KR101162190B1 - A method and apparatus for transmitting multimedia broadcast and multicast service control data - Google Patents

Abstract

The present invention provides a method and apparatus for transmitting multimedia broadcasting service (MBMS) control data. When the MBMS control data is transmitted, the method and apparatus transmit all the subframes carrying the physical broadcast channel and the synchronization channel to a single cell, thereby allowing the mobile terminal (UE) to receive only one physical broadcast channel, thereby relatively low transmission. In the premise of ensuring complexity, the UE in the two multimedia broadcasting single frequency network (MBSFN) overlapping area cells prevented the problem of not being able to determine how to arrange the physical broadcasting channel. In addition, the primary MBMS control channel (P-MCCH) is also transmitted using the corresponding subframe, so that the UE of the non-overlapping portion of the MBSFN zone where there is an overlap in one cover may have the P-MCCH and the secondary MBMS control channel (S-). After receiving the MCCH, it is possible to prevent the problem of not receiving specific MBMS service data.

Description

Method and apparatus for transmitting multimedia broadcasting service control data {A METHOD AND APPARATUS FOR TRANSMITTING MULTIMEDIA BROADCAST AND MULTICAST SERVICE CONTROL DATA}

The present invention relates to the field of communications, and more particularly, to a method and apparatus for transmitting multimedia broadcast service control data.

The Multimedia Broadcast and Multicast Service (MBMS) technology is a technology for broadcasting or multicasting multimedia data to a mobile terminal (UE) by sharing one transport link. The purpose of the MBMS service is to provide multi-user single-point, multi-point multimedia data downloads in a highly efficient, economical and shared way. MBMS system may use a dedicated carrier (E-MBMS), and may share the carrier with a single broadcast system.

The transmission method of the MBMS service can be divided into two methods, multi-cell transmission and single-cell transmission. The core of multi-cell transmission is the downstream macro diversity soft merger based on single frequency network (SFN), which transmits service data in the unit of MBSFN after multi-cell merge and synchronizes multiple cells. Is required and can also be referred to as MBSFN transmission. The MBMS service transmitting to a single cell transmits MBMS service data per cell.

In general, MBMS service data of an MBMS system transmits broadcast information of an MBMS service to a user terminal (UE) through a subframe of a fixed position among radio frames, and includes a physical broadcast channel (P-BCH) and a synchronization channel. Among them, the synchronization channel includes a primary synchronization channel (P-SCH) and a secondary synchronization channel (S-SCH). The UE receives the P-BCH, P-SCH, and S-SCH in the corresponding subframe and accesses the MBMS system, and then receives a primary MBMS control channel (P-MCCH), which is a secondary MBMS that the UE should receive. It indicates the specific position of the control channel (S-MCCH). After receiving the S-MCCH, the UE may know in which time slot which frequency specific MBMS service data is received through the MBMS time channel (MTCH). The P-BCH, P-SCH, S-SCH, P-MCCH, S-MCCH and the like are used for realizing control functions such as connection, selection, and indication before specific MBMS service data transmission, and these are called MBMS control data in a broad sense. Can be.

Currently, there are three MBMS control data transmission methods in a dedicated carrier extended multimedia broadcasting service (E-MBMS) system among long term evolution (LTE). 1 is a diagram illustrating a subframe structure of a conventional method of transmitting MBMS control data. As shown in FIG. 1, in one subframe, one rectangular zone represents one orthogonal frequency division multiplex (OFDM) code, uses Extended cyclic prefix (ECP), and subcarriers When the interval is 15KHz, one subframe has 12 OFDM codes in total, and an uncovered portion of the OFDM code indicates that the corresponding portion of data is transmitted to the UE in a single cell manner, and the portion covered by the diagonal line Indicates that it is transmitted to the UE in MBSFN manner. Such an OFDM code is used to carry specific channel data and is also called an OFDM resource. As shown in FIG. 1, P-SCH, S-SCH and primary P-BCH of a multi-cell MBMS service are transmitted in a single cell, and other parts of the corresponding subframe are transmitted in MBSFN.

2 is a diagram illustrating a subframe structure of a conventional method of transmitting a second MBMS service. As shown in FIG. 2, the P-SCH and S-SCH of the MBMS service are transmitted in a single cell, and the P-BCH and other parts of the corresponding subframe are transmitted in the MBSFN.

