Patent ID: 9172575
Filing Date: 2015-10-27
Classification: H04L

Abstract:
1. A correlator comprising: a plurality of filter sections having different non-overlapping pass-band characteristics from each other, each of the plurality of filter sections being input in parallel with an Orthogonal Frequency Division Multiplexing (OFDM) signal, which is a single received signal and has been converted to a digital signal, where one symbol period comprises an effective symbol period and a guard interval in which part of the signal of the effective symbol period has been copied, wherein the plurality of filter sections is set such that each of the different non-overlapping pass-band characteristics of filter sections are adjacent to each other; a plurality of autocorrelation generating sections, provided so as to correspond to each of the plurality of filter sections, that generate autocorrelation signals based on the signals passed through the corresponding filter sections; and an autocorrelation output section that is input with each of the autocorrelation signals and, based on each of the autocorrelation signals, either selects one of the autocorrelations or generates an autocorrelation appropriate for obtaining timing synchronization, and outputs the selected or generated autocorrelation, wherein the autocorrelation output section: extracts an autocorrelation signal having the largest maximum value from the autocorrelation signals; sets a threshold value by multiplying the extracted maximum value by a specific coefficient of less than 1; extracts from the remaining autocorrelation signals any autocorrelations having a maximum value greater than the threshold value; addition-combines the autocorrelation signal having the largest maximum value and the extracted autocorrelation signals having maximum values greater than the threshold value; and outputs the addition-combined autocorrelation signal.