WO2007131419A1

WO2007131419A1 - A method and system for transmitting broadcast multicast service

Info

Publication number: WO2007131419A1
Application number: PCT/CN2007/001382
Authority: WO
Inventors: Junwei Wang; Xiao Zhou
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2006-04-26
Filing date: 2007-04-25
Publication date: 2007-11-22
Also published as: CN101064904A; CN101064904B

Abstract

A method for transmitting broadcast multicast service. It includes among cells based on FDMA, the radio resource is determined, which is used for transmitting broadcast multicast service data among broadcast multicast cells based on multi-cell transmission. When transmitting broadcast multicast service data among broadcast multicast cells according to the determined radio resource, the neighboring cells should be limitted to use the same radio resource as that has been determined. The method can improve the reception efficiency of users in the transition zones between single cells and broadcast cells.

Description

Broadcast multicast service transmission method and system thereof

Technical field

The present invention relates to a frequency reuse technique and a broadcast multicast technology in a mobile communication network, and more particularly to a transmission method and system for a broadcast multicast service. Background technique

In order to effectively utilize limited spectrum resources, current mobile communication technologies propose to reuse frequency resources in different geographical locations of a cellular network. As shown in FIG. 1, a multiplexing state diagram for frequency multiplexing based on multiplexing factor 1 between different cells in a mobile communication network is adopted for each cell in a cellular mobile communication network with a multiplexing factor of 1. Users with the same frequency resources, and users at the edge of the cell will be interfered by users from other neighboring cells, so users at the edge of the cell will get a lower signal-to-interference ratio.

In order to solve the problem that the cell edge user is relatively poor in frequency multiplexing based on the multiplexing factor of 1, the method that can be used is to increase the value of the multiplexing factor in the frequency multiplexing process, as shown in FIG. Schematic diagram of multiplexing state of frequency multiplexing between different cells in a communication network based on multiplexing factor 3, for regular cells, frequency multiplexing processing based on multiplexing factor 3 between different cellular neighboring cells can guarantee any two The frequencies used between adjacent cells are different, but the disadvantage is that each cell can only use the original 1/3 frequency resource.

In order to solve the problem that the larger the reuse factor and the lower the frequency utilization of the cell, the industry introduces the concept of interference coordination. The interference coordination technology applied between different cells is generally managed for downlink resources, and the constraint conditions are generally added in a coordinated manner between cells (such as the processing of common channels and the scheduling of non-common channels), and the added These constraints typically limit the available time domain and/or frequency domain resources of the resource manager or limit the transmission power on a time domain frequency domain resource.

At present, Soft Frequency Reuse (SFR) is an application example of interference coordination technology. As shown in Figure 3, it is based on SFR mode between different cells in a mobile communication network. Schematic diagram of the multiplexing state of the row frequency reuse, as shown in FIG. 3, the frequency multiplexing method with the multiplexing factor greater than 1 is adopted for the cell edge regions with severe interference, and the multiplexing is adopted because the interference is small in each cell. A frequency reuse method with a factor of 1. The specific use of the multiplexing factor 3 is taken as an example. First, the entire available frequency is divided according to the multiplexing factor of 3, so that each cell obtains its own primary frequency used in the edge zone (for the main frequency, please refer to FIG. 3). Texture part); For each cell, the frequency other than the primary frequency is used as the secondary frequency of each cell (see the shaded part in Figure 3 for the secondary frequency). As can be seen from the figure, the primary frequency in cell 1 acts as the corresponding secondary frequency in cell 2, and the other is the same; in each cell, the available power on the secondary frequency is usually limited, even if it is available on the secondary frequency. The power is 4 氐 at the available power on the main frequency.

Currently, the Multimedia Broadcast Multicast Service (MBMS) proposed by the 3GPP specification supports two cell transmission modes:

One is a multi-cell transmission method, which refers to a method in which multiple cells simultaneously transmit MBMS services at the same frequency;

The other is a single-cell transmission mode, which refers to a way in which a single cell transmits MBMS services without considering the transmission situation of other cells.

When the MBMS service is transmitted by using the multi-cell transmission mode, each of the broadcast multicast cells participating in the transmission occupies a dedicated frequency resource for transmitting the MBMS service, and the frequency resource occupied by the MBMS service can no longer be used for transmission of other services. In the SFR multiplexing mode, each broadcast multicast cell directly occupies part of its own primary frequency and secondary frequency for transmitting MBMS services, and the frequency resources occupied by the MBMS service can no longer be used for the unicast service of the corresponding cell, that is, each broadcast. The multicast cell can no longer use this part of the frequency resource for the secondary frequency. At the same time, the corresponding cell that originally used this part of the frequency as the primary frequency can no longer use this part of the frequency resource as the primary frequency. Specifically, as shown in FIG. 4, it is a schematic diagram of a frequency occupation state when frequency division multiplexing is performed between different cells in a mobile communication network based on the SFR mode, and MBMS services are transmitted between different cells based on the multi-cell transmission mode, as shown in the figure. When a part of the frequency resources in the entire frequency band is used for transmitting the MBMS service, the part of the frequency band occupied by the MBMS service in the adjacent cell will no longer be able to serve the user at the cell edge, that is, some neighboring cells will lose their own primary frequency. In part, cells 2, 4, and 6 lose their own frequency components. When the cell group composed of each broadcast multicast cell that transmits the MBMS service based on the multi-cell transmission mode is adjacent to the unicast cell, if the unicast cell transmits the MBMS service on the frequency of the broadcast multicast cell, the unicast data corresponding to the high-power transmission is transmitted. When the user in the transitional section between the broadcast multicast cell and the unicast cell receives the MBMS service sent by the broadcast multicast cell, it is bound to be interfered by the unicast data service. As shown in FIG. 5, a schematic diagram of a state in which a broadcast multicast cell and a unicast cell are adjacent to each other, where cells 1, 2, 5, and 6, respectively are broadcast multicast cells, and cells 3 and 4 are respectively unicast cells. Then, the receiving performance of the user C receiving the MBMS service in the transition zone is inevitably worse than that of the users A and B.

