Cellular communications system with sectorization

• US RE45,321 E1
• Filed: 12/21/2012
• Issued: 01/06/2015
• Est. Priority Date: 09/17/1992
• Status: Expired due to Term

• Current Assignee: CommScope Technologies, LLC (CommScope Holding Company, Inc.)
• Original Assignee: ADC Telecommunications Incorporated (TE Connectivity Limited)
• Inventors: Fischer, Larry G., Russell, David S., Wala, Philip M., Brennan, Jeffrey O., Ratliff, Charles R
• Primary Examiner(s): Ghebretinsae, Temesgh
• Assistant Examiner(s): Chan, Richard
• Application Number:
  US13/725,866
• Time in Patent Office: 746 Days
• Field of Search: 455/562, 455/422.1, 379/56.2, 379/58, 379/59, 379/60
• US Class Current: 379/56.2
• CPC Class Codes: H04W 16/24 Cell structures
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 88/085 Access point devices with remote components

Abstract

A method and apparatus for sectorizing coverage of a cellular communications area includes providing a remote unit having microcell antenna units. Each microcell antenna unit is configured to cover a particular sector. The remote unit is connected to a sectorized base station unit which is connected to a mobile telecommunications switching office. Separate digitized streams representative of telephone signals received from the mobile telecommunications switching office are generated corresponding to the microcell antenna units and the separate digitized streams are multiplexed and transmitted to the remote unit. The remote unit demultiplexes the multiplexed digitized streams into the separate digitized streams corresponding to the microcell antenna units and the separate digitized streams are converted to RF signals for coverage of a particular sector by the corresponding microcell antenna unit. Separate digitized streams are separately generated for each microcell antenna unit representative of RF signals received at the microcell antenna unit for a particular sector. The separately generated digitized streams are multiplexed at the remote unit and transmitted to the sectorized base station unit. At the sectorized base station unit, the multiplexed digitized streams are demultiplexed into the separate digitized streams corresponding to microcell antenna units and the separate digitized streams are converted to RF signals for provision to the mobile telecommunications switching office. Diversity at the remote units is also provided.

Claims

1. A method of sectorizing coverage over a cellular communications area divided into a plurality of microcells each covering a subarea of the communications area and being divided into a plurality of angular sectors having separate transmitters and receivers, the method comprising performing the following steps:

receiving a number of information-bearing telephone signals from a mobile telecommunications switching office at a common base station serving the microcells within the cellular communications area;

modulating the information-bearing telephone signals onto a plurality of different analog radio-frequency carriers representing a plurality of different channel sets for respective sectors of the microcells at the base station;

combining the analog radio-frequency signals for all of the sectors into a single outbound analog signal within a predetermined radio-frequency band, representing all of the channel sets for all of the sectors;

converting the single outbound analog signal directly to a single outbound digital representation at the base station;

sending the outbound digital representation of the radio-frequency signal via a transmission means to a remote unit located in or near the subarea of at least one microcell;

at the remote unit, converting the outbound digital representation directly to a single analog representation of the entire outbound single radio-frequency signal within the same radio-frequency band and containing each of the plurality of channel sets;

sending each of the plurality of channel sets to a different one of a plurality of antenna units for the microcell, each of the antenna units being positioned so as to cover a different angular sector of the microcell;

at the antenna unit covering each sector of the microcell, receiving telephone signals within the radio-frequency band for the channel set of that sector;

sending the received telephone signals to the remote unit;

at the remote unit, combining all the received telephone signals from all the sectors to a single combined analog radio-frequency received signal containing all the channel sets for the microcell;

converting the single combined radio-frequency received signal directly to a received digital representation of the radio-frequency band of the channel sets for the sectors;

sending the received digital representation via the transmission means to the base station; and

at the centrally located base station, converting the received digital representation directly to a received analog representation;

demodulating the received analog representation to recover the individual inbound telephone signals.

2. The method of claim 1, wherein:

the step of sending the digital representation of the radio-frequency signal to the remote unit includes modulating it onto a transmit optical signal at a transmit wavelength on an optical fiber; and

the step of sending the received digital representation to the base station includes modulating it onto a receive optical signal on an optical fiber.

3. The method of claim 2, wherein the transmit and receive optical signals are sent on the same optical fiber, the transmit and receive wavelengths being different from each other.

4. The method of claim 1, wherein all the antenna units are located near the remote unit, and wherein the distance from the centrally located base station to the remote unit is greater than the distance from the remote unit to its antenna unit.

