Patent ID: 8295413
Filing Date: 2012-10-23
Classification: H04B,H04L

Abstract:
1. A Doppler frequency estimating device comprising: an inverse fast Fourier transform section which performs inverse fast Fourier transform for a channel estimation value obtained in a receiving device to obtain a channel impulse response; a selecting section which selects paths that belong to a group having a large element based on elements of paths for the channel impulse response obtained by the inverse fast Fourier transform section; a time averaging section which calculates autocorrelation values by time averaging for each of the paths selected by the selecting section; an ensemble averaging section which obtains an ensemble average value of the autocorrelation values by time averaging obtained by the time averaging section; and an estimating section which obtains a Doppler frequency associated with the ensemble average value based on a relationship characteristic indicative of a relationship between an autocorrelation value and a Doppler frequency and the ensemble average value obtained by the ensemble averaging section; wherein the relationship characteristic is divided into a plurality of regions in accordance with the autocorrelation value, and wherein the estimating section selects a region to which the ensemble average value belongs from the regions and calculates differences between autocorrelation values based on the relationship characteristic and the ensemble average value in the selected region to obtain the Doppler frequency associated with an autocorrelation value that minimizes the difference.