System and method for frequency multiplexing antenna signals

• US 5,859,854 A
• Filed: 08/28/1995
• Issued: 01/12/1999
• Est. Priority Date: 08/28/1995
• Status: Expired due to Term

• Current Assignee: Kathrein-Werke KG. (Kathrein SE)
• Original Assignee: Metawave Communications Corp.
• Inventors: Reudink, Douglas O.
• Primary Examiner(s): Kizou, Hassan
• Assistant Examiner(s): HOM, SHICK C
• Application Number:
  US08/520,000
• Time in Patent Office: 1,233 Days
• Field of Search: 370/277, 370/281, 370/343, 370/344, 370/480, 370/481, 370/307, 370/335, 370/342, 455/103, 455/118, 455/132, 455/272, 455/273, 455/275, 455/277.1, 455/277.2, 455/303, 455/340, 455/562, 455/436, 455/449, 359/124, 359/125, 375/295, 375/350, 348/10, 348/12, 348/7, 348/6, 376/465, 376/486
• US Class Current: 370/480
• CPC Class Codes: H04J 1/08 Arrangements for combining channels branching filters H01P1/213, H03H7/46

Abstract

There is disclosed an antenna system and method of operation which allows for a large number of antennas to transmit signal streams to a similarly large number of receiver/transmit ports over a single communication channel. In operation, there is created a plurality of frequency bands each identified with a particular one of the antennas. The signal streams from each antenna are mixed so that they fall within the frequency band assigned to that antenna. The reduced signal streams, which now all fall within a preselected frequency band for each antenna, are then combined into a single wide band signal stream and communicated over a single communication channel to the remote end where the signals are separated into their respective signal streams and the separated signal streams are then mixed to recreate the originally received frequencies. The system can be arranged such that a selection process allows multiple radios to connect to any channel of any antenna.

Claims

1. An antenna system for delivering signals received on a plurality of antennas to a plurality of associated receivers, said system comprising:

means for establishing a plurality of specific frequency bands, each said frequency band separated from the next by a preset margin, each one of said frequency bands assigned to a unique one of said antennas;

means for processing the signal stream received from each said antenna such that said received signal stream falls within said frequency band assigned to said antenna, wherein a processed received signal stream associated with a first said antenna and a processed received signal stream associated with a second said antenna include a same signal;

means for combining all processed signal streams into a signal stream for delivery to said receivers over a communication channel thereby providing a delivered communication channel signal stream; and

means for separating said delivered communication channel signal stream into individual signal streams corresponding to ones of said signal streams received from said antennas, each said individual signal stream for delivery to at least one of said receivers, wherein said separating means provides said delivered communication channel signal stream for selection of any one of said signal streams received from said antenna at any one of said plurality of associated receivers.

2. The invention set forth in claim 1 wherein said communication channel includes a coaxial cable.

3. The invention set forth in claim 1 wherein said communication channel includes a Fiber Optic Link.

4. The invention set forth in claim 1 wherein at least one of said receivers includes multiple diversity inputs from at least two antennas, wherein said separating means provides a signal stream received from said first antenna including said same signal to a first one of said multiple diversity inputs and a signal stream received from said second antenna including said same signal to a second one of said multiple diversity inputs.

5. The invention set forth in claim 1 wherein said communication channel includes a radio link.

6. The invention set forth in claim 1 wherein each said frequency band is approximately 15 MHz.

7. The invention set forth in claim 6 wherein said preset interband margin is approximately 5 MHz.

8. The invention set forth in claim 1 wherein the total bandwidth of said communication channel is N(B+M), where N is the number of antennas, B is the width of each said frequency band and M is the width of each said interband margin.

9. The invention set forth in claim 8 where the bandwidth of each antenna is W and wherein B equals approximately 3 times W.

10. The invention set forth in claim 9 wherein W is 14 MHz, B is approximately 50 MHz and M is approximately 20 MHz.

11. The invention set forth in claim 1 wherein said communication channel includes a transmission medium having a bandwidth of N(B+M), where N is the number of antennas, B is the width of each said frequency band and M is the width of each said interband margin.

