Diversity receiver

• US 7,970,366 B2
• Filed: 02/13/2008
• Issued: 06/28/2011
• Est. Priority Date: 02/15/2007
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Maeno, Akiko, Ido, Jun, Arita, Eiji
• Primary Examiner(s): Phu; Sanh D
• Application Number:
  US12/068,962
• Publication Number:
  US 20080238808A1
• Time in Patent Office: 1,231 Days
• Field of Search: 455/130, 455/132, 455/134, 455/272, 455/273, 343/713
• US Class Current: 455/130
• CPC Class Codes: H01Q 21/20 the units being spaced along or adjacent to a curvilinear path slotted waveguide arrays H01Q21/005; circularly or helically slotted waveguides H01Q21/0062
• CPC Class Codes: H01Q 3/24 varying the orientation by switching energy from one active radiating element to another, e.g. for beam switching
• CPC Class Codes: H01Q 3/28 varying the amplitude
• CPC Class Codes: H01Q 3/30 varying the relative phase between the radiating elements of an array H01Q3/2605, H01Q3/2658, H01Q3/2682, H01Q3/44 take precedence
• CPC Class Codes: H04B 7/0848 Joint weighting
• CPC Class Codes: H04B 7/0868 Hybrid systems, i.e. switching and combining
• CPC Class Codes: H04N 21/426 Internal components of the client ; Characteristics thereof H04N5/44 takes precedence
• CPC Class Codes: H04N 21/4263 involving specific tuning arrangements, e.g. two tuners
• CPC Class Codes: H04N 21/6112 involving terrestrial transmission, e.g. DVB-T

Abstract

A diversity receiver is provided with antennas (1a) and (1b) in a first branch and antennas (1c) and (1d) in a second branch each of which antenna gains is controlled so that the offset between the directions of directional radiation patterns for the first and second branches becomes approximately π/2. Thereby, the diversity receiver can obtain a sufficient diversity gain even when it is incorporated into an indoor television with the antennas being built thereinto in close vicinity to one another.

Claims

1. A diversity receiver comprising:

a plurality of first antennas having directional radiation patterns different from one another, for receiving a horizontally polarized broadcast radio signal;

a plurality of first variable gain amplifiers provided for said respective first antennas, for adjusting respective gains thereof;

a first adder for adding first reception signals having been received by said first antennas and gain-adjusted by said first variable gain amplifiers, to output the first added reception signal;

a plurality of second antennas having directional radiation patterns different from one another, arranged in positions different from those of said first antennas, for receiving the horizontally polarized broadcast radio signal;

a plurality of second variable gain amplifiers provided for said respective second antennas, for adjusting respective gains thereof;

a second adder for adding second reception signals having been received by said second antennas and gain-adjusted by said second variable gain amplifiers, to output the second added reception signal;

a diversity-combining circuit for diversity-combining signals based on the first and second added reception signals, to output the diversity-combined signal; and

an antenna control unit for controlling said pluralities of first and second variable gain amplifiers so that a difference between the directions of the directional radiation patterns for the first and second added reception signals maintain a predefined range.

2. The diversity receiver of claim 1, wherein the difference between the directions of the directional radiation patterns for the first and second added reception signals is within a range of π

/2±

π

/4.

3. The diversity receiver of claim 1, wherein the difference between the directions of the directional radiation pattern for the first and second added reception signals is within a range of π

/2±

π

/8.

4. The diversity receiver of claim 1, wherein the difference between the directions of directional radiation patterns for the first and second added reception signals is approximately π

/2.

5. The diversity receiver of claim 1, wherein said first and/or second antennas are arranged tilted with respect to the horizontal plane, for receiving vertically polarized broadcast radio signals.

6. The diversity receiver of claim 1, wherein said antenna control unit controls on the basis of first reception-power information, first delay-profile information, and first noise information that are obtained based on the first reception added signal;

second reception-power information, second delay-profile information, and second noise information that are obtained based on the second added reception signal; and

third noise information and error information that are obtained based on the diversity-combined signal.

7. A diversity receiver comprising:

a plurality of first antennas having directional radiation patterns different from one another, for receiving a horizontally polarized broadcast radio signal;

a selection circuit for selecting a specific output signal from signals each inputted thereinto from said first antennas;

a plurality of second antennas having directional radiation patterns different from one another, arranged in positions different from those of said first antennas, for receiving the horizontally polarized broadcast radio signal;

a plurality of variable gain amplifiers provided for said respective second antennas, for adjusting respective gains thereof;

an adder for adding reception signals having been received by said second antennas and gain-adjusted by said variable gain amplifiers, to output the second added reception signal;

a diversity-combining circuit for diversity-combining signals based on the specific output signal and the added signal, to output the diversity-combined signal; and

an antenna control unit for controlling said variable gain amplifiers as well as said selection circuit.

9. The diversity receiver of claim 7, wherein said antenna control unit controls so that directions of directional radiation patterns for the specific phase-combined signal selected by said selection circuit and the added reception signal become different from each other.

10. The diversity receiver of claim 9, wherein said antenna control unit controls so that the difference becomes approximately π

/2 between the directions of the directional radiation patterns for the specific phase-combined signal and the added reception signal.

11. The diversity receiver of claim 7, wherein said antenna control unit controls on the basis of first reception-power information, first delay-profile information, and first noise information that are obtained based on the specific phase-combined signal selected by the selection circuit;

second reception-power information, second delay-profile information, and second noise information that are obtained based on the added reception signal; and

third noise information and error information that are obtained based on the diversity-combined signal.

