scholarly journals Per User Based Interference Alignment for Uplink CoMP with Perfect CSI under Different Channel Models

2021 ◽  
pp. 444-449
Author(s):  
Amalia Eka Rakhmania ◽  
◽  
Mochammad Taufik ◽  
Aad Hariyadi ◽  
Hudiono Hudiono ◽  
...  
Keyword(s):  
Fading Channels ◽  
Additive White Gaussian Noise ◽  
Interference Alignment ◽  
Channel Models ◽  
Low Snr ◽  
Rayleigh Channel ◽  
Awgn Channel ◽  
Nakagami Fading Channel ◽  
Sum Rate ◽  
Uplink Comp

Per-user based SLNR-SINR interference alignment (IA) algorithm for uplink CoMP is evaluated under different channel models. Rayleigh, Rician, and Nakagami fading channel is used in transmission with the Additive White Gaussian Noise (AWGN) channel set as reference. Performance evaluation is based on its achievable sum rate and convergence rate by varying the channel, the number of serving cells, and UE's transmit and receive antenna combination. Assuming perfect CSI, the result shows that the maximum achievable sum rate is when the communication occurs in the AWGN channel. There are 3 bps/Hz difference between communication over Rayleigh and Nakagami channel, and 1.5 bps/Hz difference between Rician and Nakagami channel. Among the three fading channels, a smaller number of transmitting and receiving antenna in UE resulted in a higher sum rate with 58.97 bps/Hz for IA in the Nakagami channel with {3, 2, 4, 4, 2} configuration. In the low SNR region, the lowest sum rate for this configuration achieves 15.87 bps/Hz for IA in the Rayleigh channel.

scholarly journals An M-QAM Signal Modulation Recognition Algorithm in AWGN Channel

2019 ◽  
Vol 2019 ◽  
pp. 1-17
Author(s):  
Ahmed K. Ali ◽  
Ergun Erçelebi
Keyword(s):  
Fading Channels ◽  
Input Data ◽  
Additive White Gaussian Noise ◽  
Recognition Rate ◽  
Higher Order ◽  
Superior Performance ◽  
Modulation Classification ◽  
Classification Rate ◽  
Automatic Modulation Classification ◽  
Awgn Channel

Computing the distinct features from input data, before the classification, is a part of complexity to the methods of automatic modulation classification (AMC) which deals with modulation classification and is a pattern recognition problem. However, the algorithms that focus on multilevel quadrature amplitude modulation (M-QAM) which underneath different channel scenarios is well detailed. A search of the literature revealed that few studies were performed on the classification of high-order M-QAM modulation schemes such as 128-QAM, 256-QAM, 512-QAM, and 1024-QAM. This work focuses on the investigation of the powerful capability of the natural logarithmic properties and the possibility of extracting higher order cumulant’s (HOC) features from input data received raw. The HOC signals were extracted under the additive white Gaussian noise (AWGN) channel with four effective parameters which were defined to distinguish the types of modulation from the set: 4-QAM∼1024-QAM. This approach makes the classifier more intelligent and improves the success rate of classification. The simulation results manifest that a very good classification rate is achieved at a low SNR of 5 dB, which was performed under conditions of statistical noisy channel models. This shows the potential of the logarithmic classifier model for the application of M-QAM signal classification. furthermore, most results were promising and showed that the logarithmic classifier works well under both AWGN and different fading channels, as well as it can achieve a reliable recognition rate even at a lower signal-to-noise ratio (less than zero). It can be considered as an integrated automatic modulation classification (AMC) system in order to identify the higher order of M-QAM signals that has a unique logarithmic classifier to represent higher versatility. Hence, it has a superior performance in all previous works in automatic modulation identification systems.

scholarly journals SYMBOL ERROR PROBABILITY OF 16-QAM SYSTEM OVER AWGN AND RAYLEIGH FADING CHANNELS

2020 ◽  
Vol 7 ◽  
pp. 29
Author(s):  
Oluwadamilola Kehinde Oyetola ◽  
Ayodeji Akinsoji Okubanjo ◽  
Alexander Akpofure Okandeji ◽  
Peter Olufemi Alao ◽  
Martins O. Osifeko ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Fading Channels ◽  
High Speed ◽  
Service Providers ◽  
Additive White Gaussian Noise ◽  
Mathematical Expression ◽  
Symbol Error Rate ◽  
Data Services ◽  
Human Interactions ◽  
Rayleigh Channel

