WO2009132531A1

WO2009132531A1 - Method and device for indicating and obtaining the attributes of sub-frames in long term evolution network

Info

Publication number: WO2009132531A1
Application number: PCT/CN2009/070695
Authority: WO
Inventors: 马子江; 喻斌; 汪孙节; 沈武; 李大鹏
Original assignee: 中兴通讯股份有限公司
Priority date: 2008-03-14
Filing date: 2009-03-09
Publication date: 2009-11-05

Abstract

A method for indicating the attributes of sub-frames in Long Term Evolution(LTE) network is disclosed in the present invention. The method includes the steps of: writing Multicast/Broadcast over Single Frequency Network(MBSFN) sub-frames configuration information into the system broadcast message of Evolved Universal Terrestrial Radio Access Network(E-UTRAN); and sending the system broadcast message to a User Equipment(UE). A method for obtaining the attributes of sub-frames in LTE network and a device for obtaining the attributes of sub-frames in LTE network are also disclosed in the present invention. By configuring the MBSFN sub-frames configuration information in the system broadcast message of LTE, the present invention indicates whether each sub-frame of MBSFN is a MBSFN sub-frame, so as to lets UE to make the channel estimate by using MBSFN reference signal or cell-specific reference signal for each sub-frame.

Description

Method and device for indicating and acquiring subframe attributes in long term evolution network

Technical field

The present invention relates to the field of wireless communications, and in particular, to a method and apparatus for indicating and acquiring subframe attributes in an LTE (Long Term Evolution) network. Background technique

In 2005, 3GPP (3rd Generation Partnership Project) launched the LTE Research Working Group to research and design a 3.9G (improved 3G) next-generation network for the evolution of third-generation mobile communication technologies. The overall goals of its design are:

Simple system structure

*Higher transfer rate

Low cost of integration

*Good economic backward compatibility

*Flexible spectrum usage

* Flexible business support capabilities

At the 3GPP conference in November 2007, two LTE physical layer frame structures of FDD (Frequency Division Duplex) and TDD were determined, which are respectively called frame structure type 1 (frame structure applied to LTE FDD). Type 1 (as shown in Figure 1) and frame structure 2 (applies to frame structure type 2 of LTE TDD, as shown in Figure 2).

In FIG. 1, each radio frame of the LTE FDD is 10 ms, including 10 subframes (subframes, numbered #0, #1, ..., #9), and each subframe is lms, including 2 Slots, each frame consisting of 20 slots, each slot is 0.5ms, numbered #0, #1, #19.

In FIG. 2, each radio frame length of the LTE TDD is 10 ms, including 10 subframes, each subframe is lms, numbered #0, #1, ..., #9, subframe #1 (Subframe # 1) Always include DwPTS (Downlink Pilot Time Slot), GP (Guard Period) and UpPTS (Uplink Pilot Time Slot). In order to apply to LTE Different application scenarios of TDD, such as large-area coverage, different uplink and downlink service requirements, etc., LTE TDD radio frames can be configured into different uplink and downlink subframes and different GP lengths, such as configured as #1, #2, ... #6等. In configuration #0, #1, #2, #6 (as in Table 1), subframe #6 includes DwPTS, GP and UpPTS, and in configuration #3, #4, #5 (as in Table 1), subframe #6 only includes DwPTS, as shown in Table 1. Except for subframes #1 and #6, other subframes include 2 slots, each slot being 0.5 ms. Subframes #0 and #5, and DwPTS are used for downlink transmission, and in either configuration mode, subframe #2 is configured for uplink transmission. In Table 1, D indicates that the subframe is used for downlink transmission, U indicates that the subframe is used for uplink transmission, and S indicates that the subframe is a special subframe including DwPTS, GP, and UpPTS. Table 1: Uplink-downlink allocations.

