Frequency-domain compensation method for CIC filter based on OFDM modulation

Cascade integrator comb(CIC) filter can be applied to the rate-matching for quadrature modulator in OFDM modulation. The signals in frequency-domain(FD) are transformed to time-domain(TD) by IFFT module and then distorted by the passband droop of CIC filter. This problem can be solved in TD via FIR compensation filters which require expensive computation for high-rate processing. This paper presents a FD compensation method operated before IFFT module for CIC filter. The simulation shows that the proposed method performs well and can decrease computational cost largely.