scholarly journals A new scheme to enhance the performance of permutation index–differential chaos shift keying communications system

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Nizar Al Bassam ◽  
Oday Al-Jerew
Keyword(s):  
Gaussian Approximation ◽  
Energy Requirement ◽  
Reference Signal ◽  
Analytical Form ◽  
Error Performance ◽  
Shift Keying ◽  
Simulation Results ◽  
Chaos Shift Keying ◽  
Channel Environment ◽  
Differential Chaos Shift Keying

AbstractIn this paper, a new scheme based on permutation index–differential chaos shift keying is proposed, modeled, and evaluated in AWGN channel environment. Data is sent by frames, and each frame is headed by a single reference signal and followed by some information-bearing signals. Modulation is performed through permutations of a reference signal according to the mapped data. At the receiver, each incoming information-bearing signal undergoes all inverse permutation possibilities to perform a correlation with the delayed and stored version of the received reference signal. To decode the information bits, the detector selects the highest correlator outputs. The proposed scheme named single reference–permutation index–differential chaos shift keying is an enhanced version of PI-DCSK, and uses a single reference signal for multiple information-bearing ones. Hence, the energy requirement is saved by almost a half. The bit error performance is studied using the baseband system model and analytically tested using Gaussian approximation method. Results show the BER performance outperforms other standard and recently developed differentially coherent chaos systems, including Permutation Index–DCSK by an average of 2.25 dB. Moreover, the analytical form which is developed to predict the bit error rate (BER) is validated by simulation. Results demonstrate the performance in AWGN is closely matching with the simulation results, particularly at high SNR.

scholarly journals A New Scheme To Enhance The Performance Of Permutation Index-Differential Chaos Shift Keying Communications System

2021 ◽  
Author(s):  
Nizar Albassam ◽  
Oday Al-Jerew
Keyword(s):  
Gaussian Approximation ◽  
Energy Requirement ◽  
Reference Signal ◽  
Analytical Form ◽  
Error Performance ◽  
Shift Keying ◽  
Simulation Results ◽  
Chaos Shift Keying ◽  
Channel Environment ◽  
Differential Chaos Shift Keying

Abstract In this paper, a new scheme based on permutation index-differential chaos shift keying is proposed, modeled, and evaluated in AWGN channel environment. Data is sent by frames, each frame is headed by a single reference signal and followed by some information bearing signals. Modulation is performed through permutations of a reference signal according to the mapped data. At the receiver, each incoming information bearing signal undergoes all inverse permutation possibilities to perform a correlation with the delayed and stored version of the received reference signal. To decode the information bits, the detector selects the highest correlator outputs. The proposed scheme named Single Reference-Permutation Index-Differential Chaos Shift Keying (SR-PI-DCSK) is an enhanced version of PI-DCSK, and uses a single reference signal for multiple information bearing ones. Hence, the energy requirement is saved by almost a half. The bit error performance is studied using the baseband system model and analytically tested using Gaussian Approximation (GA) method. Results show the BER performance outperforms other standard and recently developed differentially coherent chaos systems, including Permutation Index-DCSK by an average of $2.25$~db. Moreover, the analytical form which is developed to predict the Bit Error Rate (BER) is validated by simulation. Results demonstrate the performance in AWGN is closely matching with the simulation results, particularly at high SNR.

scholarly journals Reference flipped-differential chaos ‎shift keying scheme for chaos- based ‎communications

2015 ◽  
Vol 4 (2) ◽  
pp. 320 ◽  
Author(s):  
Nizar N. Albassam
Keyword(s):  
High Efficiency ◽  
Gaussian Approximation ◽  
Additive White Gaussian Noise ◽  
Reference Signal ◽  
Theoretical Expression ◽  
Spreading Factor ◽  
Environment Effect ◽  
Shift Keying ◽  
Chaos Shift Keying ◽  
Differential Chaos Shift Keying

