Frequency error estimation and correction in a SAIC linear equalizer

摘要

Different from conventional equalizers, the output of an SAIC (Single Antenna Interference Cancellation) linear equalizer in GSM/EDGE wireless communication systems is a real signal combined from two real FIR (Finite Impulse Response) filter outputs. Each of the FIRs separately uses the real and imaginary components of the ½ pi de-rotated received signal as input. The real-valued output of the SAIC equalizer creates difficulty to estimate and correct the frequency errors due to receiver LO and Doppler shift. Disclosed is an efficient and effective solution to the estimation and correction of the frequency error through an assistant signal generated by two additional FIR filters. The assistant signal and the SAIC equalizer output are used to estimate the frequency error, which is combined with the SAIC equalizer output and the assistant signal to give the frequency error corrected SAIC equalizer output.