Patent ID: 7292527
Filing Date: 2007-11-06
Classification: H04L

Abstract:
1. A method in an OFDM direct conversion receiver, the method including: receiving a prescribed group of consecutive symbols in a received OFDM signal, and identifying within the prescribed group a first subgroup of the consecutive symbols and a second subgroup of the consecutive symbols, the first and second subgroups each having an equal number of symbol subgroup positions; generating complex conjugates of the prescribed pilot tones of the first subgroup of the consecutive symbols; generating a complex pilot product, for each symbol subgroup position, by multiplying the pilot tones of a second subgroup symbol at the corresponding symbol subgroup position with the respective complex conjugates of a first subgroup symbol at the corresponding symbol subgroup position; obtaining an accumulated complex value by summing the complex pilot products of the symbol subgroup positions; and calculating the frequency error from the accumulated complex value for use in correcting frequency offset.