Asymmetric digital subscriber line modem apparatus and methods therefor

A modem comprising:

• a receiver associated with a receive timing scheme;
• a transmitter associated with a transmit timing scheme;
• and
• only one timing mechanism (i) electrically coupled to the receiver and the transmitter and (ii) configured to synchronize the receive and transmit timing schemes.

A modem comprising:

• a receive re-sampler configured to receive input signals in accordance with a receive timing scheme;
• a transmit re-sampler connected, at least indirectly, to the receive re-sampler, the transmit re-sampler being configured to transmit output signals in accordance with a transmit timing scheme;
• and
• only one timing mechanism electrically coupled to the receive re-sampler and the transmit re-sampler;
• wherein the timing mechanism is configured to synchronize the receive timing scheme and the transmit timing scheme.

A method for synchronizing timing in a modem having a receiver configured to receive an input data signal and a transmitter configured to produce an output data signal, the output data signal having timing characteristics based upon a transmit coefficient signal, the method comprising:

• receiving (i) the input data signal and (ii) a receive coefficient signal in the receiver;
• re-sampling the input data signal based upon the received coefficient signal to produce an interpolated signal thereby;
• producing signal phase data based upon the interpolated signal;
• and
• updating the receive coefficient signal and the transmit coefficient signal based upon the signal phase data.