5. A method of sectorizing coverage over a cellular communications area divided into a plurality of microcells each covering a subarea of the communications area, and each divided into a plurality of sectors, the method comprising performing the following steps for each microcell:

receiving a number of information-bearing telephone signals from a mobile telecommunications switching office at a common base station serving the microcells within the cellular communications area;

generating from the information-bearing telephone signals one of a plurality of different channel sets of signals for each sector of that microcell at the base station;

combining the plurality of different channel sets into a single analog signal in a predetermined radio-frequency band;

converting the single analog signal directly to a single digital representation;

sending the digital representation via a transmission means to a remote unit located in or near the subarea;

at the remote unit, converting the digital representation directly to an analog representation of the radio-frequency signal for all channel sets within the same predetermined radio-frequency band; and

sending the radio-frequency signal for each of the plurality of channel sets to a different one of a plurality of antenna units, each of the antenna units being positioned so as to cover a different angular sector of that microcell.

6. The method of claim 5, wherein the step of sending the radio-frequency signal for each of the channel sets includes:

splitting the channel sets to form multiple parallel paths each carrying a signal representation for a different one of the channel sets; and

filtering each of the paths differently based upon the channel set carried on that path.

7. A method of sectorizing coverage over a cellular communications area divided into a plurality of microcells each covering a subarea of the communications area, each microcell being divided into a plurality of sectors, the method comprising:

at a plurality of antenna units each covering a different sector of a microcell, receiving analog telephone signals within a predetermined radio-frequency band for a channel set assigned to that sector;

sending all the analog telephone signals to a remote unit serving the sectors of the microcell, the remote unit being located in or near the subarea of the microcell;

at the remote unit for the microcell, combining all the analog telephone signals from all sectors of the microcell into a single analog signal within the same radio-frequency band as the channel sets for the sectors of the microcell;

converting the single combined analog signal directly as a whole to a received digital representation;

sending the received digital representation via the transmission means to a common base station serving the microcells of the communications area;

at the base station, converting the received digital representation to an inbound analog signal within the radio-frequency band;

demodulating the inbound analog signal to recover a plurality of information-bearing signals representing received analog telephone signals; and

sending the information-bearing signals to a mobile telecommunications switching office.

8. The method of claim 7, wherein the antenna unit for said each microcell includes one or more diversity antenna(s) covering one or more sector(s) of that microcell.

9. The method of claim 8, further comprising the steps of:

at each diversity antenna, receiving analog diversity signal(s) within the radio-frequency band for the channel set of its sector;

sending all diversity signals for said each microcell to the remote unit for said each microcell;

at the remote unit for said each microcell, converting the diversity signals from all sectors in that microcell to a diversity digital representation within the radio-frequency band; and

sending the diversity digital representation via the transmission means to the base station.

10. A method of sectorizing coverage over a cellular communications area divided into a plurality of microcells each covering a subarea of the communications area, and each divided into a plurality of sectors, the method comprising:

receiving a number of information-bearing telephone signals associated with a cellular communication service from a mobile telecommunications switching office serving the microcells within the cellular communications area;

generating from the information-bearing telephone signals one of a plurality of different channel sets of signals for each sector of the respective microcell;

receiving a plurality of additional information-bearing signals associated with at least one communication service other than the cellular communication service;

combining the plurality of different channel sets and the plurality of additional information-bearing signals into a combined radio-frequency signal;

sending the combined signal via a transmission means to a remote unit located in or near the respective subarea;

at the remote unit, sending the radio-frequency signal for each of the plurality of channel sets to a different one of a plurality of antenna units, each of the antenna units being positioned so as to cover a different angular sector of the respective microcell.

11. The method of claim 10, wherein combining the plurality of different channel sets and the plurality of additional information bearing signals comprises combining the plurality of different channel sets and the plurality of additional information bearing signals into a combined analog signal;

and

sending the combined signal comprises sending the combined analog signal via the transmission means to the remote unit in or near the respective subarea.

12. The method of claim 10, wherein combining the plurality of different channel sets and the plurality of additional information bearing signals comprises:

combining the plurality of different channel sets and the plurality of additional information bearing signals into a combined analog signal; and

converting the combined analog signal directly to a digital representation of the combined analog signal;

wherein sending the combined signal comprises sending the digital representation via the transmission means to the remote unit in or near the respective subarea.

13. The method of claim 10, wherein receiving a plurality of additional information-bearing signals associated with at least one communication service other than the cellular communication service comprises receiving a plurality of additional information-bearing signals associated with at least one of a paging service, a mobile data service, or a plain old telephone service (POTS).

14. A first unit for communicating with a remote unit over an optical communication medium, the first unit comprising:

an interface to receive a first band of channels comprising a plurality of carriers on which cellular communication from a first communication network being transmitted to a plurality of wireless communication units is modulated;

a modulator to combine the first band of channels with at least one second band of channels separate from the first band and comprising a plurality of carriers over which non-cellular communications from a second communication network different from the first communication network are carried in order to produce a combined modulated signal; and

an optical transmitter having an input coupled to an output of the modulator to provide an optical signal comprising the combined modulated signal to the remote unit via the optical communication medium;

wherein the remote unit is physically remote from the first unit.

