基于改進(jìn)時(shí)頻脊線(xiàn)的跳頻參數(shù)盲估計(jì)算法

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中圖分類(lèi)號(hào)：TN911 文獻(xiàn)標(biāo)志碼：A 文章編號(hào)：1673-2340（2025）02-0048-08

Blind estimation algorithm for frequency hopping parameters based on enhanced time-frequency ridge extraction

WANKai'，CHANGCheng2，HOUChangbol*，WUXiangyu1 （l.Schoolof Informationand CommunicationEngineering，HarbinEngineering University，Harbinl5Oool，China; 2.China AcademyofLaunchVehicle Technology，BeijinglOo854，China）

Abstract：In existing blindestimation algorithms for frequency-hoppingparameters basedon time-frequencyridges， performance degrades significantly when thesignal-to-noiseratio（SNR）fals below-5dB.Toaddressthis issue，an improvedblindestimationmethod basedontime-frequencyridges isproposed.First，the time-frequencymatrixof the receivedsignal isobtainedusing theshort-time Fourier transform（STFT）.Then，Gaussian filtering isapplied for signal smoothingand noise suppresson.Since the energy distribution offixed-frequency interference differs fromthat of frequency-hopping signals in the time-frequency matrix，an energycancelation method is used to eliminate such interference.Next，OTSU thresholding isapplied tothe matrixafter energycancelltion to further removeresidual fixed-frequency interferenceand noise，yieldingaclearer time-frequencyrepresentation.Time-frequencyridgesare thenextracted from this image，and the least-squares method is employed to fitthe hopping instants along these ridges，enabling accurateestimationof frequency-hopping parameters.Simulation resultsshow that the proposed method efectively produces clean time-frequency images evenat SNR levelsaslowas -5dB in the presence of fixed-frequency interference. The average relative estimation error of each parameter remains below 1% ，and the method demonstrates strong robustness against varying intensity and quantity of interference.

Keywords：frequencyhopping signal;parameter estimation;time-frequencyridges;fixed frequencyinterference; gaussian filtering; blind estimation algorithms; signal to noise

跳頻通信作為擴(kuò)頻技術(shù)的重要分支，通過(guò)偽隨機(jī)碼序列對(duì)載波頻率實(shí)施動(dòng)態(tài)操控，實(shí)現(xiàn)快速靈活的跳變機(jī)制。（剩余10089字）