Timing recovery for echo-cancelled discrete multitone systems

We present a novel technique for timing recovery in an echo-cancelled multicarrier system. In this scheme, both the transmit and receive clocks on a transceiver are derived from the same stable crystal oscillator. In this way, the high degree of echo rejection required by the echo canceller is affected by neither timing jitter nor sampling phase offset. The receiver compensates for the time-domain phase offset with the use of frequency-domain adaptive equalization on the echo-cancelled demodulated symbols. Cycle slips are handled by a simple rob/stuff protocol that is reflected in the operation of the frame-synchronous echo canceller. An efficient method for multicarrier echo cancellation has been proposed for ADSL. We analyze the performance of our timing recovery scheme in the context of this system.<
>