Patent ID: 8208515

Claim:
An on-vehicle communication device communicating with a mobile device through a modulated signal modulated by spread spectrum, comprising: an initial signal estimating unit for estimating initial data based on a part of the modulated signal from said mobile device; a reference signal generating unit that generates a reference signal based on the initial data estimated by said initial signal estimating unit; a partial correlating unit that calculates a correlation value between the modulated signal from said mobile device and said reference signal; and a data demodulating unit that demodulates the modulated signal from said mobile device, said data demodulating unit starting when the correlation value calculated by said partial correlating unit exceeds a threshold value, wherein said initial estimating unit comprises a table storing said initial data and a signal provided by demodulating a part of said modulated signal by a primary demodulating unit, said initial data and said signal having previously been correlated to each other.