Method for establishing time domain structure of a frame in a heterogeneous TDD systems environment

• US 8,432,838 B2
• Filed: 01/23/2009
• Issued: 04/30/2013
• Est. Priority Date: 01/23/2008
• Status: Expired due to Fees

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Kwak, Jin Sam, Noh, Min Seok, Kim, Dong Cheol, Moon, Sung Ho, Han, Seung Hee, Lee, Hyun Woo, Kwon, Yeong Hyeon
• Primary Examiner(s): Wu, Jianye
• Application Number:
  US12/812,194
• Publication Number:
  US 20100278083A1
• Time in Patent Office: 1,558 Days
• Field of Search: None
• US Class Current: 370/280
• CPC Class Codes: H04B 7/26 at least one of which is mobile
• CPC Class Codes: H04L 27/2602 Signal structure
• CPC Class Codes: H04L 27/2603 Signal structure ensuring backward compatibility with legacy system
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04W 72/00 Local resource management

Abstract

Disclosed in a method for establishing a time domain structure of a frame in a heterogeneous TDD systems environment. In other words, in a situation of coexisting heterogeneous systems comprising a first system corresponding to an existing TDD system and a second system corresponding to a new system, a method is provided for establishing a time domain structure of a second frame for the second TDD system mode to enable it to coexist with a first frame for the first TDD (Time Division Duplex) system mode, that comprises obtaining information for the first supported system type and a first ratio between the downlink region and the uplink region of the first frame structure, and then, according to the obtained information, establishing a second ratio between the downlink region and the uplink region of the second frame structure for the second system. Further, particular numerology is provided for said method.

Claims

1. In a situation of coexisting heterogeneous systems including a first system and a second system, in a method of establishing a time domain structure of a second frame used for a Time Division Duplex (TDD) mode of the second system, so that the second frame can coexist with a first frame for a TDD mode of the first system, the method of establishing a time domain structure of a frame comprising:

an information acquiring step for acquiring type information of the first system being supported and information on a first ratio, wherein the first ratio corresponds to a ratio of a downlink section length of the first frame structure to an uplink section length of the first frame structure;

a second frame structure establishing step for establishing a second frame structure for the second system based upon the acquired information; and

a ratio determining step for determining a second ratio, wherein the second ratio corresponds to a ratio of a downlink section length of the second frame structure to an uplink section length of the second frame structure.

2. The method of claim 1, wherein the ratio determining step comprises a step of setting-up a sum of the downlink section and a transmit transition gap (TTG) of the second frame or a sum of the downlink section, TTG, and a receive transition gap (RTG) of the second frame, so that the sum can be equal to or greater than a sum of the downlink section and a downlink pilot time slot (DwPTS) of the first frame.

3. The method of claim 1, wherein, in the ratio determining step, when a sum of the receive transition gap (RTG), downlink section, and transmit transition gap (TTG) of the second frame is greater than a sum of the downlink section, downlink piloting time slot (DwPTS), and guard period (GP) of the first frame, a predetermined number of OFDM symbols are excluded from a transmission.

4. The method of claim 1, wherein the ratio determining step further comprises:

a step of establishing a frame offset from a starting point of the first frame of the second frame.

5. The method of claim 4, wherein the first system corresponds to an LCR-TDD (low-chip-rate time division duplex) system, wherein the second system corresponds to an IEEE 802.16m system, and wherein a cyclic prefix (CP) length of the second frame is equal to ⅛

valid OFDM symbol time (Tu),

wherein the second ratio is set to 7;

1 when the first ratio is set to 6;

1, wherein the second ratio is set to 6;

2 when the first ratio is set to 5;

2, wherein the second ratio is set to 5;

3 when the first ratio is set to 4;

3, and

wherein each of the ratios used to set the first and second ratios corresponds to a ratio of a downlink section length to an uplink section length.

6. The method of claim 5, wherein among the second frame structure, 1 OFDM symbol is excluded from the transmission when the first ratio is 6:

1, wherein 2 OFDM symbols are excluded from the transmission when the first ratio is 5;

2, and wherein 3 OFDM symbols are excluded from the transmission when the first ratio is 4;

3.

7. The method of claim 1, wherein the first system corresponds to a 3GPP LTE TDD system, wherein the second system corresponds to an IEEE 802.16m system, and wherein a cyclic prefix (CP) length of the second frame is equal to ⅛

valid OFDM symbol time (Tu), and

wherein the information acquiring step comprises a step of additionally acquiring CP length information of the first frame and configuration index information of the first frame in the 3GPP LTE TDD system.

