Dual distributed antenna system

• US 5,513,176 A
• Filed: 08/27/1993
• Issued: 04/30/1996
• Est. Priority Date: 12/07/1990
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Dean, Richard F., Wheatley, Charles E. III, Gilhousen, Klein S., Antonio, Franklin P.
• Primary Examiner(s): MARCELO, MELVIN C
• Application Number:
  US08/112,392
• Time in Patent Office: 977 Days
• Field of Search: 370/18, 342/375, 342/433, 342/434, 343/844, 343/853, 375/1, 379/59, 379/63, 380/34, 455/276.1, 455/277.2, 455/278.1, 455/279.1, 455/283
• US Class Current: 370/335
• CPC Class Codes: H01Q 21/29 Combinations of different interacting antenna units for giving a desired directional characteristic H01Q25/00 takes precedence
• CPC Class Codes: H04B 7/022 Site diversity; Macro-diversity using two or more spaced independent antennas H04B7/04
• CPC Class Codes: H04B 7/0491 using two or more sectors, i.e. sector diversity
• CPC Class Codes: H04B 7/0671 using different delays between antennas
• CPC Class Codes: H04B 7/0845 per branch equalization, e.g. by an FIR-filter or RAKE receiver per antenna branch rake receivers as such H04B1/7115
• CPC Class Codes: H04B 7/0894 using different delays between antennas
• CPC Class Codes: H04B 7/2628 using code-division multiple access [CDMA] or spread spectrum multiple access [SSMA] H04B7/2618 takes precedence
• CPC Class Codes: H04B 7/2643 using time-division multiple access [TDMA] H04B7/2615, H04B7/2618 take precedence
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 88/085 Access point devices with remote components

Abstract

A distributed antenna system is utilized in a system for providing multipath signals which facilitate signal diversity for enhanced system performance. Each node of the antenna comprises more than one antenna. Each antenna at a common node provides a path having a different delay to the base station.

Claims

1. In a digital communication system in which at least one remote terminal communicates with other terminals through a base station using digitally modulated communication signals, said base station having an antenna system comprising:

a first set of spaced apart antennas;

a second set of spaced apart antennas, each antenna of said second set of antennas corresponding in location to a corresponding antenna of said first set of antennas;

signal distribution means for coupling said communication signals between said base station and said antennas of said first and second sets; and

delay means operatively coupled to said antennas of said first set and second set and said signal distribution means for providing a predetermined delay in said communication signals coupled between said base station and said antennas.

2. The system of claim 1 wherein said signal distribution means comprises:

first transmission cabling serially interconnecting said first set of antennas and interconnecting a first one of said first set of antennas to said base station; and

second transmission cabling serially interconnecting said second set of antennas and interconnecting a first one of said second set of antennas to said base station.

3. The system of claim 2 wherein said communication signals are generated by spread spectrum modulating information signals according to predetermined pseudorandom noise (PN) spreading codes each comprised of a predetermined sequence of binary chips each of a predetermined chip duration, and wherein said delay means comprises a plurality of delay elements disposed in said cabling between adjacent coupled ones of said antennas of said first set and between adjacent coupled ones of said antennas of said second set, each delay element providing a delay in said communication signals on an order of at least one chip duration.

4. The system of claim 1 wherein said antennas of said first set have a predetermined antenna pattern with said antennas of said first set positioned with overlapping patterns.

5. The system of claim 4 wherein said antennas of said second set have a predetermined antenna pattern wherein each antenna of said second set is positioned with substantially overlapping patterns with said corresponding antenna of said first set.

6. The system of claim 1 wherein:

said signal distribution means comprises first transmission cabling serially interconnecting said first set of antennas and interconnecting a first one of said first set of antennas to said base station; and

each antenna of said second set of antennas is operatively coupled to an antenna of said first set of antennas.

