Digital subscriber line communicating system and a transceiver in the system

A digital subscriber line communicating system for communicating between a transceiver in a central office and a transceiver in a remote terminal through a communication line, wherein, during timing recover training sequence between said central office and said remote terminal, an inside discrete multitone (DMT) symbol of a downstream sliding window is formed by a first kind of signal, and an outside DMT symbol of said downstream sliding window is formed by a second kind of signal, said first kind of signal and said second kind of signal being obtained by modulating a carrier signal but being different in phase by a predetermined angle, and

• said transceiver in said remote terminal recognizes whether a received DMT symbol belongs to a far end cross-talk duration at said remote terminal or a near end cross-talk duration at said remote terminal, by detecting a phase of an output of a fast Fourier transform of said carrier signal, so as to recognize a phase of a timing signal which represents a periodical noise duration.

A digital subscriber line communicating system for communicating between a transceiver in a central office and a transceiver in a remote terminal through a communication line, wherein, during timing recover training sequence between said central office and said remote terminal, an inside discrete multitone (DMT) symbol of a downstream sliding window is formed by a first kind of signal, and an outside DMT symbol of said downstream sliding window is formed by a second kind of signal, said first kind of signal and said second kind of signal being obtained by modulating a carrier signal but being different in phase by a predetermined angle, and

• said transceiver in said remote terminal recognizes whether a received DMT symbol belongs to a far end cross-talk duration at said remote terminal or a near end cross-talk duration at said remote terminal, by detecting a phase of an output of a quadrature phase shift keying demodulation of said carrier signal, so as to recognize a phase of a timing signal which represents a periodical noise duration.

A transceiver to be connected through a communication line, wherein, during timing recover training sequence between a central office and a remote terminal, an inside discrete multitone (DMT) symbol of a downstream sliding window is formed by a first kind of signal, and an outside DMT symbol of said downstream sliding window is formed by a second kind of signal, said first kind of signal and said second kind of signal being obtained by modulating a carrier signal but being different in phase by a predetermined angle, and

• said transceiver in said remote terminal recognizes whether a received DMT symbol belongs to a far end cross-talk duration at said remote terminal or a near end cross-talk duration at said remote terminal, by detecting a phase of an output of a fast Fourier transform of said carrier signal, so as to recognize a phase of a timing signal which represents a periodical noise duration.

A transceiver to be connected through a communication line, wherein, during timing recover training sequence between a central office and a remote terminal, an inside discrete multitone (DMT) symbol of a downstream sliding window is formed by a first kind of signal, and an outside DMT symbol of said downstream sliding window is formed by a second kind of signal, said first kind of signal and said second kind of signal being obtained by modulating a carrier signal but being different in phase by a predetermined angle, and

• said transceiver in said remote terminal recognizes whether a received DMT symbol belongs to a far end cross-talk duration at said remote terminal or a near end cross-talk duration at said remote terminal, by detecting a phase of an output of a quadrature phase shift keying demodulation of said carrier signal, so as to recognize a phase of a timing signal which represents a periodical noise duration.