Patent ID: 7738357

Claim:
A method for correcting carrier frequency offset (CFO) in a communication system receiving a plurality of data packets, each data packet including multiple data streams (M), each data packet having a payload portion including a number (L) of data symbols, each data symbol having a number (K) of tones, the method comprising: for an l th symbol in a data packet: (a) generating a per-tone CFO estimate (p tone (k)) for each of the K data tones in a data symbol based on (i) a received signal; (ii) a channel estimate; and (iii) a data estimate or pilot information; (b) assigning a weight to each p tone (k); (c) generating a per-symbol CFO estimate (p sym (l)) for the l th symbol by averaging the K weighted per-tone CFO estimates; (d) assigning a weight to each p sym (l) for the L symbols in the data packet; (e) generating a per-stream CEO estimate (p stream (m)), by averaging the L weighted per-symbol CEO estimates; (f) assigning a weight to each p stream (m); (g) generating a single data CEO estimate (p data ) by averaging the M weighted per-stream CEO estimates; (h) generating a packet CEO estimate (p packet ) using p data and/or a preamble CEO estimate (p preamble ); (i) correcting the CEO in each data stream according to p packet ; (j) repeating steps (a) through (i) for each data symbol in the data packet.