公开(公告)号：JPH1075277A

公开(公告)日：1998-03-17

申请号：JP11206597

申请日：1997-04-30

Applicant: IBM

Inventor： HUANG KUNG-SHIUH ,  MONTI STEVEN PETER ,  RUIZ ANTONIO

IPC: G06F13/00 ,  H04J11/00 ,  H04L27/26 ,  H04L29/08

Abstract: PROBLEM TO BE SOLVED: To reduce the complicatedness of a hardware and to perform variable speed services to many clients by using the integer number of (z) point IDFT modulator modules of one type and utilizing discrete multiple tone codes. SOLUTION: The clients(CLs) 1-W are provided with an encoder 6 and an IDFT modulator (IDFT) 8 and the IDFT 8 uses (z) point IDFTs which are basic IDFT modules for plural pieces depending on the number of sub channels (SCs) required by the CLs 1-W. For instance, in the case of requiring two audio channels, the CL 1 is allocated with the two SCs and provided with the two (z) point IDFTs. The encoder 6 maps signals from the CL1 to composite sub symbols, that are the discrete multiple tone codes, and outputs them to the (z) point IDFT. Thus, the complicatedness of the IDFT 8 is reduced and the communication speed of the CLs 1-W is made variable for the respective plural- folds of the SC.