KR20050108844A - Apparatus and mehtod for providing broadcasting service in a mobile communication system - Google Patents

Abstract

The present invention relates to an apparatus and method for providing a broadcast service in a mobile communication system. The present invention provides an apparatus and method for providing differentiated services to each broadcast information, increasing time diversity with respect to broadcast information symbols, and selectively transmitting and receiving only desired broadcast information. .

According to an aspect of the present invention, there is provided a method for providing a broadcast service in a mobile communication system, the method comprising: encoding each broadcast information to be transmitted in packet units, interleaving and modulating the encoded broadcast information symbols; And dividing the interleaved and modulated symbols into a minimum transmission unit, and time-division multiplexing the divided modulation symbols to transmit the symbols of the broadcast information in accordance with a required quality of service.

Description

Apparatus and method for providing broadcast service in mobile communication system {APPARATUS AND MEHTOD FOR PROVIDING BROADCASTING SERVICE IN A MOBILE COMMUNICATION SYSTEM}

The present invention relates to a mobile communication system supporting a multimedia service including voice and data services, and more particularly, to an apparatus and a method for efficiently providing a forward broadcast service in the mobile communication system.

In general, a typical cellular mobile communication system, for example, a code division multiple access (CDMA) mobile communication system such as CDMA2000, provides a unicast service that supports the same voice or data information to only one terminal. Only supports the form. However, as the communication technology develops along with the user's demand, the cellular mobile communication system is also developing in the form of supporting a broadcast or multicast service in which a plurality of mobile terminals receive the same voice or data information. In order to provide such a broadcast service, even in a mobile communication system supporting only one-way service, if a signaling is appropriately changed, a broadcast service can be supported using an existing physical layer structure. Therefore, various methods for providing a broadcast service using such a method have been proposed.

1 is a diagram for describing a transmission process of broadcast service data in a CDMA 2000 cellular mobile communication system. Hereinafter, a process of transmitting broadcast service data in a CDMA 2000 cellular mobile communication system will be described with reference to FIG. 1.

In general, since broadcast service data is transmitted in a forward direction, FIG. 1 illustrates a process of combining and transmitting data to be transmitted to a plurality of terminals in a physical layer of a base station. Referring to FIG. 1, the base station transmitter encodes a plurality of broadcast information at once. In FIG. 1, the information string 100 in which broadcast information A and broadcast information B are combined is channel-coded to generate channel-coded symbols 102. Thereafter, the interleaved and modulated broadcast information symbols are interleaved and modulated to be transmitted in consecutive time intervals in a radio signal through which the broadcast information is transmitted. At this time, the broadcast information symbols are transmitted in a predetermined transmission unit.

In general, in the CDMA 2000 cellular mobile communication system, one time interval for transmitting the symbols encoded in FIG. 1 is 20 ms. In addition, in FIG. 1, a plurality of broadcast information is encoded at a time to transmit broadcast information of various broadcast services, and then it is described to be transmitted in a 20 ms time period. However, as described above, encoding several broadcast services at once and transmitting them in a 20 ms time period has the following problems.

First, even if the broadcast information to be received is one of the broadcast information A and B shown in FIG. 1, since the broadcast information A and B are encoded at the same time, the mobile station receives all the radio signals for the broadcast information A and B. There is a problem that decoding must be performed. Second, there is a problem that the performance improvement effect due to time diversity is not obtained to the maximum because the transmission time interval is too short.

The reason for not obtaining time diversity, which is the second problem, will be described in more detail as follows. In general, a broadcast service transmits broadcast information to a plurality of mobile terminals in a forward direction. As such, since broadcast information is transmitted to a plurality of mobile terminals, it is difficult to perform forward power control applicable to a unicast service of a general mobile terminal or difficult to control forward power. Therefore, it is not possible to prevent errors of broadcast information symbols generated due to fading occurring in a wireless communication system. In order to overcome the fading of the radio channel, the transmission time interval must be larger than the coherence time of the radio channel to obtain sufficient time diversity. However, in the above-described method, since a plurality of broadcast information is included and transmitted within a time of 20 ms, sufficient time diversity cannot be obtained. This will be described with reference to FIG. 2.

FIG. 2 is a diagram for describing time diversity when a broadcast service is provided in the CDMA 2000 cellular mobile communication system shown in FIG. 1.