In order to prevent the unicast data of the unicast cell from being transmitted in the edge zone, the corresponding unicast data is interfered with the user receiving the MBMS service in the transition zone adjacent to the broadcast multicast cell, and the prior art proposes to change the primary frequency transmit power of the unicast cell. The transmission power is the same as the secondary frequency (as shown in Figure 5, the right blank portion of the frequency band is originally the primary frequency of the corresponding unicast cell, and its transmission power is changed to be the same as the secondary frequency transmission power), that is, the unicast cell 3, 4 is on the edge. The transmit power used on the primary frequency of the zone is the same as the transmit power used on the secondary frequency of the central zone, thereby avoiding interference to users receiving MBMS services in the transition zone adjacent to the broadcast multicast cell.

The foregoing processing manner may prevent the unicast cell from transmitting high-power unicast data to interfere with the user receiving the MBMS service in the transition zone adjacent to the broadcast multicast cell, but if the MBMS service occupies a relatively wide bandwidth, it may cause Some unicast cells do not occupy the primary frequency in the frequency band occupied by the MBMS service, so that the throughput of the unicast cell edge zone is lower than that of other unicast cells. As shown in FIG. 5, the unicast cell 4 is reduced. If the user C receives the MBMS service, it needs to change the transmit power of all the primary frequencies to the same as the transmit power of the secondary frequency. Therefore, the throughput of the edge zone of the unicast cell 4 is bound to be smaller than that of the unicast cell 3 edge. The throughput of the zone. In order to solve this problem, the inter-frame frequency hopping method can be used to alleviate, that is, the frequency of transmitting the MBMS service occupies the main frequency of different unicast cells, so that the probability that the MBMS service occupies the dominant frequencies of different unicast cells is the same or similar.

The inventors of the present invention have found that when frequency multiplexing is performed between different cells based on the SFR method, the primary frequency transmission power of the unicast cell edge zone is changed to the secondary frequency transmission power of the central zone. The same, the interference caused by the user receiving the MBMS service in the transition zone adjacent to the broadcast multicast cell can be reduced, but the processing manner does not improve the receiving power of the MBMS service received by the user in the transition zone, as shown in FIG. 5, Users A and B can simultaneously receive MBMS services sent by neighboring multiple cells, and therefore have higher receiving power, while user C can only receive MBMS services sent by cell 1, but cannot receive MBMS sent by other neighboring cells. Service, so its power to receive MBMS services is lower than the power of users A and B to receive MBMS services. Summary of the invention

The embodiment of the present invention provides a method for transmitting a broadcast multicast service and a system thereof, so as to solve the problem that a user receives a broadcast multicast service with a low power in a transition zone between a unicast cell and a broadcast multicast cell in the prior art.

The embodiment of the present invention provides a method for transmitting a broadcast multicast service, including the steps of: determining, by using a frequency multiplexed cell, a radio resource occupied by a broadcast multicast service data transmitted by a broadcast multicast cell based on a multi-cell transmission mode; And limiting, when the broadcast multicast cell transmits the broadcast multicast service data based on the determined radio resource, the radio resource used by the neighboring cell of the broadcast multicast cell in the determined radio resource.

The embodiment of the present invention provides a transmission system for a broadcast multicast service, including: a frequency determining unit, configured to determine, in a cell that uses frequency multiplexing, a broadcast multicast service data of a broadcast multicast cell based on a multi-cell transmission mode The occupied radio resource; the resource usage limiting unit, configured to: when the broadcast multicast service transmits the broadcast multicast service data by using the radio resource determined by the frequency determining unit, the determined radio with the neighboring cell of the broadcast multicast cell Restrictions on the wireless resources used within the resource.

The embodiment of the present invention considers that in a frequency-multiplexed cell communication environment, when a neighboring cell of a broadcast multicast cell transmits a small amount of traffic, the radio resource occupied by the broadcast multicast service transmitted by the broadcast multicast cell may be used. To the probability that the cell adjacent to the broadcast multicast cell is restricted from using the radio resource in the radio resource occupied by the broadcast multicast service data transmitted by the broadcast multicast cell, for example, the neighboring cell may be broadcast based on the transmission broadcast. Frequency resources occupied by business data, Synchronously transmitting broadcast multicast service data with the broadcast multicast cell; or letting the neighboring cell not transmit any service data or reduce power transmission service data in the frequency resource occupied by the broadcast multicast service data, thereby improving the number of broadcasts The user in the transition zone between the broadcast cell and the neighboring cell receives the received power of the broadcast multicast service, thereby improving the receiving performance of the broadcast multicast service received by the user in the transition zone. DRAWINGS

1 is a schematic diagram of a multiplexing state of frequency multiplexing based on multiplexing factor 1 between different cells in a mobile communication network;

2 is a schematic diagram of a multiplexing state of frequency multiplexing based on multiplexing factor 3 between different cells in a mobile communication network;

3 is a schematic diagram of a multiplexing state of frequency multiplexing based on an SFR method between different cells in a mobile communication network;

4 is a schematic diagram of a frequency occupation state when frequency division multiplexing is performed between different cells in a mobile communication network based on an SFR method, and MBMS services are transmitted between different cells based on a multi-cell transmission mode;

5 is a schematic diagram showing states when a broadcast multicast cell and a unicast cell are adjacent to each other;

6 is a schematic flowchart of an embodiment of a method for transmitting a broadcast multicast service according to the present invention;

7 is a schematic diagram of a processing procedure of an embodiment for performing broadcast multicast service transmission based on a frequency resource selection manner in the method of the present invention;

8 is a schematic diagram of a processing procedure of an embodiment for performing broadcast multicast service transmission based on a second frequency resource selection manner in the method of the present invention;

FIG. 9 is a schematic diagram of a frequency resource distribution state in which a primary frequency resource occupied by MBMS service data in a unicast cell is used to transmit MBMS service data in an embodiment of the present invention; FIG.