In order to effectively utilize mobile network resources, 3GPP proposes Multimedia Broadcast Multicast Service (MBMS), which provides a point-to-multipoint service in which data sources send data to multiple users in a mobile network to implement network resources. Sharing, improving the utilization of network resources, especially valuable air interface resources. MBMS service is a technology that shares network resources and transmits data from one data source to multiple targets. The MBMS defined by 3GPP can not only realize plain text low-rate message class multicast and broadcast, but also realize high-speed multimedia service group. Broadcast and broadcast, offering a wide range of rich video, audio and multimedia services.

In an LTE network, the evolved MBMS technology is called E-MBMS (Evolved MBMS). In LTE, OFDMA (Orthogonal Frequency Division Multiplex Access) transmission supports a multi-cell multicast/broadcast transmission mode. In this transmission mode, multiple cells simultaneously transmit the same wireless signal. Mobile terminals (ie UEs) in these cells are connected The same signal received from multiple cells, like the multipath of receiving a signal, is called MBSFN (Multicast/Broadcast over Single Frequency Network).

In the MBSFN transmission mode, the transmission format of the MCH (Multicast Channel) transmission channel is the same for multiple cells, and the same physical resources are used to transmit the same data.

In LTE FDD and LTE TDD, radio frames are divided into MBSFN frames (MBSFN frame) and non-MBSFN frames (Non-MBSFN frames, that is, Unicast frames); some sub-frames in MBSFN frames are transmitted using MBSFN. The mode, that is, the subframe in each MBSFN frame is further divided into an MBSFN subframe (MBSFN subframe) and a non-MBSFN subframe (Non-MBSFN subframe, that is, a unicast subframe), as shown in FIG. 3. The None-MBSFN frame means that all subframes do not use the MBSFN transmission mode, but use the unicast transmission mode.

In the MBSFN transmission mode, the signal estimation cannot use the ordinary cell-specific reference signal, but the reference signal inserted in the MBSFN subframe, which uses the MBSFN transmission mode. That is, all cells participating in the MBSFN mode use the same reference signal, which is called MBSFN reference signal (single-frequency network multicast/broadcast reference signal). In the radio frame, the MBSFN sub-frame uses the MBSFN reference signal. As shown in Figure 4. In FIG. 4, R4 represents an MBMS reference signal, each subframe includes 2 slots (slots), and the slot number is (2i, 2i+l), where i is a subframe number (subframe numbers of LTE FDD and TDD) Both are from 0..9). Referring to Figure 1 and Figure 2, the previous time slot is an even time slot (even) and the latter time slot is an odd time slot (odd).

In FDD, downlink synchronization signals are configured on subframes #0 and #5 of each radio frame, and system broadcast messages are configured, such as: SI-M on subframe #0 (SYSTEM INFORMATION MASTER, system information - main message And SI-1 (SYSTEM INFORMATION 1 , message 1 of system information) on subframe #5, so these two subframes cannot be configured as MBSFN subframes, so #1, #2, #3, #4 of FDD subframes , #6, #7, #8, #9, A total of 8 subframes can be configured as MBSFN subframes.

In TDD, downlink synchronization signals are configured on subframes #0 and #5 of each radio frame, so these two subframes cannot be configured as MBSFN subframes; subframes #1 are configured with DwPTS, GP, and UpPTS, and cannot be configured. It is an MBSFN subframe. And in the configuration #0, #1, #2, #6, the sub-frame #6 includes DwPTS, GP and UpPTS, so it cannot be configured as an MBSFN sub-frame. In configuration 3, 4, 5 The lower subframe #6 includes only the DwPTS, and can still be configured as an MBSFN subframe, and the subframe #2 is an uplink slot, so it cannot be configured as an MBSFN subframe.

In an LTE network, whether it is FDD or TDD, the UE needs to know whether each subframe of the radio frame uses MBSFN, that is, the UE needs to know that each subframe is an MBSFN subframe or a non-MBSFN subframe, so that the UE is in each sub-frame. Channel estimation is performed on the frame using an MBSFN reference signal or a Cell-specific reference signal.

