KR101191183B1 - method for transmitting and receiving data using a plurality of carriers - Google Patents

Abstract

In a data transmission / reception method according to an embodiment of the present invention, in a mobile communication system transmitting data symbols by a plurality of carriers, first multicast / broadcast data to be transmitted in units of radio frames including at least one or more of the data symbols Obtaining a; And a mobile terminal that modulates the first multicast / broadcast data in the same manner and transmits the signals through a plurality of first cells simultaneously through the same frequency band and simultaneously receives signals from the plurality of first cells. And including transmitting the first multicast / broadcast pilot for the mobile station.

OFDM, pilot, multicast, broadcast, interference

Description

Method for transmitting and receiving data using a plurality of carriers}

1A illustrates an example of a radio frame configured according to a transmission method according to an embodiment of the present invention.

1B illustrates an example of a radio frame configured according to a transmission method according to another embodiment of the present invention.

2 illustrates a radio frame transmitted by each cell transmitting different multicast / broadcast data according to an embodiment of the present invention.

3 is a diagram illustrating different OFDM symbols transmitted in a cell transmitting the same multicast / broadcast data according to an embodiment of the present invention.

4 is a diagram illustrating different OFDM symbols transmitted in a cell transmitting the same multicast / broadcast data according to another embodiment of the present invention.

The present invention relates to a data transmission / reception method in a mobile communication system, and more particularly, to a data transmission / reception method in an OFDM / OFDMA mobile communication system.

Hereinafter, orthogonal frequency division multiplexing (OFDM) will be described. The basic principle of OFDM is to divide a high-rate data stream into a large number of low-rate data streams, which are transmitted simultaneously using multiple carriers. Each of the plurality of carriers is called a subcarrier. Since orthogonality exists between the multiple carriers of the OFDM, the frequency components of the carriers can be detected at the receiving end even if they overlap each other. The high data rate data stream is converted into a plurality of low data rate data streams through a serial to parallel converter, and each subcarrier is included in the parallel data streams. After multiplying, the respective data strings are summed and sent to the receiving end.

Hereinafter, orthogonal frequency division multiple access (OFDMA) will be described. OFDMA refers to a multiple access method for realizing multiple access by providing each user with a part of subcarriers available in a system using OFDM as a modulation method. OFDMA provides each user with a frequency resource called a subcarrier, and each frequency resource is provided to a plurality of users independently of each other so that they do not overlap each other. After all, frequency resources are allocated mutually exclusive.

Hereinafter, a data transmission / reception method in the communication system using the above-described OFDMA will be described. When multicast / broadcast data is transmitted on the downlink in a cellular mobile communication system using OFDMA as a multiple access method for downlink data transmission, multiple neighbor cells may transmit the same data.

The multicast / broadcast data refers to data transmitted to at least one terminal in a mobile communication system. In addition, the multicast / broadcast data is transmitted from a plurality of cells to a plurality of terminals, and the plurality of cells transmit the same data to the terminal. In the case of transmitting the multicast / broadcast data in the communication system, by controlling a transmission method of cells neighboring the cell transmitting the data, the receiving terminal can combine and demodulate the same data transmitted from neighboring cells. This allows greater receive energy and multiple cell diversity gains.

As described above, in a cellular mobile communication system using OFDMA as a multiple access scheme for downlink data transmission, when neighboring multicast / broadcast data as a downlink, multiple neighbor cells may transmit the same data. In this case, by properly designing a transmission scheme for the same data of neighboring cells, the receiving terminal can combine and demodulate the same data sent by a plurality of cells, thereby obtaining greater reception energy and multi-cell diversity gain. have. A coupling scheme in a receiver for the same data transmitted by the plurality of cells may be divided into an RF coupling scheme and a selective coupling scheme.

Hereinafter, the RF coupling method will be described. For the RF combining scheme, the same modulation symbol must be transmitted in the same frequency-time domain at the end of the transmitting end corresponding to each of the cells transmitting the data to be combined, and the pilot for the demodulation also transmits the same pilot symbol to the same frequency. -Send in the time domain. In other words, from the receiver side, the signal received from the transmitting end corresponding to each of the plurality of cells to be RF coupled must be received in the same frequency-time domain within a certain error limit. In addition, transmission timing between transmission terminals corresponding to each of a plurality of cells transmitting the same data should be synchronized. Hereinafter, for convenience of explanation, the "transmitter corresponding to the cell" is briefly referred to as "cell".