10 is a schematic diagram of a frequency resource distribution state in which a secondary frequency resource occupied by MBMS service data in a unicast cell is used to transmit MBMS service data in an embodiment of the present invention;

FIG. 11 is a main frequency occupied by MBMS service data in a unicast cell according to an embodiment of the present invention, Schematic diagram of a frequency resource distribution state in which a secondary frequency resource is used to transmit MBMS service data; FIG. 12 is a schematic diagram of a modulation and demodulation processing procedure of a basic OFDM system;

13 is a schematic diagram of a frequency resource distribution state in which a unicast cell transmits MBMS service data by using a primary frequency occupied by MBMS service data according to an embodiment of the present invention;

Figure 14 is a diagram showing the state of specific input data before performing IFFT processing in an OFDM system according to the above embodiment of the present invention;

15 is a schematic flowchart of an implementation principle of another method for transmitting a broadcast multicast service according to the present invention;

16 is a schematic diagram of a frequency resource distribution state in which no data transmission is performed on a frequency resource occupied by MBMS service data in a unicast cell in the embodiment of the present invention;

17 is a schematic diagram of a frequency resource distribution state in which a transmission power transmission service data is reduced on a frequency resource occupied by MBMS service data in a unicast cell according to an embodiment of the present invention;

18 is a schematic diagram of a frequency resource distribution state in which a primary frequency is changed into a secondary frequency transmission service data on a frequency resource occupied by MBMS service data in a unicast cell according to an embodiment of the present invention;

FIG. 19 is a structural block diagram of an embodiment of a broadcast multicast service transmission system according to the present invention; FIG. 20 is a block diagram showing a specific structure of an embodiment of a frequency selection unit in the system of the present invention. detailed description

The embodiment of the present invention is directed to the problem that the receiving power of the MBMS service received by the user in the transition zone between the broadcast multicast cell and the neighboring cell transmitting the MBMS service in the multi-cell transmission mode is lower when the frequency is multiplexed between different cells. Considering that when the amount of transmission traffic is relatively small in the neighboring cell, there may be a probability that the radio resource occupied by the MBMS service in the broadcast multicast cell will not be used, and it is proposed that the MBMS service can be transmitted by the broadcast multicast cell in the neighboring cell. The occupied radio resources that may not be used by the transmitted service data are used to synchronously transmit MBMS service data with the broadcast multicast cell, or not transmit any service data, or reduce power transmission service data, thereby avoiding frequency resources. The waste can improve the receiving power of the MBMS service received by the user in the transition zone between the broadcast multicast cell and the neighboring cell, thereby improving the user reception in the transition zone. Receive performance of MBMS services.

In the embodiment of the present invention, the radio resource occupied by the MBMS service data of the broadcast multicast cell based on the multi-cell transmission is determined in the cell that uses frequency multiplexing; and then determined based on the broadcast multicast cell. When the radio resource transmits the MBMS service data, the neighboring cell of the broadcast multicast cell is restricted from using the same radio resource as the determined radio resource. In a preferred aspect, the cell adjacent to the broadcast multicast cell that transmits the MBMS service data includes a unicast cell, a broadcast multicast cell, a hybrid carrier cell, and the like in a predetermined area around the broadcast multicast cell, and each of the neighboring cells The strength of the radio resource used by the cell is inversely proportional to the distance of the cell from the broadcast multicast cell, that is, the closer the cell is to the broadcast multicast cell, the greater the strength of the radio resource used for the cell, and the greater the distance broadcast. The farther away the cell is, the smaller the strength of the radio resources it uses. In another preferred aspect, determining that the radio resource occupied by the broadcast multicast cell based on the multi-cell transmission mode MBMS service data includes time resources, frequency resources, and transmission power resources.

In the following, only the neighboring cell of the broadcast multicast cell is a unicast cell adjacent to the broadcast multicast cell, and the determined radio resource is a frequency resource for transmitting broadcast multicast service data, and the technical solutions of the present invention are combined with the respective drawings. The implementation principle, the specific implementation manner, and the corresponding beneficial effects can be elaborated. The specific implementation of other neighboring cells is similar to the specific implementation of the adjacent unicast cell. No more details will be given.

FIG. 6 is a schematic flowchart of an embodiment of a method for transmitting a broadcast multicast service according to the present invention, and the implementation principle thereof is as follows:

Step 10: In the frequency multiplexed cell, determine a frequency resource occupied by the broadcast multicast service data of the broadcast multi-cell transmission based on the multi-cell transmission mode; The access gateway (AGW) determines the frequency resource occupied by the broadcast multicast service data of the broadcast multicast cell based on the multi-cell transmission mode, and notifies the determined frequency resource information to the corresponding broadcast multicast cell.

Step 20: Select a corresponding frequency resource in a frequency band that is the same as the determined frequency resource that is occupied by a unicast cell adjacent to the broadcast multicast cell. Step 30: The unicast cell adjacent to the broadcast multicast cell synchronously transmits the broadcast multicast service data based on the selected frequency resource and the broadcast multicast cell based on the determined frequency resource.

In this way, based on the implementation idea of the method of the present invention, under the existing interference coordination technology, a unicast cell adjacent to a broadcast multicast cell receives broadcast multicast in a transition zone occupied by the broadcast multicast service data. All or part of the service performance, the broadcast multicast service data will continue to be transmitted to improve the receiving performance of the broadcast multicast service received by the users in the transition zone; of course, the frequency band resources occupied by the broadcast multicast service data in the unicast cell It is not possible to serve unicast users in a unicast cell at the same time.

