Device and method for correcting local oscillation frequency of radio reception device according to pilot synchronous detection

摘要

A pilot symbol detection section (1) detects and extracts pilot symbols from a despread signal. An inter-symbol phase shift detection section (2) detects the phase shifts between adjacent pilot symbols in a pilot symbol block (inter-symbol phase shifts). An inter-pilot block phase shift detection section (3) detects the phase shifts between adjacent pilot symbol blocks (inter-pilot block phase shift). An inter-symbol phase shift averaging section (4) takes the average of the inter-symbol phase shifts. An inter-pilot block phase shift averaging section (5) takes the average of the inter-pilot block phase shifts. A frequency correction determination section (6) determines an appropriate frequency correction based on the outputs of the inter-symbol phase shift averaging section (4) and the inter-pilot block phase shift averaging section (5). A frequency correction signal outputted by the frequency correction determination section (6) is used for correcting the frequency of a local oscillation signal which is used for the detection (despreading) of a received radio signal. A large frequency difference can be corrected accurately and at once regardless of whether it is at the beginning of communication or in the middle of communication.