In this case, the receiving terminal can demodulate as if a signal transmitted by one cell is received in multiple paths through different radio channel paths without having to separately distinguish the same signals received from multiple cells. In this way, the receiver can obtain the diversity gain by reception in multiple cells by having an effect as if the multipath is increased.

Hereinafter, the selective coupling method will be described. Mobile communication systems using a selective combining scheme transmit the same data through multiple cells. However, unlike the RF combining method described above, it is not necessary to finally transmit the same data at the end of the transmitting end. That is, each cell may receive the same data from a higher layer, and may modulate and transmit each data in a different manner for each cell. In addition, each cell may transmit the data to be transmitted in the same or different frequency domains, and may be transmitted in the same or different time intervals. In the case of general multicast / broadcast data transmission in which the time interval of data transmitted by each cell is not extremely different, the receiving terminal demodulates and decodes the same data transmitted from a plurality of cells for each cell. Later, it is determined whether reception is successful for each cell. Even if reception is successful in at least one cell among a plurality of cells, since reception of the data is successful, selective diversity gain by reception in multiple cells can be obtained.

The present invention has been proposed to improve a downlink transmission scheme in an OFDMA cellular mobile communication system, and an object of the present invention is to provide a method for transmitting and receiving multicast / broadcast data that can achieve multi-cell diversity. will be.

summary

In a data transmission / reception method according to an embodiment of the present invention, in a mobile communication system transmitting data symbols by a plurality of carriers, first multicast / broadcast data to be transmitted in units of radio frames including at least one or more of the data symbols Obtaining a; And a mobile terminal that modulates the first multicast / broadcast data in the same manner and transmits the signals through a plurality of first cells simultaneously through the same frequency band and simultaneously receives signals from the plurality of first cells. And including transmitting the first multicast / broadcast pilot for the mobile station.

Another data transmission and reception method according to an embodiment of the present invention, in a mobile communication system for transmitting data symbols by a plurality of carriers, multicast / broadcast to be transmitted in units of radio frames consisting of at least one or more of the data symbols Obtaining data; And modulating the multicast / broadcast data in the same manner to determine whether to transmit the data through a plurality of cells simultaneously over the same frequency band. And transmitting the indication information regarding the determination result.

In another method of transmitting and receiving data according to an embodiment of the present invention, in a mobile communication system transmitting data symbols by a plurality of carriers, multicast / broadcast data to be transmitted in units of radio frames consisting of at least one data symbol. Obtaining a; And transmitting the multicast / broadcast data through a plurality of cells, wherein each of the multicast / broadcast data transmitted through the plurality of cells is transmitted by different carriers. It is done.

Another data transmission / reception method according to an embodiment of the present invention includes a first multicast / broadcast pilot received from a plurality of first cells in a mobile terminal receiving data symbols transmitted by a plurality of carriers. Simultaneously receiving first multicast / broadcast data modulated in the same manner from the plurality of first cells through the same frequency band, wherein the plurality of first cells The first multicast / broadcast pilots received from the MSs are modulated in the same manner and transmitted simultaneously over the same frequency band.

In another method of transmitting and receiving data according to an embodiment of the present invention, in a mobile terminal that receives a signal from a mobile communication system having a plurality of cells, multicast / broadcast is modulated in the same manner to each other to the plurality of cells. Receiving indication information as to whether the transmission is simultaneously performed through the same frequency band; And jointly receiving the multicast / broadcast data according to the indication information.

Another data transmission and reception method according to an embodiment of the present invention, in a mobile terminal receiving a signal from a mobile communication system having a plurality of cells, the multicast / broadcast data transmitted from the plurality of cells (cell) It comprises a step of receiving, characterized in that each of the multicast / broadcast data transmitted through the plurality of cells is transmitted by different carriers.

Work according to the invention Example

The construction, operation and effects thereof of the present invention will be embodied according to one embodiment of the present invention described below.

The data transmission / reception method according to an embodiment of the present invention proposes an efficient pilot / data mapping structure capable of obtaining multi-cell diversity.

