Adaptive antenna device operable in accordance with different algorithms

• US 6,509,865 B2
• Filed: 02/09/2001
• Issued: 01/21/2003
• Est. Priority Date: 02/10/2000
• Status: Expired due to Term

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Takai, Kenichi
• Primary Examiner(s): Blum, Theodore M.
• Application Number:
  US09/779,472
• Publication Number:
  US 20010020918A1
• Time in Patent Office: 711 Days
• Field of Search: 342/373, 342/372, 342/368, 342/157, 342/158, 342/14, 342/16, 342/378
• US Class Current: 342/158
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• CPC Class Codes: H01Q 3/2605 Array of radiating elements provided with a feedback control over the element weights, e.g. adaptive arrays
• CPC Class Codes: H01Q 3/2611 Means for null steering; Adaptive interference nulling

Abstract

In an adaptive antenna device having directivity pattern generators operable in accordance with different algorithms, respectively, in a baseband modem, beam steering processing, null steering processing, and estimating processing of an arrival direction are executed in parallel to one another. Parameters resulting from the beam and the null steering processing are controlled by processing results of the estimating processing and are weighted and combined to individually generate directivity patterns based on the different algorithms.

Claims

1. An adaptive antenna device which comprises a plurality of antenna arrays and a base station apparatus coupled to the antenna arrays, each of the antenna arrays having a plurality of antenna elements spatially arranged, the base station apparatus comprising:

combining means for forming a directivity pattern which is combined by varying an amplitude and a phase of each radio signal received by and transmitted from the antenna elements so that radio energy is increased towards a designated direction of a communication radio wave and is canceled toward a range and a direction of a jamming wave;

the combining means comprising;

beam steering antenna pattern control means for forming a narrow beam to control an antenna gain so that a maximum portion of the antenna gain is directed to a received direction of the communication radio wave;

null steering antenna pattern control means for carrying out a control operation such that an antenna gain has a null portion directed toward a received direction of the jamming wave and concurrently has a high gain portion of the antenna gain directed toward the received direction of the communication radio wave; and

weighting means for weighting a received signal in accordance with a beam obtained by the beam steering antenna pattern control and with a beam obtained by the null steering antenna steering control, wherein the combining means forms said combining directivity pattern for transmitting by simultaneously combining said narrow beam from said beam steering antenna pattern control means and said antenna gain from said null steering antenna pattern control means in accordance with an evaluation function determined in relation to reception.

2. An adaptive antenna device as claimed in claim 1, wherein each of the beam steering antenna pattern control means comprises:

arrival direction estimation means for performing each of the beam steering antenna pattern control and the null steering antenna pattern control simultaneously or in a time division fashion at a very small time interval, so as to estimate a direction of a desired wave from different amplitudes and phases of the received radio waves received from the plurality of the antenna arrays and to produce results of the estimation;

the results of the estimation being defined as an angle profile which is representative of parameter information of the beam steering and the null steering antenna pattern control means.

3. An adaptive antenna device as claimed in claim 1, wherein the beam steering antenna pattern control means comprises:

reception means for receiving, as control information, parameters which include a beam width in question and an angle profile for determining the direction of the beam and which selectively include a previous beam width and a previous angle profile referenced only when control operation is consecutively carried out from the past; and

means for attaining the antenna pattern on the basis of the control information.

4. An adaptive antenna device as claimed in claim 1, wherein the null steering antenna pattern control means comprises:

receiving means for receiving, as control information, parameters which include an angle profile for determining a beam direction and a previous angle profile which is referenced only when control operation is consecutively carried out from the past; and

means for attaining the antenna pattern on the basis of the control information.

5. An adaptive antenna device as claimed in claim 1, further comprising:

comparing means for comparing, with each of predetermined threshold levels, each of a reception signal received through a beam patterned by the beam steering directivity control and another reception signal received through a beam patterned by the null steering directivity control, to produce a result signal representative of a result of comparison; and

combining means for combining the reception signal and another reception signal after each of the reception signal and another reception signal is weighted only when each signal exceeds the predetermined threshold level; and

repeating means for repeating the combining operation after delay time processing is carried out to delay a predetermined time.

6. An adaptive antenna device as claimed in claim 1, wherein a structure for forming a combined directivity characteristic in the base station comprises:

a portion that has a directivity generation part for the beam steering control, a CPU, and a memory; and

another portion that has a directivity generation part for the null steering control, another CPU, and another memory.

7. An adaptive antenna device which comprises a plurality of antenna arrays and a base station apparatus coupled to the antenna arrays, each of the antenna arrays having a plurality of antenna elements spatially arranged, the base station apparatus comprising:

a first directivity pattern generator, operable in accordance with a first algorithm, for generating a first transmission beam which has a first directivity pattern determined by the first algorithm;

a second directivity pattern generator, operable in accordance with a second algorithm different from the first algorithm, for generating a second transmission beam which has a second directivity pattern determined by the second algorithm; and

a combining unit for combining the first transmission beam with the second transmission beam to form a combined directivity pattern in accordance with an evaluation function determined in relation to reception.

8. An adaptive antenna device as claimed in claim 7, wherein the first algorithm and the second algorithm are used for executing beam steering control and null steering control, respectively.

9. An adaptive antenna device as claimed in claim 8, wherein the combining unit is operable to vary an amplitude and a phase of each radio signal received by and transmitted from the antenna elements so that radio energy is increased towards a designated direction of a communication radio wave and is canceled towards a range and a direction of a jamming wave.

10. An adaptive antenna device as claimed in claim 7, the base station apparatus further comprising:

a third directivity pattern generator for carrying out receiving operation of a received signal in accordance with the first algorithm to produce a first processed signal;

a fourth directivity pattern generator for carrying out receiving operation of the received signal in accordance with the second algorithm to produce a second processed signal; and

a control unit for controlling the third and the fourth directivity pattern generators so that the first and the second processed signals become optimum in phases and amplitudes.

11. An adaptive antenna device as claimed in claim 10, wherein the first and the second algorithms are determined for beam steering control and null steering control, respectively.

12. A method of controlling an adaptive antenna device, comprising:

generating a first transmission beam of a first directivity pattern in accordance with a first algorithm;

generating a second transmission beam of a second directivity pattern in accordance with a second algorithm different from the first algorithm;

combining the first and second transmission beams to produce a combined beam of a combined directivity pattern; and

controlling the combined directivity pattern in consideration of an arrival direction of a desired wave and arrival directions of jamming waves.

13. A method as claimed in claim 12, wherein the first algorithm is determined for beam steering control while the second algorithm is determined for null steering control.

14. A method as claimed in claim 13, wherein the controlling step is carried out so that the first beam has a maximum antenna gain in the arrival direction of the desired wave while the second beam has a minimum antenna gain in the arrival directions of the jamming waves.

15. A method as claimed in claim 12, wherein the controlling step comprises the steps of;

estimating the arrival directions of the desired wave and the jamming waves;

carrying out beam steering processing to produce the first beam;

carrying out null steering processing to produce the second beam; and

weighting and combining both the first and the second beams to obtain the combined beam with reference to results of the estimating.

16. A method as claimed in claim 12, wherein the controlling step comprises the steps of:

estimating the arrival directions of the desired wave and the jamming waves;

carrying out beam steering processing to produce the first beam;

carrying out null steering processing to produce the second beam;

comparing, with threshold levels, first and second signals representative of the first and the second beams;

weighting and combining both the first and the second signals to obtain the combined beam with reference to results of the estimating when the first and the second signals exceed the threshold levels, respectively, and, otherwise, carrying out a sleep mode.