Patent ID: 7515641

Claim:
An apparatus for processing a ranging channel in an orthogonal frequency division multiple access system, which is for measuring a time delay and power of each baseband signal received by a base station of the orthogonal frequency division multiple access system, the apparatus comprising: a ranging channel signal extractor for selecting a subcarrier allocated to the ranging channel among frequency-domain signals converted from the baseband signals by fast Fourier transform (FFT); and a ranging channel processor to measure a time delay by performing an addition operation of a first phase value of a received ranging complex signal selected by the ranging channel signal extractor and a second phase value corresponding to a phase rotation of the ranging complex signal, the ranging channel processor further to measure a corresponding power of the ranging complex signal by integrating a correlation between the ranging complex signal and a ranging code set, wherein the ranging channel processing comprises: a polar coordinate converter for converting the received ranging complex signal to a polar coordinate signal; a time delay phase generator for generating a phase component for the time delay of the ranging complex signal; a time correlator for estimating the time delay of the ranging channel based on output signals of the polar coordinate converter and the time delay phase generator; a pseudo noise code correlator for discriminating a predetermined pseudo noise code for the ranging channel based on an output signal of the time correlator, and eliminating the ranging complex signal of the pseudo noise code; a complex coordinate converter for converting the polar coordinate signal to a converted complex signal; an integrator for measuring the magnitude and power of a signal transferred from the ranging channel; and a comparator for comparing the signal magnitude and the power with a predetermined threshold of a receiver, the apparatus measuring the time delay and the corresponding code and power based on an output of the comparator.