Adaptive antenna radio communication device

• US 20050250564A1
• Filed: 09/26/2003
• Published: 11/10/2005
• Est. Priority Date: 09/27/2002
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Corporation of America (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Fukagawa, Takashi, Kishigami, Takaaki, Takakusaki, Keiji, Yuda, Yasuaki, Miyamoto, Shoji
• Granted Patent: US 7,333,056 B2
• Time in Patent Office: Days
• US Class Current: 455/575.700
• CPC Class Codes: G01S 3/043 Receivers
• CPC Class Codes: G01S 3/14 Systems for determining direction or deviation from predetermined direction aerial arrangements for changing or varying the orientation or the shape of the directional pattern H01Q3/00; combinations of different interacting aerial units for giving a desired directional characteristic H01Q21/29; aerials or aerial systems providing at least two radiation patterns H01Q25/00
• CPC Class Codes: H04B 7/086 using weights depending on external parameters, e.g. direction of arrival [DOA], predetermined weights or beamforming
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems

Abstract

An adaptive antenna radio communication device comprises a divided band direction estimating unit (4) for estimating the direction by calculating the cross correlations between a pilot signal and sub-carrier signals of the respective divided bands received by an array antenna (1) and calculating a spatial profile from correlation matrices determined by combining the correlation values between antenna elements of the different sub-carriers according to the output of the cross correlation calculation; a divided band array weight creating unit (5) for creating a weight of a receive array having a directional beam in the direction of estimation for each divided band; and a sub-carrier directivity creating unit (6) for creating a directivity by multiplication-combining the created receive array weight with the corresponding sub-carrier signal.

Claims

1. An adaptive antenna radio communication device comprising:

an array antenna made up of a plurality of antenna elements receiving high frequency signals that are transmitted by multi-carrier;

a demultiplexer for demultiplexing the signal received by said respective antenna elements to a plurality of sub-carrier signals;

Nd divided band direction estimating units for estimating the direction-of-arrival of a radio wave by dividing the entire communication band being said multi-carrier transmitted into Nd bands (however, Nd is 2 or more or a positive integer less than the number of sub-carriers used for multi-carrier transmission) and using sub-carrier signals belonging to the respective divided bands;

a divided band array weight creating unit for creating a weight of a receive array having a directional beam in the direction of estimation by said divided band direction estimating unit for said respective divided bands;

a sub-carrier directivity creating unit for creating a directivity by multiplication-combining the receive array weight created in each divided band with the corresponding sub-carrier signal belonging to the divided band; and

a demodulating unit for demodulating data by using the output of said sub-carrier directivity creating unit.

2. The adaptive antenna radio communication device according to claim 1,

wherein said divided band direction estimating unit calculates pilot signal correlation values with the respective input sub-carrier signals using a known pilot signal embedded in a sub-carrier signal, and estimates the direction-of-arrival based on the correlation values of the pilot signal correlation values calculated between the same sub-carrier signals received by different antenna elements.

3. The adaptive antenna radio communication device according to claim 2,

wherein said divided band direction estimating unit estimates the direction-of-arrival using correlation matrices integrating correlation matrices of the respective sub-carriers belonging to the sub-carrier signals.

4. The adaptive antenna radio communication device according to claim 2,

wherein said divided band direction estimating unit estimates the direction-of-arrival using a correlation matrix R expressed as R=V₁V₁^H+V₂V₂^H+ . . . +V_LV_L^H where L is the number of sub-carriers belonging to the sub-carrier signals;

Vk is a column vector having a pilot signal correlation value as an m-th element in the m-th antenna element with respect to the k-th sub-carrier signal; and

H is a complex conjugate transposed operator.

5. The adaptive antenna radio communication device according to claim 2,

wherein said divided band direction estimating unit estimates the direction-of-arrival by using a correlation vector integrating correlation vectors of the respective sub-carriers belonging to the sub-carrier signals.

6. The adaptive antenna radio communication device according to claim 2,

wherein said divided band direction estimating unit estimates the direction-of-arrival using a correlation vector z expressed as z=V_1X*V₁+V_2X*V₂+ . . . +V_LX*V_L where L is the number of sub-carriers belonging to the sub-carrier signals;

Vk is a column vector having a pilot signal correlation value as an m-th element in the m-th antenna element with respect to the k-th sub-carrier signal;

Vkx is an x-th element of said column vector Vk (however, x is a positive integer less than the number of antenna elements); and

* is a complex conjugate operator.

