Method and system for cellular communication with centralized control and signal processing

• US 6,016,426 A
• Filed: 10/10/1996
• Issued: 01/18/2000
• Est. Priority Date: 10/10/1996
• Status: Expired due to Term

• Current Assignee: MVS, Inc. (Magna International Incorporated)
• Original Assignee: MVS, Inc. (Magna International Incorporated)
• Inventors: Bodell, Donald H.
• Primary Examiner(s): Bost, Dwayne D.
• Assistant Examiner(s): WYCHE, MYRON
• Application Number:
  US08/729,005
• Time in Patent Office: 1,195 Days
• Field of Search: 379/56.1, 379/56.2, 455/422, 455/426, 455/555, 455/560, 455/561, 359/123, 359/124, 359/145, 359/151, 359/152
• US Class Current: 455/422.1
• CPC Class Codes: H04B 10/25759 Details of the reception of RF signal or the optical conversion before the optical fibre
• CPC Class Codes: H04W 88/085 Access point devices with remote components

Abstract

A cellular system includes wide band digital signal processing at a central office that is connected to one or more cellular sites by optical fiber cables. Data signals are exchanged between the cell sites and the central office using intensity modulated optical data signals. Control of call supervision and handling is consolidated in the central office to enable dynamic variation of wireless service reception and transmission capabilities at a cell site in response to changing demands for wireless service. Each antenna at a cell site may receive and transmit an assigned RF bandwidth using any frequency within that band. The central office processes the entire received spectrum for controlling detection and transmitting range, RF carrier frequency and transmit power level for an active channel link established between a cellular station and the system in a cell site.

Claims

1. A cellular communication system comprising:

radio frequency (RF) receiving and transmitting apparatus at a cell site, said apparatus comprising;

a radio frequency energy receiver for receiving radio frequency energy at frequencies within a predetermined range of radio frequencies and modulated by first data signals, wherein the received RF energy has a first spectral occupancy; and

a radio frequency energy transmitter for transmitting radio frequency energy at frequencies within a predetermined range of frequencies and modulated by second data signals, wherein the transmitted RF energy has a second spectral occupancy;

said cell site comprising;

downconverting means coupled to said receiver for converting the modulated radio frequency energy received by said receiver to intermediate frequency energy modulated by said first data signals and having a frequency lower than said predetermined range of frequencies of energy received by said receiver, wherein the intermediate frequency energy has the first spectral occupancy;

frequency modulating means coupled to said downconverting means for converting said downconverted energy modulated by said first data signals to first frequency modulated signals;

a first optical signal transmitter coupled to said frequency modulating means for transmitting optical signals modulated by said first frequency modulated signals;

a first optical signal receiver for converting optical signals into first electrical signals, wherein said electrical signals have the second spectral occupancy; and

upconverting means coupled to said first optical signal receiver for converting said first electrical signals into radio frequency energy at frequencies in said predetermined range of frequencies at which said transmitter transmits modulated radio frequency energy, said radio frequency energy transmitter being coupled to said upconverting means for transmitting the radio frequency energy into which said upconverter converts said first electrical signals;

a telephone switching office comprising;

a second optical signal receiver for converting the optical signals into second electrical signals;

frequency discriminating means coupled to said second optical signal receiver for frequency demodulating said second electrical signals;

switching and control means coupled to said frequency discriminating means for providing output signals corresponding to said frequency demodulated second electrical signals, said switching and control means also being connectable to a source of data signals for providing second data signals; and

a second optical signal transmitter coupled to said switching and control means for transmitting analogically m odulated optical signals corresponding to said second d ata signals; and

at least one optical fiber interconnecting said first optical signal transmitter with said second optical signal receiver and interconnecting said second output signal transmitter with said first optical signal receiver.

2. The communication system of claim 1,

wherein said switching and control means further comprises means for processing said second electrical signals for determining RF power levels of said RF energy modulated by the first data signals.

3. The communication system of claim 1,

wherein said switching and control means further comprises means for processing said output signals corresponding to said second electrical signals according to at least one selected wireless protocol.

4. The communication system of claim 1,

wherein said RF energy receiver further comprises a plurality of receiving means for receiving said RF energy modulated by said first data signals, and

wherein said switching and control means further comprises a modem and means for selecting the receiving means from which the corresponding output signals are processed at the modem.

5. The communication system of claim 1,

wherein said RF energy transmitter further comprises a plurality of transmitting means for transmitting RF energy modulated by second data signals, and

wherein said switching and control means further comprises means for selecting the transmitting means from which upconverted second electrical signals corresponding to said second data signals are transmitted.

