scholarly journals Novel Chaos Secure Communication System Based on Walsh Code

2015 ◽  
Vol 2015 ◽  
pp. 1-6
Author(s):  
Gang Zhang ◽  
Niting Cui ◽  
Tianqi Zhang
Keyword(s):  
Secure Communication ◽  
Transmission Rate ◽  
Multiple Input Multiple Output ◽  
Walsh Code ◽  
Bit Error Ratio ◽  
Shift Keying ◽  
Input Multiple Output ◽  
Communication Scheme ◽  
Chaos Shift Keying ◽  
Differential Chaos Shift Keying

A multiuser communication scheme which is a hybrid of Walsh code with DCSK and CDSK is proposed to improve low data transmission rate of Differential Chaos Shift Keying (DCSK), poor bit error ratio (BER) performance of Correlation Delay Shift Keying (CDSK), and disadvantage of orthogonality in traditional multiuser DCSK. It not only overcomes the disadvantages of DCSK and CDSK, but also has better performance than CDSK and higher transmission data rate than DCSK. It has been proved that the novel multiuser CDSK-DCSK has better properties than traditional Multiple Input Multiple Output-Differential Chaos Shift Keying (MIMO-DCSK) and Modified-Differential Chaos Shift Keying (M-DCSK). Also the multiuser interference is greatly suppressed due to the orthogonality of Walsh code.

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.

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 Secure Communication Scheme for Brain-Computer Interface Systems Based on High-Dimensional Hyperbolic Sine Chaotic System

2022 ◽  
Vol 9 ◽  
Author(s):  
Xiangzi Zhang ◽  
Xiaobin Ding ◽  
Dandan Tong ◽  
Pengbin Chang ◽  
Jizhao Liu
Keyword(s):  
Secure Communication ◽  
Brain Computer Interface ◽  
Random Number Generator ◽  
Computer Interface ◽  
High Dimensional ◽  
Hyperbolic Sine ◽  
Shift Keying ◽  
Communication Scheme ◽  
High Level ◽  
Chaos Shift Keying

Brain-Computer Interface (BCI) is a direct communication pathway between the brain and the external environment without using peripheral nerves and muscles. This emerging topic is suffering from serious issues such as malicious tampering and privacy leakage. To address this issue, we propose a novel communication scheme for BCI Systems. In particular, this scheme first utilizes high-dimensional chaotic systems with hyperbolic sine nonlinearity as the random number generator, then decorrelation operation is used to remove the physical characteristics of the output sequences. Finally, each of the sequences is applied in differential chaos shift keying (DCSK). Since each output sequence corresponds to a unique electrode, the communication data of different electrodes will not interfere with each other. Compared with popular multi-user DSCK schemes using Walsh code sequences, this scheme does not require the channel data of all electrodes while decoding. Therefore, this scheme has higher efficiency. Experimental results on communication data indicate that the proposed scheme can provide a high level of security.

scholarly journals Study of 5G-NR-MIMO Links in the Presence of an Interferer

Electronics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 732
Author(s):  
Avner Elgam ◽  
Yael Balal ◽  
Yosef Pinhasi
Keyword(s):  
Mobile Networks ◽  
Communication Systems ◽  
Multiple Input Multiple Output ◽  
Local Area ◽  
Maximum Energy ◽  
Base Station ◽  
Small Cells ◽  
Diversity Coding ◽  
Shift Keying ◽  
Input Multiple Output

Many communication systems are based on the Multiple Input, Multiple Output (MIMO) scheme, and Orthogonal Space–time Block Transmit diversity Coding (OSTBC), combined with Maximal Ratio Receive Combining (MRRC), to create an optimal diversity system. A system with optimal diversity fixes and optimizes the channel’s effects under multi-path and Rayleigh fading with maximum energy efficiency; however, the challenge does not end with dealing with the channel destruction of the multi-path impacts. Susceptibility to interference is a significant vulnerability in future wireless mobile networks. The 5th Generation New Radio (5G-NR) technologies bring hundreds of small cells and pieces of User Equipment (UE) per indoor or outdoor local area scenario under a specific Long Term Evolution (LTE)-based station (e-NodeB), or under 5G-NR base-station (g-NodeB). It is necessary to study issues that deal with many interference signals, and smart jammers from advanced communication equipment cause deterioration in the links between the UE, the small cells, and the NodeB. In this paper, we study and present the significant impact and performances of 2×2 Alamouti Phase-Shift Keying (PSK) modulation techniques in the presence of an interferer and a smart jammer. The destructive effects affecting the MIMO array and the advanced diversity technique without closed-loop MIMO are analyzed. The performance is evaluated in terms of Bit Error Rate (BER) vs. Signal to Interference Ratio (SIR). In addition, we proved the impairment of the orthogonal spectrum assumption mathematically.

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