BEAMFORMING APPARATUS AND METHOD FOR MULTI-ANTENNA SYSTEM

• US 20110032150A1
• Filed: 08/04/2010
• Published: 02/10/2011
• Est. Priority Date: 08/06/2009
• Status: Active Grant

• Current Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Original Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Inventors: PARK, Chul Gyun, JO, Kyung Tae, PARK, Joun Sup, KO, Young Chai
• Granted Patent: US 7,965,234 B2
• Time in Patent Office: Days
• US Class Current: 342/372
• CPC Class Codes: H01Q 3/2605 Array of radiating elements provided with a feedback control over the element weights, e.g. adaptive arrays

Abstract

A beamforming apparatus for a multi-antenna system includes a phase control unit including a plurality of phase shifters which respectively control the phases of signals according to a preset phase weight vector; a signal combination unit combining the signals outputted from the plurality of phase shifters; a frequency down converter down-converting the combined signal outputted from the signal combination unit into a baseband signal; an analog/digital (A/D) converter converting the baseband signal into a digital signal; and a radio frequency (RF) beamforming control unit providing a plurality of preset phase weight vectors to the phase control unit according to a preset application sequence, deciding a maximum signal-to-noise ratio (SNR) among a plurality of SNRs corresponding to the applied phase weight vectors by using the digital signal outputted from the A/D converter, and controlling the beamforming of the phase control unit by using the maximum SNR.

Claims

1. A beamforming apparatus for a multi-antenna system, comprising:

a phase control unit comprising a plurality of phase shifters which respectively control the phases of signals received from a plurality of antennas according to a preset phase weight vector;

a signal combination unit combining the signals outputted from the plurality of phase shifters;

a frequency down converter down-converting the combined signal outputted from the signal combination unit into a baseband signal;

an analog/digital (A/D) converter converting the baseband signal outputted from the frequency down converter into a digital signal; and

a radio frequency (RF) beamforming control unit providing a plurality of preset phase weight vectors to the phase control unit according to a preset application sequence, deciding a maximum signal-to-noise ratio (SNR) among a plurality of SNRs corresponding to the applied phase weight vectors by using the digital signal outputted from the A/D converter, and controlling the beamforming of the phase control unit by using the maximum SNR.

2. The beamforming apparatus of claim 1, wherein the RF beamforming control unit comprises:

a phase weight vector codebook comprising the plurality of phase weight vectors which are divided into a plurality of first to m-th arrangement ranges in consideration of phase correlations;

a phase control section applying the plurality of phase weight vectors of the phase weight vector codebook according to the preset application sequence, deciding the maximum SNR by using a comparison result among the plurality of SNRs corresponding to the applied phase weight vectors, and controlling the respective phases of the phase shifters by using the maximum SNR;

an SNR detection unit detecting SNRs for the applied phase weight vectors by using the digital signal outputted from the A/D converter; and

an SNR comparison unit comparing the detected SNRs for the applied phase weight vectors, which are outputted from the SNR detection unit, and providing the comparison result to the phase control section.

3. The beamforming apparatus of claim 2, wherein the phase control section decides a maximum SNR in a preset start arrangement range among the first to m-th arrangement range of the phase weight vector codebook, decides maximum SNRs in the other arrangement ranges by using periodicity of the SNRs which occurs depending on the arrangement ranges having the phase correlations among the plurality of phase weight vectors, and decides a maximum SNR having the greatest value among the maximum SNRs of the first to m-th arrangement ranges.

4. The beamforming apparatus of claim 3, wherein an arrangement range in which the maximum SNR is highly likely to be searched for, among the plurality of first to m-th arrangement ranges, is previously set to the start arrangement range.

5. The beamforming apparatus of claim 4, wherein an intermediate arrangement range which is expected to be favorable for reducing the search time of the maximum SNR, among the plurality of first to m-th arrangement ranges, is previously set to the start arrangement range.

6. The beamforming apparatus of claim 3, wherein the phase control unit applies all the phase weight vectors within the start arrangement range among the first to m-th arrangement range of the phase weight vector codebook, and decides the maximum SNR among the SNRs of the applied phase weight vectors.

