Apparatus and method for carrier frequency offset estimation and correction in a wireless communication system

摘要

A method is disclosed for correcting carrier frequency offset (CFO) in a received data packet that includes one or more M data streams. The data packet has a payload portion preceded by a preamble portion, the payload portion having a plurality of data symbols (L) each of which include a plurality of data tones (K). The method comprises, making a per-stream preamble CFO estimate for each data stream by correlating repeated preamble portions that precede the data packet. The per-stream preamble CFO estimates are weighted and averaged to obtain a single preamble CFO estimate. Any CFO in each received data stream is then corrected according to the preamble CFO estimate. Additionally, for an l^th data symbol in a data packet, a per-tone CFO estimate is derived and successively averaged over frequency (tones), time (symbols) and space (data steams) to derive data CFO estimate p_data. Any CFO in each received data stream may be corrected according to the data CFO estimate, and/or the preamble CFO estimate.