ADAPTIVE BIT ALLOCATION FOR VARIABLE BANDWIDTH MULTICARRIER COMMUNICATION

摘要

PROBLEM TO BE SOLVED: To synchronize a transmitter and a receiver in using a new table by determining a bit loading table relatively speedily. SOLUTION: Data are distributed among channels of an asynchronous data subscriber loop (ADSL) communication system in accordance with an adaptive algorithm which from time to time measures a signal-to-noise-ratio of the various channels and determines a margin for each channel dependent on achievement (where possible) of a given bit error rate and a desired data transmission rate. The margin distribution is achieved by augmenting the constellation signal-to-noise-ratio to enhance computational efficiency and allow redetermination of bit allocation tables during transmission as necessary. Pairs of bit allocation tables are maintained at a transmitter and receiver and one table of each pair at the transmitter and receiver is updated while the other pair is in use for controlling communication. COPYRIGHT: (C)2010,JPO&INPIT