Multichannel radio frequency transmission system to deliver wideband digital data into independent sectorized service areas

• US 5,875,396 A
• Filed: 11/13/1995
• Issued: 02/23/1999
• Est. Priority Date: 11/13/1995
• Status: Expired due to Term

• Current Assignee: Wytec International, Inc. (Competitive Cos., Inc.)
• Original Assignee: Wytec LLC (General Patent Corporation)
• Inventors: Simons, Brent S., Stockton, G. William, Schoenduve, James H., Oatman, William D.
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): Kincaid, Lester G.
• Application Number:
  US08/556,333
• Time in Patent Office: 1,198 Days
• Field of Search: 455/33.3, 455/33.1, 455/54.1, 455/56.1, 455/103, 455/5.1, 455/4.2, 455/6.1, 455/422, 455/446, 455/450, 455/500, 455/507, 455/517, 455/524, 455/526, 455/560, 455/561 , 455/562, 455/4.1, 348/6, 348/7, 348/12, 348/13, 375/260, 370/326, 370/329, 370/336, 370/339, 370/487
• US Class Current: 455/562.1
• CPC Class Codes: H04H 20/33 by plural channels
• CPC Class Codes: H04H 20/42 Arrangements for resource management
• CPC Class Codes: H04H 20/46 specially adapted for broadcast systems covered by groups H04H20/53-H04H20/95
• CPC Class Codes: H04H 20/72 of terrestrial networks
• CPC Class Codes: H04N 7/165 Centralised control of user terminal subsequent to an upstream request signal H04N7/17345; Registering at central by two-way working H04N7/17309
• CPC Class Codes: H04N 7/20 Adaptations for transmission via a GHz frequency band, e.g. via satellite

Abstract

A one-way and two-way multichannel radio frequency transmission system and method employing a sectorized broadcasting technique is described. The system and method reduces the effective bandwidth of the broadcast signal by multiplexing available channels of signals into a set of formatted independent digital bitstreams--where each of the bitstreams includes all or a portion of the available channels provided by the system program provider. The independent bitstreams are transmitted to transmitting towers using point-to-point transmission methods. The transmitting towers phase modulate and amplify the bitstreams to generate a set of independent modulated signals. Each transmitter tower includes an antenna for broadcasting the modulated signals to a sectorized service area--each sector in the service area receiving a different one of the set of independent modulated signals. The antenna includes a set of individual antenna panels--each panel for broadcasting one of the set of modulated signals. Each subscriber site demodulates, demultiplexes and selects one channel from the received modulated signal. Each transmitting tower broadcasts all of the independent modulated signals at one of a set of operating frequencies such that adjacent transmitting towers broadcast at different operating frequencies. In addition, adjacent antenna panels of a given antenna transmit at opposite transmission polarity.

Claims

1. In a wireless transmission system including a provider subsystem for providing a plurality of channels of signals, a transmission subsystem for transmitting channels of modulated signals in a wireless manner to a plurality of service areas, and a receiving subsystem for receiving said modulated channel signals, said transmission system comprising:

a means for generating from said plurality of channels a plurality of continuous modulated signals which are independent of each other, each of said independent signals representing a selectable combination of said plurality of channels, and for providing said plurality of independent signals to each of a plurality of antennas;

each of said antennas including a plurality of individual antenna sections, wherein each of said antenna sections transmits one of said independent signals whereby said independent signals are sectorially transmitted from said each antenna.

2. The transmission system as described in claim 1 wherein each of said independent signals represents different selectable combinations of said plurality of channels of signals.

3. The transmission system as described in claim 1 wherein at least two of said independent signals represent the same selectable combinations of said plurality of channels of signals.

4. The transmission system as described in claims 2 or 3 wherein said individual antenna sections are arranged in a multifaced polygonal cylindrical configuration.

5. The transmission system as described in claim 4 wherein said each antenna section has an associated transmission polarity and adjacent antenna sections have opposite associated transmission polarities.

6. The transmission system as described in claim 5 wherein said multifaced polygonal cylindrical configuration includes six of said antenna sections and wherein said each section transmits a 60°

azimuth of said one of said modulated signals.

7. The transmission system as described in claim 5 wherein said multifaced polygonal cylindrical configuration includes eight of said antenna sections and wherein said each section transmits a 45°

azimuth of said one of said modulated signals.

8. The transmission system as described in claim 7 wherein said antenna sections are horn-type antennas.

9. The transmission system as described in claim 7 wherein said antenna sections are dish-type antennas.

10. In a wireless transmission system including a provider subsystem for providing a plurality of channels of signals, a transmission subsystem including a plurality of antennas for transmitting channels of modulated signals in a wireless manner to a plurality of service areas, and a receiving subsystem for receiving said modulated channel signals, each of said antennas having an associated service area, a method comprising the steps of:

generating from said plurality of channels a plurality of continuous modulated signals which are independent of each other, each of said independent signals representing a selectable combination of said plurality of channels, and for providing said plurality of independent signals to each of a plurality of antennas;

providing said plurality of independent signals to each of a plurality of transmitting means, wherein each transmitting means has an associated service area;

transmitting said independent signals to each service area associated with said each transmitting means wherein said each service area is divided into sectors and each of said independent signals is transmitted to one corresponding sector.

11. The method as described in claim 10 wherein each of said independent signals represents different selectable combinations of said plurality of channels of signals.

