The Key Technology Of Differential Frequency Hopping Study Compression Spectrum

As a new shortwave communication technology, Differential Frequency Hopping (DFH) technology innovatively let frequency hopping, error correction coding and modulation fusion together, also can be effective against interference and channel decline. Because of this, since DFH came out, it attracted the attention of many scholars. But DFH technology do not have the frequency hopping pattern like traditional FH technology, this cause the DFH technology has strong anti-interference ability, but at the same time the receiver of DFH need to detect all possible frequency information in the whole bandwidth. So, DFH technology has high requirement for bandwidth. Based on this, this article propose a new Compressed Differential Frequency Hopping (C-DFH) that can compress the bandwidth of traditional DFH technology by using non-orthogonal frequency set for communication.Based on the above, this article proposed a Symbol by Symbol Detection Compressed Differential Frequency Hopping (SBS-CDFH) receiver, and analyzes the performance in the channel with Additive White Gaussian Noise (AWGN) and in Frequency Non-selective Rayleigh Slow Fading Channel. Then, we further propose a Sequence Detection Compressed Differential Frequency Hopping (SD-CDFH) receiver, and analyze the performance in the channel with Additive White Gaussian Noise and in Frequency Non-selective Rayleigh Slow Fading Channel. Finally, we analyze the anti-jamming performance of SD-CDFH receiver, and compared with the traditional DFH.The structure of this article is divided into five chapters. Chapter1gives the research background, research status of DFH and article structure. Chapter2first introduces the traditional DFH system, then gives the principle of SBS-CDFH receiver and analyzes the performance in AWGN channel and Rayleigh Slow Fading channel. Chapter3mainly gives the principle of SD-CDFH receiver and analyzes the performance in AWGN channel and Rayleigh Slow Fading channel. Chapter4partly analyzes the performance of anti-jamming in SD-CDFH receiver, including MTJ and PBNJ. Finally, gives the simulations compared with traditional DFH system. Chapter5 summarizes the whole actical, gives the contribution and the direction of future research.