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Cellular communications system with sectorization |
| RE40564 |
Cellular communications system with sectorization
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| Patent Drawings: | |
| Inventor: |
Fischer, et al. |
| Date Issued: |
November 4, 2008 |
| Application: |
09/747,273 |
| Filed: |
December 22, 2000 |
| Inventors: |
Fischer; Larry G. (Waseca, MN)
Russell; David S. (Minneapolis, MN)
Wala; Philip M. (Waseca, MN)
Ratliff; Charles R. (Madison, GA)
Brennan; Jeffrey O. (Waseca, MN)
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| Assignee: |
ADC Telecommunications, Inc. (Eden Prairie, MN) |
| Primary Examiner: |
Orgad; Edan |
| Assistant Examiner: |
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| Attorney Or Agent: |
Fogg & Powers LLC |
| U.S. Class: |
455/447; 398/41; 398/115; 455/561; 455/448; 455/562.1 |
| Field Of Search: |
455/403; 455/422.1; 455/560; 455/561; 455/562.1; 455/447; 455/448; 455/11.1; 455/7; 455/14; 455/520; 370/310; 370/310.2; 370/328 |
| International Class: |
H04B 1/38; H04M 1/00; H04Q 7/20; H04Q 7/30; H04Q 7/36 |
| U.S Patent Documents: |
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| Foreign Patent Documents: |
2008900; 3707244; 0166885; 0346925; 0368673; 0391597; 0468688; 2345865; 58-164007; 3-26031; 5-12374 |
| Other References: |
"And now a few words from your Customers . . . " Four pages. ADC Kentrox.COPYRGT. A Subsidiary of ADC Telecommunications, Inc. Aug. 1992.cited by other.
ADC Kentrox, News Release, "ADC Kentrox Introduces Innovative Wireless Network Access Solution Cellular Subscribers Offered a New Level of Portable Services," Mar. 1, 1993 (3 pages). cited by other.
ADC Kentrox, News Release, "First Field Trial Results Exceeds Expectations," Mar. 2, 1993 (2 pages). cited by other.
ADC Kentrox Wireless System Group CityCell.TM, 824--A Positioning white paper, (Mar. 1993) CITA Trade Show. cited by other.
"ADC Kentrox Introduces CityCell 824, A Replacement For Conventional Cell Sites; Company's Original Goal Was To Improve Fiber Optic T1 Links Between Cells, MTSOs," Telocator Bulletin, Feb. 1993(1 page). cited by other.
Ameritech, "Broadband Optical Transport Digital Microcell Connection Service--Interface and Performance Specifications. A technical descriptionof the User-Network Interface and Performance Specifications," AM TR-NIS 000117, (pp. 1-26), Issue 1, Dec.1993. cited by other.
Cellular Industry, The Day Group, "New Signal Transport Technology Digitizes The Cellular Band," 2 pages, (prior to Dec. 22, 2000). cited by other.
City Cell, Cellular Industry the Day Group, "ADC Kentrox CityCell Field Trial Yields Another First: Simultaneous Analog and Digital Calls," (1 page) (prior to Dec. 22, 2000). cited by other.
Cox, "A Radio System Proposal for Widespread Low-Power Tetherless Communications," IEEE Transactions on Communications, vol. 39(2), Feb. 1991, pp. 324-335. cited by other.
Gupta et al., "Land Mobile Radio Systems--A Tutorial Exposition", IEEE Communications Magazine, vol. 23(6), Jun. 1985, pp. 34-45. cited by other.
Ishio et al., "A Two-Way Wavelength-Division-Multiplexing Transmission and its Application to a Switched TV Distribution System," Electrical Communication Laboratories, Nipon Telegraph & Telephone Public Corporation, Yokosuka, Japan and TechnicalBureau, Nippon Telegraph & Telephone Public Corporation, Tokyo, Japan, (10 pages) (prior to Dec. 22, 2000). cited by other.
Kobb, "Personal Wireless," Special Report/Communications, IEEE Spectrum, Jun. 1993, pp. 20-25. cited by other.
Lee et al., 1993 43rd IEEE Vehicular Technology Conference, May 18-20, 1993, Personal Communication--Freedom Through Wireless Technology, PacTel Corporation, published May 18, 1993, "Intelligent Microcell Applications in PCS," pp. 722-725. cited byother.