In the method of the present invention, different cells can be frequency-multiplexed based on the interference coordination technology, for example, the frequency multiplexing process is preferably performed by using the SFR method.

In the above step 20, the occupant occupied by the unicast cell adjacent to the broadcast multicast cell is determined as:

The first type: the upper layer first obtains the frequency band allocation information of the unicast cell in the frequency reuse state; and selects the corresponding frequency in the frequency band occupied by the unicast cell and the same frequency resource according to the frequency band allocation information of the unicast cell. Resource

The high layer notifies the selected frequency resource information to the unicast cell; the subsequent higher layer dynamically adjusts the selected frequency resource in the same frequency band as the determined frequency resource occupied by the unicast cell according to the specific change information of the unicast cell. The adjusted frequency resource information is notified to the unicast cell again.

The second layer: the upper layer notifies the determined frequency resource information occupied by the broadcast multicast service data of the broadcast multicast cell to the unicast cell adjacent to the broadcast multicast cell;

The unicast cell selects the corresponding frequency resource in the same frequency band as the determined frequency resource according to the frequency band allocation information in the frequency reuse state; the subsequent unicast cell can also be at any time according to its specific change information. The selected frequency resource is dynamically adjusted in the frequency band occupied by itself and the determined frequency resource.

The following is an example of frequency reuse processing using SFR mode between cells as an example to illustrate frequency resources. W 200

The specific selection process of the source. As shown in FIG. 7, a schematic diagram of a process for completing a broadcast multicast service transmission based on a first frequency resource selection manner in the embodiment of the present invention is as follows:

1. The upper layer (such as the AGW) issues an instruction to inform the broadcast multicast cell of the broadcast multicast service data on which time resources and frequency resources are sent;

2. The upper layer (such as the AGW) issues an instruction to query the primary and secondary frequency band allocation information of the unicast cell adjacent to the broadcast multicast cell in the SFR multiplexing state, and the current traffic busyness information of the unicast cell;

3. The unicast cell counts its current unicast traffic, and obtains the corresponding traffic busyness information according to the statistical result. The unicast cell bases itself on the primary and secondary frequency band allocation information in the SFR multiplexing state and its current service. Busy information feedback to the upper level (AGW);

4. The upper layer (AGW) selects the corresponding frequency resource in the same frequency band as the broadcast multicast service data occupation frequency resource occupied by the unicast cell according to the primary and secondary frequency band allocation information and the current service busyness information fed back by the unicast cell. And selecting and notifying the same time resource to the time resource of the broadcast multicast cell; and then issuing an instruction to notify the unicast cell to send the broadcast multicast service data on the selected frequency resource and the time resource;

5. The broadcast multicast cell and the unicast cell respectively transmit the broadcast multicast service data according to the frequency resource and the time resource notified by the upper layer (AGW).

In addition, if the traffic busyness information changes due to the change of the unicast traffic in the unicast cell, the upper layer needs to correspondingly occupy the unicast cell when it knows that the traffic busyness information of the unicast cell changes. Dynamically adjusting the selected frequency resource in the same frequency band as the broadcast multicast service data occupation frequency resource, and timely notifying the adjusted selected frequency resource information to the unicast cell, for example, the unicast traffic in the unicast cell is increased. In this case, the selected frequency resource may need to be reduced. If the unicast traffic in the unicast cell is reduced, the selected frequency resource may need to be increased.

As shown in FIG. 8, a schematic diagram of a process for completing a broadcast multicast service transmission based on a second frequency resource selection manner in the embodiment of the present invention is as follows:

10. The upper layer (such as the AGW) issues an instruction to inform the broadcast multicast cell of the broadcast multicast service data on which time resources and frequency resources are sent; 20. At the same time, the upper layer (such as the AGW) also issues an instruction to inform the unicast cell adjacent to the broadcast multicast cell that the broadcast multicast service data will be sent on the time resource and the frequency resource; the unicast cell according to itself The primary and secondary frequency band allocation information in the SFR multiplexing state and the traffic busyness information obtained by statistically comparing the current unicast traffic volume are in the same frequency band as the broadcast multicast service data occupying frequency resource. Select the corresponding frequency resource;

30. The broadcast multicast cell sends the broadcast multicast service data according to the frequency resource and the time resource notified by the upper layer (AGW), and simultaneously the neighboring unicast cell according to the selected frequency resource and the time resource notified by the upper layer (AGW). Send broadcast multicast service data.

Correspondingly, if the unicast cell finds that its current traffic busyness information changes, it also needs to dynamically adjust the selection according to its changed traffic busyness information in the same frequency band as the broadcast multicast service data occupation frequency resource. Frequency resources.

Preferably, in the foregoing step 20, if the cells use the frequency multiplexing method based on interference coordination for frequency multiplexing processing, the broadcast multicast can be occupied by the unicast cell adjacent to the broadcast multicast cell. The frequency resource selected by the user in the unicast cell edge area may be selected as the frequency resource of the unicast cell edge area user service, and may also be selected as the unicast cell edge area user service. Frequency resources and frequency resources for users in the central area of the unicast cell.

