Residual frequency error estimation in an ofdm receiver

摘要

An OFDM receiver (50) configured for measuring frequency error (124) based on comparing prescribed pilot tones (114) from a prescribed group of consecutive symbols (112) in a received OFDM signal. A complex conjugate generator (104) is configured for generating complex conjugates of the prescribed pilot tones of a first subgroup (118a) of the consecutive symbols. A multiplier (106) is configured for generating a complex pilot product (120), 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 the first subgroup symbol at the corresponding symbol subgroup position. A complex summation circuit (108) sums the complex pilot products of the symbol subgroup positions to obtain an accumulated complex value (122). A error calculator (110) calculates the frequency error from the accumulated complex value for use in correcting frequency offset.