A filter circuit includes a first switch circuit that exclusively connects a first common terminal to either of a first selection terminal and a second selection terminal; a first signal terminal that is connected to the first selection terminal and that is for communicating a first communication signal belonging to a first frequency range, which is a frequency range of a first communication band; a second signal terminal that is connected to the second selection terminal and that is for communicating a second communication signal belonging to a second frequency range, which is the frequency range of a second communication band and which is at least partially overlapped with the first frequency range; and a first band pass filter one end of which is connected to the first common terminal and which uses both the first frequency range and the second frequency range as pass bands.

A transmitting and receiving circuit that transmits and receives signals using coaxial cables includes an input/output terminal that delivers and receives signals, a first port, a second port, a switch, and a ceramic-based electro-static discharge protector. The first port transfers a transmitted signal in a first transmission frequency band width and a received signal in a first reception frequency band width. The second port transfers a transmitted signal in a second transmission frequency band width and a received signal in a second reception frequency band width. The switch connects a common port to one of the first port and the second port. The common port is connected to the input/output terminal on one end of the common port and to the switch on the other end. The electro-static discharge protector is connected between the common port and the ground potential.

A frequency-selective system that may be used as, or as part of, an add/drop multiplexer. An input signal is fed to a Mach-Zehnder interferometer configured to drop, or suppress, by destructive interference, a signal component in a first frequency band from among a plurality of frequency bands. One or more bandpass filters in one arm of the Mach-Zehnder interferometer suppress other frequencies, outside of the first frequency band, so that signals at these other frequencies are not suppressed by destructive interference and are present at the output of the Mach-Zehnder interferometer. A coupler connected after the output of the Mach-Zehnder interferometer adds, into the signal path, a replacement for the dropped signal.

Front-end architecture having split triplexers for carrier aggregation and MIMO support. In some embodiments, a multiplexing architecture can include an assembly of filters configured to support carrier aggregation with one or more antennas. The assembly of filters can include a first triplexer configured to support a low-band, a mid-band, and a first high-band. The assembly of filters can further include a second triplexer configured to support the low-band, the mid-band, and a second high-band. The multiplexing architecture can further include a switch assembly implemented between the assembly of filters and respective one or more nodes associated with the one or more antennas.

Front-end architecture having split diplexers for carrier aggregation and MIMO support. In some embodiments, a multiplexing architecture can include an assembly of filters configured to support carrier aggregation with one or more antennas. The assembly of filters can include a first diplexer configured to support a mid-band and a first high-band. The assembly of filters can further include a second diplexer configured to support the mid-band and a second high-band. The multiplexing architecture can further include a switch assembly implemented between the assembly of filters and respective one or more nodes associated with the one or more antennas.

A frequency-selective system that may be used as, or as part of, an add/drop multiplexer. An input signal is fed to a Mach-Zehnder interferometer configured to drop, or suppress, by destructive interference, a signal component in a first frequency band from among a plurality of frequency bands. One or more bandpass filters in one arm of the Mach-Zehnder interferometer suppress other frequencies, outside of the first frequency band, so that signals at these other frequencies are not suppressed by destructive interference and are present at the output of the Mach-Zehnder interferometer. A coupler connected after the output of the Mach-Zehnder interferometer adds, into the signal path, a replacement for the dropped signal.

A communication system in which a constellation employing partially anti-symmetric amplitude labels is used to transmit probabilistically shaped amplitudes such that said amplitudes are also used to determine the signs applied thereto for transmission. In an example embodiment, a data transmitter is configured to use a suitable logic function (e.g., an XOR function) to place the parity generated by an FEC code into a selected amplitude bit while using the partially anti-symmetric amplitude labels to avoid placing the parity into the sign bits of the transmitted constellation symbols. In some embodiments, the FEC code can be a low-density parity-check code. Some embodiments are compatible with layered FEC coding, e.g., employing an outer FEC code and an inner FEC code. In some embodiments, FEC coding may be optional. Some embodiments can advantageously be used in communication systems relying on DMT modulation, such as the systems providing DSL access over copper wiring.

According to one embodiment, a transmitter includes a 1st circuit configured to execute a 1st band limitation by waveform shaping in a time region with respect to 1st data relating to a 1st channel to generate a 1st signal; a 2nd circuit configured to execute a 2nd band limitation by the waveform shaping in the time region with respect to 2nd data relating to a 2nd channel to generate a 2nd signal; a 3rd circuit configured to generate a 3rd signal based on the 1st signal and a 1st frequency relating to the 1st channel; a 4th circuit configured to generate a 4th signal based on the 2nd signal and a 2nd frequency relating to the 2nd channel; and a 5th circuit configured to generate a 5th signal by multiplexing the 3rd signal and the 4th signal.

A method and apparatus provide a physical uplink channel in resource blocks. Scheduling information can be received. The scheduling information can be to transmit a first physical uplink channel within a slot. The slot can include a plurality of symbols. The slot can include the first physical uplink channel and a second physical uplink channel. The first physical uplink channel can be shorter in duration than the second physical uplink channel. One or more allocated resource blocks for the first physical uplink channel can be determined based on a sub-band group and one or more resource block groups within the sub-band group. The sub-band group can include one or more sub-bands. Each sub-band can include one or more resource block groups. Each resource block group can include one or more resource blocks. A resource block can include one or more contiguous resource elements in the frequency domain. The first physical uplink channel can be transmitted in the determined one or more allocated resource blocks in the slot.

A method and apparatus provide a physical uplink channel in resource blocks. Scheduling information can be received. The scheduling information can be to transmit a first physical uplink channel within a slot. The slot can include a plurality of symbols. The slot can include the first physical uplink channel and a second physical uplink channel. The first physical uplink channel can be shorter in duration than the second physical uplink channel. One or more allocated resource blocks for the first physical uplink channel can be determined based on a sub-band group and one or more resource block groups within the sub-band group. The sub-band group can include one or more sub-bands. Each sub-band can include one or more resource block groups. Each resource block group can include one or more resource blocks. A resource block can include one or more contiguous resource elements in the frequency domain. The first physical uplink channel can be transmitted in the determined one or more allocated resource blocks in the slot.