Broadband The Mfsk Differential Frequency Hopping Anti-jamming Performance Analysis

Because of the long range transmission and high survivability, High Frequency (HF) communications is irreplaceable in the military and emergency communications. Differential Frequency Hopping (DFH) technique, due to efficiency against multi-path fading and complex interference in the high frequency communication, represents a new generation of spread spectrum HF radio technology.Because short-wave band is crowded, here this paper proposes a system model of short wave DFH based on wide band M-ary frequency shift keying. With the limited bandwidth, we improve the Bit-Error-Ratio (BER) performance by increasing convolution encoder constraint length K and using the state trellis sequence detection.Partial Band Noise Jamming (PBNJ) and Multiple Tone Jamming (MTJ) are two typical disturbances. This paper calculates and simulates the anti-jamming performance of the system in the Additive White Gaussian Noise (AWGN) channel and frequency non-selective Rayleigh fading channel.This article is divided into five chapters. Chapter 1 describes the research background, main contents and structure arrangements; Chapter 2 proposes and analyzes the theory of the system based on wide band M-ary frequency shift keying, simultaneously compares the system block diagram, the theory and the performance with the conventional DFH system; Chapter 3 analyzes the performance of the system receiver based on Fast Fourier Transform (FFT), in the AWGN channel and frequency non-selective Rayleigh fading channels with PBNJ, by numerical analysis and simulation, then compares the performance with the conventional DFH system and Frequency Hopping (FH) system; Chapter 4 analyzes the performance with MTJ based on Non-coherent energy detection in the same way as Chapter three; Chapter 5 summarizes contributions of this paper and indicates the directions of further research.