3 is a diagram illustrating a subframe structure of a conventional method of transmitting a third MBMS service. As shown in FIG. 3, the P-SCH, S-SCH, P-BCH and other parts of the corresponding subframe of the MBMS service are all transmitted in the MBSFN.

Of the three MBMS control data transmission methods described above, it is determined that all of the control channels P-MCCH and S-MCCH of the MBMS are transmitted by the MBSFN. However, specifically, whether the physical broadcast channel and the synchronization channel are transmitted in a loaded subframe, and no specific transmission position in the subframe is determined, and all three conventional methods have disadvantages.

In the first method, since the broadcast channel and the synchronization channel data of the MBMS service must occupy a part of the reference signal of the MBSFN transmission frame, that is, the pilot frequency, it has some influence on the data of the part of the subframe transmitted to the MBSFN. The fault tolerance in decoding subframe data is lowered, and at the same time, the broadcast channel must redesign the reference code, which increases the complexity of transmitting MBMS service in the MBMS system.

In the second method, the P-BCH is transmitted through the MBSFN, and the MBSFN reference signal needs to be blindly measured for P-BCH decoding. Like the first method, the transmission has a complicated problem.

The third method is the simplest transmission method, and since the complexity of system transmission is the lowest, the third method is currently selected in LTE.

However, in the third method, there may be overlap in the MBSFN cover area, which causes some problems when the UE is located in the overlap area of the MBSFN cover. 4 shows a typical situation where there is overlap in the MBSFN cover. As shown in FIG. 4, the cover ranges of MBSFN Zone 1 and MBSFN Zone 2 have overlapping portions. In order to secure MBSFN transmission, two MBSFN zones transmit broadcast information of one MBSFN zone, which is different from each other. Subframes carrying broadcast information should be transmitted to ensure that UEs located in the cover overlapping portion can normally access two MBSFN zones. However, even in this case, there is still a problem because the LTE has already determined that the system bandwidth information and the number of antennas in the system are transmitted in the P-BCH. For example, when the system bandwidth of MBSFN Zone 1 is 10M and the number of system side antennas is 1, the system bandwidth of MBSFN Zone 2 is 20M and the number of system side antennas is 2, The system information indicated by the P-BCH is different. In this situation, the UEs in the two MBSFN overlapping zone cells cannot determine which MBSFN zone to connect to and how to arrange the physical broadcast channel.

Likewise, in the second method, the problem still exists because the broadcast channel is also transmitted in the MBSFN. Although the first method does not cause the problem by transmitting the P-BCH in a single cell, the complexity of the transmission still does not provide an ideal solution.

In addition, in the conventional multi-cell MBMS control data transmission method, both the P-MCCH and the S-MCCH is transmitted in the MBSFN method, so that when the UE is in the non-overlapping portion of the MBSFN zone with the overlap in the cover, even if the non-overlapping portion A UE in a UE may receive P-MCCH and S-MCCH in another MBSFN zone, but since one MBSFN zone does not transmit MBMS service data in another zone, a UE in a non-overlapping zone may be in another MBSFN zone. Will not receive MBMS service data. However, from the UE's point of view, the received P-MCCH and S-MCCH do not know whether the P-MCCH and S-MCCH of the MBSFN zone they are in are correct or not, so the user of the UE receives the P-MCCH and S-MCCH. After that, the possibility of not receiving specific MBMS service data is large, which may adversely affect the user experience of the MBMS service.

An embodiment of the present invention provides a method for transmitting multimedia broadcast service control data, so that a UE in two MBSFN overlapping zone cells may determine how to arrange a physical broadcast channel in a precondition for securing a relatively low complexity of MBMS service transmission. You can prevent the problem.

An embodiment of the present invention provides an apparatus for transmitting multimedia broadcast service control data so as to determine how a UE in two MBSFN overlapping zone cells should arrange a physical broadcast channel under the preconditions for ensuring a relatively low complexity of MBMS service transmission. You can prevent the problem.

The technical solution of the embodiment of the present invention is realized as follows.

A multimedia broadcast service control data transmission method used in an extended multimedia broadcasting service (E-MBMS) system of a dedicated carrier,

All of the sub-frames carrying the physical broadcast channel (P-BCH) and the synchronization channel are transmitted to the mobile station (UE) in a single cell manner.

