PERFORMANCE OF FREQUENCY-MODULATED DIFFERENTIAL-CHAOS-SHIFT-KEYING COMMUNICATION SYSTEM OVER MULTIPATH FADING CHANNELS WITH DELAY SPREAD

2005 ◽  
Vol 15 (12) ◽  
pp. 4027-4033 ◽  
Author(s):  
YONGXIANG XIA ◽  
CHI K. TSE ◽  
FRANCIS C. M. LAU ◽  
GÉZA KOLUMBÁN
Keyword(s):  
Fading Channels ◽  
Communication System ◽  
Communication Systems ◽  
Multipath Fading ◽  
Equivalent Model ◽  
Delay Spread ◽  
Error Performance ◽  
Multipath Fading Channels ◽  
Shift Keying ◽  
Chaos Shift Keying

Multipath performance is an important consideration for chaos-based communication systems. In this letter, the performance of the FM-DCSK communication system over multipath fading channels is evaluated by computer simulations. Both Rayleigh fading and Ricean fading are considered, and the low-pass equivalent model of the FM-DCSK system is used in the simulation. Based on this model, we analyze the bit error performance of the system and the effects of system parameters on the bit-error performance.

A Novel Multiple-Access Correlation-Delay-Shift-Keying

2017 ◽  
Vol 27 (02) ◽  
pp. 1750025 ◽  
Author(s):  
J. Y. Duan ◽  
G. P. Jiang ◽  
H. Yang
Keyword(s):  
Fading Channels ◽  
Multiple Access ◽  
Additive White Gaussian Noise ◽  
Reference Signal ◽  
Multipath Fading ◽  
Signal Interference ◽  
Shift Keying ◽  
Chaos Shift Keying ◽  
Differential Chaos Shift Keying ◽  
Ber Performance

In Correlation-Delay-Shift-Keying (CDSK), the reference signal and the information-bearing signal are added together during a certain time delay. Because the reference signal is not strictly orthogonal to the information-bearing signal, the cross-correlation between the adjacent chaotic signal (Intra-signal Interference, ISI) will be introduced into the demodulation at the receiver. Therefore, the Bit-Error Ratio (BER) of CDSK is higher than that of Differential-Chaos-Shift-Keying (DCSK). To avoid the ISI component and enhance the BER performance of CDSK in multiuser scenario, Multiple-Access CDSK with No Intra-signal Interference (MA-CDSK-NII) is proposed. By constructing the repeated chaotic generator and applying the Walsh code sequence to modulate the reference signal, in MA-CDSK-NII, the ISI component will be eliminated during the demodulation. Gaussian approximation method is adopted here to obtain the exact performance analysis of MA-CDSK-NII over additive white Gaussian noise (AWGN) channel and Rayleigh multipath fading channels. Results show that, due to no ISI component and lower transmitting power, the BER performance of MA-CDSK-NII can be better than that of multiple-access CDSK and Code-Shifted Differential-Chaos-Shift-Keying (CS-DCSK).

scholarly journals Future OFDM-based Communication Systems Towards 6G and Beyond: Machine Learning Approaches

2021 ◽  
Vol 1 (1) ◽  
pp. 19-25
Author(s):  
Filbert H. Juwono ◽  
Regina Reine
Keyword(s):  
Machine Learning ◽  
Communication Network ◽  
Data Processing ◽  
Fading Channels ◽  
Communication Systems ◽  
Multipath Fading ◽  
Spectrum Efficiency ◽  
Learning Approaches ◽  
Multipath Fading Channels ◽  
Rate Transmission

The vision towards 6G and beyond communication systems demands higher rate transmission, massive amount of data processing, and low latency communication. Orthogonal Frequency Division Modulation (OFDM) has been adopted in the current 5G networks and has become one of the potential candidates for the future communication systems. Although OFDM offers many benefits including high spectrum efficiency and high robustness against the multipath fading channels, it has major challenges such as frequency offset and high Peak to Power Ratio (PAPR). In 5G communication network, there is a significant increase in the number of sensors and other low-power devices where users or devices may create large amount of connection and dynamic data processing. In order to deal with the increasingly complex communication network, Machine Learning (ML) has been increasingly utilised to create intelligent and more efficient communication network. This paper discusses challenges and the impacts of embedding ML in OFDM-based communication systems.

scholarly journals Design of Orthogonal Variable Spreading Factor (OVSF) Performance Simulation Program in Multipath Fading Channels

