scholarly journals DESIGN AND PERFORMANCE ANALYSIS OF ORTHOGONAL MULTI-LEVEL CODE-SHIFTED DIFFERENTIAL CHAOS SHIFT KEYING COMMUNICATION SYSTEM

2020 ◽  
Vol 24 (06) ◽  
pp. 42-56
Author(s):  
Hayder F. Fahad ◽  
◽  
Fadhil S. Hassan ◽  
Keyword(s):  
Communication System ◽  
Complexity Analysis ◽  
Additive White Gaussian Noise ◽  
Chaotic Signal ◽  
System A ◽  
Walsh Code ◽  
Shift Keying ◽  
And Performance ◽  
Chaos Shift Keying ◽  
Differential Chaos Shift Keying

Based on Orthogonal Chaotic Vector Shift Keying (OCVSK) system and Multilevel Code-Shifted Differential Chaos Shift Keying (MCS-DCSK) system, a new Multilevel Code-Shifted Differential Chaos Shift Keying (OMCS-DCSK) modulation system is proposed and designed in this paper. New orthogonal chaotic signal sets are generated using Gram-Schmidt algorithm and Walsh code function then these signals are used for bearing information bits to achieve higher data rate and better bandwidth efficiency compared with the conventional DCSK communication system. The bit error rate (BER) analysis of the OMCS-DCSK system over additive white Gaussian noise (AWGN) and multipath Rayleigh fading channel is derived and compared with the simulation results. Also, the spectral and complexity analysis of the system are presented and compared with the conventional DCSK systems. The results show that the proposed system outperforms OCVSK and MCS-DCSK in BER performance and spectral efficiency

scholarly journals Design and Performance Analysis of MISO-SRMR-DCSK System over Rayleigh Fading Channels

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Gang Zhang ◽  
Yi man Hao ◽  
Tian qi Zhang
Keyword(s):  
Performance Analysis ◽  
Fading Channels ◽  
Rayleigh Fading ◽  
Perfect Match ◽  
Rayleigh Fading Channels ◽  
Major Drawback ◽  
Shift Keying ◽  
And Performance ◽  
Chaos Shift Keying ◽  
Differential Chaos Shift Keying

The major drawback of the differential chaos shift keying (DCSK) system is that equal time and energy are spent on the reference and data signal. This paper presents the design and performance analysis of a short reference multifold rate DCSK (SRMR-DCSK) system to overcome the major drawback. The SRMR-DCSK system is proposed to enhance the data rate of the short reference differential chaos shift keying (SR-DCSK) system. By recycling each reference signal in SR-DCSK, the data slot carries N bits of data and by P times. As a result, compared with SR-DCSK, the proposed system has a higher data transmission rate and evaluates the energy efficiency with respect to the conventional DCSK system. To further improve the bit-error-rate (BER) performance over Rayleigh fading channels, the multiple-input single-output SRMR-DCSK (MISO-SRMR-DCSK) is also studied. The BER expression of the proposed system is derived based on Gaussian approximation (GA), and simulations in Rayleigh fading channels are performed. Simulation results show a perfect match with the analytical expression.

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).

A NOVEL DIFFERENTIAL CHAOS SHIFT KEYING MODULATION SCHEME

2011 ◽  
Vol 21 (03) ◽  
pp. 799-814 ◽  
Author(s):  
W. K. XU ◽  
L. WANG ◽  
G. KOLUMBÁN
Keyword(s):  
Fading Channels ◽  
Additive White Gaussian Noise ◽  
Cmos Technology ◽  
Ultra Wideband ◽  
Modulation Scheme ◽  
Delay Lines ◽  
Shift Keying ◽  
Delay Component ◽  
Chaos Shift Keying ◽  
Differential Chaos Shift Keying

In binary Differential Chaos Shift Keying (DCSK), the reference and information bearing chaotic wavelets are transmitted in two consecutive time slots. This TDMA approach provides two independent channels for the transmission of reference and information bearing wavelets but requires a delay component both in the modulator and demodulator circuits, furthermore, it halves the data attainable data rate. The wideband Radio Frequency (RF) delay lines at receiver are extremely difficult to implement with CMOS technology, therefore, the DCSK modulation cannot be exploited in many applications, such as ultra-wideband. To avoid the use of wideband RF delay lines at receiver, an alternative solution is proposed here where both the reference and information bearing wavelets are sent in the same time slot. The two wavelets are separated by Walsh codes instead of time delay. The new modulator and demodulator configurations are given, analytical expressions for the Bit Error Rate (BER) are derived and the derived BER expressions are verified by computer simulations over Additive White Gaussian Noise (AWGN) and multipath Rayleigh fading channels.

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