7. The system of claim 6 wherein said communication signals are generated by spread spectrum modulating information signals according to predetermined pseudorandom noise (PN) spreading codes each comprised of a predetermined sequence of binary chips each of a predetermined chip duration, and wherein said delay means comprises:

a first plurality of delay elements each disposed between an antenna of said second set of antennas and a corresponding antenna of said first set of antennas, each delay element providing a delay in said communication signals on an order of at least one chip duration; and

a second plurality of delay elements, each disposed between adjacent coupled ones of said antennas of said first set of antennas, each delay element providing a delay in said communication signals on an order of at least one chip duration.

8. The system of claim 6 wherein said antennas of said first set have a predetermined antenna pattern with said antennas of said first set positioned with overlapping patterns.

9. The system of claim 8 wherein said antennas of said second set have a predetermined antenna pattern wherein each antenna of said second set is positioned with substantially overlapping patterns with said corresponding antenna of said first set.

10. The system of claim 2 further comprising:

a third set of spaced apart antennas, each antenna of said third set of antennas corresponding in location to a corresponding antenna of said first set of antennas;

signal distribution means for coupling said communication signals between said base station and said antennas of said third set of antennas; and

delay means operatively coupled to said antennas of said third set and said signal distribution means for providing a predetermined delay in said communication signals coupled between said base station and said antennas.

11. The system of claim 10 wherein said signal distribution means comprises third transmission cabling serially interconnecting said third set of antennas and interconnecting a first one of said third set of antennas to said base station.

12. In a communication system in which system users communicate through a base station with remote system users, said remote system users communicating through said base station via a radio link therewith, said base station comprising:

communication terminal means for spread spectrum modulating a remote user directed information signal and providing a spread spectrum modulated remote user directed information signal, and for receiving and separately demodulating a first and second aggregate spread spectrum modulated remote system user information signal;

first antenna means for receiving a plurality of spread spectrum modulated remote system user information signals, each of said spread spectrum modulated remote system user information signals of a predetermined time delay with respect to one another, combining said plurality of spread spectrum modulated remote system user information signals to form said first aggregate spread spectrum modulated remote system user information signal and providing said first aggregate spread spectrum modulated remote system user information signals to said communication terminal means; and

second antenna means for receiving a plurality of spread spectrum modulated remote system user information signals, each of said spread spectrum modulated remote system user information signals of a predetermined time delay with respect to one another, combining said plurality of spread spectrum modulated remote system user information signals to form said second aggregate spread spectrum modulated remote system user information signal and providing said second aggregate spread spectrum modulated remote system user information signals to said communication terminal means.

13. The system of claim 12 wherein said first antenna means and said second antenna means each comprises:

a plurality of spaced apart antennas;

signal distribution means for coupling said spread spectrum modulated remote user directed information signal from said communication terminal means to each of said antennas; and

delay means operatively coupled to said antennas and said signal distribution means for providing a different predetermined delay in said spread spectrum modulated remote user directed information signal as coupled by said signal distribution means to each of said antennas.

14. The system of claim 13 wherein said spread spectrum modulated remote user directed information signal is generated by direct sequence spread spectrum modulating said remote user directed information signal with a pseudorandom noise (PN) spreading code comprised of a predetermined sequence of binary chips each of a predetermined chip duration.

15. The system of claim 14 wherein said delay means comprises a plurality of delay elements each operatively coupled to a respective one of said plurality of spaced apart antennas, each delay element providing a delay in said spread spectrum modulated remote user directed information signal, with each delay different from one another by an order of at least one chip duration.

16. In the communication system of claim 12 wherein said remote system users communicate with said system users and other remote system users through said base station by transmitting said spread spectrum modulated remote system user information signals to said base station for transfer to intended recipient system users and remote system users.

17. In the communication system of claim 13 wherein said remote system users communicate with said system users and other remote system users through said base station by transmitting said spread spectrum modulated remote system user information signals to said base station for transfer to intended recipient system users and remote system users.