In this paper, a new differential coherent chaos-based communication system is proposed and named Reference Flipped-DCSK (RF-DCSK). By utilizing the low correlation value between a chaotic segment and its flipped version, each transmitted signal will be the sum of the information bearing signal and the mirrored version of the reference signal. This enhances the bandwidth efficiency of DCSK by doubling bits rate. Additionally, noise performance is improved at typical values of the spreading factor. According to Gaussian approximation method, theoretical expression for Bit-Error-Rate (BER) is derived. The proposed scheme is simulated and compared with Differential Chaos Shift Keying (DCSK), Correlation Delay Shift Key (CDSK) and High Efficiency -Differential Chaos Shift Keying (HE-DCSK) schemes in Additive White Gaussian Noise (AWGN) environment. Effect of spreading factor is studied. Results show that the proposed scheme clearly outperforms other systems.

scholarly journals Design and Implementation of a Chaotic Scheme in Additive White Gaussian Noise Channel

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Nizar Al Bassam ◽  
Oday Jerew
Keyword(s):  
Bit Error Rate ◽  
Gaussian Noise ◽  
Chaotic Systems ◽  
Gaussian Approximation ◽  
Additive White Gaussian Noise ◽  
Design And Implementation ◽  
Shift Keying ◽  
Transmitted Signal ◽  
Chaos Shift Keying ◽  
Channel Environment

A new chaotic scheme named Flipped Chaotic On-Off Keying (FCOOK) is proposed for binary transmission. In FCOOK, the low correlation value between the stationary signal and its mirrored version is utilized. Transmitted signal for binary 1 is a chaotic segment added to its time flipped (mirrored) version within one bit duration, while in binary 0, no transmission takes place within the same bit duration. The proposed scheme is compared with the standard chaotic systems: Differential Chaos Shift Keying (DCSK) and Correlation Delay Shift Keying (CDSK). The Bit Error Rate (BER) of FCOOK is studied analytically based on Gaussian approximation method. Results show that the BER performance of FCOOK outperforms DCSK and CDSK in AWGN channel environment and with variousEb/Nolevels. Additionally, FCOOK offers a double bit rate compared with the standard DCSK.

A NEW DATA RATE ADAPTION COMMUNICATIONS SCHEME FOR CODE-SHIFTED DIFFERENTIAL CHAOS SHIFT KEYING MODULATION

2012 ◽  
Vol 22 (08) ◽  
pp. 1250201 ◽  
Author(s):  
W. K. XU ◽  
L. WANG ◽  
G. KOLUMBÁN
Keyword(s):  
Gaussian Approximation ◽  
Time Slot ◽  
Data Rate ◽  
Modulation Scheme ◽  
Noise Performance ◽  
Walsh Code ◽  
Shift Keying ◽  
Multilevel Modulation ◽  
Chaos Shift Keying ◽  
Differential Chaos Shift Keying

In a binary Transmitted Reference (TR) system each bit is encoded into two wavelets of finite duration. The information is transmitted by the sign of correlation measured between the two wavelets. The Code-Shifted Differential Chaos Shift Keying (CS-DCSK) modulation scheme transmits the two wavelets in the same time slot and applies two Walsh code sequences to keep the wavelets separated. The CS-DCSK modulation scheme is generalized here by transmitting more than one information bearing wavelets with one reference. The orthogonality of wavelets is assured by different Walsh code sequences. The new Generalized CS-DCSK (GCS-DCSK) scheme is a multilevel modulation where the symbol period is kept constant but the data rate can be varied in an adaptive manner by adding new or removing existing information bearing wavelets, each of them is isolated by Walsh code. Exploiting the Gaussian approximation, an analytical expression is derived for the noise performance of GCS-DCSK modulation. Its accuracy is verified by computer simulation.

