MULTICARRIER TRANSMISSION DEVICE, TRANSMISSION SYSTEM, MULTI-BIT NUMBER CORRECTING METHOD, AND PROGRAM

摘要

PROBLEM TO BE SOLVED: To obtain an ADSL transmission system that realizes stable communication (wherein retraining hardly occurs) without causing the transmission rate to decrease as much as possible in a noise pattern environment wherein unstable communication resulting from a line is easily caused. SOLUTION: In a multicarrier transmission type ADSL subscriber side transmission device 2 which performs data transmission by determining the numbers of multiple bits of respective carriers of a multicarrier signal according to the state of a communication line, a bit map correcting circuit 7 corrects the numbers of multiple bits of the respective carriers determined by a bit map generating circuit 6 by referring to the number of multiple bits of adjacent carriers. A bit map after the correction is supplied to a modulation and demodulation portion 4 to modulate and demodulate the respective carriers of the multicarrier signal. Consequently, a transmission error due to fine frequency variation of a noise pattern of a telephone line can be suppressed and retraining can be avoided to enable stable communication. COPYRIGHT: (C)2006,JPO&NCIPI