Merrett et al., 41st IEEE Vehicular Technology Conference, May 19-22, 1991, Gateway to the Future Technology, 91CH2944-7, British Telecom Research Laboratories, "A Cordless Access System Using Radio-Over-Fibre Techniques," pp. 921-924. cited byother.
Microwaves & RF, "Digital Transport for Cellular," Feb. 1993. cited by other.
Microwaves & RF, Mar. 1993, "Offshore Markets Gain in Size, Competitiveness, Even the smallest industry companies are expanding their global business, despite such costly distractions as ISO 9000," (pp. 33, 34, 36-39). cited by other.
O'Byme, Vehicular Technology Society 42nd VTS Conference Frontiers of Technology, From Pioneers to the 21st Century, GTE Laboratories Incorporated, "TDMA and CDMA in a Fiber-Optic Environment," vol. 2 of 2, pp. 727-731 (May 10, 1992). cited by other.
Russell, New Microcell Technology Sets Cellular Carriers Free, Telephony, Mar. 1993, pp. 40, 42 and 46. cited by other.
R. Steele. Towards a High-Capacity Digital Cellular Mobile Radio System. "Towards a High Capacity Digital Cellular Mobile Radio System," IEE Proceedings, vol. 132, Pt.F, No. 5, Aug. 1985, pp. 405-415. cited by other.
Tang, Fiber Optic Antenna Remoting for Multi-Sector Cellular Cell Sites. GTE Laboratories--Abstract (Conference Jun. 14-18, 1992). cited by other.
Titch, "Kentrox boosts coverage and capacity," Telephony Jan. 25, 1993 (1 page). cited by other.
Urban Microcell System Layout, GTE Laboratories (Conference Jun. 14-18, 1992). cited by other.
Wala, 1993 43rd IEEE Vehicular Technology Conference, May 18-20, 1993, Personal Communication--Freedom Through Wireless Technology, Waseca Technology Inc., published May 18, 1993, "A New Microcell Architecture Using Digital Optical Transport," pp.585-588. cited by other.
"ZoneMaster.TM.--Maximum Coverage For High-Capacity Locations". Decibel Multi Media MicroCELL System. 4 pages, 1993 Decibel Products. 2-83-5M. cited by other.
A Radio System Proposal Widespread Low-Power Tetherless Communication, Donald C. Cox, IEEE, vol. 290, No. 2 (Feb. 1991), pp. 328-329. cited by examiner. |
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| 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. |
| Claim: |
We claim:
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 intoa 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 commonbase 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 forrespective 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 allof the sectors; converting the signal 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 unitlocated 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 signal radio-frequency signal within the same radio-frequencyband 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 angularsector 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 theremote 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 signal combined radio-frequency received signaldirectly 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 stepof 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 wavelength 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. The 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 performingthe 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; generatingfrom the information-bearing telephone signal 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 predeterminedradio-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 thedigital 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 adifferent 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 thechannel 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 aremote 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 singleanalog 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 representationvia 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 theinbound analog signal to recover a plurality of information-bearing signals representing received analog telephone signals; and sensing 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 microcellto 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 diversitydigital representation via the transmission means to the base station.
.Iadd.10. A method of transmitting an RF signal between a base station and at least one remote unit that wirelessly communicates with at least one wireless unit, the method comprising: generating a digitized representation of the RF signal atthe base station, wherein the RF signal is a combined analog signal representing a plurality of outbound wireless transmissions for a set of channels; and transmitting the digitized representation to the remote unit..Iaddend.
.Iadd.11. The method of claim 10, wherein transmitting the digitized representation to a remote unit comprises transmitting the digitized representation to a remote antenna unit..Iaddend.
.Iadd.12. The method of claim 10, wherein generating a digitized representation of the RF signal comprises: sampling the RF signal to produce a stream of digital samples; and framing the digital samples to produce a stream of frames..Iaddend.
.Iadd.13. The method of claim 10, wherein transmitting the digitized representation to the remote unit comprises transmitting the digitized representation over a path selected from the group consisting of a fiber optic cable and a coaxialcable..Iaddend.
