Method of resolving overlaps in data transmission and user equipment therefor

• US 8,467,373 B2
• Filed: 01/12/2010
• Issued: 06/18/2013
• Est. Priority Date: 01/11/2008
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Ahn, Joon Kui, Kim, Ki Jun, Ihm, Bin Chul, Yun, Young Woo
• Primary Examiner(s): Chriss, Andrew
• Assistant Examiner(s): Cehic, Kenan
• Application Number:
  US12/686,348
• Publication Number:
  US 20100128594A1
• Time in Patent Office: 1,253 Days
• Field of Search: 370310-350, 370503-520, 455/502, 455/503
• US Class Current: 370/350
• CPC Class Codes: H04L 27/2646 using feedback from receiver for adjusting OFDM transmission parameters, e.g. transmission timing or guard interval length
• CPC Class Codes: H04L 27/2655 Synchronisation arrangements
• CPC Class Codes: H04W 56/003 Arrangements to increase tolerance to errors in transmission or reception timing
• CPC Class Codes: H04W 56/0045 compensating for timing error by altering transmission time
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 88/02 Terminal devices

Abstract

A user equipment and method of transmitting symbols by the user equipment in a wireless communication system. The method includes: generating a first symbol by adding a cyclic prefix (CP) to a first inverse fourier transformed samples, the CP being copied from the first fourier transformed samples; generating a next consecutive second symbol by adding a CP to a second inverse fourier transformed samples, the CP being copied from the second fourier transformed samples; removing samples overlapped with the first symbol from the next consecutive second symbol when the next consecutive second symbol is to be advanced in transmission timing; and transmitting the first symbol and the next consecutive second symbol to a base station.

Claims

1. A method of transmitting symbols by a user equipment in a wireless communication system, the method comprising:

receiving a timing adjustment command from a base station, the timing adjustment command advancing a transmission timing of uplink transmission;

generating a first symbol by adding a first cyclic prefix (CP) to a first inverse fourier transformed samples, the first CP being copied from the first inverse fourier transformed samples;

generating a second symbol by adding a second CP to a second inverse fourier transformed samples, the second CP being copied from the second inverse fourier transformed samples,

wherein the timing adjustment command is applied starting from the second symbol;

forming a modified second symbol by removing samples overlapped with the first symbol from the second symbol when the first symbol and the second symbol are overlapped due to the timing adjustment; and

transmitting the first symbol and the modified second symbol to the base station,

wherein the transmitted first symbol has a complete size and the transmitted modified second symbol has a partial size.

2. The method of claim 1, wherein the first and the second inverse fourier transformed samples are discrete fourier transformed before being inverse fourier transformed, respectively.

3. The method of claim 1, wherein the second symbol is advanced in transmission timing by multiple samples.

4. The method of claim 1, wherein a number of removed samples is the same as or larger than a number of samples in the second CP.

5. The method of claim 1, wherein a number of removed samples is smaller than a number of samples in the second CP.

6. The method of claim 1, wherein a number of removed samples is the same as or larger than one of 144 samples, 160 samples or 512 samples.

7. The method of claim 1, wherein a number of removed samples is smaller than one of 144 samples, 160 samples or 512 samples.

8. A user equipment used for a wireless communication system, the user equipment comprising:

a wireless communication unit configured to

receive a timing adjustment command from a base station, the timing adjustment command advancing a transmission timing of uplink transmission, and

transmit symbols to the base station; and

a symbol generation unit configured to generate the symbols,

wherein the symbol generation unit is configured to generate a first symbol by adding a first cyclic prefix (CP) to a first inverse fourier transformed samples, the first CP being copied from the first inverse fourier transformed samples,

wherein the symbol generation unit is configured to generate a second symbol by adding a second CP to a second inverse fourier transformed samples, the second CP being copied from the second inverse fourier transformed samples,

wherein the timing adjustment command is applied starting from the second symbol,

wherein the symbol generation unit is configured to form a modified second symbol by removing samples overlapped with the first symbol from the second symbol when the first symbol and the second symbol are overlapped due to the timing adjustment,

wherein the wireless communication unit configured to transmit the first symbol and the second symbol to the base station, and

wherein the transmitted first symbol has a complete size and the transmitted modified second symbol has a partial size.

