Elimination of Power Line Interference on Telephone Cables Under Frequency-Varying Conditions

A new method for the elimination of power line interference of potentially time-varying frequency, phase, and amplitude on telephone loops is presented. The proposed method is based on adaptive estimation, and subsequent elimination, of the fundamental and individual harmonic components of the induced power signal and tracking their variations over time. The structure and mathematical formulation of the proposed technique are presented, and its performance is demonstrated in a variety of scenarios. Superior performance of the proposed method over existing techniques is observed throughout all experiments. The proposed algorithm presents a simple and efficient method of elimination of narrowband interference of a potentially nonstationary nature that is suitable for real-time applications due to its structural simplicity.