In one embodiment, a method receives a downstream signal and an upstream signal in a same frequency band. The downstream signal and the upstream signal are separated into a first path and a second path. The downstream signal using the first path and the upstream signal using the second path are amplified in an analog domain. The method isolates the downstream signal and the upstream signal from one another and sends the downstream signal downstream to a subscriber device and sends the upstream signal towards a full duplex node.

In one embodiment, a method receives a downstream signal and an upstream signal in a same frequency band. The downstream signal and the upstream signal are separated into a first path and a second path. The downstream signal using the first path and the upstream signal using the second path are amplified in an analog domain. The method isolates the downstream signal and the upstream signal from one another and sends the downstream signal downstream to a subscriber device and sends the upstream signal towards a full duplex node.

A frequency division duplex (FDD) first band includes a first downlink operating band and a first uplink operating band. An FDD second band includes a second downlink operating band and a second uplink operating band. In the FDD first band and the FDD second band, (1) the first downlink operating band, second downlink operating band, first uplink operating band, and second uplink operating band are positioned in order from lowest to highest frequency. The frequency range of the first uplink operating band and that of the second uplink operating band do not overlap each other. A filter is formed in or on a first substrate having piezoelectric properties and has a pass band including the first and second uplink operating bands.

A frequency division duplex (FDD) first band includes a first downlink operating band and a first uplink operating band. An FDD second band includes a second downlink operating band and a second uplink operating band. In the FDD first band and the FDD second band, (1) the first downlink operating band, second downlink operating band, first uplink operating band, and second uplink operating band are positioned in order from lowest to highest frequency. The frequency range of the first uplink operating band and that of the second uplink operating band do not overlap each other. A filter is formed in or on a first substrate having piezoelectric properties and has a pass band including the first and second uplink operating bands.

The disclosed systems and methods for detecting mirror crosstalk between frequency bands equally above and below the center frequency of a Digital Subcarrier Multiplexing system include: a transmitter configured to insert zero-power symbols on half the frequency bands below center frequency, and insert other zero-power symbols, partially overlapping in time with the first zero-power symbols, on the other half of the frequency bands above center frequency. A receiver zeroes out ASE and other noises during the overlapping portion of all the zero-power symbols, then uses the power detected during the remaining portion of each zero-power symbol in each frequency band to accurately evaluate the mirror crosstalk from the corresponding frequency band on the opposite side of center frequency.

The disclosed systems and methods for detecting mirror crosstalk between frequency bands equally above and below the center frequency of a Digital Subcarrier Multiplexing system include: a transmitter configured to insert zero-power symbols on half the frequency bands below center frequency, and insert other zero-power symbols, partially overlapping in time with the first zero-power symbols, on the other half of the frequency bands above center frequency. A receiver zeroes out ASE and other noises during the overlapping portion of all the zero-power symbols, then uses the power detected during the remaining portion of each zero-power symbol in each frequency band to accurately evaluate the mirror crosstalk from the corresponding frequency band on the opposite side of center frequency.

In one embodiment, a method receives a downstream signal and an upstream signal in a same frequency band. The downstream signal and the upstream signal are separated into a first path and a second path. The downstream signal using the first path and the upstream signal using the second path are amplified in an analog domain. The method isolates the downstream signal and the upstream signal from one another and sends the downstream signal downstream to a subscriber device and sends the upstream signal towards a full duplex node.

In one embodiment, a method receives a downstream signal and an upstream signal in a same frequency band. The downstream signal and the upstream signal are separated into a first path and a second path. The downstream signal using the first path and the upstream signal using the second path are amplified in an analog domain. The method isolates the downstream signal and the upstream signal from one another and sends the downstream signal downstream to a subscriber device and sends the upstream signal towards a full duplex node.

A transmitter/receiver (1) up-converts, using an LO signal as a local oscillation signal, an IF signal having a predetermined frequency band, thereby generating a transmission signal RF.sub.TX. Moreover, the transmitter/receiver (1) generates a (LO+IF).sup.2 signal and a (LO−IF).sup.2 signal based on the IF signal and the LO signal. Using the LO signal obtained by adding-up of the (LO+IF).sup.2 signal and the (LO−IF).sup.2 signal, a reception signal RF.sub.RX is down-converted. Thus, a local oscillation signal generation unit of a receiving unit is not necessary.

A transmitter/receiver (1) up-converts, using an LO signal as a local oscillation signal, an IF signal having a predetermined frequency band, thereby generating a transmission signal RF.sub.TX. Moreover, the transmitter/receiver (1) generates a (LO+IF).sup.2 signal and a (LO−IF).sup.2 signal based on the IF signal and the LO signal. Using the LO signal obtained by adding-up of the (LO+IF).sup.2 signal and the (LO−IF).sup.2 signal, a reception signal RF.sub.RX is down-converted. Thus, a local oscillation signal generation unit of a receiving unit is not necessary.