METHOD, APPARATUS, AND SYSTEM FOR IDENTIFYING DIFFERENT FRAME STRUCTURES

• US 20110317597A1
• Filed: 09/09/2011
• Published: 12/29/2011
• Est. Priority Date: 03/11/2009
• Status: Active Grant

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: WAN, Lei, LV, Yongxia
• Granted Patent: US 8,780,769 B2
• Time in Patent Office: Days
• US Class Current: 370/281
• CPC Class Codes: H04L 27/2602 Signal structure
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal

Abstract

Embodiments of the present invention disclose a method, an apparatus, and a system for identifying different frame structures to ensure backward compatibility of an LTE-advanced (LTE-A) network. The method for identifying different frame structures includes: receiving a radio frame on a frequency division duplex (FDD) downlink carrier, where the radio frame includes an identifier of a frame structure; and identifying the frame structure according to the identifier of the frame structure included in the radio frame. Embodiments of the present invention also disclose a user equipment (UE), an evolved NodeB (eNB), and a system for identifying different frame structures. Through the technical solutions provided by embodiments of the present invention, LTE-A users can identify the frame structure carried on the FDD downlink carrier when accessing the network initially, but LTE users are unaware of the change of the frame structure.

Claims

1. A method for identifying different frame structures, comprising:

receiving a radio frame on a frequency division duplex (FDD) downlink carrier, wherein the radio frame comprises an identifier of a frame structure; and

identifying the frame structure according to the identifier of the frame structure comprised in the radio frame.

2. The method of claim 1, wherein the identifying the frame structure according to the identifier of the frame structure comprised in the radio frame is:

detecting the number of primary synchronization symbols (PSSs) or secondary synchronization symbols (SSSs) comprised in the radio frame within a radio frame period;

if the number is greater than the number of PSSs or SSSs comprised in an original synchronization structure, identifying that the radio frame has a frame structure carrying an uplink sounding reference symbol (SRS); and

if the number is the same as the number of PSSs or SSSs comprised in the original synchronization structure, identifying that the radio frame has the original frame structure.

3. The method of claim 1, wherein the identifying the frame structure according to the identifier of the frame structure comprised in the radio frame is:

according to a direct indication of a reserved bit on an original physical broadcast channel or dynamic broadcast channel of the radio frame, identifying that the radio frame has an original frame structure or has a frame structure carrying an uplink sounding reference symbol (SRS).

4. The method of claim 1, wherein the identifying the frame structure according to the identifier of the frame structure comprised in the radio frame is:

according to a direct indication of a reserved state of an existing uplink/downlink subframe ratio field on a dynamic broadcast channel of the radio frame, identifying that the radio frame has an original frame structure or has a frame structure carrying an uplink sounding reference symbol (SRS).

5. The method of claim 2, wherein the frame structure carrying the uplink SRS is:

a 10-ms radio frame comprising ten 1-ms subframes, inclusive of eight ordinary downlink subframes and two special subframes, wherein;

each ordinary subframe comprises two 0.5-ms timeslots, and each special subframe comprises an uplink timeslot, a guard period, and/or a downlink timeslot, wherein the uplink timeslot may carry an SRS.

6. The method of claim 2, wherein the frame structure carrying the uplink SRS is:

a frame structure period comprising N 10-ms radio frames, wherein;

each radio frame comprises ten 1-ms subframes;

each frame structure period comprises at least one special subframe and comprises other ordinary subframes;

each ordinary subframe comprises two 0.5-ms timeslots;

the special subframe comprises an uplink timeslot, a guard period, and/or a downlink timeslot, wherein the uplink timeslot may carry an SRS.

7. A user equipment (UE), comprising:

a receiving unit, configured to receive a radio frame on a frequency division duplex (FDD) downlink carrier, wherein the radio frame comprises an identifier of a frame structure; and

an identifying unit, configured to identify the frame structure according to the identifier of the frame structure comprised in the radio frame.

8. The UE of claim 7, wherein the identifying unit comprises any one of the following modules:

a number identifying module, configured to detect the number of primary synchronization symbols (PSSs) or secondary synchronization symbols (SSSs) comprised in the radio frame within a radio frame period;

if the number is greater than the number of PSSs or SSSs comprised in an original synchronization structure, identify that the radio frame has a frame structure carrying an uplink sounding reference symbol (SRS); and

if the number is the same as the number of PSSs or SSSs comprised in the original synchronization structure, identify that the radio frame has the original frame structure;

a bit identifying module, configured to identify, according to a direct indication of a reserved bit on an original physical broadcast channel (PBCH) or dynamic broadcast channel (DBCH) of the radio frame, that the radio frame has the original frame structure or has a frame structure carrying an uplink SRS; and

a state identifying module, configured to identify, according to a direct indication of a reserved state of an existing uplink/downlink subframe ratio field on the DBCH of the radio frame, that the radio frame has the original frame structure or has a frame structure carrying an uplink SRS.