2020 ◽  
Vol 4 (2) ◽  
pp. 64
Author(s):  
I Gede Arya Gangga Gajanada ◽  
Nyoman Pramaita ◽  
I Gusti Agung Komang Diafari Djuni Hartawan
Keyword(s):  
Fading Channels ◽  
Multipath Propagation ◽  
Multipath Fading ◽  
Wireless Channel ◽  
Delay Spread ◽  
Spreading Factor ◽  
Multipath Fading Channel ◽  
Multipath Fading Channels ◽  
Orthogonal Variable Spreading Factor ◽  
Ovsf Codes

The characteristics of wireless channel are determined by multipath propagation. The transmitted signal will be scattered so that it produces fading. Fading influenced by multipath component will cause delay spread which damages the signal. Thus, spread spectrum technology is used by using a bandwidth that is greater than the original signal. The objective of this study was to determine the effect of the number of multipath components on orthogonal variable spreading factor (OVSF) codes on multipath fading channels viewed from values and Bit Error Rate (BER) graphs versus Energy Bits per Noise (Eb/No). This study would compare the performance of OVSF code communication system on multipath channels by varying multipath components of 4, 8, 12, 16 and the length of OVSF codes used of 16, 8 and 4. The simulation results showed an increase in BER values when the number of multipath components was added. The more the number of multipath components used, the more the number of reflected signals that will interfere with the desired signal in the receiver. The length of the OVSF code influences the performance of the OVSF code on the multipath fading channel, because each code has a different processing gain value that is affected by the length of the code used

scholarly journals Design of a SIMO Deep Learning-Based Chaos Shift Keying (DLCSK) Communication System

Sensors ◽  
2022 ◽  
Vol 22 (1) ◽  
pp. 333
Author(s):  
Majid Mobini ◽  
Georges Kaddoum ◽  
Marijan Herceg
Keyword(s):  
Deep Learning ◽  
Channel Estimation ◽  
Fading Channels ◽  
Communication Systems ◽  
Chaotic Maps ◽  
Short Term Memory ◽  
Reference Signal ◽  
Shift Keying ◽  
Input Multiple Output ◽  
Chaos Shift Keying

This paper brings forward a Deep Learning (DL)-based Chaos Shift Keying (DLCSK) demodulation scheme to promote the capabilities of existing chaos-based wireless communication systems. In coherent Chaos Shift Keying (CSK) schemes, we need synchronization of chaotic sequences, which is still practically impossible in a disturbing environment. Moreover, the conventional Differential Chaos Shift Keying (DCSK) scheme has a drawback, that for each bit, half of the bit duration is spent sending non-information bearing reference samples. To deal with this drawback, a Long Short-Term Memory (LSTM)-based receiver is trained offline, using chaotic maps through a finite number of channel realizations, and then used for classifying online modulated signals. We presented that the proposed receiver can learn different chaotic maps and estimate channels implicitly, and then retrieves the transmitted messages without any need for chaos synchronization or reference signal transmissions. Simulation results for both the AWGN and Rayleigh fading channels show a remarkable BER performance improvement compared to the conventional DCSK scheme. The proposed DLCSK system will provide opportunities for a new class of receivers by leveraging the advantages of DL, such as effective serial and parallel connectivity. A Single Input Multiple Output (SIMO) architecture of the DLCSK receiver with excellent reliability is introduced to show its capabilities. The SIMO DLCSK benefits from a DL-based channel estimation approach, which makes this architecture simpler and more efficient for applications where channel estimation is problematic, such as massive MIMO, mmWave, and cloud-based communication systems.

scholarly journals Symbol Error Performance Analysis and Comparison Between Alamouti and MRRC Diversity Combining Scheme for Wireless Communication

2009 ◽  
Vol 2 (1) ◽  
pp. 54-66
Author(s):  
A. Khatoon ◽  
M. S. Rahman
Keyword(s):  
Wireless Communication ◽  
Fading Channels ◽  
Communication Systems ◽  
Rayleigh Fading ◽  
Rayleigh Fading Channels ◽  
Diversity Combining ◽  
Error Performance ◽  
Probability Of Error ◽  
Alamouti Scheme ◽  
Shift Keying

The symbol error performance of a wireless communication system is analyzed using diversity combining scheme in Rayleigh fading channels. The performance of the system is compared using Alamouti scheme and maximal-ratio receiver combining (MRRC) scheme. The performance results of the system are evaluated by numerical computation and by simulation using MATLAB. A detailed analysis and exact (closed-form) expressions of the probability of error of the wireless communication systems in Rayleigh fading channels are provided for both M-ary phase-shift keying (M-PSK) and M-ary quadrature amplitude modulation (M-QAM) schemes. Monte Carlo simulation shows exact match with the theoretical results. Keywords: Alamouti scheme; M-PSK; M-QAM; MRRC; Symbol error probability (SEP). © 2010 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v2i1.3000               J. Sci. Res. 2 (1), 54-66 (2010) 

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