Point-to-multipoint digital radio frequency transport

• US 10,505,635 B2
• Filed: 05/02/2016
• Issued: 12/10/2019
• Est. Priority Date: 07/19/2000
• Status: Expired due to Term

• Current Assignee: CommScope Technologies, LLC (CommScope Holding Company, Inc.)
• Original Assignee: CommScope Technologies, LLC (CommScope Holding Company, Inc.)
• Inventors: Wala, Philip M.
• Primary Examiner(s): Trinh, Sonny
• Application Number:
  US15/144,219
• Publication Number:
  US 20160248508A1
• Time in Patent Office: 1,317 Days
• Field of Search: 455 14, 455 16, 455 20, 455561
• CPC Class Codes: H03M 7/4006 Conversion to or from arithmetic code
• CPC Class Codes: H04B 10/25753 Distribution optical network, e.g. between a base station and a plurality of remote units
• CPC Class Codes: H04B 10/25754 Star network topology
• CPC Class Codes: H04B 3/02 Details
• CPC Class Codes: H04B 7/2606 Arrangements for base station coverage control, e.g. by using relays in tunnels
• CPC Class Codes: H04L 51/04 Real-time or near real-time messaging, e.g. instant messaging [IM]
• CPC Class Codes: H04L 51/48 Message addressing, e.g. address format or anonymous messages, aliases
• CPC Class Codes: H04L 51/58 Message adaptation for wireless communication
• CPC Class Codes: H04L 65/1016 IP multimedia subsystem [IMS]
• CPC Class Codes: H04L 65/1104 Session initiation protocol [SIP]
• CPC Class Codes: H04N 19/109 among a plurality of temporal predictive coding modes
• CPC Class Codes: H04N 19/139 Analysis of motion vectors, e.g. their magnitude, direction, variance or reliability
• CPC Class Codes: H04N 19/625 using discrete cosine transform [DCT]
• CPC Class Codes: H04N 19/91 Entropy coding, e.g. variable length coding [VLC] or arithmetic coding
• CPC Class Codes: H04Q 11/0067 Provisions for optical access or distribution networks, e.g. Gigabit Ethernet Passive Optical Network (GE-PON), ATM-based Passive Optical Network (A-PON), PON-Ring
• CPC Class Codes: H04Q 2011/0047 Broadcast; Multicast
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services
• CPC Class Codes: H04W 4/12 Messaging; Mailboxes; Announcements
• CPC Class Codes: H04W 4/14 Short messaging services, e.g. short message services [SMS] or unstructured supplementary service data [USSD]
• CPC Class Codes: H04W 72/30 Resource management for broadcast services
• CPC Class Codes: H04W 88/08 : Access point devices
• CPC Class Codes: H04W 88/085 : Access point devices with remote components
• CPC Class Codes: Y10S 370/906 : Fiber data distribution interface, FDDI
• CPC Class Codes: Y10S 370/907 : Synchronous optical network, SONET

Abstract

One embodiment is directed to a system for use with a coverage area in which one or more wireless units wirelessly transmit using a wireless radio frequency spectrum. The system comprises a first unit, and a plurality of second units communicatively coupled to the first unit using at least one communication medium. Each of the plurality of second units generates respective digital RF samples indicative of a respective analog wireless signal received at that second unit. Each of the plurality of second units communicates the respective digital RF samples generated by that second unit to the first unit using the at least one communication medium. The first unit digitally sums corresponding digital RF samples received from the plurality of second units to produce summed digital RF samples. The system is configured so that an input used for base station processing is derived from the resulting summed digital RF samples.

