Systems and methods for improved digital RF transport in distributed antenna systems

• US 8,948,155 B2
• Filed: 09/14/2012
• Issued: 02/03/2015
• Est. Priority Date: 01/13/2009
• Status: Expired

• Current Assignee: CommScope Technologies, LLC (CommScope Holding Company, Inc.)
• Original Assignee: ADC Telecommunications Incorporated (TE Connectivity Limited)
• Inventors: Cannon, Jeffrey J., Zavadsky, Dean, Wala, Philip M.
• Primary Examiner(s): Pham, Chi H
• Assistant Examiner(s): Boakye, Alexander O
• Application Number:
  US13/616,135
• Publication Number:
  US 20130003714A1
• Time in Patent Office: 872 Days
• Field of Search: 370/345, 370/336, 370/337, 370/329, 370/328, 370/321, 370/352, 370/376, 370/295
• US Class Current: 370/345
• 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: H04L 27/144 with demodulation using spectral properties of the received signal, e.g. by using frequency selective- or frequency sensitive elements
• CPC Class Codes: H04L 27/2338 using sampling H04L27/2331 - H04L27/2335 take precedence
• CPC Class Codes: H04W 88/085 Access point devices with remote components

Abstract

Systems and methods for improved digital RF transport in a DAS are provided. In one embodiment, a transceiver comprises: a receive path circuit including an RF reception interface coupled to an ADC, the ADC receiving a down-converted analog RF spectrum from the RF reception interface and producing a digitized RF spectrum at an input sampling rate; a logic device receiving the digitized RF spectrum and producing a first set of baseband data samples at a first sampling rate, corresponding to a first spectral region of the analog RF spectrum and a second set of baseband data samples at a second sampling rate, corresponding to a second spectral region of the analog RF spectrum. The logic device maps the first set and second sets of baseband data samples to a respective first set and second set of timeslots of a serial data stream transport frame.

Claims

1. A communication device for providing digital transport of signals in a distributed antenna system, the communication device comprising:

a reception path circuit configured to output digitized radio frequency spectrum at an input sampling rate based on input signals;

a logic device coupled to the reception path circuit and configured to receive digitized radio frequency spectrum at the input sampling rate from the reception path circuit, the logic device further configured to produce a first plurality of sets of digitized baseband data samples at a plurality of sampling rates, each set of digitized baseband data samples corresponding to a distinct spectral region of the analog radio frequency spectrum; and

wherein the logic device is further configured to map each of the first plurality of sets of digitized baseband data samples to a set of timeslots of a serial data stream transport frame.

2. The communication device of claim 1, wherein the reception path circuit is configured to receive baseband digital samples from another device;

and

wherein the reception path circuit is configured to output the digitized radio frequency spectrum based on the baseband digital samples.

3. The communication device of claim 1, wherein the reception path circuit is configured to receive baseband digital samples directly from a base transceiver station;

and

wherein the reception path circuit is configured to output the digitized radio frequency spectrum based on the baseband digital samples received directly from the base transceiver station.

4. The communication device of claim 1, wherein the reception path circuit includes a radio frequency reception interface coupled to an analog-to-digital converter, the analog-to-digital converter configured to receive down-converted analog radio frequency spectrum from the radio frequency reception interface, the analog-to-digital converter further configured to produce digitized radio frequency spectrum at an input sampling rate.

5. The communication device of claim 1, wherein each of the set of timeslots consists of a corresponding number of timeslots based on a bandwidth of the distinct spectral region corresponding with the set of timeslots.

6. The communication device of claim 1, wherein the analog radio frequency spectrum comprises non-relevant spectral regions that are not mapped onto any of the set of timeslots of the serial data stream transport frame.

7. The communication device of claim 1, the logic device including a plurality of down converters operating in parallel and receiving digitized radio frequency spectrum at the input sampling rate;

and

wherein each digital down converter is configured to convert data corresponding to a corresponding distinct spectral region into the corresponding set of digitized baseband data samples at the corresponding sampling rate, wherein the corresponding sampling rate is a function of a size of a bandwidth of the corresponding distinct spectral region.

