Multipath Delay Estimation by Jammed Pilot in OFDM System

This paper studies orthogonal frequency-division multiplexing (OFDM) system channel estimation problem in the interference environment and the channel delay estimation algorithm is proposed. The algorithm consists of the narrowband interference detection and suppression and channel time delay estimation. First of all, this paper studied the statistical characteristics of channel frequency domain response value at pilot tones, use double threshold consecutive mean excision (CME) algorithm, to detect the interference of pilot subcarriers and interference suppression. Then, the authors analyze the channel frequency response mathematical model and alternating notch periodogram (ANP) spectral estimation method is used to obtain the channel time delay estimation value. The simulation results show that the use of this improved channel estimation algorithm very close to the performance of the Expectation Maximization (EM) channel estimation algorithm with ideal channel delay for channel estimation algorithm performance and BER performance and the delay is known.