Research And Implement On Capture Of Signal In Burst Communication Of Low SNR

The burst communication system improves the ability of anti-interception and anti-interference effectively by shortening the presence time of signal in the space. In burst communications, the communication signal is always submerged in the strong noise because of the complex highly dynamic changing characteristics of communication channel, which puts forward higher requirements to the performance of burst communication system in low SNR conditions. The primary task for burst communication system is to accurately detect and capture the signal. This paper designs a signal detection algorithm which is used in the low SNR burst communication system.Based on the summary of domestic and international signal detection algorithms, this paper designs a signal detection algorithm with high-order cumulate which inhibits Gaussian noise. The Matlab simulation results show that, this algorithm meets the requirements of this project target in the low SNR conditions, but the estimation algorithms of parameters have large estimation variance which makes it hard to estimate the SNR and the beginning location of the signal precisely. In this paper, it designs an optimization scheme which uses joint frame synchronization and frequency estimation algorithm to improve the accuracy of estimation. The simulation results show that the success rate meets the requirements. This paper designs the signal detection and estimation module using the VHDL in Quartus II, and the module occupies less than 10% resources on Altera Cyclone IV. Finally, it tests the signal detection and estimation module on the DE2-115 development board in different SNR conditions. The results show that the signal detection module can work normally in various SNR conditions.Because the signal detection algorithm used high order cumulant which belongs to the blind detection algorithm, the algorithm designed in this paper not only can be applied to the burst communication of low SNR, but also can be applied to other non-cooperation communications. It’s very suitable for the emergency and military communication systems.