However, in the FDD and TDD systems for LTE networks, for E-UTRAN (Evolved Universal Terrestrial Radio Access Network, Evolved Universal Terrestrial Radio Access Network), no protocol or method has been proposed for each subframe. The information is notified to the UE.

Summary of the invention

The technical problem to be solved by the present invention is to provide a method and apparatus for indicating and acquiring subframe attributes in a long term evolution network, indicating/obtaining whether MBSFN information is used for each subframe of an MBSFN frame.

In order to solve the above problem, the present invention provides a method for indicating a subframe attribute in a long term evolution LTE network, including:

Writing single-frequency intra-network multicast/broadcast MBSFN subframe configuration information in a system broadcast message of the improved universal terrestrial radio access network E-UTRAN;

The system broadcast message is sent to the mobile terminal UE.

Further, the foregoing method for indicating a subframe attribute may further have the following features:

The base station writes the MBSFN subframe configuration information in the system broadcast message according to the preset MBSFN subframe configuration rule;

The preset MBSFN subframe configuration rule is:

10 subframes numbered 0 ~ 9 are included in one radio frame;

For FDD systems, subframes numbered 0, 4, 5, 9 in the MBSFN frame are not configured as MBSFN subframes;

For TDD systems, subframes numbered 0, 1, 2, 5, 6 in the MBSFN frame are not configured as MBSFN subframe.

The MBSFN subframe configuration information is an MBSFN indicator bit, which is used to indicate whether a subframe of the LTE MBSFN frame is an MBSFN subframe.

For the FDD system, the MBSFN indication bit is 6 bits, which respectively indicate whether the subframe of the LTE FDD numbered 1, 2, 3, 6, 7, 8 is an MBSFN subframe;

For the TDD system, the 5 bits in the MBSFN indication bit respectively indicate whether the subframe of the LTE TDD numbered 3, 4, 7, 8, 9 is an MBSFN subframe. In order to solve the above problem, the present invention also provides a method for acquiring a subframe attribute in an LTE network, including:

Writing MBSFN subframe configuration information in the system broadcast message of the E-UTRAN and transmitting it;

After receiving the system broadcast message, the UE learns whether the subframe in the MBSFN frame is configured as an MBSFN subframe according to the MBSFN subframe configuration information.

Further, the foregoing method for acquiring a subframe attribute may further have the following features:

The preset MBSFN subframe configuration rule is:

10 subframes numbered 0 ~ 9 are included in one radio frame;

For TDD systems, subframes numbered 0, 1, 2, 5, 6 in the MBSFN frame are not configured as MBSFN subframes.

The UE learns whether the subframe in the MBSFN frame is configured as an MBSFN subframe according to the preset MBSFN subframe configuration rule and the MBSFN subframe configuration information. Further, the foregoing method for acquiring a subframe attribute may further have the following features:

The MBSFN subframe configuration information is an MBSFN indicator bit, which is used to indicate whether a subframe of the LTE MBSFN frame is an MBSFN subframe;

The UE learns, according to the MBSFN indication bit, whether a subframe in the MBSFN frame is configured as an MBSFN subframe.

For the TDD system, the 5 bits in the MBSFN indication bit respectively indicate whether the subframe of the LTE TDD numbered 3, 4, 7, 8, 9, is an MBSFN subframe.

In order to solve the above problem, the present invention further provides an apparatus for acquiring a subframe attribute in an LTE network, including:

a storage module, configured to store a preset MBSFN subframe configuration rule, where, according to the configuration rule, a subframe numbered 0, 4, 5, 9 is not configured as an MBSFN subframe for an FDD system; , the subframes numbered 0, 1, 2, 5, 6 are not configured as MBSFN subframes;

An acquiring module, configured to acquire a system broadcast message from a base station, where the system broadcast message carries MBSFN subframe configuration information, and a determining module, connected to the acquiring module and the storage module, according to the configuration The rule and the MBSFN subframe configuration information determine a subframe configured as an MBSFN subframe.

