Frequency-Hopping Narrowband Interference Suppression in Spread-Spectrum Systems

Abstract

This paper studies the suppression of frequencyhopping (FH) narrowband interference (NBI) in spread-spectrum (SS) systems. Existing NBI suppression algorithms focus on the case that the center frequency of the NBI is invariant and the performance degrades severely when the NBI is frequencyhopping. In this paper, an FH-NBI suppression algorithm is proposed based on the time-domain least mean square (LMS) prediction filter. The proposed algorithm detects the instant when the NBI hops from one frequency to another, and updates the filter coefficients using a novel method, which avoids the convergence time required in the conventional LMS algorithm. Both theoretical analysis and simulation results show that the proposed algorithm can suppress FH-NBI much more effectively than the existing algorithms.