18. The system of claim 12 wherein said spread spectrum modulated remote user directed information signal is generated by direct sequence spread spectrum modulating said remote user directed information signal with a pseudorandom noise (PN) spreading code comprised of a predetermined sequence of binary chips each of a predetermined chip duration.

19. The system of claim 16 wherein said spread spectrum modulated remote user directed information signal is generated by direct sequence spread spectrum modulating said remote user directed information signal with a first pseudorandom noise (PN) spreading code comprised of a first predetermined sequence of binary chips each of a first predetermined chip duration and said spread spectrum modulated remote system user information signal is generated by direct sequence spread spectrum modulating a remote system user information signal with a second pseudorandom noise (PN) spreading code comprised of a second predetermined sequence of binary chips each of a second predetermined chip duration.

20. The system of claim 17 wherein said spread spectrum modulated remote user directed information signal and said spread spectrum modulated remote system user information signal are generated by respectively direct sequence spread spectrum modulating said remote user directed information signal and said remote system user information signal with a pseudorandom noise (PN) spreading code comprised of a predetermined sequence of binary chips each of a predetermined chip duration.

21. The system of claim 15 wherein said signal distribution means comprises a cabling system interconnecting in series said communications terminal means and said antennas.

22. The system of claim 15 wherein said signal distribution means comprises:

a primary antenna coupled to said base station; and

a plurality of secondary antennas electromagnetically coupled to said primary antenna, with each secondary antenna coupled to a corresponding one of said plurality of spaced apart antennas and respective one of said delay elements.

23. The system of claim 13 wherein said plurality of spaced apart antennas comprises omnidirectional antennas.

24. The system of claim 13 wherein said plurality of spaced apart antennas comprises directional antennas.

25. The system of claim 24 wherein at least one of said plurality of spaced apart antennas is an omnidirectional antenna.

26. The system of claim 13 wherein said plurality of spaced apart antennas comprises polarized antennas.

27. The system of claim 13 wherein said plurality of antennas of first antenna means comprises vertically polarized antennas and said plurality of antennas of second antenna means comprises horizontally polarized antennas.

28. A communication system for facilitating the communication of information signals between users of said communication system, and between users of said communication system and users of an external network, wherein certain users of said communication system use remote terminals to communicate within said communication system, via a radio link with a base station, using code division multiple access communication signals, said system comprising:

communication terminal means for receiving and direct sequence spread spectrum modulating an information signal intended for a recipient remote terminal user with a pseudorandom noise (PN) spreading code comprised of a predetermined sequence of binary chips each of a predetermined chip duration time;

first antenna means comprising multiple elements for providing multiple radiations of said spread spectrum modulated information signal with each radiation of said spread spectrum modulated information signal delayed in time with respect to one another by at least one chip duration time and for receiving said spread spectrum modulated information signal; and

second antenna means comprising multiple elements for providing multiple radiations of said spread spectrum modulated information signal with each radiation of said spread spectrum modulated information signal delayed in time with respect to one another by at least one chip duration time and for receiving said spread spectrum modulated information signal wherein each of said elements of said first antenna means is collocated with an element of second antenna means forming a node.

29. The system of claim 28 wherein said first and second antenna means each comprises:

a plurality of spaced apart antennas, each antenna corresponding to a element of said antenna means;

signal distribution means for coupling said spread spectrum modulated information signal from said communication terminal means to each of said antennas; and

delay means operatively coupled to said antennas and said signal distribution means for providing one or more chip duration time delay in said spread spectrum modulated information signal as coupled by said signal distribution means to each of said antennas.

30. The communication system of claim 29 wherein each of said elements comprises frequency conversion means for receiving said spread spectrum modulated information signal and producing said spread spectrum modulated information signal at radio frequency.

31. The communication system of claim 29 wherein each of said elements comprises means for amplifying said information spread spectrum modulated signal.

