Research Of UHF Differential Frequency-hopping Detection Technology Based On Compressed Sampling

As the wireless confrontation in the space intensified, the traditional fixed-frequency communication system has been unable to meet the requirements of modern military communications. Because of its excellent anti-interference ability and multi-site networking capability, frequency hopping communication system have been widely used in civilian and military communication. And made considerable development in the application process, resulting in a number of new frequency hopping communication technologies, such as differential frequency hopping (DFH) communications technology.As a new member of frequency hopping system, the differential frequency hopping communications systems are attracting attention increasingly, it has more excellent anti-jamming capability, and can provide higher rate of data transmission compared to conventional frequency hopping system. At present, the differential frequency hopping communication technology has been successfully applied to the short-wave communications, it can overcome the shortcomings of bandwidth-limited, serious interference, multi-path fading and other issues which is very common in short-wave communication. It achieves a set of high-speed frequency hopping and high-speed data transfer in one. However, this technology still has many difficulties in the ultra high frequency (UHF) band, such as the ADC devices are difficult to be achieved caused by high operating bandwidth, the conflict between speed and jump according to uncertainty principle and so on, these problems are plaguing the application of differential hopping communication technology in UHF-band frequency.In recent years, some foreign scholars have put forward a new theory of information acquisition-compressive sampling (also known as compressive sensing, CS) theory, which can break through the limit of conventional Shannon sampling theorem on the sampling rate at least twice of the maximum frequency of the target signal (Nyquist rate), greatly reduces the costs of data collection and information processing, probably brought a new revolution. The main object of this article is the UHF differential frequency hopping signals, through combining the compressive sample and the signal detection theory, provides a new way of the UHF differential frequency hopping detection.This paper starts from the hopping communication technologies, introduces conventional frequency hopping technology and differential frequency hopping technology in detail respectively, describes the basic working principle and the main technical indicators, and then makes a comprehensive and detailed description of the basic concepts and implementation methods of the CS theory. This paper also has study in depth on some key technologies such as the design of observation matrix, AIC system performance analysis and signal reconstruction algorithms, and detailed analysis of their implementation process and characteristics. In the following two chapters, in response to the complex electromagnetic environment of frequency hopping communication, from the views of frequency hopping detection and fixed-frequency signal separation, the paper proposed a method of UHF differential frequency hopping detection which is based on compressive sampling theory and a method of frequency hopping signal separation which is based on annihilation filtering technique, and focus on some of these critical steps and key issues were discussed in detail by computer simulation, verifies the feasibility of these theories.