Time-varying AR modeling and subspace projection for FM jammer suppression in DS/SS-CDMA systems

In this paper, we propose a new technique to effectively suppress nonstationary jammer in DS/SS communication systems. This technique combines a new scheme of instantaneous frequency (IF) estimation with the projection based interference suppression. In order to capture jammer subspace a time-varying autoregressive (TV-AR) modeling is used to estimate the IFs of the nonstationary jammers. The jammer subspace is constructed from the models governed by the estimated time-varying IFs. The estimated jamming interference is removed from the received data by subspace projection, resulting in less distortion to the desired signal. The performance of this approach is analyzed and compared with approaches using time-varying notch filtering and subspace projection method.