{'fraction_non_alphanumeric': 0.03595890410958904, 'fraction_numerical': 0.005136986301369863, 'mean_word_length': 4.735294117647059, '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}}
Design of efficient second-order spectral-null codes

An efficient recursive method has been proposed for the encoding/decoding of second-order spectral-null codes, via concatenation by Tallini and Bose. However, this method requires the appending of one, two, or three extra bits to the information word, in order to make a balanced code, with the length being a multiple of 4; this introduces redundancy. Here, we introduce a new quasi-second-order spectral-null code with the length equiv 2 (mod 4) and extend the recursive method of Tallini and Bose, to achieve a higher code rate