Certain features relate to a remote antenna unit having a multi-stage isolation sub-system for isolating uplink and downlink signal paths. A multi-stage isolation sub-system in the remote antenna unit can include a first stage device that is configured to generate a cancellation signal for canceling unwanted downlink signals received at the uplink antenna. The isolation sub-system can also include a second stage device configured to generate a cancellation signal that attenuates residual noise and intermodulation products generated in the downlink path and received in the uplink path. The multi-stage isolation sub-system can combine the cancellation signals with signals received on the uplink path in order to cancel or attenuate downlink leakage signals and residual noise present on the uplink path.

A digital signal processing circuit comprises a first equalizer circuit and a second equalizer circuit. An output of the second equalizer is used as feedback to generate an equalized signal. The output of the second equalizer circuit is based on a plurality of postcursor values and a plurality of precursor values, where the precursor values are generated based on an output of the first DFE circuit, and the postcursor values are generated independently of the output of the first DFE.

A digital signal processing circuit comprises a first equalizer circuit and a second equalizer circuit. An output of the second equalizer is used as feedback to generate an equalized signal. The output of the second equalizer circuit is based on a plurality of postcursor values and a plurality of precursor values, where the precursor values are generated based on an output of the first DFE circuit, and the postcursor values are generated independently of the output of the first DFE.

Certain features relate to a remote antenna unit having a multi-stage isolation sub-system for isolating uplink and downlink signal paths. A multi-stage isolation sub-system in the remote antenna unit can include a first stage device that is configured to generate a cancellation signal for canceling unwanted downlink signals received at the uplink antenna. The isolation sub-system can also include a second stage device configured to generate a cancellation signal that attenuates residual noise and intermodulation products generated in the downlink path and received in the uplink path. The multi-stage isolation sub-system can combine the cancellation signals with signals received on the uplink path in order to cancel or attenuate downlink leakage signals and residual noise present on the uplink path.

A Decision Feedback Equalizer (DFE) is used as the predictive filter in a Sigma-Delta feedback loop as part of a Sigma-Delta Analog-to-Digital Converter. The tap weights of the DFE are chosen to provide adaptive noise shaping for receiving signals of various frequencies multiplexed in time.

Certain features relate to a remote antenna unit having a multi-stage isolation sub-system for isolating uplink and downlink signal paths. A multi-stage isolation sub-system in the remote antenna unit can include a first stage device that is configured to generate a cancellation signal for canceling unwanted downlink signals received at the uplink antenna. The isolation sub-system can also include a second stage device configured to generate a cancellation signal that attenuates residual noise and intermodulation products generated in the downlink path and received in the uplink path. The multi-stage isolation sub-system can combine the cancellation signals with signals received on the uplink path in order to cancel or attenuate downlink leakage signals and residual noise present on the uplink path.