8. The communication device of claim 7, the logic device further comprising a serialized transmitter configured to transmit the first plurality of sets of digitized baseband data samples at the corresponding sampling rates;

and

the serialized transmitter further configured to map the first plurality of sets of digitized baseband data samples to the corresponding sets of timeslots.

9. The communication device of claim 1, wherein the first plurality of sets of digitized baseband data samples includes at least three sets of digitized baseband data samples corresponding to at least three distinct spectral regions;

and

wherein the set of timeslots includes at least three timeslots.

10. The communication device of claim 1, further comprising:

a transmission path circuit configured to output signals based on received digitized radio frequency spectrum;

the logic device further coupled to the transmission path circuit, the logic device configured to receive an input transport frame having a plurality of sets of timeslots, wherein each of the set of timeslots includes a second set of digitized baseband data samples at one of the plurality of sampling rates, the set of digitized baseband data samples for each set of timeslots corresponding to one of the distinct spectral regions of the analog radio frequency spectrum;

wherein the logic device is configured to generate a second plurality of sets of digitized data samples for each set of the timeslots at an output sampling rate; and

wherein the logic device sums at least two of the second plurality of sets of digitized data samples to produce a set of output data samples at the output sampling rate.

11. The communication device of claim 1, wherein the logic circuit comprises a field programmable device.

12. The communication device of claim 1, wherein the spectral regions are user selectable from a plurality of pre-built logic circuit configurations.

13. The communication device of claim 1, wherein a center frequency and bandwidth size that define the first spectral bandwidth are user reconfigurable.

14. A communication device for providing digital transport of signals in a distributed antenna system, the communication device comprising:

a transmission path circuit configured to output signals based on received digitized radio frequency spectrum;

a logic device coupled to the transmission path circuit and configured to receive an input transport frame having a plurality of sets of timeslots, wherein each set of timeslots includes a first plurality of sets of digitized baseband data samples at one of the plurality of sampling rates, the set of digitized baseband data samples for each set of timeslots corresponding to a distinct spectral region of analog radio frequency spectrum;

wherein the logic device is configured to generate second plurality of sets of digitized data samples for each set of the timeslots at an output sampling rate; and

wherein the logic device sums at least two of the second plurality of sets of digitized data samples to produce a set of output data samples at the output sampling rate.

15. The communication device of claim 14, wherein the logic device is configured to generate the second plurality of sets of digitized data samples by up-converting the first plurality of sets of digitized baseband data samples to distinct spectral regions at the output sampling rate.

16. The communication device of claim 14, wherein the transmission path circuit is configured to transmit baseband digital samples to another device;

and

wherein the transmission path circuit is configured to transmit the output data samples.

17. The communication device of claim 14, wherein the transmission path circuit is configured to transmit baseband digital samples directly to a base transceiver station;

and

wherein the transmission path circuit is configured to transmit the output data samples directly to the base transceiver station.

18. The communication device of claim 14, wherein the transmission path circuit includes a radio frequency transmission interface coupled to a digital-to-analog converter, the digital-to-analog converter configured to receive output data samples at the output sampling rate and configured to generate an output analog signal from the output data samples;

and

wherein the radio frequency transmission interface receives the output analog signal and up-converts the output analog signal into an analog radio frequency signal within the analog radio frequency spectrum.

19. The communication device of claim 14, the logic device including a plurality of digital up converters operating in parallel and configured to receive the second plurality of sets of digitized data samples and convert the second plurality of sets of digitized data samples into the analog radio frequency signal in the analog radio frequency spectrum.

20. The communication device of claim 19, the logic device further comprising a serialized receiver receiving the input transport frame and parsing timeslots of the transport frame to the plurality of digital up converters based on a timeslot configuration of the input transport frame.

21. The communication device of claim 14, wherein the analog radio frequency spectrum comprises non-relevant spectral regions that are not mapped to any of the set of timeslots of the serial data stream transport frame.