9. An evolved NodeB (eNB), comprising:

a generating unit, configured to generate a radio frame, wherein the radio frame comprises an identifier of a frame structure; and

a sending unit, configured to send the radio frame generated by the generating unit on a frequency division duplex (FDD) downlink carrier.

10. The eNB of claim 9, wherein the generating unit comprises any one of the following modules:

a first generating module, configured to generate a radio frame, wherein the radio frame adds at least one primary synchronization symbol (PSS) or at least one secondary synchronization symbol (SSS) on the basis of an original synchronization structure;

a second generating module, configured to generate a radio frame, wherein the radio frame uses a reserved bit on an original physical broadcast channel (PBCH) or dynamic broadcast channel (DBCH) to directly indicate whether the radio frame has the original frame structure or has a frame structure carrying an uplink sounding reference symbol (SRS); and

a third generating module, configured to generate a radio frame, wherein the radio frame uses a reserved state of an existing uplink/downlink subframe ratio field on the DBCH to directly indicate whether the radio frame has the original frame structure or has a frame structure carrying an uplink SRS.

11. A system for identifying different frame structures, comprising an evolved NodeB (eNB) and a user equipment (UE), wherein:

the eNB comprises;

a generating unit, configured to generate a radio frame, wherein the radio frame comprises an identifier of a frame structure; and

a sending unit, configured to send the radio frame on a frequency division duplex (FDD) downlink carrier, wherein the radio frame is generated by the generating unit;

the UE comprises;

a receiving unit, configured to receive the radio frame on the FDD downlink carrier; and

an identifying unit, configured to identify the frame structure according to the identifier of the frame structure comprised in the radio frame.

12. The system of claim 11, wherein the generating unit comprised by the eNB comprises:

a first generating module, configured to generate a radio frame, wherein the radio frame adds at least one primary synchronization symbol (PSS) or secondary synchronization symbol (SSS) on the basis of an original synchronization structure;

a second generating module, configured to generate a radio frame, wherein the radio frame uses a reserved bit on an original physical broadcast channel (PBCH) or dynamic broadcast channel (DBCH) to directly indicate whether the radio frame has the original frame structure or has a frame structure carrying an uplink sounding reference symbol (SRS); and

a third generating module, configured to generate a radio frame, wherein the radio frame uses a reserved state of an existing uplink/downlink subframe ratio field on the DBCH to directly indicate whether the radio frame has the original frame structure or has a frame structure carrying an uplink SRS.

13. The system of claim 11, wherein the identifying unit comprised by the UE comprises:

a number identifying module, configured to;

detect the number of primary synchronization symbols (PSSs) or secondary synchronization symbols (SSSs) comprised in the radio frame within a radio frame period;

if the number is greater than the number of PSSs or SSSs comprised in an original synchronization structure, identify that the radio frame has a frame structure carrying an uplink sounding reference symbol (SRS); and

if the number is the same as the number of PSSs or SSSs comprised in the original synchronization structure, identify that the radio frame has the original frame structure;

a bit identifying module, configured to identify, according to a direct indication of a reserved bit on an original physical broadcast channel (PBCH) or dynamic broadcast channel (DBCH) of the radio frame, that the radio frame has the original frame structure or has a frame structure carrying an uplink SRS; and

a state identifying module, configured to identify, according to a direct indication of a reserved state of an existing uplink/downlink subframe ratio field on the DBCH of the radio frame, that the radio frame has the original frame structure or has a frame structure carrying an uplink SRS.

14. A method for sending a radio frame, comprising:

generating, by a evolved NodeB (eNB), a radio frame, wherein the radio frame comprises an identifier of a frame structure;

sending, by the eNB, the radio frame on a frequency division duplex (FDD) downlink carrier.

15. The method of claim 14, wherein the generating a radio frame comprises:

adding, by the eNB, at least one primary synchronization symbol (PSS) or at least one secondary synchronization symbol (SSS) on the basis of an original synchronization structure.

16. The method of claim 14, wherein the generating a radio frame comprises:

using, by the eNB, a reserved bit on an original physical broadcast channel (PBCH) or dynamic broadcast channel (DBCH) to directly indicate whether the radio frame has the original frame structure or has a frame structure carrying an uplink sounding reference symbol (SRS).

17. The method of claim 14, wherein the generating a radio frame comprises:

using, by the eNB, a reserved state of an existing uplink/downlink subframe ratio field on the DBCH to directly indicate whether the radio frame has the original frame structure or has a frame structure carrying an uplink SRS.