In each of the transmission units shown in FIG. 2, one or more broadcast information symbols are transmitted. That is, the i th broadcast information symbols 200, the i + 1 th broadcast information symbols 201, the i + 2 th broadcast information symbols 202, and the i + 3 th broadcast information symbols 203 and i + Fourth broadcast information symbols 204 and i + 5th broadcast information symbols 205 are transmitted in successive time intervals. In addition, reference numeral 210 in FIG. 2 illustrates a power amplification response characteristic curve of a fading channel. As shown in FIG. 2, a fading radio channel may suddenly worsen in the i + 3 th broadcast information symbols 203 transmitted. Such a case in which a fading radio channel rapidly deteriorates is called a 'deep fade'. In this case, the signal-to-noise ratio of the broadcast information symbols becomes very low in the receiver, and as a result, the probability of an error occurring in the received broadcast information symbols becomes very high.

The third problem of the transmission scheme as shown in FIG. 1 is that since the encoded symbols of the broadcast information A and B are encoded and modulated at once, it is impossible to have different performances. That is, broadcast information A is information for a broadcast service for the entire service area of the base station, and broadcast information B is broadcast information A and broadcast information as shown in FIG. If B is encoded and modulated at the same time, it is impossible to have differentiated performance.

Accordingly, an object of the present invention is to provide an apparatus and method for providing a differentiated service for each broadcast information in a cellular mobile communication system.

Another object of the present invention is to provide an apparatus and method for increasing time diversity for broadcast information symbols in a cellular mobile communication system.

Still another object of the present invention is to provide an apparatus and method for selectively transmitting and receiving only desired broadcast information in a cellular mobile communication system.

According to an aspect of the present invention, there is provided a method for providing a broadcast service in a mobile communication system, the method comprising: encoding each broadcast information to be transmitted in packet units, interleaving and modulating the encoded broadcast information symbols. And dividing the interleaved and modulated symbols into a minimum transmission unit, and time-division multiplexing the divided modulation symbols to transmit the symbols of the broadcast information in accordance with a required quality of service.

According to an aspect of the present invention, there is provided an apparatus for providing a broadcast service in a mobile communication system, comprising: an encoder for encoding each broadcast information to be transmitted in packet units, and an interleaver for interleaving the encoded broadcast information symbols. And a modulator for modulating the interleaved symbols, a symbol divider for dividing the modulated symbols into minimum transmission units, and time division multiplexing the divided modulation symbols to transmit the symbols of the broadcast information in accordance with a required quality of service. Includes time division multiplexers.

DETAILED DESCRIPTION A detailed description of preferred embodiments of the present invention will now be described with reference to the accompanying drawings. It should be noted that reference numerals and like elements among the drawings are denoted by the same reference numerals and symbols as much as possible even though they are shown in different drawings. In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

3 is a diagram illustrating a method of transmitting a broadcast service according to an embodiment of the present invention in a cellular mobile communication system. Hereinafter, a method of transmitting a broadcast service according to the present invention will be described with reference to FIG. 3. In addition, FIG. 3 will be described on the assumption that there are two broadcast information for convenience of description.

The broadcast information A 301 and the broadcast information B 311 are independently channel-coded in step 320. As described above, the symbols 302 of the broadcast information A and the symbols 312 of the broadcast information B are independently interleaved and modulated through the interleaving and modulation process again in step 330. As described above, the symbols 303 of the broadcast information A and the symbols 313 of the broadcast information B that are independently interleaved and modulated are divided into the minimum transmission units in step 340. 3 illustrates units of symbols divided into eight transmission units. The divided unit may be a transmission unit different from the embodiment of FIG. 3. As described above, the symbols of each divided transmission unit are transmitted after being temporally multiplexed in step 350.

As described above with reference to FIG. 3, that is, a method of independently encoding, interleaving and modulating the broadcast information to be transmitted and then multiplexing and transmitting the same in time, has the following advantages as compared to the method described in the related art.

First, since the broadcast information A and the broadcast information B go through separate encoding processes, the receiver of the mobile terminal may receive only a radio signal for the broadcast information A. Therefore, each mobile station can perform decoding by receiving only its desired signal. Second, since the radio signals of the broadcast information A and the broadcast information B are multiplexed in time, a time diversity effect corresponding to twice as compared to the method of FIG. 2 described above in the related art can be obtained. . Third, broadcast information A and broadcast information B may be set to have different data rates and performances because independent encoding and modulation processes are applied to each other.