In the following, the frequency multiplexing between the cells based on the SFR method is taken as an example to specifically describe various situations in which the frequency resources are selected in the frequency bands occupied by the unicast cell and the frequency resources occupied by the broadcast multicast service data. Preferably, the frequency resource that is the primary frequency of the unicast cell is selected in a frequency band that is the same as the frequency resource occupied by the broadcast multicast service data that is occupied by the unicast cell adjacent to the broadcast multicast cell, so that the unicast cell is selected based on the frequency. The primary frequency resource transmits the broadcast multicast service data synchronously with the broadcast multicast cell. As shown in FIG. 9, in the embodiment of the present invention, the number of MBMS services in the unicast cell is set to Cell 3, 4 in FIG. 9 as a unicast cell, respectively, and Cell 1 , 2, 5, 6, 7 are respectively based on A multi-cell transmission mode transmits a broadcast multicast cell of MBMS service data, wherein the transmission of the MBMS service data occupies part of the secondary frequency resources of Cell 1, and occupies part of the secondary frequency resources and partial masters of Cell 3. The frequency resource also occupies part of the secondary frequency resource and all the primary frequency resources of the cell 4; H 殳 users A, B, and C are respectively located in the broadcast multicast cell, and the user D is located in the unicast cell Cell 4, typically, the user C Located in a transition zone between a broadcast multicast cell and an adjacent unicast cell. In the prior art, when a unicast cell transmits unicast data based on a primary frequency consistent with a frequency resource occupied by a broadcast multicast cell to transmit MBMS service data, the user C located in the transition zone receives the phase when receiving the MBMS service data. The neighboring unicast cell 3, 4 transmits the interference of the unicast service, in order to avoid the interference of the unicast service when the user in the transition zone receives the MBMS service data, and at the same time improve the receiving power of the MBMS service data received by the user in the transition zone, based on In the unicast cell 3, 4, the same MBMS service data can be synchronously transmitted on the main frequency band occupied by the MBMS service data transmission, and the unicast cells 3 and 4 respectively use the occupied frequency resource. The black and white grid in the middle indicates the frequency portion to transmit the MBMS service data, and the MBMS service data may also be transmitted using a part of the frequencies in the frequency portion indicated by the black and white grid.

Of course, the frequency resource that is the same as the frequency resource occupied by the broadcast multicast service data, which is occupied by the unicast cell adjacent to the broadcast multicast cell, may be selected as the frequency resource of the unicast cell secondary frequency, so that the unicast cell is based on the selected The secondary frequency resource transmits the broadcast multicast service data synchronously with the broadcast multicast cell. Specifically, as shown in FIG. 10, it is a schematic diagram of a frequency resource distribution state in which a secondary frequency resource occupied by MBMS service data in a unicast cell is used to transmit MBMS service data in the embodiment of the present invention.

The frequency resources of the primary frequency and the secondary frequency of the unicast cell may be separately selected, so that the unicast cell synchronously transmits the broadcast multicast service data according to the selected primary secondary frequency resource and the broadcast multicast cell, as shown in FIG. 11 . A schematic diagram of a frequency resource distribution state in which a primary frequency and a secondary frequency resource occupied by MBMS service data in a unicast cell are used to transmit MBMS service data in the method of the present invention.

When the unicast cell and the broadcast multicast cell synchronously transmit the broadcast multicast service data, the unicast cell transmits the broadcast multicast service data, which is also subject to the transmission power control in the interference coordinated frequency reuse state, such as subject to SFR multiplexing. Transmission power control in the state.

The following is a specific embodiment to specifically describe the specific implementation process of the method of the present invention: This embodiment takes the communication environment shown in FIG. 9 as an example, and Cell 1, 2, 5, 6, and 7 are broadcast multicast cells, respectively, Cell 3 And 4 are unicast cells respectively, assuming that the seven cells are based on communication transmission The bandwidth is 10 MHz for SFR multiplexing processing based on the multiplexing factor of 3, so that the transmission bandwidth of 10 MHz is divided into 12 sub-bands, each sub-band contains 30 sub-carriers, and one TTI is 0.5 sec. The 12 x 30 subcarriers are divided into three groups, and each cell selects one of the subcarriers as the primary subcarrier of the current cell, that is, as the primary frequency of the local cell, and other unselected two subcarriers serve as the secondary subcarrier of the cell. The carrier, that is, the secondary frequency of this cell.

The embodiment herein refers to implementing MBMS service data transmission on an Orthogonal Frequency Division Multiplex (OFDM) mobile communication system, as shown in FIG. 12, which is a schematic diagram of a modulation and demodulation process of a basic OFDM system. In the OFDM system, the user data is first subjected to channel coding and interleaving processing, and then the coded interleaved data is modulated to form user data symbols by using a modulation method (such as BPSK, QPSK, and QAM). The data symbols are then modulated onto the radio frequency after OFDM operation, wherein the reverse demodulation process is reversed from this process, and will not be repeated here.

Wherein in the OFDM operation, the user data symbols are first serial/parallel converted to form a plurality of low-rate sub-data streams, wherein each sub-data stream occupies one sub-carrier, and each sub-data stream is mapped to a corresponding sub-carrier. The above processing can be implemented by inverse discrete Fourier transform (IDFT) or inverse fast Fourier transform (IFFT) processing. Then, by adding cyclic prefix (CP, Cyclic Prefix) processing, the cyclic prefix (CP) is added to the time domain signal processed by IDFT or IFFT as a guard interval, which can greatly reduce or even eliminate inter-symbol interference, and guarantee each channel. The orthogonality between them greatly reduces the interference between channels.

The embodiment here assumes that the primary frequency occupied by the broadcast multicast cell 1 is 0 ~ 3.3 MHz, the primary frequency occupied by the unicast cell 3 is 3.4 MHz ~ 6.7 MHz, and the primary frequency occupied by the unicast cell 4 is 6.8 MHz ~ 10 MHz, The broadcast multicast cell is notified to occupy the frequency band resource between 4 MHz and 10 MHz to transmit the MBMS service data (1, 2, ..., 5, 6). It is also assumed that the frequency band for transmitting the MBMS service data allocated by the upper layer for the unicast cells 3 and 4 is the total frequency of the frequency band covered by the MBMS service data, and the unicast cell 3 will be broadcasted in the frequency band of 4 MHz - 6.7 MHz. The multicast cell synchronously transmits BMS service data, and the unicast cell 4 will transmit synchronously with the broadcast multicast cell in the frequency band of 6.8 MHz to 10 MHz. The MBMS service data, its specific frequency resource distribution status is shown in Figure 13.

