
Weijun Cheng ◽  
Teng Chen
Keyword(s):  
Fading Channels ◽  
Cumulative Distribution Function ◽  
Signal To Noise Ratio ◽  
Ergodic Capacity ◽  
Moment Generating Function ◽  
Symbol Error Rate ◽  
Cumulative Distribution ◽  
Simulation Results ◽  
End To End ◽  
The Moment

In this paper, we investigate the end-to-end performance of a dual-hop fixed gain relaying system with semiblind relay under asymmetric fading environments. In such environments, the wireless links of the considered system undergo asymmetric multipath/shadowing fading conditions, where one link is subject to only the Nakagami-m fading, the other link is subject to the composite Nakagami-lognormal fading which is approximated by using mixture gamma fading model. First, the cumulative distribution function (CDF), the moment generating function (MGF) and the moments of the end-to-end signal-to-noise ratio (SNR) are derived under two asymmetric scenarios. Then, novel closed-form expressions of the outage probability, the average end-to-end SNR, the symbol error rate and the ergodic capacity for the dual-hop system are obtained based on the CDF and the MGF, respectively. Finally, some numerical and simulation results are shown and discussed to validate the accuracy of the analytical results under different scenarios, such as varying average SNR, fading parameters per hop, the choice of the semi-blind gain and the location of relaying nodes.

scholarly journals Performance Study of Wireless Systems with Switch and Stay Combining Diversity over α-η-μ Fading Channels

2019 ◽  
Vol 9 (6) ◽  
pp. 5047-5055 ◽  
Author(s):  
A. A. Eyadeh ◽  
M. N. Al-Ta'ani
Keyword(s):  
Fading Channels ◽  
Wireless Systems ◽  
Moment Generating Function ◽  
Symbol Error Rate ◽  
Optimal Choice ◽  
Performance Study ◽  
Average Output ◽  
Channel Parameters ◽  
Average Symbol Error Rate ◽  
The Moment

In this paper, we consider a Switch and Stay Combiner (SSC) diversity scheme operating over α−η−μ fading channel. New and closed-form expressions for the average output SNR (ASNR), the moment-generating function (MGF), the outage probability (P_out), and the average symbol error rate (ASER) for M-ary quadrature amplitude modulation (QAM) signaling are derived. The expressions are obtained in terms of the well-known bivariate Fox’s H-function (BFHF). It is worth pointing out that the BFHF and the bivariate Meijer’s G-function (BMGF) have recently been used extensively in wireless communications literature to study the system's performance. The evaluated results are plotted for channel parameters of interest, and the effect of fading severity on the combiner performance is studied. Moreover, the results are shown to match those previously reported in the literature for other channel models such as η−μ as a special case, which confirms the validity of the obtained expressions. Also, insights on the optimal choice of the switching threshold are provided.

scholarly journals SER Performance of Enhanced Spatial Multiplexing Codes with ZF/MRC Receiver in Time-Varying Rayleigh Fading Channels

2014 ◽  
Vol 2014 ◽  
pp. 1-12
Author(s):  
In-Ho Lee
Keyword(s):  
Fading Channels ◽  
Rayleigh Fading ◽  
Signal To Noise Ratio ◽  
Moment Generating Function ◽  
Symbol Error Rate ◽  
Spatial Multiplexing ◽  
Maximal Ratio Combining ◽  
Rayleigh Fading Channels ◽  
Time Varying ◽  
Spatially Correlated

We propose enhanced spatial multiplexing codes (E-SMCs) to enable various encoding rates. The symbol error rate (SER) performance of the E-SMC is investigated when zero-forcing (ZF) and maximal-ratio combining (MRC) techniques are used at a receiver. The proposed E-SMC allows a transmitted symbol to be repeated over time to achieve further diversity gain at the cost of the encoding rate. With the spatial correlation between transmit antennas, SER equations forM-ary QAM and PSK constellations are derived by using a moment generating function (MGF) approximation of a signal-to-noise ratio (SNR), based on the assumption of independent zero-forced SNRs. Analytic and simulated results are compared for time-varying and spatially correlated Rayleigh fading channels that are modelled as first-order Markovian channels. Furthermore, we can find an optimal block length for the E-SMC that meets a required SER.

