研究了WVD和短時傅里葉變換兩種時頻分析方法的優勢和局限性，從兩種方法的定義出發，分析了兩者間存在的聯系，通過構造窗函數，提出一種改進的非平穩信號分析方法，并進行了相應的計算機仿真，結果表明信號的時頻特性得到了改善，該方法還適用于多分量非平穩信號的分析。
關 鍵 詞 時頻分布; 非平穩信號; 調頻信號; 參數估計

Abstract Wigner ville distribation and short time Fourier transform are the main time-frequency analysis methods. However, both of them have their advantages and limitations. On the base of the definition of the two transform, this paper analyzes the connection between them, then proposes an improved method through the construction of window function. Computer simulation shows the time-frequency character of signal is improved and the method is applicable to the analysis of multicomponent nonstationary signal.
Key words time-frequency distribution; nonstationary signal; frequency-modulated signal; parameter estimation