9. The user equipment of claim 8, wherein the first and the second inverse fourier transformed samples are discrete fourier transformed before being inverse fourier transformed, respectively.

10. The user equipment of claim 8, wherein the second symbol is advanced in transmission timing by multiple samples.

11. The user equipment of claim 8, wherein a number of removed samples is the same as or larger than a number of samples in the second CP.

12. The user equipment of claim 8, wherein a number of removed samples is smaller than a number of samples in the second CP.

13. The user equipment of claim 8, wherein a number of removed samples is the same as or larger than one of 144 samples, 160 samples or 512 samples.

14. The user equipment of claim 8, wherein a number of removed samples is smaller than one of 144 samples, 160 samples or 512 samples.

15. A method of transmitting symbols by a user equipment in a wireless communication system, the method comprising:

receiving a timing adjustment command from a base station, the timing adjustment command advancing a transmission timing of uplink transmission;

generating a first symbol by adding a first complete cyclic prefix (CP) to a first inverse fourier transformed samples, the complete CP being copied from the first inverse fourier transformed samples;

obtaining a second inverse fourier transformed samples for a second symbol,

wherein the timing adjustment command is applied starting from the second symbol;

adding a partial CP to the second inverse fourier transformed samples to generate the second symbol when a completely sized second symbol is expected to overlap a completely sized first symbol due to the timing adjustment; and

transmitting the first symbol with the complete CP and the second symbol with the partial CP to the base station,

wherein the partial CP is copied from a part of the second inverse fourier transformed samples, the part being recognized as remaining samples after excluding samples overlapping with the first symbol from samples corresponding to a complete CP of the second symbol.

16. The method of claim 15, wherein the first and the second inverse fourier transformed samples are discrete fourier transformed before being inverse fourier transformed, respectively.

17. The method of claim 15, wherein the complete CP is an unextended CP.

18. The method of claim 17, wherein a size of the complete CP is 144 or 160 samples.

19. The method of claim 15, wherein the complete CP is an extended CP.

20. The method of claim 19, wherein a size of the complete CP is 512 samples.

21. A user equipment used for a wireless communication system, the user equipment comprising:

a wireless communication unit configured to

receive a timing adjustment command from a base station, the timing adjustment command advancing a transmission timing of uplink transmission, and

transmit symbols consecutively to the base station; and

a symbol generation unit configured to generate symbols,

wherein the symbol generation unit is configured to generate a first symbol by adding a complete cyclic prefix (CP) to a first inverse fourier transformed samples, the complete CP being copied from the first inverse fourier transformed samples,

wherein the symbol generation unit is configured to obtain a second inverse fourier transformed samples for a second symbol,

wherein the timing adjustment command is applied starting from the second symbol,

wherein the symbol generation unit is configured to add a partial CP to the second inverse fourier transformed samples to generate the second symbol when a completely sized second symbol is expected to overlap a completely sized first symbol due to the timing adjustment,

wherein the wireless communication unit is configured to transmit the first symbol with the complete CP and the second symbol with the partial CP to the base station, and

wherein the partial CP is copied from a part of the second inverse fourier transformed samples, the part being recognized as remaining samples after excluding samples overlapping with the first symbol from samples corresponding to a complete CP of the second symbol.

22. The user equipment of claim 21, wherein the first and the second inverse fourier transformed samples are discrete fourier transformed before being inverse fourier transformed, respectively.

23. The user equipment of claim 21, wherein the complete CP is an unextended CP.

24. The user equipment of claim 23, wherein a size of the complete CP is 144 or 160 samples.

25. The user equipment of claim 21, wherein the complete CP is an extended CP.

26. The user equipment of claim 25, wherein a size of the complete CP is 512 samples.