Narrow-Band Interference Suppression Algorithms of DS/CDMA Based on CYC-QRD-LSL Interpolators

The imperfect statistic and spectrum characteristics of direct spread spectrum signals will effect on the performance of narrow-band interference (NBI) suppression in DS/CDMA. To resolve this problem, an improved QR-decomposition-based least squares lattice (QRD-LSL) interpolator based on cycle-counteract (CYC) nonlinear processing is proposed. Applying the discrepancy of cycle correlation characteristics between DS signal and the ambience noise, the improved interpolators can efficiently remove the DS component from the input signal of NBI suppressor. Theoretic analysis and experimental results indicate that the improved interpolator can suppress NBI in DS/CDMA effectively. Both the convergence rate and the precision achieved by CYC-QRD-LSL interpolators outperform its QRD-LSL counterparts, especially when the spectrum of DS signal is non-white.