1st Example

In this embodiment, a multicast / broadcast data mapping structure is proposed for a mobile terminal that combines and receives data according to an RF combining scheme.

As described above, in order to apply the RF combining scheme to the transmission and reception of multicast / broadcast data, the same modulation symbol should be transmitted in the same frequency-time domain for the same multicast / broadcast data transmitted from multiple cells. Pilots to help demodulate data must also transmit the same pilot symbols in the same frequency-time domain. That is, in order to combine and receive multicast / broadcast data by RF combining, synchronization of transmission timings between cells must be performed.

However, each of the cells may transmit various kinds of data. In addition, if each of the cells transmits general data instead of multicast / broadcast data, it is not necessary to transmit the same pilot between the cells in the same frequency-time domain. That is, a pilot for demodulation of data transmitted only for a terminal in a cell in a specific cell is different from the pilot of the neighbor cell in the frequency-time domain so as not to interfere with a pilot transmitted from a neighbor cell of the specific cell. It is desirable to have a batch structure.

Accordingly, this embodiment provides a pilot for efficient RF combined reception of the multicast / broadcast data in a communication system in which different kinds of data are transmitted. That is, in the present embodiment, in transmission of the multicast / broadcast data, in each cell, multiple cells of the multicast / broadcast data in addition to the general pilot used for demodulation of general data localized in the cell. Provide a new dedicated pilot for joint reception. That is, according to the present embodiment, cells transmitting the multicast / broadcast data transmit pilots dedicated to multicast / broadcast data having a common symbol modulation and frequency-time domain arrangement. For convenience of explanation, the dedicated pilot is referred to as a multicast / broadcast pilot (MBMS pilot), and a pilot for transmitting data other than the multicast / broadcast data is referred to as a general pilot.

The multicast / broadcast pilot has a symbol modulation or frequency-time domain arrangement different from that of a cell transmitting the multicast / broadcast data or neighboring cells of the cell to interfere with the general pilot. It is desirable to minimize this.

Hereinafter, the transmission pattern of the multicast / broadcast pilot will be described. In general, a pilot symbol to help demodulate each modulation symbol should be located near that modulation symbol in the frequency-time domain. This is because each pilot symbol must undergo a channel similar to the modulation symbol in order to perform accurate channel estimation in the mobile terminal receiving the pilot symbol. However, if multicast / broadcast data and other general data are transmitted together through a specific radio frame, modulation symbols of the multicast / broadcast data are scattered widely within one frame in the frequency-time domain. In case of distribution, a problem may occur that many pilot symbols are required. In order to solve this problem, this embodiment proposes to transmit the multicast / broadcast pilot only in a limited frequency band. In this case, the multicast / broadcast data is also preferably transmitted in the limited frequency band. The radio frame is generally composed of very short time units, and channel characteristics do not change significantly during the very short time, thereby limiting waste of pilot signals by limiting the multicast / broadcast pilot to a limited frequency region. Can be reduced.

Hereinafter, another transmission pattern of the multicast / broadcast pilot according to the present embodiment will be described. That is, it is preferable that the mobile communication system according to the present embodiment preferentially transmit the multicast / broadcast in the same OFDM symbol in one radio frame. In addition, when the amount of multicast / broadcast data to be transmitted in the system is large, a plurality of OFDM symbols may be transmitted in one frame. In this case, the multicast / broadcast pilot may be located in an OFDM symbol in which multicast / broadcast data is transmitted and transmitted to minimize frequency-time resources used as pilots. As described above, in the case of including the multicast / broadcast pilot through a wide frequency band, there is an advantage that a frequency diversity gain can be obtained.

According to the present embodiment, the modulation and frequency-time domain arrangement of the multicast / broadcast pilot where RF combined reception is performed is the same among a plurality of cells transmitting the multicast / broadcast data.

In addition, the mobile communication system transmits the first OFDM symbol of each frame in multicast / broadcast within that frame so that the mobile terminal knows which OFDM symbol in the radio frame currently received is used for multicast / broadcast data transmission. It is preferable to transmit information on OFDM symbol and subcarrier mapping used for data transmission.