Claims

1. A distributed antenna system comprising:

a host unit including at least one base station interface configured to couple the host unit to at least one transmitter of a base station and at least one receiver of the base station via an external interface of the base station, the host unit further including at least one cable interface, the host unit configured to derive a transmitted digital signal from a downlink analog radio frequency signal in a form suitable for wireless transmission to wireless units, the transmitted digital signal for transmission using the at least one cable interface, the host unit configured to receive the downlink analog radio frequency signal from the at least one transmitter of the base station via the at least one base station interface and the external interface of the base station, the at least one cable interface configured to receive a received digital signal, the host unit configured to derive an uplink analog radio frequency signal in a form suitable for wireless transmission to the base station via the external interface of the base station from the received digital signal, wherein the host unit is configured to output the uplink analog radio frequency signal to the at least one receiver of the base station via the at least one base station interface and the external interface of the base station;

a plurality of remote antenna units, each remote unit located at a respective site and communicatively coupled with the host unit through at least one cable, each remote unit configured to transmit an analog representation of the transmitted digital signal to a respective coverage area of the respective site, each remote antenna unit further configured to receive radio frequency signals from the respective coverage area of the respective site and to convert the radio frequency signals into a digitized received spectrum;

a summing unit communicatively coupled to the host unit through at least a first cable and at least one remote antenna unit of the plurality of remote antenna units through at least a second cable, the summing unit positioned downstream of and remote from the host unit and upstream of and remote from the at least one remote antenna unit, the summing unit including a digital summer configured to sum a first digitized spectrum derived from a signal received by the summing unit from the at least one remote antenna unit with a second digitized spectrum to generate a digitally summed signal, the second digitized spectrum being from at least one site different than the site where the at least one remote antenna unit is located, wherein the digitally summed signal is transmitted toward the host unit; and

wherein the received digital signal is derived from the digitally summed signal.

2. The distributed antenna system of claim 1, wherein the at least one remote antenna unit includes a first remote antenna unit;

and

wherein the second digitized spectrum is received by the summing unit from a second remote antenna unit of the plurality of remote antenna units.

3. The distributed antenna system of claim 2, wherein the second remote antenna unit is remote from the summing unit.

4. The distributed antenna system of claim 1, wherein the summing unit is a digital expansion unit.

5. The distributed antenna system of claim 1, wherein the host unit, summing unit, and plurality of remote antenna units are communicatively coupled over at least one communication medium.

6. The distributed antenna system of claim 5, wherein the at least one communication medium includes at least one optical communication medium;

wherein the transmitted digital signal is a transmitted digital optical signal; and

wherein the received digital optical signal is a received digital optical signal.

7. The distributed antenna system of claim 1, wherein the host unit comprises:

a second digital summer configured to sum a first input digitized spectrum, derived from the received digital signal received by the host unit from the summing unit, with a second input digitized spectrum in order to generate an output digitally summed signal;

a digital-to-analog converter configured to convert an input digital signal, derived from the output digitally summed signal, in order to generate a digital-to-analog converted analog signal; and

a mixer configured to frequency shift an input analog signal, derived from the digital-to-analog converted analog signal, in order to generate a mixed analog signal, wherein the uplink analog radio frequency signal is derived from the mixed analog signal.

8. A system for digital transport of a wireless spectrum, the system comprising:

a first unit located at a first site, the first unit including at least one cable interface;

a second unit remotely located from the first unit at a second site and communicatively coupled to the first unit by at least a first cable communicatively coupled to the at least one cable interface;

a third unit remotely located from the first unit at a third site and communicatively coupled to the second unit;

wherein the third unit is configured to receive, at the third site, a first analog wireless signal comprising first wireless spectrum and any transmissions from any wireless units within a first coverage area associated with the third unit;

wherein the third unit is configured to generate first digital samples indicative of at least a first portion of the first wireless spectrum of the first analog wireless signal;

wherein the third unit is configured to communicate the first digital samples to the second unit;

wherein the second unit is configured to digitally sum the first digital samples with second digital samples indicative of at least a second portion of a second wireless spectrum of a second analog wireless signal to produce first summed digital samples;

wherein the second unit is configured to communicate the first summed digital samples to the first unit using the first cable; and

wherein the first unit is configured to derive an uplink analog radio frequency signal, in a form suitable for wireless transmission to a base station via an external interface of the base station, from the first summed digital samples, wherein the first unit is configured to output the uplink analog radio frequency signal to at least one receiver of the base station via the external interface of the base station.

