A Novel Method for Multipath Separation and Measurement of Root Mean Square Delay Spread Based on Fractional Fourier Transform in a Multipath Channel

Based on the fractional Fourier transform (FrFT), the authors propose a novel method for multipath separation and measurement of root mean square (RMS) delay spread by using a chirp pilot symbols. Different multipath chirp components with different time delays will be concentrated on different fractional frequency points in fractional Fourier domain (FrFD) through FrFT. Meanwhile, the envelope amplitude of a concentrated component indicates the corresponding signal energy. Therefore, the different multipath components can be separated clearly and the RMS delay spread of a multipath channel can be measured accurately in FrFD.