scholarly journals Chaos Based Frequency Modulation for Joint Monostatic and Bistatic Radar-Communication Systems

2021 ◽  
Vol 13 (20) ◽  
pp. 4113
Author(s):  
Chandra S. Pappu ◽  
Aubrey N. Beal ◽  
Benjamin C. Flores
Keyword(s):  
Communication Systems ◽  
Ambiguity Function ◽  
Bistatic Radar ◽  
Detection Scheme ◽  
Nonlinear Detection ◽  
Shift Keying ◽  
Wideband Radar ◽  
Complex Target ◽  
Chaos Shift Keying ◽  
Transmitted Waveform

In this article, we propose the utilization of chaos-based frequency modulated (CBFM) waveforms for joint monostatic and bistatic radar-communication systems. Short-duration pulses generated via chaotic oscillators are used for wideband radar imaging, while information is embedded in the pulses using chaos shift keying (CSK). A self-synchronization technique for chaotic systems decodes the information at the communication receiver and reconstructs the transmitted waveform at the bistatic radar receiver. Using a nonlinear detection scheme, we show that the CBFM waveforms closely follow the theoretical bit-error rate (BER) associated with bipolar phase-shift keying (BPSK). We utilize the same nonlinear detection scheme to optimize the target detection at the bistatic radar receiver. The ambiguity function for both the monostatic and bistatic cases resembles a thumbtack ambiguity function with a pseudo-random sidelobe distribution. Furthermore, we characterize the high-resolution imaging capability of the CBFM waveforms in the presence of noise and considering a complex target.

Encryption of Analog and Digital signals through Synchronized Chaotic Systems

2011 ◽  
pp. 415-438
Author(s):  
Kehui Sun
Keyword(s):  
Secure Communication ◽  
Communication Systems ◽  
Chaotic Sequence ◽  
Digital Signals ◽  
Encryption Schemes ◽  
Shift Keying ◽  
Chaos Shift Keying ◽  
Sequence Generator ◽  
Chaotic Secure Communication ◽  
Spreading Spectrum

Chaos is characterized by aperiodic, wideband, random-like, and ergodicity. Chaotic secure communication has become one of the hot topics in nonlinear dynamics since the early 1990s exploiting the technique of chaos synchronization. As distinguished by the type of information being carried, chaos-based communication systems can be categorized into analogy and digital, including four popular techniques such as Chaos Masking, Chaos Shift Keying, Chaos Modulation, and Chaos Spreading Spectrum. In this chapter, the principles of these schemes and their modifications are analyzed by theoretical analysis as well as dynamic simulation. In addition, chaos-based cryptography is a new approach to encrypt information. After analyzing the performances of chaotic sequence and designing an effective chaotic sequence generator, the authors briefly presented the principle of two classes of chaotic encryption schemes, chaotic sequence encryption and chaotic data stream encryption.

scholarly journals A Novel Detection Scheme for EBPSK System

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Xianqing Chen ◽  
Lenan Wu
Keyword(s):  
Communication System ◽  
Communication Systems ◽  
Low Complexity ◽  
Detection Technique ◽  
Joint Detection ◽  
Phase Shift Keying ◽  
Detection Scheme ◽  
New Approach ◽  
Shift Keying ◽  
Binary Phase Shift Keying

We introduce the extended binary phase shift keying (EBPSK) communication system which is different from traditional communication systems by using a special impacting filter (SIF) for demodulation. The joint detection technique is applied at the demodulator side in order to improve the performance of the system under intersymbol interference (ISI). The main advantage of the joint detection technique, when compared to conventional threshold approaches, lies in its ability to use the amplitude and the correlation between neighboring bits, thus significantly improving performance, with low complexity. Moreover, we concentrate not only on increasing the bit rate of the system, but also on designing a bandwidth efficient communication system. Simulation results show that this new approach significantly outperforms the conventional method of using threshold decision by from 3.5 to 5 dB. The new system also occupies a narrower bandwidth. So joint detection is an effective method for EBPSK demodulation under ISI.

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.

OPTIMUM CORRELATOR-TYPE RECEIVER DESIGN FOR CSK COMMUNICATION SYSTEMS

2002 ◽  
Vol 12 (05) ◽  
pp. 1029-1038 ◽  
Author(s):  
FRANCIS C. M. LAU ◽  
CHI K. TSE
Keyword(s):  
Temporal Variation ◽  
Communication Systems ◽  
Detection Method ◽  
Error Rates ◽  
Coherent Detection ◽  
Receiver Design ◽  
Optimum Detection ◽  
Performance Benchmarks ◽  
Shift Keying ◽  
Chaos Shift Keying

In a chaos-shift-keying (CSK) digital communication system, correlators followed by a comparator are typically used for coherent detection of the signal. Such a detection method, however, does not take the temporal variation of the bit energy into consideration. In this paper, an optimum detection for a binary CSK system is derived, taking into account the temporal variation of the bit energy for minimizing the error rates. Simulations are carried out to compare the performance between the optimum receiver and a typical receiver. The results provide theoretical performance benchmarks of coherent CSK systems for future references.

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.

A Noise Eliminating Method of DCSK System Based on Multi-Layered Noise Control Materials

2012 ◽  
Vol 461 ◽  
pp. 164-168
Author(s):  
Zhen Chao Wang ◽  
Shi Bing Zhang ◽  
Yuan Yuan Liu
Keyword(s):  
Communication Systems ◽  
Colored Noise ◽  
Low Voltage ◽  
Reversed Phase ◽  
Channel Noise ◽  
Power Line Communication ◽  
Shift Keying ◽  
Communication Scheme ◽  
Simulation Results ◽  
Chaos Shift Keying

This paper proposes a new chaotic communication scheme which is developed from Differential Chaos Shift Keying (DCSK), named reversed-phase overlay DCSK. Different from DCSK, at the receiver of the improved scheme the first and the second half-symbol signals within a code period are reversed-phase overlapped before the correlation operation. Both the theoretical analysis and the simulation results show that the proposed scheme can effectively suppress the noise and improve the BER performance of DCSK if the channel noise in the first half of a code period and the second is positively correlated. The proposed scheme can be applied to the communication systems suffering with colored noise, such as Low-voltage Power Line Communication(L-PLC) system

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