Patent ID: 7222283
Filing Date: 2007-05-22
Classification: H03M

Abstract:
1. “A method of transmitting signals comprising the steps of: receiving signals to be transmitted; source encoding said signals to build a variable length error code; channel encoding the variable length error code; and transmitting the channel encoded variable length error code, wherein said step of source encoding said signals to build the variable length error code, comprises the sub-steps of:” (1) initializing the needed parameters: minimum and maximum length of codewords L (2) generating a fixed length code C of length L (3) listing and storing in the set W all the possible L (4) deleting all the words of the set W that do not satisfy the cmin distance With all codewords of C, said distance c (5) in the case where no word is found following acts 3 and 4, delecting codewords of the last group, otherwise controlling that all words of the set W are distant of bmin, the found words being then added to the code C; (6) if the required number of codewords has not been reached, repeating the acts (1) to (5) until the method finds either no further possibility to continue or the required number of codewords has been reached; (7) if the number of codewords of C is greater than S calculating, on the basis of the structure of the VLEC code, the average length AL obtained by weighting each codeword length with the probability of the source, said AL becoming the ALmin, if it is lower than ALmin, with ALmin=the minimum value of AL, and the corresponding code structure being kept in memory; said building method being moreover such that at most one bit is added at the end of each word of the set W.