1A illustrates an example of a radio frame configured according to a transmission method according to an embodiment of the present invention. The radio frame is composed of at least one data symbol and represents a predetermined unit in which data is transmitted. One radio frame may include various numbers of OFDM symbols, and as shown in the present embodiment, the radio frame may include six OFDM symbols. In this embodiment, one OFDM symbol is transmitted by a plurality of subcarriers. 1A illustrates an example in which the multicast / broadcast pilot 120 is transmitted by subcarriers belonging to a specific frequency domain. As shown, the first OFDM symbol included in the radio frame may include the general pilot 110 and the control information 130. As described above, the general pilot 110 is preferably arranged differently from each other for the cells, in the example of Figure 1a the arrangement of the general pilot 110 is different from each other for each cell. As described above, the mobile communication system includes the first OFDM symbol of each frame within the frame so that the mobile terminal knows which OFDM symbol and subcarrier in the radio frame it is currently receiving for multicast / broadcast data transmission. Information on OFDM symbols and subcarrier mapping used for multicast / broadcast data transmission may be included, and the multicast / broadcast data mapping information 160 is included in the first OFDM symbol and transmitted. As shown in FIG. 1A, the multicast / broadcast data mapping information 160 may indicate OFDM symbols and subcarriers used for multicast / broadcast data transmission directly or indirectly according to a predetermined rule. Can be. Since the pilot signal 120 is transmitted only in a specific frequency domain, the multicast / broadcast data 140 according to the pilot signal is also transmitted by subcarriers belonging to the specific frequency domain. In conclusion, while the general pilot 110 transmitted by each cell is preferably different, the multicast / broadcast pilot 120 is preferably arranged identically for each cell.

1B illustrates an example of a radio frame configured according to a transmission method according to another embodiment of the present invention. In the example of FIG. 1B, six OFDM symbols are included in one radio frame, and one OFDM symbol is transmitted by a plurality of subcarriers. As shown, the first OFDM symbol included in the radio frame may include the general pilot 110 and the control information 130. As described above, the general pilot 110 is preferably arranged differently from each other for the cells, in the example of Figure 1b the arrangement of the general pilot 110 is different from each other for each cell. The example of FIG. 1B may include the multicast / broadcast data mapping information 160, similar to the example of FIG. 1A, wherein the mapping information 160 is included in the first OFDM symbol in a radio frame. More preferred. In the example of FIG. 1B, multicast / broadcast data 140 is transmitted on the second OFDM symbol of the radio frame in cell 1 and cell 2, where cell 1 and cell 2 are the same multicast / broadcast for RF combining at the receiver. The broadcast pilot 120 also transmits in the second OFDM symbol. Accordingly, the mobile terminal acquires the multicast / broadcast data mapping information 160 transmitted through the first OFDM symbol of the frame transmitted by the cell to which the cell belongs to one of the cell 1 and the cell 2, thereby multiplying the data within the first frame. OFDM symbols used for the cast / broadcast data transmission 140 may be distinguished, and the multicast / broadcast data 140 may be converted to the multicast / broadcast data 140 using the multicast / broadcast pilot 120. ) Can be combined and received and demodulated in an RF combined manner. The OFDM symbol to which the multicast / broadcast data 140 is transmitted is not limited, and may be transmitted through a third or subsequent OFDM symbol.

The above-described embodiment has described a data transmission / reception method by a plurality of cells transmitting the same multicast / broadcast data. Hereinafter, a method of transmitting and receiving data by a plurality of cells transmitting different multicast / broadcast data will be described. As described above, the multicast / broadcast data is transmitted by multiple cells. In general, a specific cell and its neighboring cells transmit the same multicast / broadcast data. However, according to the service provider, different multicast / broadcast services may be provided in units of a specific number of cells. In this case, at a boundary of different multicast / broadcast service areas, a particular cell may transmit first multicast / broadcast data, and the remaining cells may transmit second multicast / broadcast data. In addition, when a mobile terminal located in an area capable of receiving signals from these two cells wants to receive first multicast / broadcast data in specific cells, second multicast / broadcast data transmitted by another cell The signal may act as an interference to the first multicast / broadcast data. Therefore, different multicast / broadcast data transmitted by two neighboring cells need to be prevented from being RF coupled at the receiver. To this end, in the present invention, when neighboring cells transmit different multicast / broadcast data at the same timing, it is proposed to transmit the modulation and arrangement in the frequency-time domain of the multicast / broadcast pilot differently.

