Digital Baseband Transport in Telecommunications Distribution Systems

• US 20140119281A1
• Filed: 03/15/2013
• Published: 05/01/2014
• Est. Priority Date: 10/31/2012
• Status: Active Grant

• Current Assignee: CommScope Technologies, LLC (CommScope Holding Company, Inc.)
• Original Assignee: Andrew LLC (CommScope Holding Company, Inc.)
• Inventors: KUMMETZ, THOMAS, PHILLIPS, FRED W., RANSON, CHRISTOPHER G., HANSON, VAN E.
• Granted Patent: US 8,908,607 B2
• Time in Patent Office: Days
• US Class Current: 370/328
• CPC Class Codes: H04B 1/001 Channel filtering, i.e. selecting a frequency channel within the SDR system multiplexing of multicarrier modulation signals being represented by different frequencies H04L5/06; multiplexing of multicarrier modulation signals H04L5/023
• CPC Class Codes: H04L 1/00 Arrangements for detecting or preventing errors in the information received correcting synchronisation H04L7/00
• CPC Class Codes: H04L 25/05 Electric or magnetic storage of signals before transmitting or retransmitting for changing the transmission rate
• CPC Class Codes: H04L 27/0002 analog front ends; means for connecting modulators, demodulators or transceivers to a transmission line duplex arrangements H04L5/143
• CPC Class Codes: H04W 72/02 Selection of wireless resources by user or terminal
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/1263 Mapping of traffic onto schedule, e.g. scheduled allocation or multiplexing of flows
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 88/085 Access point devices with remote components

Abstract

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.

Claims

1. (canceled)

6. A telecommunications system, comprising:

a unit for communicating, with remotely located units, channelized digital baseband signals that include call information for wireless communication, the unit including;

a channelizer section for extracting, per channel, the channelized digital baseband signals using channel filters and digital down-converters; and

a transport section for formatting the channelized digital baseband signals for transport together using a transport schedule unit for packetizing and packet scheduling the channelized digital baseband signals, wherein the transport section includes;

transport channel processors for performing decimation, filtering, and signal gain changes on the channelized digital baseband signals; and

a transport device including the transport schedule unit and a baseband signal extractor, the baseband signal extractor being adapted for extracting received channelized digital baseband signals from a transport physical interface device.

2. The telecommunications system of claim 6, wherein the channelizer section includes a signal processing subsystem configured for controlling a gain of each of a plurality of uplink digital baseband signals received from the remotely located units independently prior to summing the plurality of uplink digital baseband signals.

3. The telecommunications system of claim 2, wherein the signal processing subsystem 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 for determining a signal magnitude of an uplink digital baseband signal from a remotely located 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 for scaling the uplink digital baseband signal using the scale factor.

4. The telecommunications system of claim 6, wherein the channelizer section is configured for digitally up-converting received digital baseband signals, per channel, to produce received digital signals, and for summing the received digital signals to produce summed digital signals to be converted to analog signals.

5. The telecommunications system of claim 4, wherein the channelizer section includes, per channel:

a channel filter;

an interpolator; and

a mixer associated with a numerically controlled oscillator.

7. The telecommunications system of claim 6, wherein the transport device includes:

a framing section that includes;

a framer for interleaving samples from different digital baseband data streams into frames; and

a de-framer for extracting digital baseband data streams from frames;

an Ethernet transceiver that includes;

a first bit stream converter for converting framed digital baseband data streams to a different bit rate;

an Ethernet framer for mapping the framed digital baseband data streams into Ethernet frames;

an Ethernet de-framer for extracting digital baseband data stream frames from received Ethernet frames; and

a second bit stream converter for converting the digital baseband data stream frames to a different data bit rate; and

a high-speed transceiver for communicating signals with the transport physical interface device.

8. The telecommunications system of claim 6, wherein the transport section includes a media access controller communicatively coupled to a transport physical interface device, the media access controller being configured for allowing a multiple access scheme on a digital transport communication medium between the unit and the remotely located units for asynchronous transport.