22. The communication device of claim 14, the logic device including a plurality of down converters operating in parallel and receiving digitized radio frequency spectrum at the input sampling rate;

and

wherein each digital down converter is configured to convert data corresponding to a corresponding spectral region into the corresponding set of digitized baseband data samples at the corresponding sampling rate, wherein the corresponding sampling rate is a function of a size of a bandwidth of the corresponding spectral region.

23. The communication device of claim 14, wherein the plurality of sets of digitized baseband data samples includes at least three sets of digitized baseband data samples corresponding to at least three spectral regions;

and

wherein the set of timeslots includes at least three timeslots.

24. The communication device of claim 14, further comprising:

a reception path circuit configured to output digitized radio frequency spectrum;

a logic device coupled to the reception path circuit and configured to receive digitized radio frequency spectrum at an input sampling rate from the reception path circuit, the logic device further configured to produce a second plurality of sets of digitized baseband data samples at a plurality of sampling rates, each set of digitized baseband data samples corresponding to a spectral region of the analog radio frequency spectrum; and

wherein the logic device is further configured to map each set of digitized baseband data samples to the set of timeslots of the serial data stream transport frame.

25. A method for providing digital transport of signals in a distributed antenna system, the method comprising:

multiplexing a plurality of sets of digitized baseband signals into a serial data stream by assigning each set of digitized baseband signals to a corresponding timeslot of a transport frame, wherein each of the plurality of sets of digitized baseband signals corresponds to a distinct spectral region of radio frequency spectrum, wherein each of the plurality of sets of digitized baseband signals has a corresponding sampling rate; and

transmitting the transport frame.

26. The method of claim 25, further comprising:

receiving digital samples of analog radio frequency spectrum sampled at an initial sampling rate; and

generating the plurality of sets of digitized baseband signals in parallel based on the received digital samples of analog radio frequency spectrum.

27. The method of claim 25, wherein generating each set of digitized baseband signals comprises filtering the received digital samples of the analog radio frequency spectrum to pass only digital samples corresponding to the distinct spectral region corresponding to the set of digitized baseband signals.

28. The method of claim 25, wherein the first plurality of sets of digitized baseband signals includes at least three sets of digitized baseband signals corresponding to at least three spectral regions.

29. The method of claim 25, further comprising:

receiving configuration information, the configuration information identifying a plurality of relevant spectral regions within the radio frequency spectrum;

selecting a build from a plurality of builds stored in a data storage device based on the configuration information; and

programming a field programmable device by transferring the build to the filed programmable device.

30. The method of claim 29, wherein the configuration information identifies a center frequency and bandwidth size for defining the first spectral region.

31. A method for providing digital transport of signals in a distributed antenna system, the method comprising:

receiving an input transport signal comprising a transport frame having a plurality of timeslots;

parsing the input transport signal into a plurality of sets of digitized baseband signals based on a timeslot configuration of the input transport signal;

converting the plurality of sets of digitized baseband signals from first sampling rates to an output sampling rate; and

summing at least two of the plurality of sets of digitized baseband signals to produce a set of output data samples.

32. The method of claim 31, further comprising:

converting the set of output data samples to an analog radio frequency signal through a digital-to-analog converter.

33. The method of claim 31, wherein converting the plurality of sets of baseband signals further comprising generating a plurality of sets of radio frequency samples corresponding to a first spectral region of analog radio frequency spectrum.

34. The method of claim 31, wherein the first plurality of sets of digitized baseband signals includes at least three sets of digitized baseband signals corresponding to at least three spectral regions.

35. The method of claim 31, further comprising:

receiving configuration information identifying a plurality of relevant spectral regions within the analog radio frequency spectrum;

selecting a build from a plurality of builds stored in a data storage device based on the configuration information; and

programming a field programmable device by transferring the build to the field programmable device.

36. The method of claim 35, wherein the configuration information identifies a center frequency and bandwidth size for defining the first spectral region.