12. The method as described in claim 10 wherein at least two of said independent signals represent the same selectable combinations of said plurality of channels of signals.

13. The method as described in claims 11 or 12 wherein said plurality of independent signals are transmitted such that adjacent sectors receive opposite polarity signals.

14. The method as described in claim 13 wherein each of said plurality of independent signals is a 60°

azimuth signal.

15. The method as described in claim 13 wherein each of said plurality of independent signals is a 45°

azimuth signal.

16. A wireless transmission system comprising:

a provider subsystem for converting a plurality of channels of signals into a plurality of formatted independent digital datastreams, each of said formatted digital datastreams representing a selectable combination of said plurality of channels;

a transmitter subsystem including a plurality of transmitter means each having an associated service area, said each transmitter means modulating each of said formatted digital datastreams into a corresponding modulated signal so as to generate a plurality of continuous modulated signals which are independent of each other, said each service area being divided into a plurality of sectors and said each transmitter means transmitting each of said independent signals to one corresponding sector within its associated service area;

a receiver subsystem including a plurality of receiver means in each sector within each service area for converting one of said independent signals into its corresponding formatted digital datastream and selecting one channel of signals of said portion of plurality of channels from said corresponding formatted digital datastream.

17. The transmission system as described in claim 16 wherein each of said independent formatted digital datastreams represents different selectable combinations of said plurality of channels of signals.

18. The transmission system as described in claim 16 wherein at least two of said independent formatted digital datastreams represent the same selectable combinations of said plurality of channels of signals.

19. The transmission system as described in claim 17 or 18 wherein said provider subsystem comprises a plurality of means for generating said each formatted digital datastream, each of said means for generating each of said digital datastreams including means for encoding said plurality of channels into a plurality of intermediate digital datastreams and means for formatting and multiplexing said plurality of intermediate digital datastreams into said each formatted digital datastream.

20. The transmission system as described in claim 19 wherein said means for formatting and multiplexing formats said formatted digital datastreams into a single ATM formatted digital datastream.

21. The system as described in claim 20 wherein said each transmitter means transmits said modulated signals at one of a set of operating frequencies.

22. The system as described in claim 21 wherein said plurality of channels of signals includes previously compressed digital television signals.

23. The system as described in claim 22 wherein said plurality of channels of signals also includes digital computer system signals.

24. The system as described in claim 23 wherein said encoding means formats said intermediate digital datastreams according to SONET SDH formatting.

25. The system as described in claim 24 wherein said formatting and multiplexing means performs frequency division multiplexing.

26. The system as described in claim 25 wherein said means for encoding comprises an analog-to-digital converter and a means for compressing digital signals.

27. The system as described in claim 26 wherein said means for compressing uses an MPEG compression format.

28. The system as described in claim 27 wherein said each transmitter means includes an antenna for transmitting said independent modulated signals, each antenna having a plurality of individual antenna sections for transmitting one of said independent signals and each section having an associated transmission polarity, wherein adjacent antenna sections have opposite associated transmission polarities.

29. The system as described in claim 28 wherein said individual antenna sections are arranged in a multifaced polygonal cylindrical configuration.

30. The system as described in claim 29 wherein said each receiver means further includes means for transmitting RF signals and said each transmitter means further includes means for receiving said RF signals from said receiver means so as to enable two-way transmission between said transmitter subsystem and said receiver subsystem.

31. In a wireless transmission system, a method for transmitting and receiving signals comprising the steps of:

converting a plurality of channels of signals into a plurality of formatted digital datastreams, each of said formatted digital datastreams representing a selectable combination of said plurality of channels;

modulating each of said formatted digital datastreams to generate a corresponding modulated signal thereby generating a plurality of continuous modulated signals which are independent of each other;

providing said plurality of independent signals to each of a plurality of transmitting means, wherein each transmitting means has an associated service area;

transmitting said independent signals to each service area associated with said each transmitting means, wherein said each service area is divided into a plurality of sectors and each sector receives one of said independent signals;

receiving said one independent signal; and

converting said one independent signal into a signal usable by a given I/O device.

32. The method as described in claim 31 wherein each of said independent formatted digital datastreams represents different selectable combinations of said plurality of channels of signals.

33. The method as described in claim 31 wherein at least two of said independent formatted digital datastreams represent the same selectable combinations of said plurality of channels of signals.

34. The method as described in claim 32 or 33 wherein said step of converting a plurality of channels of signals into a plurality of independent formatted digital datastreams, further comprises the step of encoding said portion of said channels into an intermediate digital datastream and the step of multiplexing and formatting said intermediate digital datastream into said each formatted digital datastream.

35. The method as described in claim 34 further including the step of formatting said plurality of formatted digital datastreams into a single formatted digital datastream representing said plurality of formatted digital datastreams, wherein said single digital datastream is reconstructed into said plurality of formatted digital datastreams prior to said modulation step.

36. The method as described in claim 35 wherein said independent modulated signals are transmitted at one of a set of operating frequencies.

37. The method as described in claim 36 wherein said each independent datastream is modulated into a square root staggered QPSK (SQR-SQPSK) formatted modulated signal.

38. The method as described in claim 37 further including the steps of amplifying said modulated signal with an amplifier and a doubler power amplifier to generate a staggered QPSK modulated signal before the step of transmitting said modulated signals to said service area.