scholarly journals Exact Performance Analysis of Amplify-and-Forward Bidirectional Relaying over Nakagami-m Fading Channels with Arbitrary Parameters

Energies ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1277
Author(s):  
Dong Qin ◽  
Yuhao Wang ◽  
Tianqing Zhou
Keyword(s):  
Fading Channels ◽  
Signal To Noise Ratio ◽  
Ergodic Capacity ◽  
Moment Generating Function ◽  
Amplify And Forward ◽  
Relay Systems ◽  
Signal Error ◽  
Bidirectional Relaying ◽  
Fading Parameter ◽  
The Moment

The exact performance of amplify-and-forward (AF) bidirectional relay systems is studied in generalized and versatile Nakagami-m fading channels, where the parameter m is an arbitrary positive number. We consider three relaying modes: two, three, and four time slot bidirectional relaying. Closed form expressions of the moment generating function (MGF), higher order moments of signal-to-noise ratio (SNR), ergodic capacity, and average signal error probability (SEP) are derived, which are different from previous works. The obtained expressions are very concise, easy to calculate, and evaluated instantaneously without a complex summation operation, in contrast to the nested multifold numerical integrals and truncated infinite series expansions used in previous work, which lead to computational inefficiency, especially when the fading parameter m increases. Simulation results corroborate the correctness and tightness of the theoretical analysis.

scholarly journals Performance Analysis of AF Relays with Maximal Ratio Combining in Nakagami-m Fading Environments

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Dong Qin ◽  
Yuhao Wang ◽  
Tianqing Zhou
Keyword(s):  
Performance Metrics ◽  
Signal To Noise Ratio ◽  
Ergodic Capacity ◽  
Moment Generating Function ◽  
Maximal Ratio Combining ◽  
Modulation Scheme ◽  
Amplify And Forward ◽  
Generalized Gaussian Noise ◽  
The Moment ◽  
Fading Environments

This paper investigates the maximal ratio combining (MRC) performance of an amplify and forward (AF) relay system in Nakagami-m fading environments. The study considers a general scenario with distinct m fading parameters for the following three links, source to relay link, and source to destination link and relay to destination link. We derive new closed form expressions for the statistics of important performance metrics, including the moment generating function, outage probability, higher order moments of equivalent signal to noise ratio (SNR), ergodic capacity, and average symbol error probability (SEP) of common modulation types. In particular, we focus on analytical SEP expressions in the context of an additive white generalized Gaussian noise (AWGGN). As an active area of research, generalized noise receives much attention for its flexible model. However, analytical performance of modulation scheme in generalized noise type has not been found in open literature for AF relaying with MRC despite its practical usefulness. Without the help of analytical solutions, the SEP in generalized noise can only be obtained by a large number of repeated simulation experiments. Therefore, we present the general SEP expression by using special Fox’s H function. Simulation results verify the accuracy of our theoretical analysis and show that the diversity order of MRC criterion linearly depends upon Nakagami parameters of three links.

Performance Analysis of Multi-Hop Multi-Branch Amplify-and-Forward Cooperative Communication Over Rician Fading Channels

2019 ◽  
Vol 29 (09) ◽  
pp. 2050148
Author(s):  
Hadi Fathollahi ◽  
Mohammad H. Madani
Keyword(s):  
Fading Channels ◽  
Cooperative Communication ◽  
Channel Model ◽  
Asymptotic Expression ◽  
Signal To Noise Ratio ◽  
Moment Generating Function ◽  
Maximal Ratio Combining ◽  
Rician Fading ◽  
Amplify And Forward ◽  
Rician Fading Channels

Performance of multi-hop multi-branch amplify and forward (AF) cooperative communication over Rician fading channels is presented in this paper by a novel analysis method. Rician distribution is used to analyze the system because this channel model is useful in aerospace wireless communication channels. We derive an asymptotic expression for the statistics of the received signal-to-noise ratio (SNR) in the system under study with well-known moment-generating function (MGF)-based approach with maximal ratio combining (MRC) scheme. Moreover, for comparative analysis in different branches and hops, outage probability and symbol error ratio are derived. Finally, numerical simulation results are provided to confirm the theoretical results. These results are presented to illustrate the considerable performance improvement achieved by the increasing number of branches and hops.