An apparatus for transmitting multimedia broadcasting service control data used in an extended multimedia broadcasting service (E-MBMS) system of a dedicated carrier,

A subframe generation module for generating a subframe carrying a physical broadcast channel (P-BCH) and a synchronization channel, and

And a control data transmission module for transmitting the subframes generated by the subframe generation module to the UE in a single cell manner.

As can be seen from the above description, the MBMS control data transmission method and apparatus of the present invention transmits all subframes carrying a physical broadcast channel and a synchronization channel to a single cell when the MBMS control data is transmitted, resulting in a relatively low transmission complexity. In the precondition to be secured, the UE can be secured to receive only one physical broadcast channel, thereby preventing a problem in which the UE in the two MBSFN overlapping zone cells cannot determine how to arrange the physical broadcast channel.

1 is a diagram illustrating a subframe structure of a conventional method of transmitting MBMS control data.
2 is a diagram illustrating a subframe structure of a conventional method of transmitting MBMS control data.
3 is a diagram illustrating a subframe structure of a third method of transmitting MBMS control data.
4 shows a typical situation where there is overlap in the MBSFN cover.
5 is a diagram showing a subframe structure of the MBMS control data transmission method of Embodiment 1 of the present invention.
6 is a diagram showing a subframe structure of the MBMS control data transmission method of Embodiment 2 of the present invention.
7 is a diagram showing a subframe structure of the MBMS control data transmission method of Embodiment 3 of the present invention.
8 is a view showing the structure of the MBMS control data transmission apparatus of the embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS In order to make the object, technical solution and advantages of the present invention clearer and clearer, the present invention will be described in more detail with reference to the accompanying drawings.

In the embodiment of the present invention, when transmitting MBMS control data, a UE transmits only one P-BCH under the precondition that all subframes carrying an MBMS broadcast channel and a synchronization channel are transmitted to a single cell, thereby ensuring relatively low transmission complexity. In this case, the UE in the two MBSFN overlapping zone cells can prevent the problem of being unable to determine how to arrange the physical broadcast channel.

5 is a diagram showing a subframe structure of the MBMS control data transmission method of Embodiment 1 of the present invention. As shown in FIG. 5, all of the subframes carrying the MBMS broadcast channel and the synchronization channel are transmitted to a single cell, and at the same time, the P-BCH that occupies the OFDM resource in which the pilot frequency is located is deleted and among the existing subframes. Only the P-BCH carried in the OFDM resource other than the OFDM resource in which the pilot frequency is located is left. The purpose of deleting the P-BCH occupying the OFDM resource in which the existing pilot frequency is located is to lower the transmission complexity and, of course, does not need to be deleted.

Transmitting the P-BCH to a single cell ensures that the UE can only receive one P-BCH, preventing the UE in two MBSFN overlapping zone cells from determining how to arrange the physical broadcast channel. It became.

6 is a diagram showing a subframe structure of the MBMS control data transmission method of Embodiment 2 of the present invention. As shown in FIG. 6, the present embodiment additionally carries a P-MCCH in a corresponding subframe and transmits it to the UE based on Embodiment 1, and the S-MCCH uses MBSFN indicated by the P-MCCH. It is carried on a subframe to be transmitted and the specific resource location of the P-MCCH on the corresponding subframe can be determined according to demand. It is most preferable to load among the empty OFDM resources that are not occupied by other channels among the subframes, and for example, are loaded at any empty OFDM resource positions other than the P-BCH, P-SCH, S-SCH and pilot frequencies. Can be.

If the P-MCCH is also transmitted to a single cell, the UE can ensure that the UE receives only the P-BCH of one MBSFN zone, so that the UE located in the non-overlapping portion of the MBSFN zone with the overlap on the cover can have the P-MCCH and S- After receiving the MCCH, the problem of not being able to receive subsequent MBMS service data is prevented.