9. (canceled)

16. A distributed antenna system comprising:

at least two remote units for wirelessly transmitting signals in a coverage area;

a head end unit for communicating, with the at least two remote units, channelized digital baseband signals that include call information for wireless communication;

a channelizer section for extracting, per channel, the channelized digital baseband signals using channel filters and digital down-converters; and

a transport section for formatting the channelized digital baseband signals for transport together using a transport schedule unit for packetizing and packet scheduling the channelized digital baseband signals, wherein the transport section includes;

transport channel processors for performing decimation, filtering, and signal gain changes on the channelized digital baseband signals; and

a transport device including the transport schedule unit and a baseband signal extractor, the baseband signal extractor being adapted for extracting received channelized digital baseband signals from a transport physical interface device.

10. The distributed antenna system of claim 16, wherein the channelizer section and the transport section are in the head end unit.

11. The distributed antenna system of claim 16, wherein the channelizer section and the transport section are in at least one of the at least two remote units.

12. The distributed antenna system of claim 16, further comprising a signal processing subsystem configured for controlling 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.

13. The distributed antenna system of claim 12, further comprising an extension unit between the head end unit and the at least two remote units, wherein the signal processing subsystem is in the extension unit.

14. The distributed antenna system of claim 12, wherein the signal processing subsystem 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 for determining a signal magnitude of an uplink digital baseband signal from a remote unit, determining a peak average based on the signal magnitude, and determine a scale factor based on the peak average,

wherein a variable gain block associated with the signal envelope peak detector is configured for scaling the uplink digital baseband signal using the scale factor.

15. The distributed antenna system of claim 16, wherein the channelizer section is configured for digitally up-converting received digital baseband signals, per channel, to produce received digital signals, and for summing the received digital signals to produce summed digital signals to be converted to analog signals.

17. The distributed antenna system of claim 16, wherein the transport device includes:

a framing section that includes;

a framer for interleaving samples from different digital baseband data streams into frames; and

a de-framer for extracting digital baseband data streams from frames;

an Ethernet transceiver that includes;

a first bit stream converter for converting framed digital baseband data streams to a different bit rate;

an Ethernet framer for mapping the framed digital baseband data streams into Ethernet frames;

an Ethernet de-framer for extracting digital baseband data stream frames from received Ethernet frames; and

a second bit stream converter for converting the digital baseband data stream frames to a different data bit rate; and

a high-speed transceiver for communicating signals with the transport physical interface device.

18. The distributed antenna system of claim 16, wherein the transport section includes a media access controller communicatively coupled to a transport physical interface device, the media access controller being configured for allowing a multiple access scheme on a digital transport communication medium between the head end unit and the at least two remote units for asynchronous transport.

19. (canceled)

20. A telecommunications system, comprising:

a unit for communicating, with remotely located units, channelized digital baseband signals that include call information for wireless communication, the unit including;

a transport section for formatting the channelized digital baseband signals for transport together using a transport schedule unit for packetizing and packet scheduling the channelized digital baseband signals; and

a signal processing subsystem configured for controlling a gain of each of a plurality of uplink digital baseband signals received from the remotely located units independently prior to summing the plurality of uplink digital baseband signals, wherein the signal processing subsystem includes;

a variable gain block associated with a signal envelope peak detector for scaling summed uplink digital baseband signals;

a shifter device for shifting the summed uplink digital baseband signals; and

a saturate device for clipping the summed uplink digital baseband signals at a level selected by the shifter device.

21. The telecommunications system of claim 20, wherein the transport section includes:

transport channel processors for performing decimation, filtering, and signal gain changes on the channelized digital baseband signals; and

a transport device including the transport schedule unit and a baseband signal extractor, the baseband signal extractor being adapted for extracting received channelized digital baseband signals from a transport physical interface device.