6. The communication system of claim 1,

wherein said switching and control means further comprises means for controlling power levels at which the RF energy transmitter transmits said RF energy into which said upconverter converts said first electrical signals.

7. The communication system of claim 1,

wherein said switching and control means further comprises means for controlling a frequency at which the RF energy transmitter transmits said RF energy into which said upconverter converts said first electrical signals.

26. The cellular communication system of claim 1,

wherein the office comprises frequency modulating means coupled to the switching and control means and to the second optical signal transmitter for frequency modulating the second data signals;

and

wherein the cell site further comprises a frequency discriminator coupled to the optical signal receiver for frequency demodulating the first electrical signals and wherein the upconverting means is coupled to the frequency discriminator for converting the frequency demodulated first electrical signals into radio frequency energy at frequencies within said predetermined range of frequencies at which the radio frequency transmitter transmits modulated radio frequency energy.

8. A cellular communication system comprising:

radio frequency receiving apparatus at a cell site, said apparatus comprising;

a radio frequency energy receiver for receiving radio frequency (RF) energy at frequencies within a predetermined range of radio frequencies and modulated by data signals, wherein the RF energy has a predetermined spectral occupancy;

downconverting means coupled to said radio frequency receiver for converting the data signal modulated RF energy received by said radio frequency receiver to energy modulated by said data signals having a frequency lower than said predetermined range of frequencies of energy received by said radio frequency receiver, wherein the lower frequency energy has a spectral occupancy which is the same as the predetermined spectral occupancy; and

an optical signal transmitter coupled to said downconverting means for transmitting optical signals modulated by said energy modulated by said data signals having a frequency lower than said predetermined range of frequencies of energy received by said radio frequency receiver;

a telephone switching office comprising;

an optical signal receiver for converting the optical signals into electrical signals;

an analog to digital converter (ADC) coupled to the optical receiver, wherein the ADC digitizes the electrical signals; and

switching and control means coupled to said ADC for providing output signals corresponding to said digitized electrical signals; and

at least one optical fiber interconnecting said optical signal transmitter with said optical signal receiver.

28. The system of claim 8, wherein the office further comprises a channelizer coupled to the ADC, to the switching and control means and to a digital distributor, wherein the channelizer segments the digitized electronic signals into spectral bands and wherein the digital distributor is coupled to the switching and control means, includes at least one output and selectively routes the segmented digitized electrical signals to the at least one distributor output according to spectral band.

9. A cellular communication system comprising:

a telephone switching office comprising;

switching and control means for providing data signals;

a synthesizer coupled to the switching and control means for providing a digital representation of a composite envelope of the data signals;

a digital to analog converter ("DAC") coupled to the digital synthesizer, wherein the DAC converts the digital representation of the data signals to analog form; and

an optical signal transmitter coupled to said DAC for transmitting optical signals analogically modulated by said data signals as converted by the DAC;

radio frequency transmitting apparatus at a cell site, said apparatus comprising;

an optical signal receiver for converting optical signals into electrical signals, wherein said electrical signals have a predetermined spectral occupancy;

upconverting means coupled to said optical signal receiver for converting said electrical signals into radio frequency energy at frequencies in a predetermined range of frequencies, wherein the radio frequency energy has a spectral occupancy which is the same as the predetermined spectral occupancy; and

a radio frequency energy transmitter coupled to said upconverting means for transmitting the radio frequency energy into which said upconverter converts said electrical signals, wherein said transmitted radio frequency energy is at the frequencies within the predetermined range of radio frequencies at which said transmitter transmits modulated radio frequency energy; and

at least one optical fiber interconnecting said optical signal transmitter with said optical signal receiver.

29. The system of claim 9, wherein the office further comprises a digital distributor coupled to the synthesizer and to the switching and control means, wherein the distributor segments the data signals according to spectral band.

10. A cellular communication system comprising:

at least one cell site comprising a radio frequency receiving and transmitting apparatus, the radio frequency receiving and transmitting apparatus comprising;

at least one radio frequency energy receiver for receiving radio frequency (RF) energy at frequencies within a predetermined range of radio frequencies and modulated by first data signals;

a first optical signal transmitter coupled to the radio frequency receiver for transmitting optical signals analogically modulated by the first data signals;

at least one radio frequency energy transmitter for transmitting radio frequency energy at frequencies within a predetermined range of radio frequencies and modulated by first electrical signals; and

a first optical signal receiver coupled to the radio frequency transmitter for converting optical signals analogically modulated by second data signals into the first electrical signals;

a central telephone switching office comprising;

a second optical signal receiver for converting the optical signals modulated by the first data signals into second electrical signals;