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 PERFORMANCE ANALYSIS OF QUADRATURE CHAOS SHIFT

2020 ◽  
Vol 60 (1) ◽  
pp. 1-11
Author(s):  
Hesham Adnan Alabbasi ◽  
Izz Kadhum Abboud ◽  
Fadhil Sahib Hasan
Keyword(s):  
Fading Channel ◽  
Rayleigh Fading ◽  
Reference Signal ◽  
Data Rate ◽  
Rayleigh Fading Channel ◽  
Superior Performance ◽  
Experimental Simulation ◽  
Shift Keying ◽  
Simulation Results ◽  
Chaos Shift Keying

One of the most famous techniques of non-coherent differential chaos shift keying (DCSK) is Quadrature chaos shift keying (QCSK) system, this system suffered from lowering the data rate and increasing the bit energy during the bit transmission even though its rate doubling the one of the DCSK. Short reference (SR) algorithm is proposed for the QCSK system to design the SR-QCSK communication system that enhances these drawbacks. The main idea of the short reference technique is minimizing the length of the reference chaotic signal (β) at a transmitter by a factor P comparing to produce R samples for the new reference signal while the length of the information-bearing signal remained unchanged, this occurs by duplicating the reference signal P times to get the same length as the conventional QCSK. Therefore, the symbol duration is reduced from 2βTc to (R+β)Tc. The data rate and energy saving improvement factor in a percent form is derived and compared with the QCSK and DCSK systems. Also, the BER analytical expression is derived for the SR-QCSK in additive white Gaussian noise and Rayleigh fading channel. The experimental simulation results proved that the theory derivation gives a good analysis tracking for the BER performance. The SR-QCSK system is compared with other DCSK techniques and the simulation results show that it has a superior performance in the multipath Rayleigh fading channel.

scholarly journals Analysis and Design of an Energy Efficient Differential Coherent Chaos Based System in Additive White Gaussian Noise Environment

2017 ◽  
Vol 2017 ◽  
pp. 1-9
Author(s):  
Nizar Al Bassam ◽  
Oday D. Jerew
Keyword(s):  
Gaussian Approximation ◽  
Additive White Gaussian Noise ◽  
Superior Performance ◽  
Error Performance ◽  
Simple Correlation ◽  
Spreading Factor ◽  
Analysis And Design ◽  
Comparison Results ◽  
Shift Keying ◽  
Chaos Shift Keying

A new differential coherent chaos based scheme is proposed and named as Differential Chaos ON-OFF Keying (DCOOK). The proposed scheme provides reduction in bit energy and better bit error performance at large spreading factor. This is achieved by presenting each transmitted bit by either identical segment or no transmission within same bit duration. The receiver performs simple correlation between the received signal and its delayed version to determine the transmitted information utilizing the low correlation between the noise signals. The bit error rate (BER) performance of the proposed scheme is evaluated analytically using Gaussian Approximation (GA) method and compared with the simulation results. The results show excellent agreement between the derived expression and simulation. Moreover, the BER of DCOOK scheme is compared with the standard chaos systems: Chaos ON-OFF Keying (COOK), Differential Chaos Shift Keying (DCSK), and Correlation Delay Shift Keying (CDSK). The comparison results show that DCOOK scheme can always achieve superior performance compared to COOK and CDSK schemes and even exceeds the performance of DCSK scheme at typical spreading factor values.

A Simplified GCS-DCSK Modulation and Its Performance Optimization

2016 ◽  
Vol 26 (13) ◽  
pp. 1650213 ◽  
Author(s):  
Weikai Xu ◽  
Lin Wang ◽  
Chong-Yung Chi
Keyword(s):  
Power Allocation ◽  
Performance Optimization ◽  
Gaussian Approximation ◽  
System Model ◽  
Optimal Power Allocation ◽  
Optimal Power ◽  
Proposed Model ◽  
Shift Keying ◽  
Simulation Results ◽  
Chaos Shift Keying

In this paper, a simplified Generalized Code-Shifted Differential Chaos Shift Keying (GCS-DCSK) whose transmitter never needs any delay circuits, is proposed. However, its performance is deteriorated because the orthogonality between substreams cannot be guaranteed. In order to optimize its performance, the system model of the proposed GCS-DCSK with power allocations on substreams is presented. An approximate bit error rate (BER) expression of the proposed model, which is a function of substreams’ power, is derived using Gaussian Approximation. Based on the BER expression, an optimal power allocation strategy between information substreams and reference substream is obtained. Simulation results show that the BER performance of the proposed GCS-DCSK with the optimal power allocation can be significantly improved when the number of substreams [Formula: see text] is large.

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