Wireless communication had transformed the mode of human interactions in recent times, distance is no longer a barrier as messages can be sent several miles apart within few seconds. In addition, the pervasive adoption of mobile communication system had engendered researchers to device new and effective technologies to enhance Quality of Service (QOS) offered by service providers. This is obvious in the deployment of trending mobile generations such as 2G, 3G and 4G systems for high speed voice and data services. Nevertheless, these systems are still embattled with unpredictable impairment such as noise in fading channels that impedes optimal system performance. In this paper, performance evaluation of 16–Quadrature Amplitude Modulation (16-QAM) system over Additive White Gaussian Noise (AWGN) and Rayleigh Channels using simulated and theoretical approach is presented. Theoretical mathematical expression for Symbol Error Rate(SEP) was derived, and simulation was setup using MATLAB/SIMULINK for performance evaluation. The results show that SEP is dependent on signal-noise-ratio (SNR) for both methods. However, SEP wasvery high for Rayleigh channel as compared with AWGN.

Performance Comparison between DPSK and OQPSK modulation approaches in multi environments channels with Matlab Simulink models

2019 ◽  
Vol 7 (1) ◽  
pp. 30-39
Author(s):  
Fatima faydhe Al- Azzawi ◽  
Faeza Abas Abid ◽  
Zainab faydhe Al-Azzawi
Keyword(s):  
Phase Shift ◽  
Fading Channels ◽  
Additive White Gaussian Noise ◽  
Block Codes ◽  
Performance Comparison ◽  
Phase Shift Keying ◽  
Differential Phase Shift ◽  
Matlab Simulink ◽  
Communication Industry ◽  
Shift Keying

Phase shift keying modulation approaches are widely used in the communication industry. Differential phase shift keying (DPSK) and Offset Quadrature phase shift keying (OQPSK) schemes are chosen to be investigated is multi environment channels, where both systems are designed using MATLAB Simulink and tested. Cross talk and unity of signals generated from DPSK and OQPSK are examined using Cross-correlation and auto-correlation, respectively. In this research a proposed system included improvement in bit error rate (BER) of both systems in  the additive white Gaussian Noise (AWGN) channel, by using the convolutional and block codes, by increasing the ratio of energy in the specular component to the energy in the diffuse component (k) and  the diversity order BER in the fading channels will be improved in both systems.    

scholarly journals Threshold Computation for Spatially Coupled Turbo-Like Codes on the AWGN Channel

Entropy ◽  
2021 ◽  
Vol 23 (2) ◽  
pp. 240
Author(s):  
Muhammad Umar Farooq ◽  
Alexandre Graell i Amat ◽  
Michael Lentmaier
Keyword(s):  
Gaussian Noise ◽  
Belief Propagation ◽  
Additive White Gaussian Noise ◽  
Maximum A Posteriori ◽  
Prediction Methods ◽  
Threshold Analysis ◽  
A Posteriori ◽  
Awgn Channel ◽  
Efficient Prediction ◽  
Binary Erasure Channel

In this paper, we perform a belief propagation (BP) decoding threshold analysis of spatially coupled (SC) turbo-like codes (TCs) (SC-TCs) on the additive white Gaussian noise (AWGN) channel. We review Monte-Carlo density evolution (MC-DE) and efficient prediction methods, which determine the BP thresholds of SC-TCs over the AWGN channel. We demonstrate that instead of performing time-consuming MC-DE computations, the BP threshold of SC-TCs over the AWGN channel can be predicted very efficiently from their binary erasure channel (BEC) thresholds. From threshold results, we conjecture that the similarity of MC-DE and predicted thresholds is related to the threshold saturation capability as well as capacity-approaching maximum a posteriori (MAP) performance of an SC-TC ensemble.