Specifically, as shown in FIG. 14, is a schematic diagram of a specific input data state before performing IFFT processing in an OFDM system according to the above embodiment of the present invention, in which a transmission bandwidth of 4 MHz to 10 MHz is occupied in a broadcast multicast cell 1 (MBMS Cell 1). Input BMS service data (1, 2, ... 5, 6); and occupy 4MHz ~ 6.7MHz transmission bandwidth in Unicast Cell 3 to input MBMS service data (5, 6); The transmission bandwidth of 6.8 ΜΗζ - 10 MHz is occupied in the broadcast cell 4 (Unicast Cell 4) to input the MBMS service data (1, 2, 3, 4).

It can be seen that, in the foregoing method proposed by the present invention, by using a frequency band covered by a frequency resource occupied by a broadcast multicast service data broadcasted by a broadcast multicast cell in a unicast cell adjacent to a broadcast multicast cell, and a broadcast multicast The cell synchronously transmits the broadcast multicast service data, so that the receiving power of the broadcast multicast service received by the user in the transition zone between the broadcast multicast cell and the unicast cell can be improved, thereby improving the receiving of the broadcast multicast service by the user in the transition zone. Receive performance.

The technical solution of the present invention also considers that the problem that the user receives the broadcast multicast service data in the transition zone between the broadcast multicast cell and the adjacent unicast cell is low, possibly due to the unicast cell transmitting the unicast data pair transition. The interference caused by the user in the zone is too large. In fact, when the unicast traffic is small, the unicast cell may not transmit any service data in the frequency band covered by the frequency resource occupied by the broadcast multicast service data. Including unicast service data and broadcast multicast service data, or transmitting unicast service data by reducing transmission power, thereby reducing interference caused by users receiving broadcast multicast service data in the transition zone, and improving the transition zone in disguise The user receives the received power of the broadcast multicast service data, thereby improving the receiving performance of the user receiving the broadcast multicast service data in the transition zone.

Referring to FIG. 15, the figure is a schematic flowchart of another embodiment of a method for transmitting a broadcast multicast service according to the present invention. The implementation process is as follows:

Step 100: In a cell that uses frequency reuse (such as interference multiplexing based frequency reuse, typically, such as SFR), determine a frequency resource occupied by a broadcast multicast service data transmitted by a broadcast multicast cell based on a multi-cell transmission mode. ;

The high-level (such as AGW) may determine that the broadcast multicast cell transmits the broadcast multicast service data. The occupied frequency resource, and notifying the determined frequency resource information to the broadcast multicast cell and the adjacent unicast cell respectively;

Step 200: The broadcast multicast cell transmits the broadcast multicast service data on the determined frequency resource, and at the same time, in the unicast cell adjacent to the broadcast multicast cell, in the same frequency band as the determined frequency resource. No transmission of any service data (including unicast service data and broadcast multicast service data), or transmission of unicast service data by reducing the transmission power mode, thereby reducing the reception of broadcast multicast service data by users in the transition zone The interference caused by the user in the transition zone improves the receiving performance of the broadcast multicast service data.

According to the foregoing embodiment, refer to FIG. 16 , which is a schematic diagram of a frequency resource distribution state in which no data transmission is performed on a frequency resource occupied by MBMS service data in a unicast cell in the embodiment of the present invention, and thus In unicast cells 3 and 4, no traffic data transmission will be performed in the same frequency band as the frequency resource occupied by the broadcast multicast cell transmission MBMS service data, including no unicast service data transmission and no transmission. Transmission of MBMS service data, etc.

Please refer to FIG. 17, which is a schematic diagram of MBMS service data in a unicast cell in the embodiment of the present invention. It can be seen that in the unicast cells 3 and 4, the MBMS service data is transmitted in the occupied and broadcast multicast cells. In the frequency band with the same frequency resource, the primary frequency transmission power and the secondary frequency transmission power are both reduced, and then the service data (including unicast service data and broadcast multicast) is transmitted based on the primary frequency and the secondary frequency after reducing the transmission power respectively. Business data).

Referring to FIG. 18, it is a schematic diagram of a frequency resource distribution state in which a primary frequency is changed into a secondary frequency transmission service data on a frequency resource occupied by MBMS service data in a unicast cell according to an embodiment of the present invention. In the unicast cells 3 and 4, the primary frequency transmission power is reduced to the secondary frequency transmission power data (including the unicast service data and the frequency band occupied by the MBMS service data occupied by the broadcast multicast cell). Broadcast multicast service data).

Referring to FIG. 19, which is a structural block diagram of an embodiment of a broadcast multicast service transmission system according to the present invention, which includes a frequency determining unit 10 and a resource usage limiting unit 20, wherein resource usage restrictions are used. The unit 20 further includes a frequency selection unit 201 and a service data transmission unit 202, wherein the specific functions of the respective constituent units are as follows:

The frequency determining unit 10 is configured to determine, in a cell that uses frequency multiplexing, a radio resource occupied by a broadcast multicast service data transmitted by a broadcast multicast cell based on a multi-cell transmission mode (for example, it may be occupied by transmitting broadcast multicast service data) Frequency resource, time resource, and transmission power resource, etc., the following description uses the radio resource determined here as a frequency resource for transmitting broadcast multicast service data as an example); the resource use restriction unit 20 is configured to broadcast multicast When the cell transmits the broadcast multicast service data based on the radio resource determined by the frequency determining unit 10, the radio resource used in the determined radio resource is restricted to the neighboring cell of the broadcast multicast cell, where it includes:

The frequency selection unit 201 is configured to select a corresponding frequency resource in a frequency band that is the same as the frequency resource determined by the frequency determining unit 10 occupied by the neighboring cell of the broadcast multicast cell;

The service number transmission unit 202 is configured to synchronize the transmission of the broadcast multicast service data by the neighboring cell based on the frequency resource selected by the frequency selection unit 201 and the frequency resource determined by the broadcast determining unit 10 by the broadcast multicast cell.

