Modeling and Analysis of the Anti-Jamming (AJ) Spread Spectrum System Using Quantized Chaotic Sequence with LDPC for Reliable Data Link

Due to the capability of interference rejection and low probability of interception (LPI), the spread spectrum technique is widely used in modern data link. However, its wideband, low power spectral density (PSD) signal may result in the degradation of the reliable data communication. To compensate this drawback, utilization of low density parity check (LDPC) can significantly reduce the required signal-to-noise ratio (SNR) per information bit for fixed bit error rate (BER), while quantized chaotic sequence makes the fixed energy-per-bit Eb for the quality of reliable data communication. In this work, toward an appropriate anti-jamming (AJ) spread spectrum system using chaotic waveform against possible jamming scenarios, the 1-bit quantized chaotic sequence generated from the chaotic waveform using the Logistic Map is utilized as the spreading code as well as the differential chaos shift keying (DCSK) as the modulation scheme. The simulation results shows that, under single-tone jamming (STJ), the power requirement of the spread spectrum requires only about -5 dB power for the fixed BER of 10-6 in additive white Gaussian noise (AWGN). Obviously, it shows that SNR per information bit requirement of the system for the targeted BER has been greatly reduced due to the use of LDPC and quantized chaotic sequence.