.Iadd.14. A method of transmitting wireless transmissions between a base station and a remote unit that wirelessly communicates with at least one wireless unit, the method comprising: generating a set of RF analog modulated channel carriersrepresenting outbound transmissions, wherein each RF analog modulated channel carrier corresponds, in a one-to-one relationship, to a channel in a set of channels used by the remote unit; combining the set of RF analog modulated channel carriers into acombined RF signal; generating a digitized representation of the combined RF signal to the base station; and transmitting the digitized representation to the remote unit..Iaddend.
.Iadd.15. The method of claim 14, wherein transmitting the digitized representation to a remote unit comprises transmitting the digitized representation to a remote antenna unit..Iaddend.
.Iadd.16. The method of claim 14, wherein generating a digitized representation of the RF signal comprises: sampling the RF signal to produce a stream of digital samples; and framing the digital samples to produce a stream of frames..Iaddend.
.Iadd.17. The method of claim 14, wherein transmitting the digitized representation to the remote unit comprises transmitting the digitized representation over a path selected from the group consisting of a fiber optic cable and a coaxialcable..Iaddend.
.Iadd.18. A method of transmitting RF signals between a base station and a remote unit that wirelessly communicates with at least one wireless unit, the method comprising: receiving a plurality of outbound input signals from a network, whereinthe plurality of outbound input signals correspond to a set of channels used by the remote unit; generating an RF analog outbound channel carrier for each channel in the set of channels used by the remote unit; analog modulating each of the pluralityof outbound input signals onto a corresponding one of the RF analog outbound channel carriers, thereby generating a plurality of RF analog modulated channel carriers; combining the plurality of RF analog modulated channel carriers into a combined RFsignal; generating a digitized representation of the combined RF signal at the base station; and transmitting the digitized representation to the remote unit..Iaddend.
.Iadd.19. A method of transmitting RF signals between a remote unit and a base station, the method comprising: receiving at the remote unit an inbound combined RF signal comprising a plurality of inbound RF signals from a plurality of mobileunits; generating a digitized representation of the combined RF signal at the remote unit; and transmitting the digitized representation to the base station..Iaddend.
.Iadd.20. A method of transmitting RF signals between a remote unit and a base station, the method comprising: receiving at the remote unit a combined RF signal comprising a plurality of simultaneous inbound RF signals in a set of channels froma plurality of mobile units; digitizing the combined RF signal; and transmitting the digitized combined RF signal to the base station..Iaddend.
.Iadd.21. A method of transmitting cellular telephone transmissions between a base station and a mobile unit, the method comprising: generating a digitized representation of a first RF signal at the base station, wherein the first RF signal isa combined analog signal representing all outbound cellular telephone transmissions for a set of channels used by a cell remote from the base station; transmitting the digitized representation to the cell; generating a second RF signal from thedigitized representation of the first RF signal at the cell; and broadcasting the second RF signal to the mobile unit..Iaddend.
.Iadd.22. A method of transmitting RF signals between a base station and a plurality of mobile units, the method comprising: generating a set of RF analog modulated channel carriers representing outbound RF signals, wherein each RF analogmodulated channel carrier corresponds, in a one-to-one relationship, to a channel in a set of channels used by a remote unit; combining the set of RF analog modulated channel carriers into a first combined RF signal, wherein the first combined RF signalrepresents outbound RF signals; generating a digitized representation of the first combined RF signal at the base station; transmitting the digitized representation to the remote unit; generating a second RF signal from the digitized representation ofthe first RF signal at the remote unit; and broadcasting the second RF signal to the plurality of mobile units..Iaddend.
.Iadd.23. A method of transmitting RF signals between a base station and a plurality of mobile units, the method comprising: receiving a plurality of outbound input signals from a network, wherein the plurality of outbound input signalscorrespond to a set of channels used by a remote unit; generating an RF analog outbound channel carrier for each channel in the set of channels used by the remote unit; analog modulating each of the plurality of outbound input signals onto acorresponding one of the RF analog outbound channel carriers, thereby generating a plurality of RF analog modulated channel carriers; combining the plurality of RF analog modulated channel carriers into a first combined RF signal; generating adigitized representation of the first combined RF signal at the base station; transmitting the digitized representation to the remote unit; generating a second combined RF signal from the digitized representation of the first combined RF signal at theremote unit; and broadcasting the second combined RF signal from the remote unit to the plurality of mobile units..Iaddend.