The present invention configures the MBSFN subframe configuration information in the system broadcast message of the LTE to indicate whether each subframe of the MBSFN is an MBSFN subframe, so that the UE uses the MBSFN reference signal or the cell-specific reference signal for channel estimation on each subframe. .

BRIEF abstract

1 is a schematic diagram of a LTE FDD frame structure type 1 in the prior art;

2 is a schematic diagram of an LTE TDD frame structure type 2 in the prior art; 3 is a schematic diagram of an MBSFN frame and an MBSFN subframe indication of an LTE FDD in the prior art; FIG. 4 is a schematic diagram of an MBSFN reference signal configured in an MBSFN subframe in the prior art; FIG. 5 is a flowchart of a method according to an embodiment of the present invention. ;

Figure 6 is a schematic illustration of an apparatus in accordance with an embodiment of the present invention. Preferred embodiment of the invention

In the present invention, in the system broadcast message of the E-UTRAN, the MBSFN subframe configuration information is written and transmitted. After receiving the system broadcast message, the UE may learn, according to the MBSFN subframe configuration information, which subframe in the MBSFN frame is an MBSFN subframe, and which subframe is a non-MBSFN subframe.

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

As shown in FIG. 5, the embodiment of the present invention includes the following steps:

Step 501: The base station writes MBSFN subframe configuration information in the system broadcast message of the E-UTRAN, and sends the MBSFN subframe configuration information;

The base station may write the MB SFN subframe configuration information in the system broadcast message according to the preset MBSFN subframe configuration rule.

Preferably, the preset MBSFN subframe configuration rule is:

10 subframes numbered 0 ~ 9 are included in one radio frame;

Preferably, the MBSFN subframe configuration information may be carried in SIB2 (System Information Block Type 2 Information, System Information 1) or SI-1 (SYSTEM Message 1) in the system broadcast message of the E-UTRAN;

Preferably, the MBSFN subframe configuration information is an MBSFN indication bit, which is used to indicate whether a subframe of the LTE MBSFN frame is an MBSFN subframe; Preferably, the MBSFN indication bit is 6 bits, and for the FDD system, whether the subframe of the LTE FDD numbered 1, 2, 3, 6, 7, 8 is an MBSFN subframe, respectively; for the TDD system, the MBSFN The 5 bits in the indication bit respectively indicate whether the subframe of the LTE TDD numbered 3, 4, 7, 8, 9, is an MBSFN subframe.

Step 502: After receiving the system broadcast message, the UE learns, according to the MBSFN subframe configuration information, whether a number of subframes in the MBSFN frame are configured as MBSFN subframes.

Preferably, the UE, according to the preset MBSFN subframe configuration rule and the MBSFN subframe configuration information, whether the subframe in the MBSFN frame is configured as an MBSFN subframe;

If the MBSFN subframe configuration information is an MBSFN indication bit, the UE learns, according to the MBSFN indication bit, whether a subframe in the MBSFN frame is an MBSFN subframe.

Step 503: The UE performs channel estimation on the MBSFN subframe of the MBSFN frame by using the MBSFN reference signal, and performs channel estimation on the other non-MBSFN subframe using the cell-specific reference signal.

As shown in FIG. 6, the apparatus for acquiring a subframe attribute in an LTE network according to an embodiment of the present invention is located

In the UE, including:

The following is a more detailed description of the specific application examples:

Application example one: In the LTE FDD system, the system broadcast message sent by the E-UTRAN carries the MBSFN subframe configuration information;

Each radio frame (Radio Frame) includes 10 subframes numbered 0-9, that is, subframes numbered #0, #1, ....#8, #9;

The preset MBSFN subframe configuration rule is: subframe #4, #9 of one radio frame cannot be configured as an MBSFN subframe; in addition, since the known subframe #0, #5 cannot be configured as an MBSFN subframe, therefore, # 0, #4, #5, #9 cannot be configured as an MBSFN subframe. The MBSFN subframe configuration information can be used to indicate whether other subframes of the radio frame are MBSFN subframes.