7. The beamforming apparatus of claim 3, wherein the phase control section applies two preset phase weight vectors within the start arrangement range among the first to m-th arrangement ranges of the phase weight vector codebook, and decides the maximum SNR among the SNRs of phase weight vectors preceding or succeeding the phase weight vector having the large SNR, according to a comparison result obtained by comparing the magnitudes of the applied two phase weight vectors.

8. A beamforming method which is applied to a multi-antenna system comprising a phase control unit comprising a plurality of phase shifters which respectively control the phases of signals received from a plurality of antennas according to a preset phase weight vector;

a signal combination unit combining the signals outputted from the plurality of phase shifters;

a frequency down converter down-converting the combined signal outputted from the signal combination unit into a baseband signal; and

an A/D converter converting the baseband signal outputted from the frequency down converter into a digital signal, the beamforming method comprising;

performing an SNR detection operation of providing a plurality of phase weight vectors contained in a preset phase weight vector codebook to the phase control unit according to a preset application sequence, and detecting a plurality of SNRs corresponding to the applied phase weight vectors by using the digital signal outputted from the A/D converter;

performing an SNR comparison operation of comparing the magnitudes of the plurality of SNRs;

performing a maximum SNR decision operation of deciding a maximum SNR according to the comparison result among the plurality of SNRs; and

performing a beamforming operation of controlling beamforming of the phase control unit by using the maximum SNR.

9. The beamforming method of claim 8, wherein the phase weight vector codebook comprises the plurality of phase weight vectors which are divided into a plurality of first to m-th arrangement ranges in consideration of phase correlations.

10. The beamforming method of claim 9, wherein, in the performing of the maximum SNR decision operation, the plurality of phase weight vectors of the phase weight vector codebook are applied according to the preset application sequence, the plurality of SNRs corresponding to the applied phase weight vectors are compared, and the maximum SNR is decided by using the comparison result.

11. The beamforming method of claim 10, where the performing of the maximum SNR decision operation comprises:

performing a first maximum SNR decision operation of deciding a maximum SNR in a preset start arrangement range among the first to m-th arrangement ranges of the phase weight vector codebook;

performing a second maximum SNR decision operation of deciding maximum SNRs in the other arrangement ranges by using the periodicity of the SNRs which occurs depending on arrangement ranges having the phase correlations among the plurality of phase weight vectors; and

performing a third maximum SNR decision operation of deciding a maximum SNR having the greatest value among the SNRs of the first to m-th arrangement ranges.

12. The beamforming method of claim 11, wherein an arrangement range in which the maximum SNR is highly likely to be searched for, among the plurality of first to m-th arrangement ranges, is previously set to the start arrangement range.

13. The beamforming method of claim 12, wherein an intermediate arrangement range which is expected to be favorable for reducing the search time of the maximum SNR, among the plurality of first to m-th arrangement ranges, is previously set to the start arrangement range.

14. The beamforming method of claim 12, wherein, in the performing of the first maximum SNR decision operation, a maximum SNR is decided among the SNRs of all the phase weight vectors within the start arrangement range among the first to m-th arrangement ranges of the phase weight vector codebook.

15. The beamforming method of claim 12, wherein, in the performing of the first maximum SNR decision operation, the magnitudes of two preset phase weight vectors within the start arrangement range among the first to m-th arrangement ranges of the phase weight vector codebook are compared, and a maximum SNR is decided among the SNRs of phase weight vectors preceding or succeeding the phase weight vector having the large SNR according to the comparison result.

16. The beamforming method of claim 12, wherein, in the performing of the second maximum SNR decision operation, the maximum SNRs in the other arrangement ranges are decided by using the periodicity of the SNRs which occurs depending on the arrangement ranges having the phase correlations among the plurality of phase weight vectors.

17. The beamforming method of claim 12, wherein, in the performing of the second maximum SNR decision operation, the magnitude of the maximum SNR of the start arrangement range and the magnitude of a maximum SNR of another arrangement range adjacent to the start arrangement range are compared, and a maximum SNR having the greatest value is decided among the SNRs of the arrangement ranges preceding or succeeding the arrangement range having the larger SNR by using the periodicity of the SNRs which occurs depending on the phase correlations among the plurality of phase weight vectors.