12. The invention set forth in claim 1 wherein said processing means includes at least one tunable filter element.

13. The invention set forth in claim 1 wherein said separating means includes at least one tunable filter element.

14. The invention set forth in claim 1 wherein said separating means includes means for selecting certain of said signal streams prior to delivery to the respective receivers.

15. A method of delivering high frequency signals received on a plurality of discrete inputs to a remotely located plurality of associated discrete utilization ports, said method comprising the steps of:

establishing a plurality of specific frequency bands, each said frequency band separated from the next by a preset margin and each said frequency band assigned to a unique one of said inputs;

processing the signal stream received at each said discrete input such that said received signal stream falls within said frequency band assigned to said input;

combining all processed signal streams into a communication signal stream for delivery to said ports over one or more communication channels;

splitting said combined communication signal stream into a plurality of substantially identical combined communication signal streams, wherein each one of said plurality of substantially identical combined communication signal streams is associated with a particular one of said utilization ports; and

separating a select one of said received signal streams from said substantially identical combined communication signal stream associated with a particular utilization port for delivery to said particular utilization port, wherein any one of said received signal streams may be selected for delivery to said particular utilization port.

16. The method set forth in claim 15 wherein said separating step includes the step of:

adjusting a local oscillator to a frequency corresponding to a particular processed signal stream for delivery of said select received signal stream to said particular utilization port.

17. The method set forth in claim 15 wherein said separating step includes the step of:

selecting certain of the signal streams for delivery to the particular discrete utilization port.

18. The method set forth in claim 15 wherein said combining step includes the step of:

selecting certain of the signal streams for delivery to said ports.

19. The method set forth in claim 15 wherein said processing step includes the step of:

filtering the signals under control of a filter tuned to the frequency selected for an associated antenna.

20. A signal delivery system for delivering communication signals received from a plurality of sources to a plurality of utilization devices, said system comprising:

channel allocation circuitry for establishing a plurality of specific communication bands, each said communication band separated from the next by an established frequency margin, each one of said communication bands assignable to a unique one of said signal sources;

said channel allocation circuitry further operable for processing the signal stream received from each said signal source such that said received signal stream falls within said frequency band assigned to said source;

summing circuitry for combining all processed signal streams into a reduced number of signal streams for delivery to the utilization devices;

separating circuitry for expanding the processed and summed signal stream into individual signal streams, each signal stream for delivery to one of said utilization devices;

means for monitoring signals selected from the group consisting of the signal stream received from said signal sources and said processed signal streams, said monitoring means also for selecting ones of the processed signals to be expanded from the processed and summed signal stream based upon characteristics of the monitored signals;

means controlled by information received from an external source for selecting at least one of said ones of the signals to be expanded from the processed and summed signal stream based upon criteria contained within the received information; and

means for delivering the processed and summed signal streams from the summing circuitry to the separating circuitry.

21. The invention set forth in claim 20 wherein one of said characteristics is the power level of the received signals.

22. The invention set forth in claim 20 wherein the delivery means includes a high band width communication medium.

23. The invention set forth in claim 22 wherein the communication medium is fiber optics.

24. The invention set forth in claim 22 wherein the communication medium is microwave.

25. The invention set forth in claim 22 wherein the communication medium is coaxial cable.

26. The invention set forth in claim 20 wherein the signal sources are at different physical locations and wherein the processed signals from each of the locations are delivered to summing circuitry common to all of the locations.

27. A method for delivering communication signals received from a plurality of sources to a plurality of utilization devices, said method comprising the steps of:

establishing a plurality of specific communication bands, each said communication band separated from the next by an established frequency margin, each one of said communication bands assignable to a unique one of said utilization devices;

processing the signal stream received from ones of said signal sources such that the received signal stream falls within a selectable one of said communication bands;

delivering the processed signal streams by combining said processed signal streams into a reduced number of signal streams for delivery to the utilization devices; and

expanding the delivered processed and combined signal streams into individual signal streams corresponding to said processed ones of said received signal streams, each individual signal stream for delivery to the one of said utilization devices said select one of said communication bands is assigned.

