New timing extraction method and data interpolation for block demodulation

The conventional timing extraction method for block demodulation requires a large amount of calculation, a high-speed A/D (analog/digital) converter and a large memory size. A method that overcomes these disadvantages is proposed. It calculates accurate frequency and phase of symbol timing from only two extracted spectra by using a modified discrete Fourier transform (DFT). Thus it requires less calculation than the conventional method. In addition, interpolation of stored data is used to reduce the sampling rate. As a result the method can use a slower A/D converter and has a reduced memory requirement. The lower limit of the number of samples per symbol can be reduced to about 2.5.