Apparatus and method for calibrating transmission paths in a multicarrier communication system using multiple antennas

• US 20070037519A1
• Filed: 08/08/2006
• Published: 02/15/2007
• Est. Priority Date: 08/08/2005
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd. (Samsung Group)
• Original Assignee: Samsung Electronics Co. Ltd. (Samsung Group)
• Inventors: Kim, Jong-In, Kim, Byung-Ki
• Granted Patent: US 7,389,193 B2
• Time in Patent Office: Days
• US Class Current: 455/63.400
• CPC Class Codes: H04B 17/21 for calibration; for correcting measurements
• CPC Class Codes: H04L 2025/03426 transmission using multiple-input and multiple-output channels
• CPC Class Codes: H04L 2025/03802 Signalling on the reverse channel
• CPC Class Codes: H04L 25/0204 of multiple channels
• CPC Class Codes: H04L 25/0232 by interpolation between sounding signals
• CPC Class Codes: H04L 25/03343 Arrangements at the transmitter end
• CPC Class Codes: H04L 27/261 Details of reference signals
• CPC Class Codes: H04L 27/2626 Arrangements specific to the transmitter only
• CPC Class Codes: H04L 27/2647 Arrangements specific to the receiver only equalisation H04L27/01

Abstract

An apparatus and method for calibrating transmission paths in a multicarrier communication system using multiple antennas are provided. In the transmission path calibrating apparatus, a calibration processor generates reference signals to estimate distortions in phase and amplitude in transmission paths, allocates the generated reference signals to subcarriers which are different in each of the transmission paths, and calculates calibration vectors for the transmission paths using the generated reference signals and received reference signals received through the transmission paths. A baseband module IFFT-processes the generated reference signals allocated to the subcarriers and sends the IFFT signals in the transmission paths.

Claims

1. An apparatus for calibrating transmission paths in a multicarrier communication system using multiple antennas, comprising:

a calibration processor for generating reference signals to estimate distortions in phase and amplitude in transmission paths, allocating the generated reference signals to subcarriers which are different in each of the transmission paths, and calculating calibration vectors for the transmission paths using the generated reference signals and received reference signals received through the transmission paths; and

a baseband module for inverse-fast-Fourier-transform (IFFT)-processing the generated reference signals allocated to the subcarriers and sending the IFFT signals in the transmission paths.

2. The apparatus of claim 1, wherein the baseband module corrects beam weight vectors using the calibration vectors and forms beams using the corrected beam weight vectors.

3. The apparatus of claim 1, wherein the calibration processor comprises:

a reference signal generator for generating the reference signals by which to estimate distortions in phase and amplitude in the transmission paths and allocating the generated reference signals to the subcarriers which are different in each of the transmission paths;

a fast Fourier transform (FFT) processor for separating the received reference signals which have passed through the transmission paths into subcarrier signals;

an interpolator for estimating reference signals of subcarrier to which the generated reference signals are not allocated by interpolating the subcarrier signals; and

a calibration vector calculator for calculating the calibration vectors for the respective transmission paths using the interpolated reference signals and the received reference signals.

4. The apparatus of claim 2, wherein the baseband module comprises:

a plurality of IFFT processors for IFFT-processing the generated reference signals allocated to the subcarriers and sending the IFFT signals in the transmission paths;

a beam weight vector calculator for correcting beam weight vectors using the calibration vectors; and

a beamformer for forming beams using the corrected beam weight vectors.

5. A method of calibrating transmission paths in a multicarrier communication system using multiple antennas, comprising the steps:

generating reference signals to estimate distortions in phase and amplitude in transmission paths and allocating the generated reference signals to subcarriers which are different in each of the transmission paths;

inverse-fast-Fourier-transform (IFFT)-processing the generated reference signals allocated to the subcarriers and sending the IFFT signals in the transmission paths; and

calculating calibration vectors for the transmission paths using the generated reference signals and received reference signals received through the transmission paths.

6. The method of claim 5, further comprising:

correcting beam weight vectors using the calibration vectors; and

forming beams using the corrected beam weight vectors.

7. The method of claim 5, wherein the calibration vector calculating step comprises:

separating the received reference signals which have passed through the transmission paths into subcarrier signals;

estimating reference signals of subcarrier to which the generated reference signals are not allocated by interpolating the subcarrier signals; and

calculating the calibration vectors for the respective transmission paths using the interpolated reference signals and the received reference signals.

8. The method of claim 5, wherein the subcarriers to which the generated reference signals are allocated are subcarriers other than pilot subcarriers.

9. The method of claim 5, wherein the subcarriers to which the generated reference signals are allocated are pilot subcarriers.

10. An apparatus for calibrating transmission paths in a multicarrier communication system using multiple antennas, comprising:

a calibration processor for generating reference signals, allocating the generated reference signals to subcarriers in each of the transmission paths, and calculating calibration vectors using the generated reference signals and received reference signals received through the transmission paths; and

a baseband module for processing the generated reference signals allocated to the subcarriers and sending the processed signals in the transmission paths.

11. The apparatus of claim 10, wherein the baseband module corrects beam weight vectors using the calibration vectors from the calibration processor and forms beams using the corrected beam weight vectors.

12. The apparatus of claim 10, wherein the calibration processor comprises:

a reference signal generator for generating the reference signals and allocating the generated reference signals to the subcarriers in each of the transmission paths;

a processor for separating the received reference signals which have passed through the transmission paths into subcarrier signals;

an interpolator for estimating reference signals of subcarrier to which the generated reference signals are not allocated by interpolating the subcarrier signals; and

a calibration vector calculator for calculating the calibration vectors for the respective transmission paths using the interpolated reference signals and the received reference signals.

13. The apparatus of claim 10, wherein the baseband module comprises:

a plurality of processors for processing the generated reference signals allocated to the subcarriers and sending the processed signals in the transmission paths;

a beam weight vector calculator for correcting beam weight vectors using the calibration vectors; and

a beamformer for forming beams using the corrected beam weight vectors.

14. A method of calibrating transmission paths in a multicarrier communication system using multiple antennas, comprising the steps:

generating reference signals and allocating the generated reference signals to subcarriers in each of the transmission paths;

processing the generated reference signals allocated to the subcarriers and sending the processed signals in the transmission paths; and

calculating calibration vectors for the transmission paths using the generated reference signals and received reference signals received through the transmission paths.

15. The method of claim 14, further comprising:

correcting beam weight vectors using the calibration vectors; and

forming beams using the corrected beam weight vectors.

16. The method of claim 14, wherein the calibration vector calculating step comprises:

-separating the received reference signals which have passed through the transmission paths into subcarrier signals;

estimating reference signals of subcarrier to which the generated reference signals are not allocated by interpolating the subcarrier signals; and

calculating the calibration vectors for the respective transmission paths using the interpolated reference signals and the received reference signals.

17. The method of claim 14, wherein the subcarriers to which the generated reference signals are allocated are subcarriers other than pilot subcarriers.

18. The method of claim 14, wherein the subcarriers to which the generated reference signals are allocated are pilot subcarriers.