7. The adaptive antenna radio communication device according to claim 1,

wherein said divided band direction estimating unit further has a path search unit for calculating a delay profile by calculating a cross correlation between respective input sub-carrier signals using a known pilot signal embedded in the sub-carrier signal and detecting a plurality of path arrival timings from the delay profile, and estimates the direction-of-arrival based on the correlation value of the pilot signal correlation value calculated between the same sub-carrier signals received by different antenna elements in the respective path arrival timing.

8. The adaptive antenna radio communication device according to claim 7,

wherein said divided band direction estimating unit estimates the direction-of-arrival using a correlation matrix integrating correlation matrices of the respective sub-carriers detected in the respective sub-carriers belonging to the sub-carrier signals.

9. The adaptive antenna radio communication device according to claim 7,

wherein said divided band direction estimating unit estimates the direction-of-arrival using a correlation matrix R expressed as

$R=\sum _{}^{}$

k=1L⁢

∑

p=1S⁢

Vk⁡

(p)⁢

Vk⁡

(p)H

where L is the number of sub-carriers belonging to the sub-carrier signals;

Vk(p) is a column vector having the pilot signal correlation values as an m-th element in the m-th antenna element of the p-th arrival path (the number of whole arrival paths is specified as S) with respect to the k-th sub-carrier signal; and

H is a complex conjugate transposed operator.

10. The adaptive antenna radio communication device according to claim 7,

wherein said divided band direction estimating unit estimates the direction-of-arrival using a correlation vector integrating correlation vectors of the respective sub-carriers detected in the respective sub-carriers belonging to the sub-carrier signals.

11. The adaptive antenna radio communication device according to claim 7,

wherein said divided band direction estimating unit estimates the direction-of-arrival using a correlation vector z expressed as

$z=\sum _{}^{}$

k=1L⁢

∑

p=1S⁢

Vkx⁡

(p)*Vk⁡

(p)

where L is the number of sub-carriers belonging to the sub-carrier signals;

Vk(p) is a column vector having the pilot signal correlation values as an m-th element in the m-th antenna element of the p-th arrival path (the number of whole arrival paths is specified as S) with respect to the k-th sub-carrier signal and * is a complex conjugate operator.

12. The adaptive antenna radio communication device according to claim 3,

wherein said divided band direction estimating unit estimates the direction-of-arrival by any one of the MUSIC method, ESPRIT method, CAPON method and Fourier method using said correlation matrix R.

13. The adaptive antenna radio communication device according to claim 8,

wherein said divided band direction estimating unit estimates the direction-of-arrival by any one of the MUSIC method, ESPRIT method, CAPON method or Fourier method using said correlation matrix R.

14. The adaptive antenna radio communication device according to claim 3,

wherein said divided band direction estimating unit has a spatial smoothing processing unit for performing spatial smoothing processing on the correlation matrix R and estimates the direction-of-arrival by using any one of the MUSIC method, ESPRIT method, CAPON method and Fourier method to the output from the spatial smoothing processing unit.

15. The adaptive antenna radio communication device according to claim 5,

wherein said divided band direction estimating unit has a spatial smoothing processing unit for performing spatial smoothing processing on said correlation matrix R and estimates the direction-of-arrival by using any one of the MUSIC method, ESPRIT method, CAPON method and Fourier method to the output from said spatial smoothing processing unit.

16. The adaptive antenna radio communication device according to claim 7, wherein said divided band direction estimating unit has a spatial smoothing processing unit for performing spatial smoothing processing on the correlation matrix R and estimates the direction-of-arrival by using any one of the MUSIC method, ESPRIT method, CAPON method and Fourier method to the output from the spatial smoothing processing unit.

17. The adaptive antenna radio communication device according to claim 8, wherein the divided band direction estimating unit has a spatial smoothing processing unit for performing spatial smoothing processing on the correlation matrix R and estimates the direction-of-arrival by using any one of the MUSIC method, ESPRIT method, CAPON method and Fourier method to the output from the spatial smoothing processing unit.

18. The adaptive antenna radio communication device according to claim 3,

wherein said divided band direction estimating unit has a unitary converting unit for performing unitary conversion processing on the correlation matrix R and estimates the direction-of-arrival by using anyone of the MUSIC method, ESPRIT method, CAPON method and Fourier method to the output from the unitary converting unit.