9. The system of claim 8, wherein the third unit is remotely located from the second unit and communicatively coupled to the second unit through at least a second cable.

10. The system of claim 9, wherein the third unit is configured to communicate the first digital samples to the second unit using the second cable.

11. The system of claim 8, wherein the first unit is a host unit;

and

wherein the third unit is a remote antenna unit.

12. The system of claim 11, wherein the second unit is a digital expansion unit.

13. The system of claim 8, wherein the second digital samples are received at the second unit from a fourth unit remotely located from the second unit at a fourth site.

14. The system of claim 13, wherein the fourth unit is configured to receive, at the fourth site, the second analog wireless signal comprising the second wireless spectrum and any transmissions from any wireless units within a second coverage area associated with the fourth unit.

15. The system of claim 8, wherein the third unit comprises:

a respective analog-to-digital converter configured to digitize the first analog wireless signal in order to produce the first digital samples.

16. The system of claim 8, wherein the third unit is configured to generate the first digital samples by frequency shifting the first analog wireless signal and digitizing the frequency-shifted first analog wireless signal.

17. The system of claim 8, wherein the third unit is configured to generate the first digital samples by down converting the first analog wireless signal and digitizing the down-converted first analog wireless signal.

18. The system of claim 8, wherein the second portion of the second wireless spectrum overlaps in wireless spectrum with the first portion of the first wireless spectrum.

19. The system of claim 8, wherein the second portion of the second wireless spectrum covers the same frequency range as the first portion of the first wireless spectrum.

20. The system of claim 8, wherein the first unit comprises:

a digital summer configured to digitally sum first input digital samples with second input digital samples in order to produce output digital samples, the first input digital samples derived from the first summed digital samples;

a digital-to-analog converter configured to convert an input digital signal, derived from the output digital samples, in order to generate a digital-to-analog converted analog signal; and

a mixer configured to frequency shift an input analog signal, derived from the digital-to-analog converted analog signal, in order to generate a mixed analog signal, wherein the uplink analog radio frequency signal is derived from the mixed analog signal.

21. A first unit used in digital transport of a wireless spectrum, the first unit comprising:

a first cable interface configured to communicatively couple the first unit to a second upstream unit located remotely from the first unit at a second site through a first cable;

a second cable interface configured to communicatively couple the first unit to a third downstream unit located remotely from the first unit at a third site, the second cable interface configured to receive first digital samples from the third downstream unit, the first digital samples indicative of at least a first portion of a first wireless spectrum of a first analog wireless signal comprising the first wireless spectrum and any transmission received at the third downstream unit positioned at the third site from any wireless units within a first coverage area associated with the third downstream unit;

a digital summer configured to digitally sum the first digital samples with second digital samples indicative of at least a second portion of a second wireless spectrum of a second analog wireless signal to produce first summed digital samples;

wherein the first cable interface is configured to communicate the first summed digital samples to the second upstream unit using the first cable, wherein the second upstream unit is configured to derive an uplink analog radio frequency signal from the first summed digital samples in a form suitable for wireless transmission to a base station via an external interface of the base station, wherein the second upstream unit is configured to output the uplink analog radio frequency signal to at least one receiver of the base station via the external interface of the base station.

22. The first unit of claim 21, wherein the first unit is a digital expansion unit;

wherein the second upstream unit is a host unit; and

wherein the third downstream unit is a remote antenna unit.

23. The first unit of claim 21, wherein the second digital samples are received at the first unit from a fourth downstream unit remotely located from the first unit at a fourth site;

and

wherein the fourth downstream unit is configured to receive, at the fourth site, the second analog wireless signal comprising the second wireless spectrum and any transmissions from any wireless units within a second coverage area associated with the fourth downstream unit.

24. The first unit of claim 21, wherein the second portion of the second wireless spectrum overlaps in wireless spectrum with the first portion of the first wireless spectrum.

25. The first unit of claim 21, wherein the second portion of the second wireless spectrum covers the same frequency range as the first portion of the first wireless spectrum.