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

• US 8,270,387 B2
• Filed: 01/13/2010
• Issued: 09/18/2012
• Est. Priority Date: 01/13/2009
• Status: Active Grant

• 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
• Assistant Examiner(s): BOAKYE, ALEXANDER O
• Application Number:
  US12/686,488
• Publication Number:
  US 20100177760A1
• Time in Patent Office: 979 Days
• Field of Search: 370/345, 370/336, 370/337, 370/329, 370/328, 370/321, 370/352, 370/376, 370/295, 370/281, 370/294, 370/458, 370/395.41, 370/462, 370/468, 370/4, 370/478, 370/480, 370/498, 375/350, 375/229
• 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 digital-analog radio transceiver for providing digital transport of signals on a radio-frequency (RF) distributed antennal system, the transceiver comprising:

a receive path circuit including an RF reception interface coupled to an analog-to-digital converter, the analog-to-digital converter 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 coupled to the receive path circuit and receiving the digitized RF spectrum at the input sampling rate, the logic device producing a first set of baseband data samples at a first sampling rate, the first set of baseband data samples corresponding to a first spectral region of the analog RF spectrum, the logic device further producing a second set of baseband data samples at a second sampling rate, the second set of baseband data samples corresponding to a second spectral region of the analog RF spectrum;

wherein the logic device maps the first set of baseband data samples at the first sampling rate to a first set of timeslots of a serial data stream transport frame and maps the second set of baseband data samples at the second sampling rate to a second set of timeslots of the transport frame.

2. The transceiver of claim 1, wherein the first set of timeslots consists of a first number of timeslots based on a bandwidth of the first spectral region and the second set of timeslots consists of a second number of timeslots based on a bandwidth of the second spectral region.

3. The transceiver of claim 1, wherein the analog RF spectrum comprises a third spectral region between the first spectral region and the second spectral region, wherein data from the third spectral region is not mapped onto timeslots of the transport frame.

4. The transceiver of claim 1, the logic device including at least a first digital down converter and a second digital down converter, the first digital down converter and the second digital operating in parallel and each receiving the digitized RF spectrum at the input sampling rate;

the first digital down converter converting data corresponding to the first spectral region of the analog RF spectrum into the first set of digital baseband data at the first sampling rate, where the first sampling rate is a function of a size of a bandwidth of the first spectral region;

the second digital down converter converting data corresponding to the second spectral region of the analog RF spectrum into the second set of digital baseband data at the second sampling rate, where the second sampling rate is a function of a size of a bandwidth of the second spectral region.

5. The transceiver of claim 4, the logic device further comprising a serialized transmitter receiving the first set of digital baseband data at the first sampling rate and the second set of digital baseband data at the second sampling rate and mapping the first set of digital baseband data to the first set of timeslots and the second set of digital baseband data to the second set of timeslots.

6. The transceiver of claim 1, further comprising:

a transmission path circuit including an RF transmission interface coupled to an digital-to-analog converter;

the logic device further coupled to the transmission path circuit, the logic device receiving an input transport frame having a plurality of timeslots, wherein a first set of the plurality of timeslots includes a third set of baseband data samples at the first sampling rate, the third set of baseband data samples corresponding to the first spectral region of the analog RF spectrum, and wherein a second set of the plurality of timeslots includes a fourth set of baseband data samples at the second sampling rate, the fourth set of baseband data samples corresponding to the second spectral region of the analog RF spectrum;

wherein the logic device up-converts the third set of baseband data samples at the first sampling rate to a first set of RF data samples corresponding to the first spectral region at an output sampling rate;

wherein the logic device up-converts the fourth set of baseband data samples at the second sampling rate to second set of RF data samples corresponding to the second spectral region at the output sampling rate;

wherein the logic device sums the first set of RF data samples with the second set of RF data samples to produce a set of output data samples at the output sampling rate;

wherein the digital-to-analog converter receives the output data samples at the output sampling rate and generates an output analog signal from the output data samples;

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

7. The transceiver of claim 6, the logic device including at least a first digital up converter and a second digital up converter, the first digital up converter and the second digital up converter operating in parallel,

the first digital up converter receiving the third set of digital baseband signals and converting the third set of digital baseband signals into the first set of RF data samples corresponding to the first spectral region of the analog RF spectrum at the output sampling rate;

the second digital up converter receiving the fourth set of digital baseband samples and converting the third set of digital baseband signals into the second set of RF data samples corresponding to the second spectral region of the analog RF spectrum at the output sampling rate.

8. The transceiver of claim 7, the logic device further comprising a serialized receiver receiving the input transport frame and parsing timeslots of the transport frame to the first digital up converter and the second digital up converter based on a timeslot configuration of the input transport frame.

9. The transceiver of claim 6, wherein the analog RF spectrum comprises a third spectral region between the first spectral region and the second spectral region, wherein data from the third spectral region is not mapped onto timeslots of the input transport frame.