15. The first unit of claim 14, wherein the at least one second communication network comprises one of a paging network, a mobile data network, or a plain old telephone service (POTS) network.

16. A method of communicating from a first unit to a remote unit over a communication medium, the method comprising:

producing a framed signal from a representation of a wireless signal, the wireless signal for wirelessly communicating with a plurality of remote wireless communication units, the wireless signal comprising a plurality of channels, the plurality of channels comprising a first band of carriers on which information for a first cellular service is modulated and a second band of carriers, separate from the first band, on which information for a second wireless service, different from the first cellular service, is modulated; and

transmitting a transmission signal from the first unit to the remote unit over the communication medium;

wherein the transmission signal is derived from at least a portion of the framed signal; and

wherein the remote unit is physically remote from the first unit.

17. The method of claim 16, wherein the representation of the wireless signal comprises a digital representation of the wireless signal.

18. The method of claim 16, wherein the framed signal comprises a plurality of frames.

19. The method of claim 18, wherein each frame comprises at least one of control data and monitoring data.

20. The method of claim 18, wherein each frame comprises error detection and correction data.

21. The method of claim 18, wherein each frame comprises data associated with multiple services.

22. The method of claim 16, wherein the plurality of carriers comprises at least one of a plurality of radio frequency carriers and a plurality of intermediate frequency carriers.

23. The method of claim 16, wherein the communication medium comprises an optical communication medium and the transmission signal comprises an optical transmission signal.

24. The method of claim 16, wherein the first unit receives the first band of carriers in the form of an analog combined signal.

25. A system comprising:

a first unit; and

a plurality of second units, each of the plurality of second units located remotely from the first unit;

wherein the first unit is optically coupled to each of the plurality of second units;

wherein the first unit is configured to receive a first downstream radio frequency signal associated with a first cellular service and a second downstream radio frequency signal associated with a wireless service other than the first cellular service;

wherein each of the first and second downstream radio frequency signals comprises a respective band;

wherein the first unit is configured to communicate a downstream optical signal to each of the second units via a respective downstream optical fiber, the downstream optical signal derived from the first downstream radio frequency signal and the second downstream radio frequency signal;

wherein each of the second units is configured to reconstruct a version of the first downstream radio frequency signal from the downstream optical signal received at the respective second unit;

wherein each of the second units is configured to reconstruct a version of the second downstream radio frequency signal from the downstream optical signal received at the respective second unit; and

wherein the reconstructed version of the first downstream radio frequency signal produced at each of the second units is radiated from an antenna associated with the respective second unit.

26. The system of claim 25, wherein the downstream optical signal communicated from the first unit to each second unit comprises:

an analog representation of the first downstream radio frequency signal; and

an analog representation of the second downstream radio frequency signal.

27. The system of claim 25, wherein each second unit is configured to receive first and second upstream cellular radio frequency signals;

wherein each second unit is configured to communicate a respective upstream optical signal to the first unit that is derived from both the first and second upstream cellular radio frequency signals received at the respective second unit;

wherein the first unit is configured to output a first base upstream cellular radio frequency signal from each of the upstream optical signals received at the first unit from each of the second units;

wherein the first unit is configured to output a second base upstream radio frequency signal from each of the upstream optical signals received at the first unit from each of the second units;

wherein the first base upstream cellular radio frequency signal is derived from the first upstream cellular radio frequency signals received at the second units; and

wherein the second based upstream cellular radio frequency signal is derived from the second upstream cellular radio frequency signals received at the second units.

28. A system comprising:

a first unit comprising a plurality of optical transmitters and a plurality of optical receivers; and

a plurality of remote units, each remote unit coupled to a respective one of the plurality of optical transmitters in the first unit via a respective downstream optical link and to a respective one of the plurality of optical receivers in the first unit via a respective upstream optical link;

wherein the first unit is configured to receive a plurality of downstream signal inputs, each of the downstream signal inputs associated with one of a plurality of communication services, at least one of the downstream signal inputs associated with a cellular communication service and at least one of the downstream signal inputs associated with a service different from the cellular communication service;

wherein the first unit is further configured to combine the plurality of downstream signal inputs to form a combined downstream signal for transmission to at least one of the plurality of remote units via the respective optical transmitter;

wherein each of the remote units is configured to separate the downstream signal inputs from the combined downstream signal and to radiate the downstream signal associated with the cellular communication service via a respective antenna.

29. The system of claim 28, wherein the at least one downstream signal input associated with a service different from the cellular communication service is associated with one of a paging service, a mobile data service, a video service, or a plain old telephone service (POTS).

30. The system of claim 28, wherein the first unit is further configured to combine control information for the plurality of remote units with the plurality of downstream signal inputs to form the combined downstream signal.