| 摘要 |
PURPOSE: A PN(Pseudo Noise) code trace time delay loop device using an interpolator in a wireless communication system is provided to generate timing error signals by using samples of an interpolation filter in order to obtain PN code synchronization with small over-sampling, and to form a closed loop, thereby restoring timing and extracting exact symbols. CONSTITUTION: An interpolation unit(10) includes an interpolator(11) and a decimator(12). The interpolator(11) generates two samples per synchronized symbol from an input signal(IS). The decimator(12) decimates the two samples. A timing error detector(20) detects timing error values from a signal passing through the interpolation unit(10). A loss pass filter(30) filters a predetermined frequency band only in order to stabilize the detected timing error values. A PN code generator(40) generates a PN code. The first and the second PN code period delayers(41,42) make the outputted PN code for a half chip lead period or a half chip lag period. A LEAD/LAG delay signal detector and quantizer(50) detects a lead/lag signal quantized by the timing error values, and leads or lags a position of a current decimation point. |