The third advantage will be described in more detail below. For example, broadcast information A is transmitted at a data transmission rate of 100 kbps using a coding rate of 0.2 (1/5) and a QPSK modulation scheme, and broadcast information B is 400 kbps using a coding rate of 0.4 (2/5) and a 16QAM modulation scheme. Suppose we are transmitting at data rate of. In this case, the broadcast information A may serve a relatively large area at a relatively low data transmission rate. On the other hand, broadcast information B has a relatively high data rate and can serve only a relatively small area. As such, the service area expansion and the data transmission rate can be individually set for each broadcasting information, which is a great advantage when operating a mobile communication system.

In the third advantage described above, at this time, the broadcast information A and the broadcast information B may be composed of completely different information, such as different TV channels, or may be composed of information having different image or sound quality with respect to the same information. That is, broadcast information made to have a general video and sound quality and broadcast information made to have a high quality video and sound quality can be transmitted to one TV channel. This is separately coded, interleaved, and modulated as in FIG. 3. In this case, the mobile terminal can receive broadcast information that has a general video and audio quality that can be received even at a low signal-to-noise ratio in a region where the wireless channel reception environment is relatively poor. In addition, the mobile terminal can receive broadcast information that has high quality video and audio quality that can be received only at a high signal-to-noise ratio in a region where the wireless channel environment is relatively good.

FIG. 3 described above has described an example in which two broadcast information are multiplexed in time. However, the same may be applied to three or more pieces of broadcast information. That is, it can be extended to a plurality of broadcast information.

4 is a diagram illustrating a radio signal when eight broadcast information are multiplexed in time using a method according to an exemplary embodiment of the present invention.

In FIG. 4, the radio signal A for broadcast information A is generated in the same manner as in FIG. You can get the city. In general, the time diversity obtained when temporally multiplexing a plurality of broadcast information in the same manner as in FIGS. 3 and 4 is determined by how many broadcast information are temporally multiplexed. In FIG. 4, since eight broadcast information are multiplexed in time, eight times the time diversity can be obtained compared to the case of transmitting in the same manner as in FIG.

5 is a block diagram of a broadcast information transmitter of a base station in a cellular mobile communication system according to an exemplary embodiment of the present invention. Hereinafter, a block configuration and operation of a broadcast information transmitter of a base station according to the present invention will be described in detail with reference to FIG. 5.

5 illustrates an example of a transmitter for transmitting N different broadcast information. That is, it is configured to accommodate the case in which the invention of FIG. 3 is expanded. The broadcast information 1 501 and the broadcast information 2 503 broadcast information N 505 of FIG. 5 become broadcast information received from an upper system of the base station. Although not shown in the drawings of the present invention, the upper system may be a broadcast server (BCMCS Server) or a broadcast controller (BCMCS Controller). In addition, since the broadcast server or the broadcast controller cannot be directly connected to the base station, the broadcast server or the broadcast controller may be a packet data service node (PDSN) or a gateway (GW) that connects the broadcast server or the broadcast controller and the base station. Therefore, the broadcast information 501, 503, ..., 505 may actually show a state stored in the buffer of the base station.

The data thus stored are input to the corresponding broadcast information sub-transmitters 502, 504,..., 506, respectively. The broadcast information sub-transmitters 502, 504, ..., 506 perform channel encoding on the input broadcast information as described with reference to FIG. The broadcast information sub-transmitters 502, 504, ..., 506 divide the symbols to be transmitted into the minimum transmission units. As such, the symbols divided into symbols of the smallest transmission unit are input to the time division multiplexer 507. The time division multiplexer 507 time-divisions and outputs the input signal as described above with reference to FIG. 3 or 4. This time division is performed by the control of the broadcast information transmission controller 508. That is, the broadcast information transmission controller 508 determines which symbol of which broadcast information is to be transmitted in which time period, and outputs a signal for controlling this to the time division multiplexer 507. In addition, the broadcast information controller 508 may control to transmit specific broadcast information symbols over several time intervals. The operation thereof will be described with reference to the accompanying drawings. The broadcast information transmission controller 508 also determines how to time multiplex the given broadcast information symbols.

The symbols output from the time division multiplexer 507 are input to a code division multiplexing / or orthogonal frequency division modulation (CDM / OFDM) signal generator 509. The input signal is transmitted through an IFFT process to become a spreading and / or OFDM signal to become a CDM signal.