scholarly journals Performance Analysis of RIS-Assisted FSO Communications over Fisher–Snedecor F Turbulence Channels

2021 ◽  
Vol 11 (21) ◽  
pp. 10149
Author(s):  
Caslav Stefanovic ◽  
Máximo Morales-Céspedes ◽  
Ana García Armada
Keyword(s):  
Fading Channels ◽  
Direct Detection ◽  
Signal To Noise Ratio ◽  
Moment Generating Function ◽  
Cumulative Distribution ◽  
Model Parameters ◽  
Free Space Optical ◽  
F Distribution ◽  
The Moment ◽  
Analytical Expressions

The Fisher–Snedecor (F-S) F distribution has recently been introduced as a tractable turbulence-induced (TI) fading model that fits well with the experimental data. This paper provides a performance evaluation of a free-space optical (FSO) re-configurable intelligent surface (RIS)-assisted communications (ACs) link over the F-S F TI fading channels, assuming the intensity modulation–direct detection (IM–DD) technique. In particular, novel and closed-form (C-F) analytical expressions for the probability density function (PDF) and cumulative distribution function (CDF) of the end-to-end signal-to-noise ratio (SNR) in terms of Gaussian hyper-geometric functions are efficiently derived. Capitalizing on the obtained results, novel C-F analytical expressions for the moment generating function (MMGF), outage probability (OP), average bit error rate (BER) and ergodic channel capacity (Cγ) of the FSO RIS-ACs system over the F-S F TI fading channels are provided and numerically evaluated under the various TI fading severity conditions. Furthermore, the second-order (S-O) statistical expressions for the level crossing rate (LCR) and average fade duration (AFD) are obtained and thoroughly examined for various FSO RIS-ACs system model parameters.

scholarly journals Symbol Error Probability of DF Relay Selection over Arbitrary Nakagami-mFading Channels

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
George C. Alexandropoulos ◽  
Paschalis C. Sofotasios ◽  
Khuong Ho-Van ◽  
Steven Freear
Keyword(s):  
Fading Channels ◽  
Relay Selection ◽  
Error Probability ◽  
Signal To Noise Ratio ◽  
Moment Generating Function ◽  
Symbol Error Probability ◽  
Decode And Forward ◽  
Shift Keying ◽  
Relaying Systems ◽  
The Moment

We present a new analytical expression for the moment generating function (MGF) of the end-to-end signal-to-noise ratio of dual-hop decode-and-forward (DF) relaying systems with relay selection when operating over Nakagami-mfading channels. The derived MGF expression, which is valid for arbitrary values of the fading parameters of both hops, is subsequently utilized to evaluate the average symbol error probability (ASEP) ofM-ary phase shift keying modulation for the considered DF relaying scheme under various asymmetric fading conditions. It is shown that the MGF-based ASEP performance evaluation results are in excellent agreement with equivalent ones obtained by means of computer simulations, thus validating the correctness of the presented MGF expression.

scholarly journals On the Error Rate Analysis of Dual-Hop Amplify-and-Forward Relaying in Generalized-KFading Channels

2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
George P. Efthymoglou ◽  
Nikolaos Bissias ◽  
Valentine A. Aalo
Keyword(s):  
Fading Channels ◽  
Error Rate ◽  
Signal To Noise Ratio ◽  
Geometric Mean ◽  
Moment Generating Function ◽  
Error Rates ◽  
Maximal Ratio Combining ◽  
Closed Form Expression ◽  
Amplify And Forward ◽  
Amplify And Forward Relaying

We present novel and easy-to-evaluate expressions for the error rate performance of cooperative dual-hop relaying with maximal ratio combining operating over independent generalized- fading channels. For this system, it is hard to obtain a closed-form expression for the moment generating function (MGF) of the end-to-end signal-to-noise ratio (SNR) at the destination, even for the case of a single dual-hop relay link. Therefore, we employ two different upper bound approximations for the output SNR, of which one is based on the minimum SNR of the two hops for each dual-hop relay link and the other is based on the geometric mean of the SNRs of the two hops. Lower bounds for the symbol and bit error rates for a variety of digital modulations can then be evaluated using the MGF-based approach. The final expressions are useful in the performance evaluation of amplify-and-forward relaying in a generalized composite radio environment.

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