2 illustrates a radio frame transmitted by each cell transmitting different multicast / broadcast data according to an embodiment of the present invention. As shown, cells a and b transmit the same first multicast / broadcast data to each other at the same timing, and cell c transmits second multicast / broadcast data different from cell a or b at the same timing. . That is, cells a and b are cells included in an area providing the same multicast / broadcast data service, and cell c represents a cell included in an area providing another multicast / broadcast data service. Cell a, cell b and cell c transmit respective OFDM symbols 210, 220, and 230, and each OFDM symbol may be formed as shown. That is, the first multicast / broadcast data is transmitted by the OFDM symbols 210 and 220, and the second multicast / broadcast data is transmitted by the OFDM symbol 230. As shown in FIG. 2, the cell a transmits a multicast / broadcast pilot 240 for receiving first multicast / broadcast data, and the cell b transmits the first multicast / broadcast data. The multicast / broadcast pilot 250 for reception is transmitted, and the multicast / broadcast pilots 240 and 250 transmitted by the two cells are identical to each other. However, cell c transmits a multicast / broadcast pilot 260 for receiving second multicast / broadcast data, and thus the structure of the multicast / broadcast pilot 260 transmitted by cell c. Is different from the structure of the pilots 240 and 250 transmitted by the cells a and b. Therefore, the pilot signal 260 transmitted by the cell c is different from the modulation scheme or the time transmitted or the frequency domain transmitted compared to the pilot signals 240 and 250 transmitted by the cells a and b. can do. That is, like the 1 multicast / broadcast data and the 2 multicast / broadcast data, multicast / broadcast pilots having different structures are transmitted for different multicast / broadcast data, and the mobile terminal transmits the multicast / broadcast pilots having different structures. Receive data with less interference. In order to transmit and receive multicast / broadcast pilots having different structures, a plurality of multicast / broadcast pilot structures are required. For example, in FIG. 2, two structures, a pilot structure for cells a and b and a pilot structure for cell c, are required. In this case, the information on the multicast / broadcast data transmission transmitted through the first OFDM symbol of each radio frame is related to which multicast / broadcast pilot structure is used for the multicast / broadcast data. It can be transmitted including information.

Second Example

Hereinafter, a mapping structure for multicast / broadcast data by the selective combining method will be described.

As described above, the mobile terminal receiving the signal by the selective combining method separately demodulates and decodes the multicast / broadcast data received in each cell. That is, a pilot dedicated to multicast / broadcast data for combining and receiving signals received from a plurality of cells by RF combining is not necessary, and demodulation of multicast / broadcast data with only a pilot for general data demodulation in each cell is required. And selective combinations are possible. The multicast / broadcast data refers to data transmitted from a plurality of cells, and the multicast / broadcast data is transmitted to at least one or more mobile terminals. The multicast / broadcast data includes the same content, but need not be modulated in the same way at the end of each cell, transmitted in the same time interval, or transmitted in the same frequency domain. As described above, the mobile terminal demodulates and decodes the data received in each cell.

The present embodiment proposes a mobile communication system that switches to transmitting a multicast / broadcast pilot when the RF communication is supported in the same communication system and not transmitting a multicast / broadcast pilot when the RF communication is not supported. do. As described above, in the mobile communication system supporting different combined reception methods, it is preferable to transmit indication information about the combined reception method supported by the mobile communication system to the mobile terminal. There is no limitation on how the indication information is transmitted. For example, it is possible to broadcast indication information about a combined reception method supported by each cell through a broadcast channel. Or, for each mobile terminal attempting to connect to a specific cell, indication information about the combined reception scheme supported by the specific cell may be transmitted through the procedure for the connection. By transmitting such indication information, to each terminal belonging to a specific cell or to all terminals belonging to the cell, whether the current mobile communication system supports RF combining or selective combining for multicast / broadcast data or pilot type is used. Information about the multicast / broadcast data pilot or not.