8. A diversity receiver comprising:

a plurality of first antennas for receiving a horizontally polarized broadcast radio signal;

a phase combiner for combining signals each inputted from said first antennas with a fixed phase, to output the plurality of phase-combined signals;

a selection circuit for selecting a specific phase-combined signal from the phase-combined signals;

a plurality of second antennas having directional radiation patterns different from one another, arranged in positions different from those of said first antennas, for receiving the horizontally polarized broadcast radio signal;

a plurality of variable gain amplifiers provided for said respective second antennas, for adjusting respective gains thereof;

an adder for adding reception signals having been received by said second antennas and gain-adjusted by said variable gain amplifiers, to output the added reception signal;

a diversity-combining circuit for diversity-combining signals based on the specific phase-combined signal and the added reception signal, to output the diversity-combined signal; and

an antenna control unit for controlling said selection circuit as well as said variable gain amplifiers.

12. A diversity receiver comprising:

a plurality of first antennas for receiving a horizontally polarized broadcast radio signal;

a first phase combiner for combining signals each inputted from said first antennas with a first fixed phase, to output the plurality of first phase-combined signals;

a first selection circuit for selecting a first specific phase-combined signal from the first phase-combined signals;

a plurality of second antennas arranged in positions different from those of said first antennas, for receiving the horizontally polarized broadcast radio signal;

a second phase combiner for combining signals each inputted from said second antennas with a second fixed phase, to output the plurality of second phase-combined signals;

a second selection circuit for selecting a second specific phase-combined signal from the second phase-combined signals;

a diversity-combining circuit for diversity-combining signals based on the first and second specific phase-combined signals, to output the diversity-combined signal; and

an antenna control unit for controlling said first and second selection circuits.

13. The diversity receiver of claim 12, wherein said antenna control unit controls so that directions of directional radiation patterns for the first and second specific phase-combined signals selected by said first and second selection circuit, respectively, become different from each other.

14. The diversity receiver of claim 13, wherein said antenna control unit controls so that the difference becomes close to π

/2 between the directions of the directional radiation patterns for the first and second specific phase-combined signals selected by said first and second selection circuit, respectively.

15. The diversity receiver of claim 12, wherein said antenna control unit controls on the basis of first reception-power information, first delay-profile information, and first noise information that are obtained based on the first phase-combined signal selected by said first selection circuit;

second reception-power information, second delay-profile information, and second noise information that are obtained based on the second phase-combined signal selected by said second selection circuit; and

third noise information and error information that are obtained based on the diversity-combined signal.

16. A diversity receiver comprising:

a plurality of first antennas for receiving a horizontally polarized broadcast radio signal;

a phase combiner for combining signals each inputted from said first antennas with a first fixed phase, to output the plurality of phase-combined signals;

a first selection circuit for selecting a specific phase-combined signal from the phase-combined signals;

a plurality of second antennas arranged in positions different from those of said first antennas, for receiving the horizontally polarized broadcast radio signal;

a second selection circuit for selecting a specific second-antenna output signal, from signals each inputted thereinto from said second antennas;

a diversity-combining circuit for diversity-combining signals based on the specific phase-combined signal and the specific second-antenna output signal, to output the diversity-combined signal; and

an antenna control unit for controlling said first and second selection circuits.

17. The diversity receiver of claim 16, wherein said antenna control unit controls so that the directions of directional radiation patterns for the specific phase-combined signal selected by said first selection circuit and the specific second-antenna output signal selected by said second selection circuit become different from each other.

18. The diversity receiver of claim 17, wherein said antenna control unit controls so that the difference becomes close to π

/2 between the directions of the directional radiation patterns for the specific phase-combined signal selected by said first selection circuit and the specific second-antenna output signal selected by said second selection circuit.

19. The diversity receiver of claim 16, wherein said antenna control unit controls on the basis of first reception-power information, first delay-profile information, and first noise information that are obtained based on the specific phase-combined signal selected by said first selection circuit;

second reception-power information, second delay-profile information, and second noise information that are obtained based on the specific second-antenna output signal selected by said second selection circuit; and

third noise information and error information that are obtained based on the diversity-combined signal.

20. A diversity receiver comprising:

a plurality of first antennas for receiving a horizontally polarized broadcast radio signal;

a first selection circuit for selecting a specific first-antenna output signal, from signals inputted thereinto from said first antennas;

a plurality of second antennas arranged in positions different from those of said first antennas, for receiving the horizontally polarized broadcast radio signal;

a second selection circuit for selecting a specific second-antenna output signal, from signals inputted thereinto from said second antennas;

a diversity-combining circuit for diversity-combining signals based on the specific first-antenna output signal and the specific second-antenna output signal, to output the diversity-combined signal; and

an antenna control unit for controlling said first and second selection circuits so that a difference between the directions of directional radiation patterns for the specific first-antenna output signal selected by said first selection circuit and the specific second-antenna output signal selected by said second selection circuit maintains a predefined range.

21. The diversity receiver of claim 20, wherein said antenna control unit controls so that the difference becomes close to π

/2 between the directions of the directional radiation patterns for the specific first-antenna output signal selected by said first selection circuit and the specific second-antenna output signal selected by said second selection circuit.

22. The diversity receiver of claim 20, wherein said antenna control unit controls on the basis of first reception-power information, first delay-profile information, and first noise information that are obtained based on the specific first-antenna output signal selected by said first selection circuit;

second reception-power information, second delay-profile information, and second noise information that are obtained based on the specific second-antenna output signal selected by said second selection circuit; and

third noise information and error information that are obtained based on the diversity-combined signal.