.Iadd.24. A first communication device for communicating with a second communication device in a wireless communications system over a communication medium, the first communication device comprising: a digital unit that outputs a digitalrepresentation of an analog signal, the analog signal comprising a single signal that includes a plurality of RF channels, the plurality of RF channels including at least one of information being transmitted to a plurality of remote wirelesscommunication units and information being transmitted from the plurality of remote wireless communication units; wherein the first communication device transmits a transmission signal over the communication medium to the second communication device; wherein the transmission signal includes the digital representation; and wherein the second communication device is physically remote from the first device..Iaddend.
.Iadd.25. The first communication device of claim 24 wherein the first communication device is an antenna unit in a wireless telephone communication system and the second communication device is located at a base station..Iaddend.
.Iadd.26. The first communication device of claim 25 wherein the first communication device includes an antenna for receiving wireless RF telephone transmissions from mobile units located in a cell associated with the antenna unit..Iaddend.
.Iadd.27. The first communication device of claim 25 wherein the digital unit is a broadband digitizer..Iaddend.
.Iadd.28. The first communication device of claim 25 wherein the transmission signal includes one of control data and error checking data..Iaddend.
.Iadd.29. The first communication device of claim 25 wherein the digital representation comprises a first digital representation and wherein the transmission signal further includes a second digital representation that has been multiplexed withthe first digital representation..Iaddend.
.Iadd.30. The first communication device of claim 29 wherein the second digital representation is a diversity signal..Iaddend.
.Iadd.31. The first communication device of claim 29 wherein the second digital representation is a representation of at least a portion of a radio frequency spectrum, the portion comprising a plurality of channels..Iaddend.
.Iadd.32. The first communication device of claim 25 wherein the transmission signal includes at least one of control data and error checking data..Iaddend.
.Iadd.33. The first communication device of claim 25 wherein the digital representation is a first digital representation and wherein the transmission signal includes a second digital representation multiplexed with the first digitalrepresentation..Iaddend.
.Iadd.34. The first communication device of claim 33 wherein the second digital representation is a diversity signal..Iaddend.
.Iadd.35. The first communication device of claim 24 wherein the first communication device is located at a base station and the second communication device is an antenna unit in a wireless telephone communication system..Iaddend.
.Iadd.36. The first communication device of claim 35 wherein the transmission signal includes one of control data and error checking data..Iaddend.
.Iadd.37. The first communication device of claim 35 wherein the digital unit is a broadband digitizer..Iaddend.
.Iadd.38. The first communication device of claim 35 wherein the transmission signal includes at least one of control data and error checking data..Iaddend.
.Iadd.39. The first communication device of claim 24, wherein the communication medium includes an optical fiber..Iaddend.
.Iadd.40. The first communication device of claim 39 further comprising a transmitter and wherein the optical fiber couples the transmitter to the second communication device..Iaddend.
.Iadd.41. The first communication device of claim 24, wherein the first communication device includes a digitally modulated laser..Iaddend.
.Iadd.42. In a wireless communication system, a method of transmitting communications between a first communication device and a second communication device, the first communication device comprising an antenna unit associated with a cell, thesecond communication device remotely located from the first communication device, the method comprising: receiving at the second communication device a composite analog signal that as a single composite signal includes a plurality of RF channels; digitizing the composition analog signal into a digitized signal representing the plurality of RF channels; transmitting the digitized signal over a communication medium from the second communication device to the first communication device..Iaddend.
.Iadd.43. The method of claim 42 wherein the second communication device is located at a base station..Iaddend.
.Iadd.44. The method of claim 43 wherein the receiving is performed at the base station..Iaddend.
.Iadd.45. The method of claim 43 wherein the digitized signal comprises a first digitized signal and wherein the method further comprises transmitting a second digitized signal over the communications medium from the first communication deviceto the second communication device..Iaddend.
.Iadd.46. The method of claim 45 further comprising combining at the base station a plurality of separate analog outbound telephone signals into the composite analog signal..Iaddend.
.Iadd.47. The method of claim 46 wherein the second digitized signal represents a broadband digitization of a composite analog signal that includes a plurality of RF channels..Iaddend.
.Iadd.48. The method of claim 42 further comprising, after transmitting, reconstructing the composite analog signal from the digitized signal at the first communication device..Iaddend.