32. In a digital communication system where signals intended for transfer to a receiving terminal are transmitted from a transmitting terminal as digitally modulated signals, wherein said receiving terminal in receiving multipath propagations of each digitally modulated signal requires a minimum predetermined time difference between multipath propagations of each digitally modulated signal as received for demodulation thereof to provide said signals intended for said receiving terminal, a method for creating multipath propagations of said transmitted digitally modulated signals wherein each multipath propagation is of at least said minimum predetermined time difference with respect to another upon reception at said receiving terminal, said method comprising the steps of:

providing a plurality of spaced apart dual antenna elements;

providing from said transmitting terminal a communication signal to each of said antennas;

providing a different predetermined delay in said communication signal as provided to each of said dual antennas elements; and

providing a different predetermined delay in said communication signal as provided to each antenna of said dual antenna elements.

33. The method of claim 32 wherein said communication signals in said transmitting terminal are generated by spread spectrum modulating said signals intended for transfer according to a pseudorandom noise (PN) spreading code comprised of a predetermined sequence of binary chips each of a predetermined chip duration, and wherein, said step of providing said different predetermined delay in said communication signal as provided to each of said dual antenna elements comprises providing a delay on the order of at least one chip duration.

34. In a communications system in which an information signal is modulated at a first station with a pseudorandom noise (PN) code, comprised of a predetermined sequence of code chips each of a predetermined time duration, with said PN modulated noise signal modulated upon a carrier for transmission, an antenna system comprising:

a plurality of antennas coupled in series and coupled to said first station;

a plurality of delay elements each disposed in series between adjacent coupled ones of said antennas;

a first station delay coupled to said first station;

a secondary plurality of antennas coupled in series and coupled to said first station delay, each of said second plurality of antennas positioned with a corresponding one of said first plurality of antennas; and

a secondary plurality of delay elements each disposed in series between adjacent coupled ones of said antennas of said secondary plurality of antennas.

35. The system of claim 34 wherein at least one of said plurality of antennas comprises an omnidirectional antenna.

36. The system of claim 34 wherein at least one of said plurality of antennas comprises a directional antenna.

37. The system of claim 34 wherein each of said delay elements of said first and second plurality of delays provides a delay of at least twice said predetermined time duration of said code chips and said first station delay provides a delay on the order of said predetermined time duration of said code chips.

38. The system of claim 35 wherein each of said delay elements of said first and second plurality of delays provides a delay of at least said predetermined time duration of said code chips and said first station delay provides a delay on the order of the sum of said delays of said first plurality of delay elements.

39. The system of claim 34 wherein said plurality of antennas and said second plurality of antennas comprise omnidirectional and directional antennas positioned with overlapping patterns.

40. The system of claim 34 wherein said plurality of antennas comprises polarized antennas with a first polarization and wherein said second plurality of antennas comprises polarized antennas with a second polarization.

41. An antenna system for transmitting and/or receiving a spread spectrum modulated information signal wherein said spread spectrum modulated information signal is generated by spread spectrum modulating an information signal with a pseudorandom noise code comprised of a predetermined sequence of code chips each of a predetermined chip duration, said antenna system comprising:

a first set of serially coupled antenna elements;

a second set of serially coupled antenna elements, each antenna of said first set collocated with an corresponding antenna of said second set;

a set of delay elements positioned such that a least one delay element is interposed between each of said antenna elements of said first and second sets; and

an additional delay coupled in series with said second set of antenna elements such that every signal received and transmitted by said second set of antenna elements is delayed thereby.

42. The antenna system of claim 41 wherein each antenna element comprises means for frequency converting said spread spectrum modulated information signal.

43. The antenna system of claim 41 wherein each antenna element comprises means for amplifying of said spread spectrum modulated information signal.

