Jump Frequently Point Sequence Estimation And Frame Detection

Frequency Hopping(FH) communication which has excellent anti-interference and anti-fading capacity is widely used in the wireless communications. The synchronization of FH is an important guarantee for FH communication, the reconnaissance of synchronous signal of FH communication is an effective way to identifying the synchronization methods of FH system, and detection of synchronous frequencies of FH is the main task of the reconnaissance of synchronous signal of FH. With the rapid development of high-speed FH system, the speed and bandwidth of FH system is increasing, the real-time performance and reliability of synchronous frequencies'detection will directly affect the performance of the reconnaissance of synchronous signal of FH, so that fast and accurately detect the synchronous frequencies become a hot research topic recently.In this background, based on the corresponding relationship between the frequency-points and frequency sequences of FH, this paper uses the frequency-pot sequences as research subjects, elaborates the main links of detection of synchronous frequency-pots and exploringly researches the methods which used in estimating the frequency-pots sequence and detecting the synchronous frequency-pots in FH system based on understanding the characters of FH signal in-depth. The main contents of this paper are:1. We describe the basic working principle and key technologies of FH communication system in detail and give the simulation result of FH signal combined with its characteristics.2. According to the time - frequency analysis theory, We sum up two methods of estimating the instantaneous frequency of FH signal based STFT-FFT and SPWVD-FFT frequency-hopping signal instantaneous frequency estimation, analyses and comprise the performance of frequency measurement about these methods, the results of simulation indicate that the frequency measurement accuracy of STFT-FFT is higher than SPWVD-FFT-based, real-time capability is better too.3. We study the pre-processing method for measured frequency data, simulation results show that this method effectively reduces the impact of errors which contained in measured frequency data ,and is propitious to accurately estimate the frequency-pot sequences.4. We introduce three frame sync detection methods which used in FH frequency-pots sequence and comprise the synchronization detection performance of these methods at different levels of error through simulation, the results show that the match-threshold method is not only has stronger applicability of decision synchronous but also has higher detection probability combining with detection model of frame synchronization.