{'fraction_non_alphanumeric': 0.029182879377431907, 'fraction_numerical': 0.0, 'mean_word_length': 5.952702702702703, '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}}
Potential multicarrier and spread spectrum systems for future aviation data links

We examine the potential use of several multicarrier (MC) and spread spectrum (SS) systems for future aviation data links. These techniques are seeing widespread research, development, and deployment in commercial terrestrial settings, and offer many advantages over more traditional approaches. We consider direct-sequence (DS) SS, orthogonal frequency division multiplexing (OFDM), and variations of code-division multiple access (CDMA). A comparison of the characteristics of these techniques is provided, and application to an aeronautical environment is also discussed. This comparison addresses bandwidth efficiency and throughput, performance, security, and implementation issues. Example analytical and simulation results for performance on a two-ray dispersive channel, and in the presence of interference, are provided, and allow some insight into how the size of the list of candidate schemes for future investigation might be reduced