In addition, the scheme of combined reception supported by the cell of the mobile communication system may be switched or fixed by a specific condition. That is, a specific cell may support RF coupling and then support selective coupling under specific conditions. However, in order to support RF coupling, synchronization must be maintained between cells, and the combined reception scheme supported by the cells of the mobile communication system is more preferably fixed. That is, since synchronization is maintained between cells belonging to a service area and synchronization is not maintained between cells belonging to another service area, cells in which synchronization is maintained support RF coupling, and cells in which synchronization is not maintained are selective coupling only. Can support For example, even if synchronization between terrestrial base stations is achieved by GPS or signaling between base stations, synchronization with underground base stations may not be. In this case, it is possible to support the RF coupling scheme between the ground base stations, which are kept in sync, and to support the selective coupling scheme between ground / underground base stations or underground / underground base stations, which are not kept in sync with each other.

The mobile terminal according to the present embodiment uses the multicast / broadcast pilot for multicast / broadcast data demodulation when it is informed from the cell that it supports RF combining or multicast / broadcast pilot. In addition, when informed that the multicast / broadcast pilot is not supported, the general pilot should be used for multicast / broadcast data demodulation. In conclusion, by receiving the indication information, the mobile terminal can select a possible combined reception scheme.

In the case of supporting selective combining, even though multicast / broadcast data transmitted by multiple cells are the same data, they do not go through RF combining, and thus, each demodulation and decoding act as interference. In particular, since multicast / broadcast data is transmitted to an unspecified number of terminals in a cell, neighboring cells may act as a large interference since transmission is performed at a large power so that a terminal near a cell boundary can also be received.

Therefore, in the present embodiment, when the multicast / broadcast data transmitted by the plurality of neighbor cells does not support RF combining for the same multicast / broadcast data transmitted by the multiple neighbor cells and supports selective combining, the multicast / broadcast data transmitted by the multiple cells are different. It provides a communication system transmitted in the frequency domain. As described above, even if a plurality of cells transmit the same data, the mobile terminal does not combine and receive a signal from the plurality of cells by an RF combining method. It is desirable to transmit data. As described above, data does not need to be transmitted in the same modulation scheme, in the same frequency domain, or in the same time interval for the selective combined reception. Thus, the same multicast / broadcast data is data provided from an upper layer. Is the same, and the last end of each cell may transmit the same data in different ways. As a result, the present embodiment provides a method in which a plurality of cells transmitting the same multicast / broadcast data use different frequency domains to reduce interference at a receiving side. Of course, according to an embodiment of the present invention, a method of transmitting the same multicast / broadcast data using different time domains is also possible. However, even though the transmitting side transmits data in different time domains, the receiving side may receive data at the same time depending on the influence of the channel. Therefore, transmitting data using different frequency domains may cause interference on the receiving side. More efficient at reducing The method of transmitting to the different frequency domains uses a different subcarrier. The plurality of cells may send indication information about cells transmitting the same multicast / broadcast data (in terms of a higher layer) to the mobile terminal to aid in selective combined reception of the mobile terminal. In addition, the multicast / broadcast data from the plurality of cells is more preferably encoded by an error correction code. The type of the error correcting code is not limited, and for example, a CRC check method is possible. The mobile terminal may receive indication information regarding a plurality of cells transmitting the same data, receive a signal from a plurality of cells indicated by the indication information, and perform a CRC check on the received signals to successfully receive the received information. You can see if this is done.

3 is a diagram illustrating different OFDM symbols transmitted in a cell transmitting the same multicast / broadcast data according to an embodiment of the present invention. As shown, cells a and b belong to the same service area, where cells a and b transmit the same multicast / broadcast data. Also, cell c is a different service than cell a or b. The cell c transmits data different from the cell a or b, belonging to an area Service B. Each of the cells a, b, and c transmits the OFDM symbols 310, 320, and 330, respectively. Note that it is not a matter of whether the pilots transmitted by the cells a, b are identical in the embodiment of FIG. In the present embodiment, the same multicast / broadcast data 340 and 350 are transmitted to the OFDM symbols 310 and 320 transmitted by the cells a and b, except that the two multicast / broadcast data 340 350 is transmitted to different frequency domains. When the mobile communication system according to the present embodiment is received by a selective combining method rather than an RF combining method, even if the cells (cells a and b) transmitting the same data are transmitted multicast / broadcast data 340, The 350 transmits the data in different frequency domains using different subcarriers so as not to interfere with each other.

