Communications apparatus using adaptive antenna

• US 20040139897A1
• Filed: 01/09/2004
• Published: 07/22/2004
• Est. Priority Date: 01/10/2003
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Oishi, Yasuyuki, Toda, Takeshi, Nakaya, Yuta, Hara, Shinsuke
• Granted Patent: US 7,499,727 B2
• Time in Patent Office: Days
• US Class Current: 114/1
• CPC Class Codes: H04B 17/20 of receivers
• CPC Class Codes: H04B 7/0842 Weighted combining

Abstract

A communications apparatus using an adaptive antenna having in a high frequency unit an antenna unit including a plurality of antenna elements and a plurality of adjustment units, provided corresponding to the plurality of antenna elements, for adjusting directivity of an entire antenna, comprising:

an interference wave element extraction unit for extracting an interference wave element other than a requested signal from a received signal by the antenna unit when an adjustment value of the adjustment unit is perturbed in a 1 symbol time; and

an adaptive control unit for performing adaptive control on the adjustment value such that the extracted interference wave element can be minimized.

Claims

1. A communications apparatus using an adaptive antenna having in a high frequency unit an antenna unit including a plurality of antenna elements and a plurality of adjustment units provided corresponding to the plurality of antenna elements for adjusting directivity of an entire antenna, comprising:

an interference wave element extraction unit extracting an interference wave element other than a requested signal to be received by said communications apparatus from a received signal by the antenna unit when an adjustment value of the adjustment unit is perturbed in a 1 symbol time used in said communications apparatus; and

an adaptive control unit performing adaptive control on the adjustment value such that the extracted interference wave element can be minimized.

2. The apparatus according to claim 1, wherein:

the plurality of antenna elements comprise a feed antenna element and one or more no-feed antenna elements near the feed antenna element;

the adjustment unit is a variable reactance circuit unit connected to each no-feed antenna element; and

the adjustment value is a variable reactance value.

3. The apparatus according to claim 1, wherein:

the adjustment unit is a weight unit corresponding to each of the plurality of antenna elements;

the antenna unit further comprises a composing circuit unit for composing a weighted signal from each antenna element; and

the adjustment value is a weight value of the weight unit.

4. The apparatus according to claim 1, wherein

said communications apparatus converts a transmission data sequence into a parallel data sequence, and each of the converted data sequences is transmitted in parallel by a plurality of carriers having different frequencies;

and

said interference wave element extraction unit extracts as the interference wave element a virtual subcarrier element as a carrier not used in data communications in a plurality of carriers.

5. The apparatus according to claim 1, wherein

said interference wave element extraction unit extracts an interference wave element using a result of a Fourier transform of a digitized signal of the received signal.

6. The apparatus according to claim 1, wherein

said interference wave element extraction unit extracts an interference wave element using a result of a Wavelet transform of a digitized signal of the received signal.

7. The apparatus according to claim 1, wherein

said interference wave element extraction unit extracts an interference wave element using received data obtained when the adjustment value is perturbed in one of two symbols and received data obtained when the adjustment value is not perturbed in the other symbol.

8. The apparatus according to claim 7, wherein

said interference wave element extraction unit uses received data obtained by repeatedly perturbing each adjustment value of the plurality of adjustment units for each sample in one symbol.

9. The apparatus according to claim 7, wherein

said interference wave element extraction unit uses received data obtained by sequentially and continuously perturbing each adjustment value of the plurality of adjustment units for a plurality of samples in one symbol.

10. The apparatus according to claim 1, wherein

said interference wave element extraction unit extracts an interference wave element from the received signal obtained in a format in which a section of perturbing an adjustment value of the adjustment unit in the one symbol and a section of not perturbing any adjustment value of a plurality of adjustment units are included.

11. The apparatus according to claim 1, wherein

said communications apparatus comprises the antenna unit, the interference wave element extraction unit, and the adaptive control unit;

the antenna unit comprises a plurality of diversity branches provided in spatially different positions; and

said communications apparatus further comprises a weight composite unit for weight composing a signal from each diversity branch.

12. The apparatus according to claim 11, wherein

the adaptive control unit is in each of the plurality of diversity branches, and independently performs control of each adjustment value.

13. The apparatus according to claim 11, further comprising

a cooperative control unit performing cooperative control of each adaptive control unit for each adaptive control unit in the plurality of diversity branches.

14. The apparatus according to claim 1, further comprising

an adjustment value setting unit setting to a predetermined value an adjustment value of an adjustment unit other than a part of adjustment units so that an influence of adjustment by a part of adjustment units can be evaluated in the plurality of adjustment units.

15. The apparatus according to claim 1, wherein

said adaptive control unit performs control of the adjustment value in a steepest gradient method.

16. A communications apparatus using an adaptive antenna having in a high frequency unit an antenna unit including a plurality of antenna elements and a plurality of adjustment units provided corresponding to the plurality of antenna elements for adjusting directivity of an entire antenna, comprising:

interference wave element extraction means for extracting an interference wave element other than a requested signal to be received by said communications apparatus from a received signal by the antenna unit when an adjustment value of the adjustment unit is perturbed in a 1 symbol time used in said communications apparatus; and

adaptive control means for performing adaptive control on the adjustment value such that the extracted interference wave element can be minimized.