| 摘要 |
<p>METHOD AND DEVICE FOR ACQUIRING THE INITIAL PHASE OF THE CLOCK IN A SYNCHRONOUS DATA RECEIVER In a synchronous data transmission system wherein data transmission is achieved by modulating a carrier wave of frequency fc at the signaling rate 1/T, a method for determining the initial phase value by which the phase of the receiver clock is to be varied during an initial synchronization operation during which a synchronization signal, the spectrum of which includes two distinct lines at frequencies f1 = fc - 1/2T and f2 = fc + 1/2T, is transmitted comprising the steps of:a) sampling the synchronization signal fed into the receiver at the rate 1/T which is a multiple of the signaling rate, to provide a signal x(kT) where k = a, 1, ...,b) multiplying the signal x(T) by itself to provide a signal s(kT),c) computing the coefficient Co, which corresponds to the frequency 1/T, of the discrete Fourier transform of signal s(kT) from N samples thereof, the number N being determined from the resolution R = 1/NT required to overcome the effects of the frequency components, other than the component at frequency 1/T, of signal s(kT), andd) computing the phase of coefficient Co that repre sents the initial phase value by which the phase of the receiver clock is to be varied.</p> |