6 is an internal block diagram of the broadcast information sub-transmitter of FIG. 5 according to the present invention. Hereinafter, an internal block configuration and operation of the broadcast information sub-transmitter of FIG. 5 according to the present invention will be described in detail with reference to FIG. 6.

Referring to FIG. 6, broadcast information is input to the encoder 601. The encoder 601 selects an appropriate encoding to match the channel situation with the channel encoder. Such an encoding method may be set in advance or may be controlled by the control of the transmitter controller 604. The channel coded symbols are input to the interleaver 602. The interleaver 602 is interleaved under the control of the transmitter control unit 604. This interleaving method is also interleaved in a method most suitable for transmission, and the control of the interleaver 602 is controlled by the transmitter control unit 604. The interleaved symbols are then input to modulator 603 and modulated. The modulator 603 is modulated and output by one of modulation methods such as BPSK, QPSK, 16QAM, etc. under the control of the transmitter controller 604. 6 is an internal configuration of each sub-transmitters 502, 504,... 506. As such, each sub-transmitter 502, 504,... 506 has a separate transmitter control unit 604, an encoder 601, an interleaver 602, and a modulator 603. This is to apply an in-channel coding scheme, an independent interleaving scheme, and an independent modulation scheme.

In FIG. 6, the transmitter control unit 604 is configured for each sub-transmitters 502, 504,..., 506. However, one sub-transmitter 502, 504,... 506 can be controlled simultaneously without having the transmitter control unit 604 inside each sub-transmitters 502, 504,... 506. There may also be a transmitter control unit. In this case, one transmitter control unit controls the encoding, interleaving, and modulation of the respective sub-transmitters 502, 504,..., 506.

7 is a flowchart illustrating a case where a plurality of broadcast information is transmitted from a base station of a cellular mobile communication system according to an embodiment of the present invention. Hereinafter, a control process when a plurality of broadcast information is transmitted from a base station of a cellular mobile communication system according to the present invention will be described with reference to FIG. 7.

The transmitter of the base station collects broadcast information to be transmitted in packet units in step 701. That is, the process of receiving broadcast information to be serviced. The process of collecting broadcast information to be serviced as described above is performed when an initial broadcast service is performed and when symbols, which are encoded, interleaved, and modulated, are transmitted on one packet, and all the symbols divided into the minimum units to be transmitted are transmitted. . After collecting the broadcast information, the transmitter of the base station proceeds to step 702 to determine which coding scheme, interleaving scheme, and modulation scheme to apply to the collected packet for each broadcast information. This determination process is a process performed by the transmitter controller 604 of FIG. 6 described above.

Therefore, after determining the encoding, interleaving, and modulation scheme of the broadcast information to be transmitted, the base station transmitter proceeds to step 703 to encode the broadcast information according to the determined scheme, and performs interleaving and modulation. After this process, the base station transmitter proceeds to step 704 to split the last modulated symbols into the smallest transmission unit. As an example, when the 20ms signal is divided into 16 minimum transmission units, each minimum transmission unit has a signal corresponding to 1.25ms.

Thereafter, the base station transmitter proceeds to step 705 to determine which part of the signal divided by the minimum transmission unit. For example, the operation 705 may be described as follows. If the 20ms signal is divided into 16 1.25ms time intervals, it is to determine which section of the 16 1.25ms time intervals to transmit. The signal of the minimum transmission unit for each broadcast information whose transmission is determined in step 705 is transmitted in step 707 after time multiplexing in step 706.

The process of selecting, time-multiplexing and transmitting the divided signals described in steps 705 through 707 encodes, interleaves and modulates one broadcast information with respect to one packet, and splits the modulated symbols to divide the transmitted signal. It continues until all are exhausted. That is, after performing step 707, the base station transmitter checks whether it is time to collect new broadcast information using the above criteria. If it is time to collect new broadcast information as a result of the check, the process proceeds to step 701, and if not, steps 705 to 707 are repeatedly performed.

8 is a diagram illustrating a method for receiving only a broadcast signal desired by a mobile terminal of a cellular mobile communication system according to an embodiment of the present invention. Hereinafter, a method for receiving only a broadcast signal desired by a mobile terminal of a cellular mobile communication system according to the present invention will be described with reference to FIG. 8. FIG. 8 illustrates only two broadcast signals, broadcast signal A and broadcast signal B, to facilitate explanation of the present invention.