(1) The base station writes MBSFN subframe configuration information in a system broadcast message (SIB2) sent by the E-UTRAN;

The configuration information may be an MBSFN subframe number, or may be an MBSFN indicator Byte (referred to as an MBSFN indicator Byte), that is, a bitmap representation manner for indicating whether a subframe of the LTE MBSFN frame is an MBSFN. The subframe, for example, represents the subframes #1, #2, #3, #6, #7, #8 of the MBSFN frame by 6 bits.

(2) After receiving the system broadcast message, the UE may learn, according to the subframe configuration information, which subframe in the MBSFN frame is configured as an MBSFN subframe, and which subframe is a non-MBSFN subframe;

At this time, the UE learns that the subframes #0, #4, #5, and #9 are not configured as MBSFN subframes according to the preset MBSFN subframe configuration rule, that is, when the network side configures the MBSFN subframe, Including subframes #0, #4, #5, #9, the subframes that can be configured as MBSFN subframes have the following six: #1, #2, #3, #6, #7, #8.

Specifically, when the configuration information is MBSFN subframe number information, the UE may determine which subframe is configured as an MBSFN subframe according to the following principles:

When the number of subframes is 1, it can be determined that the subframe numbered 1 is configured as an MBSFN subframe; when the number of subframes is 2, it is determined that the subframes numbered 1, 2 are configured as MBSFN subframes; When the number of subframes is 3, it is determined that subframes numbered 1, 2, and 3 are configured as MBSFN subframes; when the number of subframes is 4, subframes with numbers 1, 2, 3, and 6 are determined to be configured. For the MBSFN subframe, when the number of subframes is 5, it is determined that the subframes numbered 1, 2, 3, 6, and 7 are configured as MBSFN subframes; when the number of subframes is 6, the number is determined to be 1, The subframes of 2, 6, 7, 8, are configured as MBSFN subframes. When the configuration information is the MBSFN indication bit, the UE can know which subframe of the MBSFN frame is configured as an MBSFN subframe, and which subframe is a non-MBSFN subframe, according to whether each of the 6 MBSFN indication bits is 0 or 1. .

(3) The UE performs channel estimation using the MBSFN reference signal in the MBSFN subframe of the MBSFN frame, and performs channel estimation using the Cell-specific reference signal in other non-MBSFN subframes.

Application example two:

In the LTE TDD system, the system broadcast message sent by the E-UTRAN carries the subframe attribute of the radio frame, that is, the MBSFN subframe configuration information;

The preset MBSFN subframe configuration rule is: Subframes #0, #1, #2, #5, #6 of a radio frame cannot be configured as MBSFN subframes, so 5 bits can be used to represent other sub-frames of the radio frame. Whether the frame is an MBSFN subframe.

(1) The base station indicates the bit in the system broadcast message (SIB2 or SI-1) transmitted by the E-UTRAN by using the MBSFN, that is, the sub-frame of the MBSFN frame is represented by 5 bits using a bitmap representation. 3, #4, #7, #8, #9 Whether it is an MBSFN subframe. As shown in table 2.

