Advanced Blanking Nonlinearity for Mitigating Impulsive Interference in OFDM Systems

• Published in: IEEE transactions on vehicular technology Vol. 66; no. 1; pp. 146 - 158
• Main Authors: Epple, Ulrich, Schnell, Michael
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-01-2017; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Blanking; Blanking nonlinearity (BN); Computer simulation; Demodulation; Frequency division multiplexing; Frequency-domain analysis; impulsive interference; Interference; interference mitigation; Iterative methods; Nonlinearity; OFDM; Orthogonal Frequency Division Multiplexing; orthogonal frequency division multiplexing (OFDM); Receivers; Signal to noise ratio; Subcarriers; Wireless communication systems; Wireless communications
• ISSN: 0018-9545; 1939-9359
• DOI: 10.1109/TVT.2016.2535374

In this paper, we introduce advancements of the conventional blanking nonlinearity (BN) for orthogonal frequency-division multiplexing (OFDM)-based systems, which is referred to in the following as advanced BN. Blanking is a common measure for mitigating impulsive interference that often occurs in wireless communication systems. Although the BN removes impulsive interference reliably, it possesses various drawbacks for OFDM-based systems. In particular, the choice of the blanking threshold (BT), to decide whether a received sample is blanked, is a critical issue. We present an algorithm for determining the optimal BT to maximize the signal-to-noise-and-interference ratio (SINR) after blanking. Another drawback is that the entire received signal is discarded during a blanking interval, despite the fact that only a fraction of the spectrum of the OFDM signal might be affected by interference. We show how blanking can be limited to subcarriers that are actually affected by interference. Further, we show how these measures can be combined and how a priori information obtained in an iterative loop can be incorporated into the proposed scheme. Simulation results incorporating realistic channel and interference models demonstrate the effectiveness of the proposed scheme.