As shown in FIG. 20, it is a block diagram of a specific structure of an embodiment of a frequency selection unit in the system of the present invention, which specifically includes a frequency band allocation acquisition subunit 2011, a frequency selection subunit 2012, and a selection frequency adjustment subunit 2013, wherein each component unit The specific role is as follows:

a frequency band allocation obtaining subunit 2011, configured to determine frequency band allocation information of a neighboring cell of a broadcast multicast cell in a multiplexed state;

The frequency selection sub-unit 2012 is configured to select, according to the frequency band allocation information determined by the frequency band allocation acquisition sub-unit 2011, the corresponding frequency resource in a frequency band that is occupied by the neighboring cell and is the same as the frequency resource determined by the frequency determining unit 10;

The frequency adjustment subunit 2013 is configured to dynamically adjust the frequency resource that the frequency selection subunit 2012 has selected in the frequency band that is occupied by the neighboring cell and is the same as the frequency resource determined by the frequency determining unit 10.

In the system of the present invention, if the frequency multiplexing mode between different cells is the frequency multiplexing mode based on interference coordination, the frequency selecting unit 201 may be small in the vicinity of the broadcast multicast cell. The frequency resource selected by the area and the frequency resource determined by the frequency determining unit 10 is selected as the frequency resource of the unicast cell edge area user monthly service, and may also be selected as the frequency resource of the user service in the neighboring cell center area, and may also be selected at the same time. A frequency resource serving a user in a neighboring cell edge area and a frequency resource serving a user in a neighboring cell center area. Therefore, in the system of the present invention, a first transmission power control unit may be further included on the basis of the foregoing composition structure of FIG. 18, and the transmission data for the service data transmission unit 202 in the adjacent cell based on the transmission power in the interference coordination frequency reuse state. The process of transmitting broadcast multicast service data is power controlled.

For example, when the frequency multiplexing process is performed by using the SFR method between different cells, the frequency selection unit 201 may select the frequency resource that is the primary frequency of the neighboring cell, or may select the frequency resource that is the secondary frequency of the neighboring cell, and may also be selected as the neighboring cell master. The frequency resource of the frequency and the frequency resource that is the secondary frequency of the neighboring cell. Therefore, in the system of the present invention, a second transmission power control unit may be further included on the basis of the foregoing structure of FIG. 18 for transmitting the transmission power to the service data transmission unit 202 in the neighboring cell based on the transmission power in the SFR multiplexing state. The process of broadcasting multicast service data is power controlled.

In another aspect, the resource usage restriction unit 20 may also limit the neighboring cells of the broadcast multicast cell to include unicast service data and broadcast multicast service data to reduce interference caused by users receiving broadcast multicast service data in the transition zone. , thereby improving the receiving performance of the user receiving the broadcast multicast service data in the transition zone.

On the other hand, the resource usage restriction unit 20 may also limit the neighboring cells of the broadcast multicast cell to reduce the power transmission service data in the frequency band occupied by the same frequency resource, including reducing the primary frequency transmission power therein, or The primary frequency and the secondary frequency transmission power are both reduced to transmit service data (including unicast service data and broadcast multicast service data). It can also reduce the interference caused by users receiving broadcast multicast service data in the transition zone, thereby improving the receiving performance of users receiving broadcast multicast service data in the transition zone.

In the above system according to the embodiment of the present invention, the cell adjacent to the broadcast multicast cell that transmits the MBMS service data includes a unicast cell and a broadcast multicast cell in a predetermined area around the broadcast multicast cell. And a mixed carrier cell or the like, and the strength of the resource usage restriction unit 20 limiting the radio resources used by each cell in the neighboring cell is inversely proportional to the distance of the cell from the broadcast multicast cell, that is, the cell closer to the broadcast multicast cell The resource use restriction unit 20 has a higher intensity of restriction on the radio resources used, and the farther the distance from the broadcast multicast cell is, the smaller the strength of the resource use restriction unit 20 to limit the radio resources used.

For details of the implementation of other specific technologies in the transmission system of the broadcast multicast service of the present invention, refer to the related technical details in the foregoing method of the present invention, and no further details are provided herein. The spirit and scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of the inventions

Claims

Claim

A method for transmitting a broadcast multicast service, comprising the steps of:

Determining, by the frequency multiplexed cell, a radio resource occupied by the broadcast multicast service data of the broadcast multicast area based on the multi-cell transmission mode;

When the broadcast multicast cell transmits broadcast multicast service data based on the determined radio resource, the neighboring cell that restricts the broadcast multicast cell uses the same radio resource as the determined radio resource.

2. The method according to claim 1, wherein the radio resource occupied by the broadcast multicast service data by the broadcast multicast cell is determined by a higher layer;

Notifying the determined radio resource information to the broadcast multicast cell.

"

3. The method according to claim 1, wherein the determined radio resource is a frequency resource.

The method according to claim 3, wherein the limiting the wireless resource used by the neighboring cell comprises: a source;

The neighboring cell synchronously transmits the broadcast multicast service data based on the determined frequency resource and the broadcast multicast cell based on the determined frequency resource.

The method of claim 4, wherein the process of selecting a corresponding frequency resource specifically includes:

And acquiring, by the upper layer, the frequency band allocation information of the neighboring cell in the frequency reuse state; and selecting, according to the acquired cell frequency band allocation information, the corresponding frequency resource in a frequency band that is occupied by the neighboring cell and is the same as the determined frequency resource;

The upper layer notifies the neighboring cell of the selected frequency resource information.