a second optical signal transmitter for transmitting the optical signals modulated by the second data signals;

switching and control means coupled to the second optical signal receiver and to the second optical signal transmitter for providing the second data signals, for processing the second electrical signals corresponding to the radio frequency energy modulated by the first data signals received at the at least one RF energy receiver of the at least one cell site and for processing the second data signals corresponding to the radio frequency energy into which the at least one RF energy transmitter of the at least one cell site converts the first electrical signals;

an analog to digital converter (ADC) coupled to the second optical receiver and to the switching and control means, wherein the ADC digitizes the second electrical signals; and

a digital distributor coupled to a synthesizer and to the switching and control means, wherein the distributor segments the second data signals according to spectral band; and

at least one optical fiber interconnecting the first optical signal transmitter with the second optical signal receiver and the first optical receiver with the second optical signal transmitter.

11. The communication system of claim 10, wherein the switching and control means processes the second electrical signals corresponding to the radio frequency energy modulated by the first data signals received at a selected one of the at least one RF energy receivers of the least one cell site according to at least one selected wireless protocol.

12. The communication system of claim 10, wherein the switching and control means selects one of the at least one RF receivers of the at least one cell site from which the corresponding second electrical signals are processed.

13. The communication system of claim 10, wherein the switching and control means processes the second electrical signals for determining RF power levels of the RF energy modulated by the first data signals.

14. The communication system of claim 10, wherein the switching and control means selects one of the at least one RF energy transmitters of the at least one cell site from which the first electrical signals corresponding to the second data signals are transmitted.

15. The communication system of claim 10,

wherein the switching and control means controls power levels at which the at least one RF energy transmitter of the least one cell site transmits the RF energy into which the first electrical signals are converted.

16. The communication system of claim 10, wherein the switching and control means controls a frequency at which the at least one RF energy transmitter of the at least one cell site transmits the RF energy into which the first electrical signals are converted.

17. A cellular communication system comprising:

radio frequency receiving apparatus at a cell site, said apparatus comprising;

a radio frequency energy receiver for receiving radio frequency (RF) energy at frequencies within a predetermined range of radio frequencies and modulated by data signals;

downconverting means coupled to said radio frequency receiver for converting the data signal modulated RF energy received by said radio frequency receiver to energy modulated by said data signals having a frequency lower than said predetermined range of frequencies of energy received by said radio frequency receiver; and

an optical signal transmitter coupled to said downconverting means, wherein said optical signal transmitter transmits optical signals modulated by said energy modulated by said data signals having a frequency lower than said predetermined range of frequencies of energy received by said radio frequency receiver;

wherein said cell site further comprises frequency modulating means coupled to said downconverting means for converting said downconverted energy modulated by said data signals to frequency modulated signals;

wherein said optical signal transmitter is coupled to said frequency modulating means for transmitting optical signals modulated by said frequency modulated signals;

a telephone switching office comprising;

an optical signal receiver for converting the optical signals into electrical signals,

switching and control means coupled to said optical signal receiver for providing output signals corresponding to said electrical signals, and

frequency discriminating means coupled to said optical signal receiver for frequency demodulating said electrical signals; and

at least one optical fiber interconnecting said optical signal transmitter with said optical signal receiver.

18. A cellular communication system comprising:

radio frequency (RF) receiving and transmitting apparatus at a cell site, said apparatus comprising;

a radio frequency energy receiver for receiving radio frequency energy at frequencies within a predetermined range of radio frequencies and modulated by first data signals, and

a radio frequency energy transmitter for transmitting radio frequency energy at frequencies within a predetermined range of frequencies and modulated by second data signals;

said cell site comprising;

downconverting means coupled to said receiver for converting the modulated radio frequency energy received by said receiver to intermediate frequency energy modulated by said first data signals and having a frequency lower than said predetermined range of frequencies of energy received by said receiver;

a first optical signal transmitter coupled to said downconverting means for transmitting optical signals modulated by said intermediate frequency energy;

a first optical signal receiver for converting optical signals into first electrical signals;

upconverting means coupled to said first optical signal receiver for converting said first electrical signals into radio frequency energy at frequencies in said predetermined range of frequencies at which said transmitter transmits modulated radio frequency energy, said radio frequency energy transmitter being coupled to said upconverting means for transmitting the radio frequency energy into which said upconverter converts said first electrical signals; and

frequency modulating means coupled to said downconverting means for converting said downconverted energy modulated by said first data signals to first frequency modulated signals, wherein said first optical signal transmitter is coupled to said frequency modulating means for transmitting optical signals modulated by said first frequency modulated signals;

a telephone switching office comprising;

a second optical signal receiver for converting optical signals into second electrical signals;

switching and control means coupled to said second optical signal receiver for providing output signals corresponding to said second electrical signals, said switching and control means also being connectable to a source of data signals for providing the second data signals;

a second optical signal transmitter coupled to said switching and control means for transmitting analogically modulated optical signals corresponding to said second data signals; and

frequency discriminating means coupled to said second optical signal receiver for frequency demodulating said second electrical signals; and

at least one optical fiber interconnecting said first optical signal transmitter with said second optical signal receiver and interconnecting said second optical signal transmitter with said first optical signal receiver.