10. The transceiver of claim 1, wherein the logic circuit comprises a field programmable device.

11. The transceiver of claim 1, wherein the first spectral region and second spectral region are user selectable from a plurality of pre-built logic circuit configurations.

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

13. A digital-analog radio transceiver for providing digital transport of signals on a radio-frequency (RF) distributed antennal system, the transceiver comprising:

a transmission path circuit including an RF transmission interface coupled to an digital-to-analog converter;

a logic device further coupled to the transmission path circuit, the logic device receiving an input transport frame having a plurality of timeslots, wherein a first set of the plurality of timeslots includes a first set of baseband data samples at first sampling rate, the third set of baseband data samples corresponding to a first spectral region of an analog RF spectrum, and wherein a second set of the plurality of timeslots includes a second set of baseband data samples at a second sampling rate, the second set of baseband data samples corresponding to a second spectral region of the analog RF spectrum;

wherein the logic device up-converts the first set of baseband data samples at the first sampling rate to a first set of RF data samples corresponding to the first spectral region at an output sampling rate;

wherein the logic device up-converts the second set of baseband data samples at the second sampling rate to second set of RF data samples corresponding to the second spectral region at the output sampling rate;

wherein the logic device sums the first set of RF data samples with the second set of RF data samples to produce a set of output data samples at the output sampling rate;

wherein the digital-to-analog converter receives the output data samples at the output sampling rate and generates an output analog signal from the output data samples;

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

14. The transceiver of claim 13, wherein the analog RF spectrum comprises a third spectral region between the first spectral region and the second spectral region, wherein data from the third spectral region is not mapped onto timeslots of the input transport frame.

15. A method for providing digital transport of signals on a radio-frequency (RF) distributed antennal system, the method comprising:

receiving digital samples of an analog RF spectrum sampled at an initial sampling rate;

generating a first set of digital baseband data of the first spectral region at a first sampling rate;

in parallel with generating the first set of digital baseband data, generating a second set of digital baseband data of the second spectral region at a second sampling rate;

multiplexing the first set of digital baseband data and the second set of digital baseband data into a serial data stream by assigning the first set of digital baseband signals to a first set of timeslots of a transport frame and the second set of digital baseband signals to a second set of timeslots of the transport frame; and

transmitting the transport frame.

16. The method of claim 15, wherein the first sampling rate is determined from a bandwidth size of the first spectral region and the second sampling rate is determined from a bandwidth size of the second spectral region.

17. The method of claim 15, wherein generating the first set of digital baseband data of the first spectral region further comprises filtering the digital samples of the analog RF spectrum to pass only data signals corresponding to the first spectral region;

and

wherein generating the second set of digital baseband data of the second spectral region further comprises filtering the digital samples of the RF spectrum to pass only data signals corresponding to the second spectral region.

18. The method of claim 15, wherein the first set of timeslots consists of a first number of timeslots based on a bandwidth of the first spectral region and the second set of timeslots consists of a second number of timeslots based on a bandwidth of the second spectral region.

19. The method of claim 15, wherein the analog RF spectrum comprises a third spectral region between the first spectral region and the second spectral region, wherein data from the third spectral region is not mapped onto timeslots of the transport frame.

20. The method of claim 15, further comprising:

receiving configuration information, the configuration information identifying a plurality of relevant spectral regions within the analog RF 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.

21. The method of claim 20, wherein the configuration information identifies a center frequency and bandwidth size for defining the first spectral region.

22. A method for providing digital transport of signals on a radio-frequency (RF) distributed antennal system, the method comprising:

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

parsing the input transport signal into at least a first set of baseband signal and a second set of baseband signals based on a timeslot configuration of the input transport signal;

upconverting the first set of baseband signals from a first sampling rate to an output sampling rate;

in parallel with upconverting the first set of baseband signals, upconverting the second set of baseband signals from a second sampling rate to the output sampling rate;

summing the upconverted first set of baseband signals with the upconverted second set of baseband signals to produce a set of output data samples; and

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

23. The method of claim 22, wherein upconverting the first set of baseband signals further comprises generating a first set of RF data samples corresponding to a first spectral region of an analog RF spectrum;

and

wherein upconverting the second set of baseband signals further comprises generating a second set of RF data samples corresponding to a second spectral region of the analog RF spectrum.

24. The method of claim 23, wherein the analog RF spectrum comprises a third spectral region between the first spectral region and the second spectral region, wherein data from the third spectral region is not mapped onto timeslots of the input transport frame.

25. The method of claim 22, wherein the timeslot configuration of the input transport signal comprises a first set of timeslots consisting of a first number timeslots corresponding to a bandwidth of the first spectral region and a second set of timeslots consisting of a second number of timeslots corresponding to a bandwidth of the second spectral region.

26. The method of claim 22, further comprising:

receiving configuration information, the configuration information identifying a plurality of relevant spectral regions within an analog RF 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.

27. The method of claim 26, wherein the configuration information identifies a center frequency and bandwidth size for defining a first spectral region.