For example, the 5 bits are Bit0~4 for indicating the MBSFN subframe, that is, Bit 0 corresponds to subframe #3, Bit 1 corresponds to subframe #4, Bit 2 corresponds to subframe #7, Bit 3 corresponds to subframe #8, and Bit 3 corresponds to subframe #8. Bit 4 corresponds to subframe #9; when Bit = 1 , it indicates that the subframe corresponding to the bit is an MBSFN subframe; when Bit = 0, it indicates that the subframe corresponding to the bit is a non-MBSFN subframe. Table 2: 5 bits are used to indicate MBSFN subframe attributes on MBSFN frames

For another example, in order to be similar to the representation of MBSFN subframes in an LTE FDD system, namely: The MBSFN subframe of the LTE TDD is represented by 6 bits, wherein the 5 bits are the same as the indication of the LTE FDD, and respectively indicate whether the subframe #3, #4, #7, #8, #9 of the MBSFN frame are MBSFN subframes. ; The remaining 1 bit of the 6 bits, meaningless or used for other information indication. As shown in Table 3.

Table 3: 5 bits out of 1 6 bits to indicate the MBSFN subframe genus on the MBSFN frame

(2) After receiving the MBSFN indicator Byte in the system broadcast message, the UE in the cell can know several subframes of the MBSFN frame according to each bit of 5 bits being set to 0 or 1. Configured as an MBSFN subframe.

(3) Then, the UE performs channel estimation by using the MBSFN reference signal in the MBSFN subframe of the MBSFN frame, and performs channel estimation by using the Cell-specific reference signal in other Non-MBSFN subframes.

While the invention has been described in connection with the specific embodiments, the modifications and variations may be Such modifications and variations are considered to be within the scope of the invention and the scope of the appended claims.

Industrial applicability

The present invention provides a method for indicating and acquiring a subframe attribute in an LTE network, and a device for acquiring a subframe attribute in an LTE network, by using MBSFN subframe configuration information in a system broadcast message of the E-UTRAN, so that the UE learns the MBSFN frame. Whether the subframe in the subframe is configured as an MBSFN subframe, so that the UE uses the MBSFN reference signal or the cell-specific reference signal to perform channel estimation on each subframe.

Claims

Claim

A method for indicating a subframe attribute in an LTE network, including:

The system broadcast message is sent to the mobile terminal UE.

2. The method of claim 1 wherein:

The preset MBSFN subframe configuration rule is:

10 subframes numbered 0 ~ 9 are included in one radio frame;

3. The method of claim 1 or 2, wherein:

4. The method of claim 3, wherein:

For the TDD system, the 5 bits in the MBSFN indication bit respectively indicate whether the subframe of the LTE TDD numbered 3, 4, 7, 8, 9 is an MBSFN subframe.

5. A method for obtaining a subframe attribute in an LTE network, including:

Write MBSFN subframe configuration information in the system broadcast message of the E-UTRAN and send it out; after receiving the system broadcast message, the UE learns according to the MBSFN subframe configuration information.

Whether a subframe in an MBSFN frame is configured as an MBSFN subframe.

6. The method of claim 5, wherein:

The preset MBSFN subframe configuration rule is:

10 subframes numbered 0 ~ 9 are included in one radio frame;

For TDD systems, subframes numbered 0, 1, 2, 5, 6 in MBSFN frames are not configured as MBSFN subframes.

7. The method of claim 6 wherein:

The UE learns whether the subframe in the MBSFN frame is configured as an MBSFN subframe according to the preset MBSFN subframe configuration rule and the MBSFN subframe configuration information.

8. The method according to any one of claims 5 to 7, wherein:

9. The method of claim 8 wherein:

10. An apparatus for acquiring a subframe attribute in an LTE network, including:

a storage module, configured to store a preset MBSFN subframe configuration rule, where, according to the configuration rule, a subframe numbered 0, 4, 5, 9 is not configured as an MBSFN subframe for an FDD system; , the subframes numbered 0, 1, 2, 5, 6 are not configured as MBSFN subframes; An acquiring module, configured to acquire a system broadcast message from a base station, where the system broadcast message carries MBSFN subframe configuration information;

And a determining module, configured to connect to the acquiring module and the storage module, to determine, according to the configuration rule and the MBSFN subframe configuration information, a subframe configured as an MBSFN subframe.