19. The adaptive antenna radio communication device according to claim 5,

wherein said divided band direction estimating unit has a unitary converting unit for performing unitary conversion processing on the correlation matrix R and estimates the direction-of-arrival by using any one of the MUSIC method, ESPRIT method, CAPON method and Fourier method to the output from the unitary converting unit.

20. The adaptive antenna radio communication device according to claim 7,

wherein said divided band direction estimating unit has a unitary converting unit for performing unitary conversion processing on the correlation matrix R and estimates the direction-of-arrival by using anyone of the MUSIC method, ESPRIT method, CAPON method and Fourier method to the output from the unitary converting unit.

21. The adaptive antenna radio communication device according to claim 8,

wherein said divided band direction estimating unit has a unitary converting unit for performing unitary conversion processing on the correlation matrix R and estimates the direction-of-arrival by using any one of the MUSIC method, ESPRIT method, CAPON method and Fourier method to the output from the unitary converting unit.

26. The adaptive antenna radio communication device according to claim 1, further comprising:

in a radio system being multi-carrier transmitted in a time division duplex (TDD) method,

a sub-carrier transmission weight creating unit using a weight of a receive array created in the divided band array weight creating unit as a weight of a transmission array; and

a sub-carrier transmission directivity creating unit for transmitting a directional beam using a weight of a transmission array common to the respective divided bands.

27. The adaptive antenna radio communication device according to claim 1, further comprising:

in a radio system being multi-carrier transmitted in a time division duplex (TDD) method or a frequency division duplex (FDD) method,

a sub-carrier transmission weight creating unit for calculating a weight of a transmission array in order to create a transmitting directional beam in the direction of estimation giving maximum received power among all directions of estimation by said divided band direction estimating units; and

a sub-carrier transmission directivity creating unit for transmitting a directional beam common to the entire divided band using the weight of the transmission array.

28. The adaptive antenna radio communication device according to claim 1, further comprising:

in a radio system being multi-carrier transmitted in a time division duplex (TDD) method or a frequency division duplex (FDD) method,

a sub-carrier transmission weight creating unit for calculating a deviation of the estimation direction outputted from said divided band direction estimating unit, calculating a weight of a transmission array for creating a transmitting directional beam in the average direction of direction estimation values outputted from all of said divided band direction estimating units when the deviation is less than the predetermined value, or calculating the weight of the transmission array in the direction of estimation giving a predetermined number of the upper received power among all of the divided bands when the deviation is greater than the predetermined value.

29. The adaptive antenna radio communication device according to claim 1,

wherein the multi-carrier transmission uses sub-carrier signals to which orthogonal frequency division multiplexing (OFDM) is applied.

32. The adaptive antenna radio communication device according to claim 1,

wherein the multi-carrier transmission uses sub-carrier signals in which users multiplex by code division in the direction of frequency axis or time axis.

35. The adaptive antenna radio communication device according to claim 32,

wherein a weight of a transmission array or a weight of a receive array is created for the respective multiplexed users for directional receiving.

38. The adaptive antenna radio communication device according to claim 35,

wherein said divided band array weight creating unit has a directional beam in the direction estimation result of the divided band direction estimating unit in its divided band and creates a weight of a receive array for creating a null in the estimation direction of other multiplexed users.

41. The adaptive antenna radio communication device according to claim 35,

wherein said sub-carrier transmission weight creating unit has a directional beam in the direction of a desired user and creates a weight of a transmission array for creating a null in the direction of other multiplexed users.

22. An adaptive antenna radio communication device comprising:

an array antenna made up of a plurality of antenna elements receiving high frequency signals that are transmitted by multi-carrier;

a demultiplexer for demultiplexing the signal received by the respective antenna elements to a plurality of sub-carrier signals;

an entire band direction estimating unit for estimating the direction-of-arrival using sub-carrier signals in the entire communication band being multi-carrier transmitted;

Nd divided band direction estimating units for estimating the direction-of-arrival of a radio wave by dividing the entire communication band into Nd bands (however, Nd is 2 or more, or a positive integer less than the number of sub-carriers used for multi-carrier transmission) and using sub-carrier signals belonging to the respective divided bands;

a direction estimation result selecting unit for selecting and outputting an estimation value of said entire band direction estimating unit when the deviation of the direction estimation results in said Nd divided band direction estimating units is less than the predetermined value, and for outputting an estimation value of said divided band direction estimating unit when the deviation is greater than the predetermined value; and

a divided band array weight creating unit for creating a weight of a receive array having a directional beam in the direction of estimation using the output of said direction estimation result selecting unit.