4 is a diagram illustrating different OFDM symbols transmitted in a cell transmitting the same multicast / broadcast data according to another embodiment of the present invention. Each of the cells a, b, and c transmits the OFDM symbols 410, 420, and 430, respectively. Note that it does not matter whether the pilots transmitted by the cells a, b are the same. In the present embodiment, the same multicast / broadcast data 440 and 450 are transmitted to the OFDM symbols 410 and 420 transmitted by the cells a and b, except that the two multicast / broadcast data 440, 450 is transmitted to different frequency domains. As described above, when the example of FIG. 4 is received by a selective coupling scheme rather than an RF coupling scheme, even though the cells (cells a and b) transmit the same data, the cells a and b transmit. The two multicast / broadcast data 440 and 450 transmit the data in different frequency domains using different subcarriers so as not to interfere with each other. In this embodiment, there is no limitation in the frequency domain in which the multicast / broadcast data is transmitted. As shown in FIG. 3, multicast / broadcast data transmitted from each cell may be transmitted over the entire frequency domain. In this case, there may be an advantage of increasing the effect of frequency diversity. In addition, as shown in FIG. 4, multicast / broadcast data transmitted from each cell may be transmitted over some frequency domains. In this case, since the channel estimation can be transmitted by including the pilot symbol only in a limited frequency region, there may be an advantage of reducing pilot waste.

Those skilled in the art through the above description can be seen that various changes and modifications can be made without departing from the spirit of the present invention. Therefore, the technical scope of the present invention is not limited to the contents described in the detailed description of the specification.

The data transmission / reception scheme according to the present invention is an efficient pilot / data mapping structure capable of obtaining RF combined gain or selective combined gain for multi-cell transmission for downlink transmission of multicast / broadcast data in an OFDMA cellular mobile communication system. There is an advantage to present.

Claims (20)