In contrast to Embodiment 1, this embodiment additionally carries an MBMS call channel in a corresponding subframe. Since the MBMS call channel is transmitted in a single cell manner, the same cell covered by different MBSFN zones can receive only one MBMS call channel, so that the UE only needs to monitor this one call channel. This prevents the situation in which different MBSFN zones must monitor multiple MBMS call channels arranged in subframes transmitted in the MBSFN scheme, thereby making the UE more convenient for eavesdropping and saving power. Similarly, the specific position in which the MBMS call channel is carried in the corresponding subframe is any position, and it is most preferable to load it among the empty OFDM resources not occupied by other channels among the subframes, for example, P-BCH and P-. Any empty OFDM resource location other than the SCH, S-SCH, P-MCCH and pilot frequency may be loaded. Of course, the MBMS call channel does not necessarily have to be loaded using the corresponding subframe.

In addition, if there are more empty OFDM resources in the subframe, single-cell MBMS service data can be loaded using the empty OFDM resources (parts indicated by MBMS in the drawing) to fully utilize system resources. The specific loading position is any position, and it is most preferable to load among empty OFDM resources not occupied by other channels among the subframes. For example, P-BCH, P-SCH, S-SCH, P-MCCH, MBMS Any empty OFDM resource location other than the call channel and pilot frequency may be loaded.

Substantially, the specific OFDM resource positions including the P-BCH, P-SCH, S-SCH, P-MCCH, MBMS call channel, single cell MBMS service data and pilot frequency in a subframe may be any positions, Do not overlap. In addition, based on the transmission of all subframes carrying the MBMS broadcast channel and the synchronization channel in a single cell, it is separately combined with the specific loading method used for P-BCH, P-MCCH, MBMS call channel or single cell MBMS service data. In other words, various embodiments may be combined, which will not be described herein any further.

The above embodiment is an embodiment in which a subframe has a subcarrier spacing of 15 KHz, and all general MBMS systems have such a subframe structure. However, any subframe structure may be applied to the inventive concept of the exemplary embodiment, and examples thereof include a subframe structure having a 7.5 KHz subcarrier spacing. There are only six OFDM codes in subframes of a 7.5KHz subcarrier interval, in which case specific OFDM resources may be arranged in the manner of FIG. 7.

7 is a diagram showing a subframe structure of the MBMS control data transmission method of Embodiment 3 of the present invention. As shown in FIG. 7, the OFDM resources are relatively small, and in order to ensure sufficient channel resources, the S-SCH and the partial P-BCH may need to occupy OFDM resources in which some pilot frequencies are located. It is similar to the situation where the subcarrier spacing is 15 KHz, which will not be discussed further here.

8 is a view showing the structure of the MBMS control data transmission apparatus of the embodiment of the present invention. As shown in Figure 8, the device,

A subframe generation module 801 for generating a subframe carrying an MBMS broadcast channel and a synchronization channel, and

The subframe generation module 801 includes a subframe transmission module 802 for transmitting all of the subframes generated by the subframe to the UE in a single cell manner.

The subframe generation module 801 further includes a broadcast channel loading unit 803 that loads a physical broadcast channel into an empty OFDM resource other than the OFDM resource occupied by the pilot frequency in the subframe to further reduce transmission complexity. Can be.

In addition, the subframe generation module 801 may further include a main control channel loading unit 804 which loads a P-MCCH in the subframe, most preferably in an empty OFDM resource occupied by no other channel. In this way, the UE of the non-overlapping portion of the MBSFN zone having an overlap on one cover prevents the problem of not receiving specific MBMS service data after receiving the P-MCCH and S-MCCH, and additionally, different MBSFNs. In zone coverage situations, the system reduces the complexity of transmitting MBMS control data.

At the same time, the subframe generation module 801 may additionally include a call channel loading unit 805 which loads an MBMS call channel in the subframe, most preferably in an empty OFDM resource occupied by no other channel. As a result, when different MBSFN zones cover the same cell, it is possible to avoid the situation where multiple branched MBMS call channels have to be placed in subframes having different MBSFNs relative to the MBSFN zones, thereby allowing the UE to easily listen. To save power.

The subframe generation module 801 additionally includes a single cell service loading unit 806 that loads single cell MBMS service data in the subframe, most preferably in an empty OFDM resource occupied by no other channel. This is preferable, so that system resources can be fully utilized.

The subframes generated by the subframe generation module 801 may be subframes having a 15KHz subcarrier spacing, or may be subframes having a 7.5KHz subcarrier spacing. The device can be installed in a facility such as a base station.

Specific operations performed by each module and unit in the device embodiment may refer to the detailed description in the method embodiment, which will not be described herein any further. All the above embodiments are based on the dedicated carrier extension multimedia broadcasting service E-MBMS system, but are applicable to other MBMS systems.

