Synchronization apparatus, synchronization method for synchronizing timing

A synchronization apparatus comprising:

• an acquisition unit that acquires a received signal, a plurality of patterns of synchronization signals each comprised of a plurality of symbols being defined, the received signal including the synchronization signal of one of the plurality of patterns, and the received signal being sampled by using a plurality of samples per one symbol;
• a correlation processor that derives a correlation value indicating correlation between each of a plurality of reference signals produced by extracting symbols from the synchronization signal of each pattern at a predetermined interval and the received signal acquired by the acquisition unit;
• a controller that compares the correlation value for each pattern and for each sample derived by the correlation processor with a threshold value and that, (1) when all correlation values are equal to or less than the threshold value, causes the correlation processor to perform the same process, incorporating the received signal newly acquired by the acquisition unit, and that (2) when at least one correlation value is larger than the threshold value, changes symbols extracted to produce respective reference signals before causing the correlation processor to perform the same process, incorporating the received signal newly acquired by the acquisition unit;
• a first selector that selects one of the plurality of patterns when all symbols of the synchronization signal have been extracted to produce the reference signals and at least one correlation value is larger than the threshold value;
• and
• a second selector that derives for each sample the correlation value indicating correlation between the synchronization signal of the pattern selected by the first selector and the received signal newly acquired by the acquisition unit and selects a timing of sampling based on the derived correlation value.