Patent ID: 7173984
Filing Date: 2007-02-06
Classification: H04B,H04L,H04M,H04Q

Abstract:
1. A digital subscriber line communicating method comprising the step of: performing training for data communication using DMT symbols, by utilizing a telephone line as a high speed data communication line and by informing a reference signal having a frequency of 400 Hz and being synchronized with a TCM ISDN, under a TCM ISDN cross-talk environment, one period of said TCM ISDN being different from an integral multiple of said DMT symbols, said step of performing training comprising the steps of: transmitting a first kind of said DMT symbols from a transmitting side to a receiving side; and transmitting a second kind of said DMT symbols from said transmitting side to said receiving side; each of said first kind of said DMT symbols and each of said second kind of said DMT symbols having 4-value QAM signal points; each of said 4-value QAM signal points in said first DMT symbols having a phase difference of 90 degrees from each of said 4-value QAM signal points in said second DMT symbols, whereby the phase of said reference signal is informed from said transmitting side to said receiving side.