As can be seen from the above embodiment, the method and apparatus for transmitting MBMS control data of the present invention transmits all subframes carrying the MBMS broadcast channel and the synchronization channel to a single cell when the MBMS control data is transmitted, thereby ensuring a relatively low transmission complexity. In the precondition, the UE in the two MBSFN overlapping zone cells can prevent the problem of not being able to determine how to arrange the physical broadcast channel. In addition, the P-MCCH may also be transmitted using the corresponding subframe, so that the UE of the non-overlapping portion of the MBSFN region having an overlap in one cover may receive specific MBMS service data after receiving the P-MCCH and S-MCCH. This can further prevent missing problems and reduce the complexity of the system transmitting MBMS control data in different MBSFN zone cover situations. In addition, the MBMS call channel is also transmitted using the corresponding subframe, so that multiple branched MBMS call channels must be placed in subframes having different MBSFNs relative to the MBSFN zones when different MBSFN zones cover the same cell. Prevents the situation and allows the UE to facilitate interception and save power. Single-cell MBMS service data can also be transmitted using the remaining resources in the subframes, thereby fully utilizing system resources and improving transmission efficiency of the MBMS system.

It should be understood that the above are only preferred embodiments of the present invention and do not limit the protection scope of the present invention. All modifications, equivalent substitutions, improvements, etc., which are carried out within the spirit and principles of the present invention, should all be included within the protection scope of the present invention.

Claims (18)

A multimedia broadcasting service control data transmission method implemented by a multimedia broadcasting service (MBMS) control data transmission apparatus communicating with a mobile terminal (UE),
And transmitting all subframes carrying a physical broadcast channel (P-BCH) and a synchronization channel to a mobile station (UE) in a single cell manner. The method of claim 1,
And transmitting the physical broadcast channel (P-BCH) into an empty OFDM resource other than an orthogonal frequency division multiplex (OFDM) resource occupied by a pilot frequency in the subframe. The method according to claim 1 or 2,
And transmitting a primary MBMS control channel (P-MCCH) in the subframe to the UE. The method of claim 3,
And loading the P-MCCH in empty OFDM resources not occupied by other channels in the subframes. The method according to claim 1 or 2,
And transmitting an MBMS call channel in the subframe to a UE. The method of claim 5,
And loading the MBMS call channel into empty OFDM resources not occupied by other channels in the subframes. The method according to claim 1 or 2,
And transmitting single cell MBMS service data to the UE in the subframe. The method of claim 7, wherein
And loading the single-cell MBMS service data into an empty OFDM resource not occupied by other channels in the subframes. The method according to claim 1 or 2,
The subframe has a subcarrier spacing of 15KHz or subcarrier spacing of 7.5KHz. An apparatus for transmitting multimedia broadcasting service (MBMS) control data,
A subframe generation module for generating a subframe carrying a physical broadcast channel (P-BCH) and a synchronization channel, and
And a control data transmission module for transmitting all of the subframes generated by the subframe generation module to a mobile terminal (UE) in a single cell manner. The method of claim 10,
The sub frame generation module,
And a broadcast channel loading unit for loading a physical broadcast channel (P-BCH) into an empty OFDM resource other than an orthogonal frequency division multiplex (OFDM) resource occupied by a pilot frequency among the subframes. . The method according to claim 10 or 11, wherein
The sub frame generation module,
And a main control channel loading unit carrying a main MBMS control channel (P-MCCH) in the sub-frame. The method of claim 12,
The main control channel loading unit,
Specifically, the apparatus for transmitting multimedia broadcasting service control data, wherein a P-MCCH is loaded in empty OFDM resources not occupied by other channels in the subframe. The method according to claim 10 or 11, wherein
The sub frame generation module,
And a call channel loading unit which loads an MBMS call channel among empty OFDM resources not occupied by other channels in the subframes. The method according to claim 10 or 11, wherein
The sub frame generation module,
And a single cell service loading unit for loading the single cell MBMS service data into an empty OFDM resource not occupied by other channels in the subframes. The method according to claim 10 or 11, wherein
And a subframe generated by the subframe generation module has a 15KHz subcarrier spacing or a 7.5KHz subcarrier spacing. delete delete

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