.Iadd.49. The method of claim 48 further comprising broadcasting the reconstructed composite analog signal into the cell..Iaddend.
.Iadd.50. The method of claim 42 wherein the communications medium is optical fiber..Iaddend.
.Iadd.51. In a wireless communication system, a method of transmitting communications between a first communication device and a second communication device, the first communication device comprising an antenna unit associated with a cell, thesecond communication device remotely located from the first communication device, the method comprising: receiving at the first communication device a composite analog signal that as a single composite signal includes a plurality of RF channels; digitizing the composite analog signal into a digitized signal representing the plurality of RF channels; transmitting the digitized signal over a communication medium from the first communication device to the second communication device..Iaddend.
.Iadd.52. The method of claim 51 wherein the second communication device is located at a base station..Iaddend.
.Iadd.53. The method of claim 52 wherein the receiving is performed by an antenna at the first communication device receiving a plurality of wireless RF transmissions from telephones located in the cell..Iaddend.
.Iadd.54. The method of claim 52 further comprising reconstructing the composite analog signal from the digitized signal at the base station after transmitting..Iaddend.
.Iadd.55. The method of claim 54 further comprising separating individual channels out of the composite analog signal after reconstructing the composite analog signal from the digitized signal..Iaddend.
.Iadd.56. The method of claim 52 wherein the digitized signal comprises a first digitized signal and wherein the method further comprises transmitting a second digitized signal over the communications medium the second digitized signal beingtransmitted from the second communication device to the first communication device..Iaddend.
.Iadd.57. The method of claim 56 further comprising combining at the base station a plurality of separate analog outbound telephone signals into a composite analog signal, and digitizing the composite analog signal as a single signal to formthe second digitized signal..Iaddend.
.Iadd.58. The method of claim 57 wherein at least one of control data and error checking data is transmitted over the communication medium with the second digitized signal..Iaddend.
.Iadd.59. The method of claim 51 further comprising reconstructing the composite analog signal from the digitized signal after transmitting the digitized signal over the communication medium..Iaddend.
.Iadd.60. The method of claim 51 wherein the communications are mobile telephone transmissions..Iaddend.
.Iadd.61. The method of claim 51 wherein at least one of control data and error checking data is transmitted over the communication medium with the digitized signal..Iaddend.
.Iadd.62. The method of claim 51 further comprising multiplexing the digitized signal with another digital signal prior to transmitting the digitized signal over the communication medium..Iaddend.
.Iadd.63. The method of claim 62 wherein the another digitized signal is a diversity signal..Iaddend.
.Iadd.64. A wireless communications system in communication with an antenna that receives wireless radio frequency signals from wireless units over a plurality of channels within a frequency band, wherein the antenna outputs an analog radiofrequency signal including the frequency band, the system comprising: a first unit in communication with a second unit using at least one communication medium, the first unit including: a broadband digitizer unit, in communication with the antenna, thatoutputs a digitized stream that includes a digitized representation of the frequency band of the analog radio frequency signal, wherein the frequency band includes the plurality of channels; and wherein the digitizer unit applies a transmission signalto the at least one communication medium for transmission to the second unit, wherein the transmission signal is at least in part derived from the digitized stream; and wherein the second unit includes a digital unit that receives the transmissionsignal from the communication medium and generates a reconstructed analog radio frequency signal including the frequency band, the reconstructed analog radio frequency signal being derived from the transmission signal received by the second digitalunit..Iaddend.
.Iadd.65. The system of claim 64 wherein the wireless radio frequency signals include transmissions from mobile telephones located in a cell associated with the first unit..Iaddend.
.Iadd.66. The system of claim 64 wherein the transmission signal includes at least one of control data and error checking data..Iaddend.
.Iadd.67. The system of claim 64 wherein the communications medium is optical fiber..Iaddend.
.Iadd.68. The system of claim 64 wherein the transmission signal is a digitally multiplexed signal..Iaddend.
.Iadd.69. The system of claim 68 wherein the digital representation output by the broadband digitizer is a first digital representation and wherein the transmission signal includes a diversity digital representation of the frequency banddigitally multiplexed with the first digital representation..Iaddend.
.Iadd.70. The system of claim 64 wherein the wireless communications are mobile telephone signals..Iaddend. |
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