8. The method of claim 7, wherein, when the CP length of the first frame corresponds to a normal CP and when the first ratio is 1:

3,

the second ratio is set to 2;

6 or 3;

5 when the configuration index of the first frame is 0, wherein the second ratio is set to 3;

5 when the configuration index of the first frame is 1, wherein the second ratio is set to 3;

5 when the configuration index of the first frame is 2, wherein the second ratio is set to 3;

5 when the configuration index of the first frame is 3, wherein the second ratio is set to 3;

5 when the configuration index of the first frame is 4, wherein the second ratio is set to 2;

6 or 3;

5 when the configuration index of the first frame is 5, wherein the second ratio is set to 3;

5 when the configuration index of the first frame is 6, wherein the second ratio is set to 3;

5 when the configuration index of the first frame is 7, wherein the second ratio is set to 3;

5 when the configuration index of the first frame is 8, and

wherein each of the ratios used to set the first and second ratios corresponds to a ratio of a downlink section length to an uplink section length.

9. The method of claim 7, wherein, when the CP length of the first frame corresponds to a normal CP and when the first ratio is 2:

2,

the second ratio is set to 4;

4 when the configuration index of the first frame is 0, wherein the second ratio is set to 5;

3 when the configuration index of the first frame is 1, wherein the second ratio is set to 5;

3 when the configuration index of the first frame is 2, wherein the second ratio is set to 5;

3 when the configuration index of the first frame is 3, wherein the second ratio is set to 5;

3 when the configuration index of the first frame is 4, wherein the second ratio is set to 4;

4 when the configuration index of the first frame is 5, wherein the second ratio is set to 5;

3 when the configuration index of the first frame is 6, wherein the second ratio is set to 5;

3 when the configuration index of the first frame is 7, wherein the second ratio is set to 5;

3 when the configuration index of the first frame is 8, and

wherein each of the ratios used to set the first and second ratios corresponds to a ratio of a downlink section length to an uplink section length.

10. The method of claim 7, wherein, when the CP length of the first frame corresponds to a normal CP and when the first ratio is 3:

1,

the second ratio is set to 6;

2 when the configuration index of the first frame is 0, wherein the second ratio is set to 6;

2 when the configuration index of the first frame is 1, wherein the second ratio is set to 6;

2 when the configuration index of the first frame is 2, wherein the second ratio is set to 7;

1 when the configuration index of the first frame is 3, wherein the second ratio is set to 7;

1 when the configuration index of the first frame is 4, wherein the second ratio is set to 6;

2 when the configuration index of the first frame is 5, wherein the second ratio is set to 6;

2 when the configuration index of the first frame is 6, wherein the second ratio is set to 7;

1 or 6;

2 when the configuration index of the first frame is 7, wherein the second ratio is set to 7;

1 when the configuration index of the first frame is 8, and

wherein each of the ratios used to set the first and second ratios corresponds to a ratio of a downlink section length to an uplink section length.

11. The method of claim 10, wherein the second frame is set-up to have a frame offset of 300 us from a starting point of the first frame.

12. The method of claim 11, wherein, when the configuration index of the first frame is 7 and when the second ratio is 6:

2, the second frame is set-up to be delayed for a predetermined time starting from a point corresponding to the frame offset at the starting point of the first frame within a receive transition gap (RTG) range of the second frame.

13. The method of claim 7, wherein, when the CP length of the first frame corresponds to an extended CP and when the first ratio is 1:

3,

the second ratio is set to 3;

5 when the configuration index of the first frame is any one of 0 to 6, and

wherein each of the ratios used to set the first and second ratios corresponds to a ratio of a downlink section length to an uplink section length.

14. The method of claim 7, wherein, when the CP length of the first frame corresponds to an extended CP and when the first ratio is 2:

2,

the second ratio is set to 4;

4 when the configuration index of the first frame is 0 or 6, and wherein the second ratio is set to 5;

3 when the configuration index of the first frame is any one of 1, 2, 3, 5, and 6, and

wherein each of the ratios used to set the first and second ratios corresponds to a ratio of a downlink section length to an uplink section length.

15. The method of claim 7, wherein, when the CP length of the first frame corresponds to an extended CP and when the first ratio is 3:

1,

the second ratio is set to 6;

2 or 7;

1 when the configuration index of the first frame is 0, wherein the second ratio is set to 6;

2 or 7;

1 when the configuration index of the first frame is 1, wherein the second ratio is set to 7;

1 when the configuration index of the first frame is 2, wherein the second ratio is set to 7;

1 when the configuration index of the first frame is 3, wherein the second ratio is set to 6;

2 when the configuration index of the first frame is 4, wherein the second ratio is set to 6;

2 when the configuration index of the first frame is 5, wherein the second ratio is set to 7;

1 when the configuration index of the first frame is 6, and

wherein each of the ratios used to set the first and second ratios corresponds to a ratio of a downlink section length to an uplink section length.