19. A cellular communication system comprising:

a telephone switching office comprising;

switching and control means for providing data signals;

an optical signal transmitter coupled to said switching and control means for transmitting optical signals analogically modulated by said data signals; and

frequency modulating means coupled to the switching and control means and to the optical signal transmitter for frequency modulating the data signals;

radio frequency transmitting apparatus at a cell site, said apparatus comprising;

an optical signal receiver for converting optical signals into electrical signals;

upconverting means coupled to said optical signal receiver for converting said electrical signals into radio frequency energy at frequencies in a predetermined range of frequencies;

a radio frequency energy transmitter coupled to said upconverting means for transmitting the radio frequency energy into which said upconverter converts said electrical signals, wherein said transmitted radio frequency energy is at the frequencies within the predetermined range of radio frequencies at which said transmitter transmits modulated radio frequency energy; and

a frequency discriminator coupled to the optical signal receiver for frequency demodulating the electrical signals and wherein the upconverting means is coupled to the frequency discriminator for converting the frequency demodulated electrical signals into radio frequency energy at frequencies within the predetermined range of frequencies; and

at least one optical fiber interconnecting said optical signal transmitter with said optical signal receiver.

20. A cellular communication system comprising:

radio frequency (RF) receiving and transmitting apparatus at a cell site, said apparatus comprising;

a radio frequency energy receiver for receiving radio frequency energy at frequencies within a predetermined range of radio frequencies and modulated by first data signals, and

a radio frequency energy transmitter for transmitting radio frequency energy at frequencies within a predetermined range of frequencies and modulated by second data signals;

said cell site comprising;

downconverting means coupled to said receiver for converting the modulated radio frequency energy received by said receiver to intermediate frequency energy modulated by said first data signals and having a frequency lower than said predetermined range of frequencies of energy received by said receiver;

a first optical signal transmitter coupled to said downconverting means for transmitting optical signals modulated by said intermediate frequency energy;

a first optical signal receiver for converting optical signals into first electrical signals;

upconverting means coupled to said first optical signal receiver for converting said first electrical signals into radio frequency energy at frequencies in said predetermined range of frequencies at which said transmitter transmits modulated radio frequency energy, said radio frequency energy transmitter being coupled to said upconverting means for transmitting the radio frequency energy into which said upconverter converts said first electrical signals; and

a frequency discriminator coupled to the optical signal receiver for frequency demodulating the first electrical signals and wherein the upconverting means is coupled to the frequency discriminator for converting the frequency demodulated first electrical signals into radio frequency energy at frequencies within said predetermined range of frequencies at which the radio frequency transmitter transmits modulated radio frequency energy;

a telephone switching office comprising;

a second optical signal receiver for converting optical signals into second electrical signals;

switching and control means coupled to said second optical signal receiver for providing output signals corresponding to said second electrical signals, said switching and control means also being connectable to a source of data signals for providing the second data signals;

a second optical signal transmitter coupled to said switching and control means for transmitting analogically modulated optical signals corresponding to said second data signals; and

frequency modulating means coupled to the switching and control means and to the second optical signal transmitter for frequency modulating the second data signals; and

at least one optical fiber interconnecting said first optical signal transmitter with said second optical signal receiver and interconnecting said second optical signal transmitter with said first optical signal receiver.

21. A cellular communication system comprising:

radio frequency receiving apparatus at a cell site, said apparatus comprising;

a radio frequency energy receiver for receiving radio frequency (RF) energy at frequencies within a predetermined range of radio frequencies and modulated by data signals;

downconverting means coupled to said radio frequency receiver for converting the data signal modulated RF energy received by said radio frequency receiver to energy modulated by said data signals having a frequency lower than said predetermined range of frequencies of energy received by said radio frequency receiver; and

an optical signal transmitter coupled to said downconverting means, wherein said optical signal transmitter transmits optical signals modulated by said energy modulated by said data signals having a frequency lower than said predetermined range of frequencies of energy received by said radio frequency receiver;

a telephone switching office comprising;

an optical signal receiver for converting the optical signals into electrical signals;

switching and control means coupled to said optical signal receiver for providing output signals corresponding to said electrical signals; and

an analog to digital converter (ADC) coupled to the optical receiver and to the switching and control means, wherein the ADC digitizes the electrical signals; and

at least one optical fiber interconnecting said optical signal transmitter with said optical signal receiver.

