Analysis and compensation of frequency offset in co-site adjacent channel interference suppression

Due to the mismatch of the circuit oscillators, there will always be a frequency offset between the transmitter and the receiver. In the adjacent channel interference (ACI) suppression system using the reconstruction and cancellation method, the frequency offset decreases the accuracy of the reconstructed signal and introduces a time-varying term in the interference cancellation, resulting in poor performance of the ACI suppression. In this paper, the relationship between the normalized frequency offset, signal-to-noise ratio and the loss of interference suppression capability is analyzed through formula derivation and simulation. The validity of the frequency offset compensation method based on the pilot sequence is verified, and the relationship between the sequence length and the estimation accuracy is given. This paper provides necessary method reference and data support for the engineering of ACI suppression.