Research On Demodulation Algorithms Of Short Burst Signals

In the recent years, because of good adaptability and strong resistance to interception, short burst signals technology are widely used in the military and civilian fields, so the study of short burst signals receiving technology are of great theoretical and practical value. This paper focuses on the study of demodulation of short burst signals, mainly includes signal detection, timing synchronization and carrier synchronization technology, the work and contributions of this paper are as follows:1. Based on the detailed analysis of the short-time signal detection algorithm nowadays, a new short burst signal detection algorithm-Two Window bispectrum detection algorithm is proposed, which can solve the ineffective problem that exist in time-domain detection algorithm under low-SNR. With the characteristics of some real short burst signals, a design of signal detection scheme which suits for short burst signals is proposed and realized.2. Carrier frequency offset estimation and phase deviation estimation are realized using a forward non-data aided algorithm. By analyzing the characteristics between maximum likelihood frequency offset estimation algorithm and signal autocorrelation function, a related Tretter frequency offset estimation algorithm is put forward, which has good performance in low SNR conditions; In order to solve the problem of maximum likelihood frequency offset algorithm's narrow estimation scope, an improved L&R algorithm based on the idea of one estimation per two-step is proposed, the improved method expands the scope of frequency offset estimation while maintains performance. At last, analysis and simulation of classical algorithm and improved algorithm are carried out on various aspects.3. From the perspective of non-cooperation, short-term timing error estimation algorithm suit for short burst signals is studied. Through the analysis of real signal, a timing error estimation algorithm is given. Then, a project-based timing synchronization platform structure is designed and the feasibility of the algorithm is verified.4. Combined with the project platform, the characteristics of GPU technology are described, and the platform structure for signal processing is designed. Then, the author design the demodulation process of short burst signal and carry out the demodulation of received short burst signal.