In FIG. 8, it is assumed that the base station separately encodes, interleaves, and modulates broadcast information A and broadcast information B as described above, and divides them into eight minimum transmission units. In this case, the mobile station to receive the broadcast information A selectively receives only the signal for the broadcast information A among the signal for the broadcast information A and the signal for the broadcast information B, which are time multiplexed as shown in FIG. 8. This may be performed by receiving broadcast information only at the time when broadcast information A is received. As such, the mobile station that receives only the symbols of broadcast information desired by the mobile station can obtain a desired signal through a reverse process of a method in which symbols of broadcast information are encoded, interleaved, and modulated. In addition, this reverse process is performed by receiving the received symbols as much as a unit that can be processed in reverse process.

9 is an internal block diagram of a receiver of a mobile terminal for receiving a broadcast signal in a cellular mobile communication system according to an embodiment of the present invention. Hereinafter, an internal configuration and operation of a receiver of a mobile terminal for receiving a broadcast signal in a cellular mobile communication system according to the present invention will be described in detail with reference to FIG. 9.

The broadcast signal receiver of FIG. 9 inputs the received broadcast signal to the CDM / OFDM signal detector 901. The CDM / OFDM signal detector 901 detects a radio signal in accordance with a transmission method of a broadcast signal transmitted from a base station under the control of the first controller 907. That is, when the base station transmits the broadcast signal in the CDM scheme, the base station converts the signal in the CDM scheme and outputs the signal.

In addition, the first controller 907 controls the CDM / OFDM signal detector 901 and checks in which time period a signal for broadcast information to be received is transmitted. That is, the first controller 907 transmits to the CDM / OFDM signal detector 901 which section a signal for the broadcast information A is received from among the radio signals received as shown in FIG. 8. Through this, the CDM / OFDM signal detector 901 receives only a radio signal of an appropriate time period in which broadcast information desired by the CDM / OFDM signal is received. Therefore, the first controller 907 included in the mobile terminal receiver stops the operation of the CDM / OFDM signal detector 901 in a time interval in which broadcast information other than the radio signal for the desired broadcast information is received. The consumption can be minimized. The signal processed by the CDM / OFDM signal detector 901 is input to the channel estimator and corrector 902.

The channel estimator and corrector 902 estimates a channel with respect to the received wireless signal and then performs channel correction. The channel correction is necessary for correcting the distortion generated in the phase or amplitude in the wireless channel and is essential in the receiver of the wireless device. The signal output from the channel estimator and corrector 902 is input to the demodulator 903 and demodulated. The demodulated signal in the demodulator 903 is stored in the coded symbol storage 904. The coded symbol store 904 stores them until all coded coded symbols for a packet are received. As such, when all encoded symbols for one packet are received, the encoded symbol buffer 904 outputs the stored encoded symbols to the de-interleaver 905. The interleaver 905 deinterleaves the input coded symbols and outputs them. The deinterleaved symbols are input to the channel decoder 906. The channel decoder performs decoding according to a channel encoding method. The decoded information is broadcast information and is reproduced by the mobile terminal or by another device connected to the mobile terminal.

The channel estimator and corrector 902 and demodulator 903, the coded symbol store 905, the de-interleaver 905, and the channel decoder 906 are controlled by a second controller 908. The first controller 907 and the second controller 908 may be configured as one controller 910 and may be implemented in a processor of a mobile terminal or as a separate control device.

10 is a control flowchart of broadcast information reception in a mobile terminal of a cellular mobile communication system according to an exemplary embodiment of the present invention. Hereinafter, a process of receiving and processing a broadcast service provided from a base station in a mobile terminal of a cellular mobile communication system according to the present invention will be described with reference to FIG. 10.

In step 1001, the mobile terminal receiver checks whether the current time is a time interval for receiving a signal for broadcast information. In step 1001, it is determined by the first controller 907 of FIG. 9 whether it is a time interval for receiving a signal for broadcast information to be received. In step 1001, if it is time interval to receive a signal of broadcast information to be received, the mobile terminal proceeds to step 1002 to receive a signal of broadcast information, and estimates and corrects a channel using the received broadcast information signal. And demodulation. After channel estimation and correction are performed on the signal received in step 1002, the mobile station stores the demodulated signal in the encoded symbol buffer 904 in step 1003. The reason for storing the symbols in the encoded symbol buffer 904 is as described above.

