Digital baseband transport in telecommunications distribution systems
A telecommunications system is provided that includes a unit for communicating channelized digital baseband signals with remotely located units. The channelized digital baseband signals include call information for wireless communication. The unit includes a channelizer section and a transport section. The channelizer section can extract, per channel, the channelized digital baseband signals using channel filters and digital down-converters. The transport section can format the channelized digital baseband signals for transport together using a transport schedule unit for packetizing and packet scheduling the channelized digital baseband signals. A signal processing subsystem can control a gain of uplink digital baseband signals, independently, that are received from the remotely located units prior to summing the uplink digital baseband signals.
1. A distributed antenna system, comprising:
a head end unit configured to communicate channelized digital baseband signals with remotely located units, the channelized digital baseband signals including call information for wireless communication, the head end unit including circuitry configured to:
receive downlink signals from at least one base station;
process the downlink signals into downlink channelized digital baseband signals using a channelizer circuitry including a channel filter, an interpolator, and a mixer associated with an oscillator;
format the downlink channelized digital baseband signals for transport together;
packetize and packet schedule the downlink channelized digital baseband signals into downlink packetized baseband signals; and
transmit the downlink packetized baseband signals to the remotely located units.
2. The distributed antenna system of claim 1 , wherein the circuitry is further configured to:
receive uplink packetized baseband signals from the remotely located units;
extracting uplink channelized digital baseband signals from the uplink packetized baseband signals;
process the uplink channelized digital baseband signals into uplink signals; and
communicate the uplink signals to the at least one base station.
3. The distributed antenna system of claim 1 , wherein the circuitry is further configured to:
receive uplink packetized baseband signals from the remotely located units;
extracting uplink channelized digital baseband signals from the uplink packetized baseband signals;
process the uplink channelized digital baseband signals into uplink signals;
sum the uplink signals into a summed uplink signal; and
communicate the summed uplink signal to the at least one base station.
4. The distributed antenna system of claim 3 , wherein the circuitry is further configured to:
control a gain of each of a plurality of the uplink channelized digital baseband signals.
5. The telecommunications system of claim 1 , wherein the circuitry is further configured to:
interleave samples from different digital downlink packetized baseband signals into downlink framed digital baseband data streams;
convert the downlink framed digital baseband data streams to a different bit rate;
map the downlink framed digital baseband data streams into downlink Ethernet frames; and
communicate the downlink Ethernet frames to the remotely located units.
6. The telecommunications system of claim 1 , wherein the circuitry is configured to process the downlink signals into downlink channelized digital baseband signals at least in part by performing filtering and signal gain changes on the digital baseband signals.
7. A distributed antenna system, comprising:
a head end unit configured to communicate channelized digital baseband signals with remotely located units, the channelized digital baseband signals including call information for wireless communication, the head end unit including circuitry configured to:
receive uplink packetized baseband signals from the remotely located units;
extracting uplink channelized digital baseband signals from the uplink packetized baseband signals;
process the uplink channelized digital baseband signals into uplink signals using a channelizer circuitry including a channel filter, an interpolator, and a mixer associated with an oscillator; and
communicate at least one of the uplink signals and a summation of the uplink signals to the at least one base station.
8. The distributed antenna system of claim 7 , wherein the circuitry is further configured to:
receive downlink signals from at least one base station;
process the downlink signals into downlink channelized digital baseband signals;
format the downlink channelized digital baseband signals for transport together;
packetize and packet schedule the downlink channelized digital baseband signals into downlink packetized baseband signals; and
transmit the downlink packetized baseband signals to the remotely located units.
9. The distributed antenna system of claim 7 , wherein the circuitry is configured to communicate at least one of the uplink signals and a summation of the uplink signals to the at least one base station by being configured to communicate the uplink signals to the at least one base station.
10. The distributed antenna system of claim 7 , wherein the circuitry is further configured to sum the uplink signals into a summed uplink signal; and
wherein the circuitry is configured to communicate at least one of the uplink signals and a summation of the uplink signals to the at least one base station by being configured to communicate the summed uplink signal to the at least one base station.
11. The distributed antenna system of claim 7 , wherein the circuitry is further configured to:
control a gain of each of a plurality of the uplink channelized digital baseband signals;
sum the uplink signals into a summed uplink signal; and
wherein the circuitry is configured to communicate at least one of the uplink signals and a summation of the uplink signals to the at least one base station by being configured to communicate the summed uplink signal to the at least one base station.
12. The telecommunications system of claim 7 , wherein the circuitry is further configured to:
receive uplink Ethernet frames from remotely located units;
extract uplink digital baseband data stream frames from the uplink Ethernet frames;
convert the uplink framed digital baseband data streams to a different bit rate; and
extract digital uplink packetized baseband signals from the uplink framed digital baseband data streams.
13. A distributed antenna system comprising:
at least two remote units configured to wirelessly transmit signals in a coverage area;
a head end unit configured to communicate, with the at least two remote units, channelized digital baseband signals that include call information for wireless communication;
extraction circuitry configured to extract the digital baseband signals; and
transport circuitry configured to:
format the digital baseband signals for transport together using a transport schedule unit, wherein the transport schedule unit is configured to packetize and packet schedule the digital baseband signals;
process the channelized digital baseband signals using a channelizer circuitry including a channel filter, an interpolator, and a mixer associated with an oscillator; and
extract received channelized digital baseband signals from a transport physical interface device.
14. The distributed antenna system of claim 13 , wherein the extraction circuitry and the transport circuitry are in the head end unit.
15. The distributed antenna system of claim 13 , wherein the extraction circuitry and the transport circuitry are in at least one of the at least two remote units.
16. The distributed antenna system of claim 13 , further comprising signal processing circuitry configured to control a gain of each of a plurality of uplink digital baseband signals received from the at least two remote units independently prior to summing the plurality of uplink digital baseband signals.
17. The distributed antenna system of claim 16 , further comprising an extension unit between the head end unit and the at least two remote units, wherein the signal processing circuitry is in the extension unit.
18. The distributed antenna system of claim 16 , wherein the signal processing circuitry includes:
a summer;
variable gain blocks, each of the variable gain blocks being associated with a signal envelope peak detector of a plurality of signal envelope peak detectors,
wherein the signal envelope peak detector is configured to determine a signal magnitude of an uplink digital baseband signal from a remote unit, determining a peak average based on the signal magnitude, and determining a scale factor based on the peak average,
wherein a variable gain block associated with the signal envelope peak detector is configured to scale the uplink digital baseband signal using the scale factor.
19. The distributed antenna system of claim 13 , wherein the extraction circuitry is configured to:
digitally up-convert received digital baseband signals to produce received digital signals; and
sum the received digital signals to produce summed digital signals to be converted to analog signals.
20. The distributed antenna system of claim 13 , wherein the transport circuitry includes:
framing circuitry that includes:
a framer configured to interleave samples from different digital baseband data streams into frames; and
a de-framer configured to extract digital baseband data streams from frames;
an Ethernet transceiver that includes:
a first bit stream converter configured to convert framed digital baseband data streams to a different bit rate;
an Ethernet framer configured to map the framed digital baseband data streams into Ethernet frames;
an Ethernet de-framer configured to extract digital baseband data stream frames from received Ethernet frames; and
a second bit stream converter configured to convert the digital baseband data stream frames to a different data bit rate; and
a high-speed transceiver configured to communicate signals with the transport physical interface device.