{'fraction_non_alphanumeric': 0.022298456260720412, 'fraction_numerical': 0.0, 'mean_word_length': 4.959183673469388, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Time-varying channel estimation based on pilot tones in OFDM systems

The time-varying channel estimation methods for OFDM systems based on pilot tones are investigated. Grouped and equispaced pilot tones to estimate the channel impulse response (CIR) of some given moments are used. The CIR of other moments over one OFDM symbol is estimated by a new low-pass interpolation method proposed in this paper. The simulation results show that the normal mean-square error (NMSE) of the proposed method is smaller than the linear interpolation method and model-based interpolation method.