44. An antenna system for transmitting and/or receiving a spread spectrum modulated information signal wherein said spread spectrum modulated information signal is generated by spread spectrum modulating an information signal with a pseudorandom noise code comprised of a predetermined sequence of code chips each of a predetermined chip duration, said antenna system comprising:

a set of delay elements, each delay element providing a delay time on the order of a multiple of one chip duration in length;

a set of antennas;

a system of cabling coupling said antennas and said delay elements in a serial string, wherein each of said delay elements is coupled between predetermined pairs of said antennas;

a second set of delay elements, each delay element providing a delay time on the order of multiple of one chip duration in length;

a second set of antennas, each antenna of said second set collocated with an antenna of said first set;

a initial delay element having a delay time on the order of one chip duration in length; and

a second system of cabling coupling said second set of antennas and each of said second set of delay elements in a serial string, wherein each delay element of said second set of delay elements is coupled between predetermined pairs of said antennas and wherein said initial delay element is coupled in series therewith.

45. An antenna system for transmitting and/or receiving a spread spectrum modulated information signal coupled to a base station wherein said spread spectrum modulated information signal is generated by spread spectrum modulating an information signal with a pseudorandom noise code comprised of a predetermined sequence of code chips each of a predetermined chip duration, said antenna system comprising:

a set of delay elements, each delay element providing a delay time on the order of a multiple of one chip duration in length;

a first set of antennas, each having an antenna coverage area;

a system of cabling coupling each of said antennas of said first set to said base station and coupling one said delay elements between said base station and at least one antenna of said first set;

a second set of delay elements, each delay element providing a delay time on the order of a multiple of one chip duration in length;

a second set of antennas, each having an antenna coverage area, and wherein each particular antenna of said second set of antennas corresponds to a particular antenna of said first set in that the antenna coverage area of said particular antenna of said first set and the antenna coverage area of said particular antenna of said second set are substantially the same; and

a second system of cabling coupling each of said antennas of said second set to said base station and coupling one said second set of delay elements between said base station and at least one antenna of said second set such that each antenna of said second set has a different delay with respect to said base station than said corresponding antenna of said first set of antennas with respect to said base station.

46. In a digital communication system in which at least one remote terminal communicates with other terminals through a base station using digitally modulated communication signals, said base station having an antenna system comprising:

a first set of spaced apart antennas;

a second set of spaced apart antennas, each antenna of said second set of antennas corresponding in location to a corresponding antenna of said first set of antennas;

signal distribution means for coupling said communication signals between said base station and each antenna of said first and second sets; and

delay means operatively coupled in series with each of said antennas of said first and second sets and said signal distribution means for providing a predetermined delay in said communication signals between said base station and each antenna of said first and second set.

47. An apparatus in a digital communication system in which at least one remote terminal communicates with a base station using digitally modulated communication signals, said apparatus comprising:

a base station having at least two independent receivers;

a first set of spaced apart antennas;

a second set of spaced apart antennas, each antenna of said second set of antennas corresponding in location to a corresponding antenna of said first set of antennas thereby forming a first aggregate antenna pattern;

first signal distribution means for coupling said communication signals between a first one of said at least two independent receivers of said base station and said first and second sets of antennas;

first delay means operatively coupled such that each antenna of said first set of antennas and said second set of antennas exhibits a different delay with respect to said first one of said at least two independent receivers of said base station;

a third set of spaced apart antennas;

a fourth set of spaced apart antennas, each antenna of said fourth set of antennas corresponding in location to a corresponding antenna of said third set of antennas thereby forming a second aggregate antenna pattern;

second signal distribution means for coupling said communication signals between a second one of said at least two independent receivers of said base station and said third and fourth sets of antennas; and

second delay means operatively coupled such that each antenna of said third set of antennas and said fourth set of antennas exhibits a different delay with respect to said second one of said at least two independent receivers of said base station and such that a particular antenna of said third set of antennas and a particular corresponding antenna of said fourth set of antennas exhibits a different delay with respect to said base station than a particular antenna of said first set of antennas and a particular corresponding antenna of second set of antennas having a corresponding first aggregate antenna pattern overlapping a corresponding second aggregate antenna pattern of said particular antenna of said third set of antennas and a particular corresponding antenna of said fourth set of antennas.