Apparatus and method for time-varying cyclic delay diversity in a wireless communication system

• US 8,259,631 B2
• Filed: 12/01/2008
• Issued: 09/04/2012
• 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
• Primary Examiner(s): LEVITAN, DMITRY
• Application Number:
  US12/325,457
• Publication Number:
  US 20090141620A1
• Time in Patent Office: 1,373 Days
• Field of Search: 370/310, 370/328, 370/345, 370/349, 370/350, 375/259, 375/260, 375/267, 375/295, 455/403, 455/422, 455/91, 455101-105
• US Class Current: 370/310
• 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 Time-Varying Cyclic Delay Diversity (TV-CDD) in a wireless communication system, the method comprising:

determining whether there is a preamble zone or a data zone of a frame; and

when there is the preamble zone of the frame, shifting each of a transmission timing of a partial antenna path signal corresponding to the preamble zone to a first timing and shifting a transmission timing of a remaining antenna path signal corresponding to the preamble zone to a second timing; and

when there is the data zone of the frame, maintaining a timing of a reference antenna path signal and shifting each transmission timing of a remaining antenna path signal corresponding to the data zone to a third timing,

wherein the first timing is earlier than a reference timing designating an accurate Fast Fourier Transform (FFT) sampling point of a data zone, and the second and the third timings are later than the reference timing.

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

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

4. The method of claim 1, wherein a length of an entire shift for the partial antenna path signal corresponding to the preamble zone corresponds to a length of an entire shift for the remaining antenna path signal corresponding to the preamble zone.

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

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

7. An apparatus for applying a Time-Varying Cyclic Delay Diversity (TV-CDD) in a wireless communication system, the apparatus comprising:

an Inverse Fast Fourier Transform (IFFT) unit for performing an IFFT operation for a sampling data corresponding to a preamble zone of a frame or a sampling data corresponding to a data zone of the frame, to be transmitted; and

a cycle shift unit for determining whether there is the preamble zone of the frame or there is the data zone of the frame, and for, when there is the preamble zone of the frame, shifting each of a transmission timing of a partial antenna path signal corresponding to the preamble zone to a first timing and shifting a transmission timing of a remaining antenna path signal corresponding to the preamble zone to a second timing, and for, when there is the data zone of the frame, maintaining a reference antenna path signal and shifting each of a transmission timing of a remaining antenna path signal corresponding to the data zone to a third timing,

wherein the first timing is earlier than a reference timing designating an accurate Fast Fourier Transform (FFT) sampling point of a data zone, and the second and third timings are later than the reference timing.

8. The apparatus of claim 7, wherein the reference time comprises a start time of an FFT window.

9. The apparatus of claim 7, wherein a shift value of the partial antenna path signal corresponding to the preamble zone and a shift value of the remaining antenna path signal corresponding to the preamble zone are the same in magnitude.

10. The apparatus of claim 7, wherein a length of an entire shift for the partial antenna path signal corresponding to the preamble zone corresponds to a length of an entire shift for the remaining antenna path signal corresponding to the preamble zone.

11. The apparatus of claim 7, further comprising a Cyclic Prefix (CP) generator for inserting a CP into the shifted signal of an antenna path for transmission.

12. A method for applying a Time-Varying Cyclic Delay Diversity (TV-CDD) in a wireless communication system, the method comprising:

converting a plurality of signals corresponding to a plurality of antennas into a partial antenna path signal or a remaining antenna path signal of time domain each;

shifting a transmission timing of each of the antenna path signals, according to whether there is a preamble zone of a frame or there is a data zone of the frame;

inserting Cyclic Prefix (CP) in each of the shifted antenna path signals; and

transmitting each of the shifted antenna path signals inserted with the CP through the plurality of antennas,

wherein the step of shifting each of the antenna path signals according to whether there is a preamble zone of a frame or there is a data zone of the frame, comprises;

determining a reference antenna path signal designating an accurate Fast Fourier Transform (FFT) sampling point of a data zone of the converted plurality of antenna path signals;

when there is the preamble zone of the frame, shifting a first one of the converted plurality of antenna path signals except the reference antenna path signal, to a first timing which is earlier than a transmission timing of the reference antenna path signal, and shifting a second one of the converted plurality of antenna path signals except the reference antenna path signal, to a second timing which is later than a transmission timing of the reference antenna path signal; and

when there is the data zone of the frame, maintaining the reference antenna path signal and shifting all the converted plurality of antenna path signals except the reference antenna path signal, to a third timing which is later than a transmission timing of the reference antenna path signal.

13. The apparatus of claim 12, wherein a shift value of the partial antenna path signal corresponding to the preamble zone and a shift value of the remaining antenna path signal corresponding to the preamble zone are the same in magnitude.

14. The apparatus of claim 12, wherein a length of an entire shift for the partial antenna path signal corresponding to the preamble zone corresponds to a length of an entire shift for the remaining antenna path signal corresponding to the preamble zone.

15. An apparatus for applying a Time-Varying Cyclic Delay Diversity (TV-CDD) in a wireless communication system, the apparatus comprising:

a plurality of Inverse Fast Fourier Transform (IFFT) units for converting a plurality of signals corresponding to a plurality of antennas into a partial antenna path signal or a remaining antenna path signal of time domain each;

a plurality of cycle shift units for shifting a timing of each of the antenna path signals, according to whether there is a preamble zone of a frame or there is a data zone of the frame;

a plurality of Cyclic Prefix (CP) generators for inserting CP in each of the shifted antenna path signals; and

a plurality of transmitters for transmitting each of the shifted antenna path signals inserted with the CP through the plurality of antennas,

wherein each of the cycle shift units;

determines a reference antenna path signal of the converted plurality of antenna path signals;

when there is the preamble zone of the frame, shifts a first one of the converted plurality of antenna path signals, except the reference antenna path signal, to a first timing which is earlier than a transmission timing of the reference antenna path signal, and shifts a second one of the converted plurality of antenna path signals, except the reference antenna path signal, to a second timing which is later than a transmission timing of the reference antenna path signal; and

when there is the data zone of the frame, shifts all the converted plurality of antenna path signals except the reference antenna path signal, to the third timing which is later than a transmission timing of the reference antenna path signal.

16. The apparatus of claim 15, wherein a shift value of the partial antenna path signal corresponding to the preamble zone and a shift value of the remaining antenna path signal corresponding to the preamble zone are the same in magnitude.

17. The apparatus of claim 15, wherein a length of entire shift for the partial antenna path signal corresponding to the preamble zone corresponds to a length of entire shift for the remaining antenna path signal corresponding to the preamble zone.