28. The invention set forth in claim 27 wherein the processing step includes the steps of:

monitoring the signal sources; and

selecting which of the processed signals are to be expanded based upon characteristics of the monitored signals.

29. The invention set forth in claim 28 wherein said selecting step further includes the step of:

accepting information received from a source other than the signal strength of the associated source signals for selecting which of the signals are to be expanded.

30. The invention set forth in claim 28 wherein one of the characteristics is the power level of the received signals.

31. The invention set forth in claim 27 wherein said expanding step includes the step of:

monitoring the processed signals for selecting which of the monitored signals are to be expanded based upon characteristics of the monitored signals.

32. The invention set forth in claim 31 wherein said monitoring step further includes the step of:

receiving control signals from an external source for controlling which of the processed signals are to be expanded.

33. The invention set forth in claim 27 wherein the delivery step includes use of a high band width communication medium.

34. The invention set forth in claim 33 wherein the communication medium is fiber optics.

35. The invention set forth in claim 33 wherein the communication medium is microwave.

36. The invention set forth in claim 33 wherein the communication medium is coaxial cable.

37. The invention set forth in claim 27 wherein the signal sources are at different physical locations.

38. The method set forth in claim 37 wherein the processed signals from each of the locations are summed common to all of the locations.

39. A transmission system for delivering signals received from a plurality of radios to a plurality of associated antennas, said system comprising:

means for establishing a plurality of specific frequency bands, each said frequency band separated from the next by a preset margin, each one of said frequency bands assigned to a unique one of said radios;

means for processing the signal stream received from each said radio such that said received signal stream falls within said frequency band assigned to said radio;

means for combining all processed signal streams into a signal stream for delivery to said antennas over a communication channel;

means for separating said delivered communication channel signal stream into individual signal streams corresponding to ones of said signal streams received from said antennas, each said individual signal stream for delivery to at least one of said receivers, wherein said separating means provides said delivered communication channel signal stream for selection of any one of said signal streams received from said antenna at any one of said plurality of associated receivers; and

means at least partially controlled by information received from an external source for selecting at least one of said ones of the signals to be separated from the delivered communication channel signal stream for a particular one of said plurality of associated receivers.

40. The invention set forth in claim 39 wherein said communication channel includes a coaxial cable.

41. The invention set forth in claim 39 wherein said communication channel includes a Fiber Optic Link.

42. A method for bidirectional transmission between a plurality of antennas and a plurality of transmitters/receivers, said method comprising:

establishing a first plurality of specific frequency bands for transmission from the antennas to the transmitters/receivers;

establishing a second plurality of specific frequency bands for transmission from the transmitters/receivers to the antennas;

processing the signal streams received from the antennas and from the transmitters/receivers such that the received signal streams fall within the respective bands assigned to said antennas and to said transmitters/receivers;

combining the processed signals from the antennas into a first signal stream for delivery to said transmitters/receivers and combining the processed signals from the transmitters/receivers into a second signal stream for delivery to said antennas;

delivering both said first and said second signal streams to the respective destination of said signal stream;

splitting said first delivered signal stream into a plurality of substantially identical combined communication signal streams, wherein each one of said plurality of substantially identical combined communication signal streams is associated with a particular one of said plurality of transmitters/receivers;

separating a select one of said signal streams received from the antennas from said substantially identical combined communication signal stream associated with a particular utilization port for delivery to said particular transmitter/receiver, wherein any one of said signal streams received from the antennas may be selected for delivery to said particular transmitter/receiver; and

selecting at least under partial control of information received from an external source at least one of said ones of the signals to be delivered to said particular transmitter/receiver.

43. The invention of claim 42 wherein said delivering step includes the step of:

placing said first and said second signal streams on a common transmission media.