Upstream data transmission

A transmitter for transmitting digital data to an A/D converter via an analog channel, the transmitter comprising:

• a precoder being configured to precompensate a sequence of input signal points for ISI in the analog channel and being characterized by an original constellation and an extended constellation, a majority of the signal points of the original constellation being quantization levels of the A/D converter, and the extended constellation including at least one signal point that is not a quantization level of the A/D converter.

A process for communicating data over an analog channel in both downstream and upstream directions, comprising:

• monitoring a quantity representative of an echo level caused by downstream data transmission;
• resetting a power level for downstream transmissions over the analog channel to a lower value in response to determining that the echo level interferes with upstream data transmissions over the analog channel.

A transceiver for transmitting and receiving digital data via a mixed channel that includes a digital network and an analog channel serially connected to the digital network, comprising:

• a transmitter capable of error-encoding digital data and of transmitting encoded data downstream to a target transceiver via the mixed channel;
• and
• a receiver capable of error-decoding received digital data transmitted upstream from the target transceiver via the mixed channel, the transmitter configured to reduce downstream transmission power in response to determining that echo from downstream transmissions interferes with upstream transmissions from the target transceiver.

A receiver capable of receiving signals from a mixed channel that includes a digital network and an analog channel serially connected to the digital network, the receiver comprising:

• a Viterbi decoder configured to process the received signals in a manner responsive to reliability information derived from the signals, the reliability information being indicative of potential magnitudes of quantization noise in the received signals.