In a mobile communication system for transmitting data symbols by multiple carriers, Constructing first multicast / broadcast data to be transmitted in radio frame units of at least one data symbol; And Modulate the first multicast / broadcast data in the same manner and transmit the same multicast / broadcast data through transmission terminals corresponding to each of a plurality of first cells simultaneously through the same frequency band; Transmitting a first multicast / broadcast pilot including a first multicast / broadcast pilot for a mobile terminal that simultaneously receives signals from transmitters corresponding to each of the plurality of first cells; Method of transmitting and receiving data using a plurality of carriers comprising a. The method of claim 1, The first multicast / broadcast pilot is transmitted by a carrier belonging to a specific frequency domain. Method of transmitting and receiving data using a plurality of carriers characterized in that. The method of claim 1, The first multicast / broadcast pilot is transmitted by at least one specific data symbol. Method of transmitting and receiving data using a plurality of carriers characterized in that. The method of claim 1, The structures of the first multicast / broadcast pilots transmitted through transmission terminals corresponding to each of the plurality of first cells are identical to each other. Method of transmitting and receiving data using a plurality of carriers characterized in that. 5. The method of claim 4, The pilot structure may include a modulation scheme of the pilot signal, a time interval in which the pilot signal is transmitted, and a frequency band in which the pilot signal is transmitted. Method of transmitting and receiving data using a plurality of carriers characterized in that. The method of claim 1, Configuring second multicast / broadcast data transmitted in units of the radio frame; The second multicast / broadcast data is modulated in the same manner to be transmitted through transmission terminals corresponding to each of the plurality of second cells simultaneously over the same frequency band. Transmitting a second multicast / broadcast pilot including a second multicast / broadcast pilot for a mobile terminal simultaneously receiving signals from transmitting terminals corresponding to each of the plurality of second cells; Method of transmitting and receiving data using a plurality of carriers comprising. The method of claim 6, The pilot structure for the second multicast / broadcast pilot is different from the pilot structure for the first multicast / broadcast pilot. Method of transmitting and receiving data using a plurality of carriers characterized in that. The method of claim 6, Transmitting indication information including information about the first multicast / broadcast pilot and the second multicast / broadcast pilot; A method for transmitting and receiving data using a plurality of carriers, characterized in that it further comprises. In a mobile communication system for transmitting data symbols by multiple carriers, Configuring multicast / broadcast data to be transmitted in radio frame units of at least one data symbol; And Modulating the multicast / broadcast data in the same manner and determining whether to transmit the multicast / broadcast data through transmission terminals corresponding to each of a plurality of cells simultaneously over the same frequency band; And Transmitting indication information regarding the determination result; Method of transmitting and receiving data using a plurality of carriers comprising a. 10. The method of claim 9, In the case of modulating the multicast / broadcast data in the same manner and transmitting the same through the transmitting terminals corresponding to each of the plurality of cells simultaneously over the same frequency band, Transmitting a multicast / broadcast pilot for a mobile terminal that simultaneously receives a signal from transmission terminals corresponding to each of the plurality of cells; A method for transmitting and receiving data using a plurality of carriers, characterized in that it further comprises. In a mobile communication system for transmitting data symbols by multiple carriers, Configuring multicast / broadcast data to be transmitted in radio frame units of at least one data symbol; And Transmitting the multicast / broadcast data through transmission terminals corresponding to each of a plurality of cells, Each of the multicast / broadcast data transmitted through transmission terminals corresponding to each of the plurality of cells is transmitted by different carriers. Method of transmitting and receiving data using a plurality of carriers characterized in that. In a mobile terminal receiving data symbols transmitted by multiple carriers, The first multicast / broadcast data modulated in the same manner using the first multicast / broadcast pilot received from the transmitting terminals corresponding to each of the plurality of first cells, respectively, through the same frequency band. Simultaneously receiving from the transmitting end corresponding to each of the cells, The first multicast / broadcast pilots received from transmitters corresponding to each of the plurality of first cells are modulated in the same manner and transmitted simultaneously over the same frequency band. Method of transmitting and receiving data using a plurality of carriers characterized in that. The method of claim 12, The first multicast / broadcast pilot is transmitted by a carrier belonging to a specific frequency domain Method of transmitting and receiving data using a plurality of carriers characterized in that. The method of claim 12, The first multicast / broadcast pilot is transmitted by at least one specific data symbol. Method of transmitting and receiving data using a plurality of carriers characterized in that. The method of claim 12, The second multicast / broadcast data modulated in the same manner by using a second multicast / broadcast pilot received from transmitting terminals corresponding to each of the plurality of second cells, through the same frequency band. Simultaneously receiving from the transmitting end corresponding to each of the cells, The second multicast / broadcast pilots received from the transmitting terminals corresponding to each of the plurality of second cells are modulated in the same manner and transmitted simultaneously over the same frequency band. Method of transmitting and receiving data using a plurality of carriers characterized in that. 16. The method of claim 15, The second multicast / broadcast pilot is modulated in a different manner than the first multicast / broadcast pilot and transmitted over different frequency bands in different time intervals. Method of transmitting and receiving data using a plurality of carriers characterized in that. 16. The method of claim 15, Receiving indication information including information about the first multicast / broadcast pilot and the second multicast / broadcast pilot; A method for transmitting and receiving data using a plurality of carriers, characterized in that it further comprises. In a mobile terminal receiving a signal from a mobile communication system having a plurality of cells, Receiving indication information as to whether multicast / broadcast is modulated in the same manner with each other and transmitted simultaneously on the same frequency band by transmitting terminals corresponding to each of the plurality of cells; And Combining and receiving the multicast / broadcast data according to the indication information; Method of transmitting and receiving data using a plurality of carriers comprising a. 19. The method of claim 18, When the multicast / broadcast data is modulated in the same manner with each other and transmitted simultaneously through the same frequency band by transmission terminals corresponding to each of the plurality of cells, Transmitting terminals corresponding to each of the plurality of cells through multicast / broadcast data modulated in the same manner to each other through the same frequency band by using a multicast / broadcast pilot received from transmitting terminals corresponding to each of the plurality of cells Simultaneously receiving from A method for transmitting and receiving data using a plurality of carriers, characterized in that it further comprises. In a mobile terminal receiving a signal from a mobile communication system having a plurality of cells, Receiving multicast / broadcast data transmitted from transmitters corresponding to each of the plurality of cells, Each of the multicast / broadcast data transmitted through transmission terminals corresponding to each of the plurality of cells is transmitted by different carriers. Method of transmitting and receiving data using a plurality of carriers characterized in that.

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