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

2017 ◽  
Vol 27 (02) ◽  
pp. 1750025 ◽  
Author(s):  
J. Y. Duan ◽  
G. P. Jiang ◽  
H. Yang

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).

2011 ◽  
Vol 21 (03) ◽  
pp. 799-814 ◽  
Author(s):  
W. K. XU ◽  
L. WANG ◽  
G. KOLUMBÁN

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.


2018 ◽  
Vol 27 (14) ◽  
pp. 1850233 ◽  
Author(s):  
Hong Min Zhou ◽  
Ying Zhang ◽  
Ying Yu

In multi-carrier differential chaos shift keying (MC-DCSK) system, channel noises pollute both the reference and data signals, resulting in deteriorated performance. To reduce noises in received signals in MC-DCSK, a novel noise reduction MC-DCSK (NR-MC-DCSK) system is proposed in this paper. The proposed system utilizes duplicated chaotic samples, rather than different ones, as the reference. At the receiver side, identical samples can be averaged before correlation detection, which helps decrease the noise interferences and thus brings performance improvement. Theoretical bit error rate (BER) expressions are derived and verified by simulation results for additive white Gaussian noise and multipath Rayleigh fading channels. Finally, comparisons to MC-DCSK and other DCSK-based systems are given to confirm the superiority of the proposed system in BER performance.


2015 ◽  
Vol 4 (2) ◽  
pp. 320 ◽  
Author(s):  
Nizar N. Albassam

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.


Electronics ◽  
2021 ◽  
Vol 10 (19) ◽  
pp. 2343
Author(s):  
Ya-Qiong Jia ◽  
Guo-Ping Jiang ◽  
Hua Yang ◽  
Bin Yu ◽  
Ming-Di Du

A new fractional-order multi-carrier M-ary differential chaos shift keying system with multilevel code-shifted modulation (MC-MDCSK-MCS) is presented in this paper. The proposed system adopts multiple subcarriers, on which multiple MCS-MDCSK-modulated signals are transmitted simultaneously. Moreover, M-ary modulation has been combined with the proposed system to achieve a higher bit rate. On the receiver side, the recovered reference signal is first averaged and then used for MCS-MDCSK demodulation, which helps improve performance. We analyze the bit error rate (BER) of the proposed system and verify our theoretical derivations with the simulation results over additive white Gaussian noise (AWGN) and Rayleigh fading channels. Finally, related comparisons are completed, which show that the MC-MDCSK-MCS system is excellent and promising.


2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Gang Zhang ◽  
Yi man Hao ◽  
Tian qi Zhang

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.


2017 ◽  
Vol 27 (01) ◽  
pp. 1850008 ◽  
Author(s):  
Nguyen Xuan Quyen

A high-efficiency differential-chaos-shift-keying (HE-DCSK) system has been proposed previously for the improvement of both bit-rate and bit-error-rate (BER) performance in comparison with the conventional DCSK system. This improvement made HE-DCSK be a promising solution for chaos-based communications. However, the performance of this system was just investigated under an additive white Gaussian noise (AWGN) channel. This is main motivation for our work to evaluate the performance of HE-DCSK over a typical wireless channel which is simultaneously affected by white noise, fading, multipath, and delay spread. The operation of the transmitter and receiver over the wireless channel is modeled and described. The BER performance is evaluated by theoretical analysis using Gaussian approximation and discrete integration. The numerical results obtained by Monte Carlo simulations are presented to verify the analyzed performance. Obtained results point out that the HE-DCSK system not only performs better than other DCSK-based ones under wireless channels but also can exploit the multipath characteristic to improve the performance.


2020 ◽  
Vol 24 (06) ◽  
pp. 42-56
Author(s):  
Hayder F. Fahad ◽  
◽  
Fadhil S. Hassan ◽  

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


2005 ◽  
Vol 15 (12) ◽  
pp. 4027-4033 ◽  
Author(s):  
YONGXIANG XIA ◽  
CHI K. TSE ◽  
FRANCIS C. M. LAU ◽  
GÉZA KOLUMBÁN

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.


Sensors ◽  
2022 ◽  
Vol 22 (1) ◽  
pp. 333
Author(s):  
Majid Mobini ◽  
Georges Kaddoum ◽  
Marijan Herceg

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.


2021 ◽  
Vol 107 ◽  
pp. 182-193
Author(s):  
Aliyu Ahmed ◽  
Adeyemi Abel Ajibesin

The essence of my paper is to intricately look at data transfer with various modulation techniques over various communication channels. And run simulations to uncover the Bit Error Rate (BER) of various relevant scenarios. I will evaluate the performance of modulation techniques from Binary Phase Shift Keying (BPSK or 2PSK) to 16PSK and other modulation techniques with the consideration of time. Their performance will be evaluated and analyzed by calculating their probability of bit error rate (BER) versus the Energy per bit to spectral noise density (Eb/No) over various wireless channel models such as the Additive White Gaussian Noise (AWGN), Rayleigh channel and Ricean channel. My simulation results will graphically display the effective performance of each communication scenario; it will give us a better understanding of why performances of data communications techniques.


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