APPARATUS AND METHOD FOR TIME-VARYING CYCLIC DELAY DIVERSITY IN A WIRELESS COMMUNICATION SYSTEM

• US 20090141620A1
• Filed: 12/01/2008
• Published: 06/04/2009
• Est. Priority Date: 11/30/2007
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: HWANG, Yong-Sun, PARK, Jeong-Soon, SHIN, Yong-Won
• Granted Patent: US 8,259,631 B2
• Time in Patent Office: Days
• US Class Current: 370/210
• CPC Class Codes: H04B 7/0671 using different delays between antennas
• CPC Class Codes: H04L 27/2626 Arrangements specific to the transmitter only
• CPC Class Codes: H04L 27/2665 Fine synchronisation, e.g. by positioning the FFT window

Abstract

An apparatus and method for Time-Varying Cyclic Delay Diversity (TV-CDD) in a wireless communication system are provided. The method includes, if there is a signal of an antenna path to be transmitted, determining if a current time corresponds to a preamble zone within a frame and, if the current time corresponds to the preamble zone within the frame, shifting a partial antenna path signal forward compared to a reference timing and shifting a remaining partial antenna path signal equally or backward compared to the reference timing.

Claims

1. A method for applying a shift in a transmitter of a wireless communication system, the method comprising:

if there is a signal of an antenna path to be transmitted, determining if a current time corresponds to a preamble zone within a frame; and

if the current time corresponds to the preamble zone within the frame, shifting a partial antenna path signal forward compared to a reference timing and shifting a remaining partial antenna path signal equally or backward compared to the reference timing.

2. The method of claim 1, wherein the reference timing comprises a start time of an Inverse Fast Fourier Transform (IFFT) window.

3. The method of claim 1, wherein a shift value of the partial antenna path signal and a shift value of the remaining partial antenna path signal are the same in magnitude.

4. The method of claim 1, further comprising, when a current time corresponds to a data zone within the frame, shifting a remaining antenna path signal backward compared to the reference timing without shifting a reference antenna path signal.

5. The method of claim 4, wherein at least one of a length of an entire shift and a frequency selectivity is set to be similar for the preamble zone and data zone.

6. The method of claim 5, wherein, in the case of the preamble zone, the length of the entire shift is an amount of time between the shifted partial antenna path signal and the shifted remaining partial antenna path signal and, in the case of the data zone, the length of the entire shift is an amount of time between the reference antenna path signal and the remaining antenna path signal.

7. The method of claim 1, wherein the signal of an antenna path to be transmitted is a signal processed by an IFFT operation.

8. The method of claim 1, further comprising inserting a Cyclic Prefix (CP) into the shifted signal of an antenna path for transmission.

9. The method of claim 1, further comprising identifying a structure of the frame for the determining if the current time corresponds to the preamble zone within the frame.

10. An apparatus for applying a shift in a transmitter of a wireless communication system, the apparatus comprising:

an Inverse Fast Fourier Transform (IFFT) unit for performing an IFFT operation for a signal of an antenna path to be transmitted; and

a cycle shift unit for determining if a current time corresponds to a preamble zone within a frame and, if the current time corresponds to the preamble zone within the frame, for shifting a partial antenna path signal among the IFFT operated signals forward compared to reference timing and shifting a remaining partial antenna path signal equally or backward compared to the reference timing.

11. The apparatus of claim 10, wherein the reference time comprises a start time of an IFFT window.

12. The apparatus of claim 10, wherein a shift value of the partial antenna path signal and a shift value of the remaining partial antenna path signal are the same in magnitude.

13. The apparatus of claim 10, wherein, if a current time corresponds to a data zone within the frame, the cyclic shift unit shifts a remaining antenna path signal backward compared to reference timing without shifting a reference antenna path signal among the IFFT operated signals.

14. The apparatus of claim 13, wherein at least one of a length of an entire shift and a frequency selectivity is set to be similar for the preamble zone and data zone.

15. The apparatus of claim 14, wherein in the case of the preamble zone, the length of the entire shift is an amount of time between the shifted partial antenna path signal and the shifted remaining partial antenna path signal and, in the case of the data zone, the length of the entire shift is an amount of time between the reference antenna path signal and the remaining antenna path signal.

16. The apparatus of claim 10, further comprising a CP generator for inserting a Cyclic Prefix (CP) into the shifted signal of an antenna path for transmission.

17. The apparatus of claim 10, wherein the cycle shift unit identifies a structure of the frame for the determining if the current time corresponds to the preamble zone within the frame.