| 摘要 |
A physical layer transceiver of a home network station connected to a telephone medium has an architecture enabling adaptation of detection circuitry based on received network signals to enable reliable recovery of data signals. The physical layer transceiver includes an input amplifier that amplifies network signals according to one of 128 gain settings set by a receiver gain control signal. A signal conditioning circuit includes an envelope detector configured for outputting an envelope of the amplified received signal, and an energy detector configured for outputting an energy signal of the amplified received signals. The envelope signal and the energy signal are supplied to slicer threshold circuits, configured for outputting noise, peak, data event and energy event signals based on noise threshold, peak threshold, data transition threshold, and energy threshold signals, respectively. A digital controller controls the input amplifier gain and the threshold values, and adjusts the gain and threshold values based on the noise event signal and the peak event signal within an access ID (AID) interval. The physical layer transceiver also includes a calibration circuit for calibrating a common mode voltage reference signal in the physical layer transceiver to a minimum noise threshold level while isolating any network signals from the physical layer transceiver. The common mode voltage signal is initially set at a maximum value and supplied to the noise slicer threshold circuit. The common mode voltage signal is successively decreased until the common mode voltage signal falls below the minimum noise slice threshold. The calibrated value corresponds to the common mode voltage signal configuration setting at the time the noise slicer threshold circuit transitions from a 1 to a zero. Calibration insures that the baseline of the envelope signal is within 20 millivolts of the minimum noise slicer threshold during operation.
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