Patent ID: 6026122
Filing Date: 2000-02-15
Classification: H04L

Abstract:
A transfer process comprising a modulation phase, a modulated signal transfer phase, and a demodulation phase,said modulation phase comprising:a convolutional encoding step for inputting successive digital bits, encoding the successive digital bits to generate successive first convolutional codes corresponding to the successive digital bits and representing successive original signal points each having non-precoded coordinates in a vector space;a modulo preceding step for precoding each of the non-precoded coordinates of the original signal points with a modulo operation, to generate successive modulo-precoded vector signal points having modulo-precoded coordinates for the successive original signal points; anda modulating step for generating a modulated analog signal containing information on the successive modulo-precoded vector signal points,wherein, in said modulated signal transfer phase, said modulated analog signal is transferred from said modulation phase to said demodulation phase, and has a first frequency characteristic which changes the successive modulo-precoded vector signal points contained in said modulated analog signal to successive inter-symbol interfered signal points, andsaid demodulation phase comprising:a demodulating step for receiving said modulated analog signal containing the information on the successive inter-symbol-interfered signal points, and generating a demodulated analog signal indicating the successive inter-symbol-interfered signal points;a modulo hard decision step for receiving said demodulated analog signal, determining said successive inter-symbol-interfered signal points in said demodulated analog signal by hard decision, and obtaining a series of successive second convolutional codes corresponding to the determined successive inter-symbol-interfered signal points of which the information are contained in the modulated analog signal which is recently received, based on a predetermined relationship between the inter-symbol-interfered signal points and the first convolutional codes;a soft decision step for determining the most likely series of values for the successive first convolutional codes based on said series of successive second convolutional codes, by soft decision; anda decoding step for obtaining successive second digital bits by decoding the most likely series of values for the successive first convolutional codes.