The method of claim 5, wherein the process of selecting the corresponding frequency resource further includes:

The upper layer dynamically adjusts in the same frequency band occupied by the neighboring cell as the determined frequency resource The selected frequency resource; and 'notifying the neighboring cell of the adjusted frequency resource information.

The method according to claim 4, wherein the process of selecting the corresponding frequency resource specifically includes:

The high layer notifies the determined neighboring cell of the frequency resource information occupied by the broadcast multicast service data of the broadcast multicast cell;

The neighboring cell allocates information according to its own frequency band in the frequency reuse state, and occupies itself

The method of claim 7, wherein the process of selecting the corresponding frequency resource further includes:

The neighboring cell dynamically adjusts the selected frequency resource in a frequency band that is occupied by itself and is the same as the determined frequency resource.

9. The method of any of claims 1-8, wherein the frequency multiplexing is frequency multiplexing based on interference coordination.

The method according to claim 9, wherein the selecting a frequency resource refers to: selecting a frequency resource serving the user of the neighboring cell edge area; and/or

Selecting a frequency resource serving the user of the neighboring cell center area.

The method according to claim 9, wherein the transmitting broadcast broadcast service data of the neighboring cell is subject to transmission power control in an interference coordinated frequency reuse state.

12. The method of any of claims 1-8, wherein the frequency multiplexing is soft frequency multiplexing based on interference coordination.

The method according to claim 12, wherein the selecting a frequency resource refers to: selecting a frequency resource that is a dominant frequency of a neighboring cell; and/or

The frequency resource that is the secondary frequency of the neighboring cell is selected.

14. The method according to claim 12, wherein the transmitting broadcast broadcast service data of the neighboring cell is subject to transmission power control in a soft frequency reuse state.

The method according to claim 3, wherein the restricting use of a neighboring cell The wireless resources are specifically: The transmission of data.

The method according to claim 3, wherein the limiting the radio resources used by the neighboring cells is:

The neighboring cell reduces power transmission service data in a frequency band that is the same as the determined frequency resource.

The method according to claim 16, wherein the reducing the power transmission service data is specifically: transmitting the service data on the primary frequency and the secondary frequency thereof based on the secondary frequency transmission power.

The method according to claim 16, wherein the reducing the power transmission service data is specifically: reducing the transmission power of the primary frequency and the secondary frequency to transmit the service data.

19. The method according to claim 1, wherein the strength of limiting the radio resources used by each of the neighboring cells is inversely proportional to the distance of the cells from the broadcast multicast cell.

The method according to claim 1, wherein the neighboring cell is a unicast cell in a predetermined area around the broadcast multicast cell.

The method according to claim 15, 16, 17, or 18, wherein the service data is: unicast service data and/or broadcast multicast service data.

22. A transmission system for a broadcast multicast service, comprising:

a frequency determining unit, configured to determine, in a cell that uses frequency multiplexing, a radio resource occupied by a broadcast multicast service data transmitted by a broadcast multicast cell based on a multi-cell transmission mode;

And a resource usage limiting unit, configured to restrict, when the broadcast multicast cell transmits the broadcast multicast service data based on the radio resource determined by the frequency determining unit, the neighboring cell of the broadcast multicast cell to use the same radio resource as the determined radio resource.

The system according to claim 22, wherein the radio resource determined by the frequency determining unit is a frequency resource.

The system of claim 23, wherein the resource usage restriction unit comprises: a frequency selection unit, configured to select a frequency resource in a frequency band that is the same as a frequency resource determined by a frequency determining unit occupied by a neighboring cell of a broadcast multicast cell;

The service data transmission unit is configured to synchronously transmit the broadcast multicast service data by using the frequency resource selected by the neighboring cell based on the frequency selection unit and the frequency resource determined by the broadcast multicast cell based on the frequency determining unit.

The system of claim 24, wherein the frequency selection unit comprises: a frequency band allocation acquisition sub-unit, configured to acquire frequency band allocation information of a neighboring cell of a broadcast multicast cell in a frequency reuse state;

a frequency selection subunit, configured to acquire frequency band allocation information and frequency resources acquired by the subunit according to the frequency band allocation.

The system according to claim 25, wherein the frequency selection unit further comprises a selection frequency adjustment subunit, configured to be in a frequency band occupied by the neighboring cell and having the same frequency resource as determined by the frequency determining unit. Dynamically adjust the frequency resource selected by the frequency selection subunit.

27. The system of claim 24, 25 or 26, wherein the frequency selection unit selects a frequency resource that is served by a user adjacent to the cell edge area; and/or

Select the frequency resource that serves the users in the central area of the neighboring cell.

The system according to claim 27, further comprising a first transmission power control unit, configured to transmit broadcast multicast to the service data transmission unit in the neighboring cell based on the transmission power in the interference coordination frequency reuse state The process of business data is power controlled.

29. The system of claim 24, 25 or 26, wherein the frequency selection unit selects a frequency resource that is the primary frequency of the neighboring cell; and/or

The system according to claim 29, further comprising a second transmission power control unit, configured to transmit a broadcast multicast service to the service data transmission unit in the neighboring cell based on the transmission power in the soft frequency reuse state. The process of data is power controlled.

The system according to claim 23, wherein the resource usage restriction unit is limited The transmission of data.

The system according to claim 23, wherein the resource use restriction unit limits the neighboring cell to reduce power transmission service data in a frequency band that is occupied by the same frequency resource.

The system according to claim 22, wherein the strength of the radio resource used by the resource usage limiting unit to each cell in the neighboring cell is inversely proportional to the distance of the cell from the broadcast multicast cell.

The system according to claim 22, wherein the neighboring cell is a unicast cell in a predetermined area around the broadcast multicast cell.

The system according to claim 31 or 32, wherein the service data is: unicast service data and/or broadcast multicast service data.