22. The system of claim 21, wherein the office further comprises a channelizer coupled to the ADC, to the switching and control means and to a digital distributor, wherein the channelizer segments the digitized electronic signals into spectral bands and wherein the digital distributor is coupled to the switching and control means, includes at least one output and selectively routes the segmented digitized electrical signals to the at least one distributor output according to spectral band.

23. A cellular communication system comprising:

a telephone switching office comprising;

switching and control means for providing data signals; and

an optical signal transmitter coupled to said switching and control means for transmitting optical signals analogically modulated by said data signals;

radio frequency transmitting apparatus at a cell site, said apparatus comprising;

an optical signal receiver for converting optical signals into electrical signals;

upconverting means coupled to said optical signal receiver for converting said electrical signals into radio frequency energy at frequencies in a predetermined range of frequencies,

a radio frequency energy transmitter coupled to said upconverting means for transmitting the radio frequency energy into which said upconverter converts said electrical signals, wherein said transmitted radio frequency energy is at the frequencies within the predetermined range of radio frequencies at which said transmitter transmits modulated radio frequency energy; and

a digital to analog converter ("DAC") coupled to the optical signal transmitter, to the switching and control means and to a digital synthesizer, wherein the synthesizer is coupled to the switching and control means and provides a digital representation of a composite envelope of the data signals, wherein the DAC converts the digital representation of the data signals to analog form and wherein the optical signal transmitter transmits optical signals modulated by the data signals as converted by the DAC; and

at least one optical fiber interconnecting said optical signal transmitter with said optical signal receiver.

24. The system of claim 23, wherein the office further comprises a digital distributor coupled to the synthesizer and to the switching and control means, wherein the distributor segments the data signals according to spectral band.

25. A cellular communication system comprising:

radio frequency receiving apparatus at a cell site, said apparatus comprising;

a radio frequency energy receiver for receiving radio frequency (RF) energy at frequencies within a predetermined range of radio frequencies and modulated by data signals, wherein the RF energy has a predetermined spectral occupancy;

downconverting means coupled to said radio frequency receiver for converting the data signal modulated RF energy received by said radio frequency receiver to energy modulated by said data signals having a frequency lower than said predetermined range of frequencies of energy received by said radio frequency receiver, wherein the lower frequency energy has a spectral occupancy which is the same as the predetermined spectral occupancy;

frequency modulating means coupled to said downconverting means for converting said downconverted energy modulated by said data signals to frequency modulated signals;

an optical signal transmitter coupled to said frequency modulating means for transmitting optical signals modulated by said frequency modulated signals, wherein the frequency modulated signals are modulated by said data signals and have a frequency lower than said predetermined range of frequencies of energy received by said radio frequency receiver;

a telephone switching office comprising;

an optical signal receiver for converting the optical signals into electrical signals;

frequency discriminating means coupled to said optical signal receiver for frequency demodulating said electrical signals; and

switching and control means coupled to said frequency discriminating means for providing output signals corresponding to said frequency demodulated electrical signals; and

at least one optical fiber interconnecting said optical signal transmitter with said optical signal receiver.

27. A cellular communication system comprising:

a telephone switching office comprising;

switching and control means for providing data signals;

frequency modulating means coupled to the switching control means for frequency modulating the data signals; and

an optical signal transmitter coupled to said frequency modulating means for transmitting optical signals analogically modulated by said frequency modulated data signals;

radio frequency transmitting apparatus at a cell site, said apparatus comprising;

an optical signal receiver for converting optical signals into electrical signals, wherein said electrical signals have a predetermined spectral occupancy;

a frequency discriminator coupled to the optical signal receiver for frequency demodulating the electrical signals;

upconverting means coupled to said frequency discriminator for converting the frequency demodulated electrical signals into radio frequency energy at frequencies in a predetermined range of frequencies, wherein the radio frequency energy has a spectral occupancy which is the same as the predetermined spectral occupancy; and

a radio frequency energy transmitter coupled to said upconverting means for transmitting the radio frequency energy into which said upconverter converts said electrical signals, wherein said transmitted radio frequency energy is at the frequencies within the predetermined range of radio frequencies at which said transmitter transmits modulated radio frequency energy; and

at least one optical fiber interconnecting said optical signal transmitter with said optical signal receiver.