On the Mutual Information and Low-SNR Capacity of Memoryless Noncoherent Rayleigh-Fading Channels

2008 ◽  
Vol 54 (7) ◽  
pp. 3221-3231 ◽  
Author(s):  
SÉbastien de la Kethulle de Ryhove ◽  
Ninoslav Marina ◽  
Geir E. Oien
Keyword(s):  
Mutual Information ◽  
Fading Channels ◽  
Rayleigh Fading ◽  
Rayleigh Fading Channels ◽  
Low Snr

scholarly journals BER Performance Analysis of Non-Coherent Q-Ary Pulse Position Modulation Receivers on AWGN Channel

Sensors ◽  
2021 ◽  
Vol 21 (18) ◽  
pp. 6102
Author(s):  
Xianhua Shi ◽  
Yimao Sun ◽  
Jie Tian ◽  
Maolin Chen ◽  
Youjiang Liu ◽  
...  
Keyword(s):  
Gaussian Noise ◽  
Additive White Gaussian Noise ◽  
Theoretical Formula ◽  
Pulse Position Modulation ◽  
Error Performance ◽  
Optimal Receiver ◽  
Awgn Channel ◽  
Simulation Results ◽  
The Relationship ◽  
Better Than

This paper introduces the structure of a Q-ary pulse position modulation (PPM) signal and presents a noncoherent suboptimal receiver and a noncoherent optimal receiver. Aiming at addressing the lack of an accurate theoretical formula of the bit error rate (BER) of a Q-ary PPM receiver in the additive white Gaussian noise (AWGN) channel in the existing literature, the theoretical formulas of the BER of a noncoherent suboptimal receiver and noncoherent optimal receiver are derived, respectively. The simulation results verify the correctness of the theoretical formulas. The theoretical formulas can be applied to a Q-ary PPM system including binary PPM. In addition, the analysis shows that the larger the Q, the better the error performance of the receiver and that the error performance of the optimal receiver is about 2 dB better than that of the suboptimal receiver. The relationship between the threshold coefficient of the suboptimal receiver and the error performance is also given.

scholarly journals A New Reliability Ratio Weighted Bit Flipping Algorithm for Decoding LDPC Codes

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Chakir Aqil ◽  
Ismail Akharraz ◽  
Abdelaziz Ahaitouf
Keyword(s):  
Gaussian Noise ◽  
Additive White Gaussian Noise ◽  
Ldpc Codes ◽  
Low Density ◽  
Parity Check ◽  
Coding Gain ◽  
Decoding Complexity ◽  
Low Density Parity Check ◽  
Awgn Channel ◽  
Infinite Loop

In this study, we propose a “New Reliability Ratio Weighted Bit Flipping” (NRRWBF) algorithm for Low-Density Parity-Check (LDPC) codes. This algorithm improves the “Reliability Ratio Weighted Bit Flipping” (RRWBF) algorithm by modifying the reliability ratio. It surpasses the RRWBF in performance, reaching a 0.6 dB coding gain at a Binary Error Rate (BER) of 10−4 over the Additive White Gaussian Noise (AWGN) channel, and presents a significant reduction in the decoding complexity. Furthermore, we improved NRRWBF using the sum of the syndromes as a criterion to avoid the infinite loop. This will enable the decoder to attain a more efficient and effective decoding performance.

PERFORMANCE OF QAM-OFDM SYSTEM OVER RAYLEIGH FADING CHANNEL IN WEI BULL NOISE DISTRIBUTION

2021 ◽  
Vol 25 (Special) ◽  
pp. 1-157-1-166
Author(s):  
Nabaa I. Abed ◽  
◽  
Ghanim A.AL Rubaye ◽  
Keyword(s):  
Fading Channels ◽  
Communication Networks ◽  
Orthogonal Frequency Division Multiplexing ◽  
Rayleigh Fading ◽  
Additive White Gaussian Noise ◽  
Wireless Networking ◽  
Ofdm System ◽  
Exact Match ◽  
Communication Industry ◽  
Non Gaussian

The phenomenal increase in the usage of mobile devices and wireless networking tools in recent years has resulted in the communication industry needing higher data speeds for connections and bandwidth. As a result, multi-carrier modulation has been suggested as a reliable and effective method of transmitting data over difficult communication networks such as selective fading channels. Orthogonal Frequency Division Multiplexing (OFDM) is a highly effective multi-carrier technique that can meet users' high demands. Many studies have looked into this technique, mostly as a way to counteract fading and Additive White Gaussian Noise (AWGN). As a result, the performance evaluation of the QAM-OFDM system in the presence of multi-path Rayleigh fading in Weibull noise is examined in this article. Furthermore, bit error rate performance (BER) is computed using the optimal derivation of the real system contaminated by compound Gaussian and non-Gaussian (Weibull) noise distributions at the OFDM demodulator output. The derived result is an exact match to the simulated result over various scenarios introduced by the MATLAB software package.

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