24. The adaptive antenna radio communication device according to claim 22, further comprising:

in a radio system being multi-carrier transmitted in a time division duplex (TDD) method or a frequency division duplex (FDD) method,

a sub-carrier transmission weight creating unit for calculating a weight of a transmission array that forms a transmitting directional beam in the respective divided bands based on the estimated direction result selected by said direction estimation result selecting unit; and

a sub-carrier transmission directivity creating unit for transmitting a directional beam being multiplied the transmitting sub-carrier signal by the transmission array weight in the respective divided bands.

30. The adaptive antenna radio communication device according to claim 22,

wherein the multi-carrier transmission uses sub-carrier signals to which orthogonal frequency division multiplexing (OFDM) is applied.

33. The adaptive antenna radio communication device according to claim 22,

wherein the multi-carrier transmission uses sub-carrier signals in which users multiplex by code division in the direction of frequency axis or time axis.

36. The adaptive antenna radio communication device according to claim 33,

wherein a weight of a transmission array or a weight of a receive array is created for the respective multiplexed users for directional receiving.

39. The adaptive antenna radio communication device according to claim 36,

wherein said divided band array weight creating unit has a directional beam in the direction estimation result of the divided band direction estimating unit in its divided band and creates a weight of a receive array for creating a null in the estimation direction of other multiplexed users.

42. The adaptive antenna radio communication device according to claim 36,

wherein said sub-carrier transmission weight creating unit has a directional beam in the direction of a desired user and creates a weight of a transmission array for creating a null in the direction of other multiplexed users.

23. An adaptive antenna radio communication device comprising:

an array antenna made up of a plurality of antenna elements receiving high frequency signals that are transmitted by multi-carrier;

a demultiplexer for demultiplexing the signal received by said respective antenna elements to a plurality of sub-carrier signals;

an entire band direction estimating unit for estimating the direction-of-arrival using sub-carrier signals in the entire communication band being multi-carrier transmitted;

Nd divided band direction estimating units for dividing the entire communication band into Nd bands (however, Nd is 2 or more, or a positive integer less than the number of sub-carriers used for multi-carrier transmission) and estimating the direction-of-arrival of a radio wave by using sub-carrier signals belonging to the respective divided bands;

a direction estimation result selecting unit for detecting an angle spread from the spatial profile calculated in said entire band direction estimating unit, for selecting and outputting an estimation value of said entire band direction estimating unit when the angle spread is less than the predetermined value, or outputting an estimation value of the divided band direction estimating unit when the angle spread is greater than the predetermined value; and

a divided band array weight creating unit for creating a weight of a receive array having a directional beam in the direction of estimation using the output of said direction estimation result selecting unit.

25. The adaptive antenna radio communication device according to claim 23, further comprising:

in a radio system being multi-carrier transmitted in a time division duplex (TDD) method or a frequency division duplex (FDD) method,

a sub-carrier transmission weight creating unit for calculating a weight of a transmission array that forms a transmitting directional beam in the respective divided bands based on the estimated direction result selected by said direction estimation result selecting unit; and

a sub-carrier transmission directivity creating unit for transmitting a directional beam being multiplied the transmitting sub-carrier signal by the weight of the transmission array in the respective divided bands.

31. The adaptive antenna radio communication device according to claim 23,

wherein the multi-carrier transmission uses sub-carrier signals to which orthogonal frequency division multiplexing (OFDM) is applied.

34. The adaptive antenna radio communication device according to claim 23,

wherein the multi-carrier transmission uses sub-carrier signals in which users multiplex by code division in the direction of frequency axis or time axis.

37. An adaptive antenna radio communication device according to claim 34,

wherein a weight of a transmission array or a weight of a receive array is created for the respective multiplexed users for directional receiving.

40. The adaptive antenna radio communication device according to claim 37,

wherein said divided band array weight creating unit has a directional beam in the direction estimation result of the divided band direction estimating unit in its divided band and creates a weight of a receive array for creating a null in the estimation direction of other multiplexed users.

43. The adaptive antenna radio communication device according to claim 37,

wherein said sub-carrier transmission weight creating unit has a directional beam in the direction of a desired user and creates a weight of a transmission array for creating a null in the direction of other multiplexed users.