APPARATUS AND METHOD FOR ESTIMATING VELOCITY IN MOBILE COMMUNICATION SYSTEM

摘要

An apparatus and a method for estimating the speed in a mobile communication system are provided to detect the maximum doppler frequency by means of the CDF(Cumulative Density Function). A power spectrum measuring device(400) collects the constant number of samples from the signal of a pilot channel de-modulator and performs the DFT(Discrete Fourier Transform) or DCT(Discrete Cosine Transform) calculation about the collected samples so that the PSD(Power Spectrum Density) values relating the number N of frequency bins are calculated. A noise estimator(402) estimates the noise by the power spectrum values about above the number N'+1 of bins among the power spectrum values. A noise remover(404) subtracts the noise estimation value of the noise estimator from the power spectrum values and outputs the subtracted value. A CDF calculator(406) cumulates the power spectrum values from the noise remove according to the CDF and outputs the cumulated values. A doppler frequency detector(408) calculates the detection threshold by means of the cumulated values, compares the cumulated values with the threshold and detects the maximum doppler frequency.