After storing the encoded symbols, the method proceeds to step 1004 to determine whether it is time to perform channel encoding. As such, a criterion for checking whether to perform channel encoding may be determined by checking whether all of the encoded symbols for one packet are received. When the channel decoding is performed at step 1004, the mobile station proceeds to step 1005 to perform deinterleaving and channel decoding on the signal stored in the encoded symbol buffer. Through this, desired broadcast information is restored.

On the other hand, if the check symbols of step 1004 have not received all the coding symbols for a packet, the mobile terminal returns to step 1001 and attempts to receive an additional signal.

In the broadcast service method of the present invention described with reference to FIGS. 3 to 10, the mobile terminal receives only a radio signal of a specific time in order to recover specific broadcast information. To this end, the mobile terminal needs to know in which time period the radio signal transmitted is a signal of broadcast information desired by the mobile station. The base station may transmit a control channel or a signaling channel separate from the mobile terminal in which time interval broadcast information desired by the mobile terminal is received. In this way, the base station may inform the mobile station of the broadcast information transmitted from the base station to all mobile terminals through the control channel and the signaling channel, or may inform each mobile terminal.

Meanwhile, in the broadcast service method of the present invention described with reference to FIGS. 3 to 10, the packet signal for the specific broadcast information is divided at regular intervals and then periodically transmitted. However, the method of multiplexing and transmitting signals of other broadcast information in the present invention may be configured not necessarily to be divided at uniform intervals. That is, the present invention can be applied even when the transmission interval for one piece of broadcast information is not constant.

FIG. 11 is a diagram illustrating another embodiment in which a broadcast information packet is transmitted according to an embodiment of the present invention. Hereinafter, timing of transmission of a broadcast information packet according to another embodiment of the present invention will be described with reference to FIG. 11. Shall be.

11 illustrates an example in which a signal for broadcast information A is transmitted in an uneven transmission interval. In addition, when a signal for broadcast information A is transmitted, the transmission time interval is also changed to 1, 2, 1, 4, and 1 times the minimum transmission unit. In such a case, if the minimum transmission unit and / or transmission time information and / or transmission interval information are transmitted in a control channel or signaling channel transmitted by the base station, the receiver of the mobile station attempts to restore itself. It is possible to appropriately receive a signal for broadcast information. As described above, the control channel may be transmitted to a specific terminal, may be transmitted in a bundle of terminals, or all information may be transmitted at once. In brief, the information on the channel received by the terminal may be transmitted to each terminal through a control channel or a signaling channel. Alternatively, it is possible to deliver information on the time point and reception interval at which the broadcast service should be received to all mobile terminals receiving the same broadcast service. Alternatively, the terminal may be configured to broadcast all the information broadcast by the base station to receive all of the terminals receiving the broadcast service and receive the minimum transmission unit or / or transmission time information and / or transmission interval information desired by the base station. .

11, when a signal of one packet is divided and transmitted, the modulation method applied to each divided part need not be the same. That is, even if the divided first part of the same packet is transmitted in QPSK and the second part is transmitted in 16QAM, the method described in the present invention can be applied in the same manner. In this case, the base station may also inform the modulation scheme through the control channel or the signaling channel, which modulation is transmitted using which modulation. In addition, the interleaving method and the channel encoding method may be transmitted in the same manner.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the scope of the following claims, but also by those equivalent to the scope of the claims.

As described above, when the present invention is applied, there is an advantage that a sufficient time diversity effect can be obtained when providing a broadcast service in a mobile communication system. In addition, the terminal can receive only the information desired by the user has the advantage of reducing power consumption. In addition, since each broadcast service is transmitted independently, there is an advantage of providing a diversified broadcast service such as high quality, medium quality, or low quality.

1 is a view for explaining a process of transmitting broadcast service data in a CDMA 2000 cellular mobile communication system;

FIG. 2 is a diagram for describing time diversity when a broadcast service is provided in a CDMA 2000 cellular mobile communication system as shown in FIG. 1;

3 is a view for explaining a method for transmitting a broadcast service according to an embodiment of the present invention in a cellular mobile communication system;

4 is a diagram illustrating a radio signal when eight broadcast information are multiplexed in time using a method according to an embodiment of the present invention;

5 is a block diagram illustrating a broadcast information transmitter of a base station in a cellular mobile communication system according to an embodiment of the present invention;

6 is a block diagram illustrating an internal block of the broadcast information sub-transmitter of FIG. 5 according to the present invention;

7 is a control flowchart when a base station of a cellular mobile communication system transmits a plurality of broadcast information according to an embodiment of the present invention;

8 is a diagram illustrating a method for receiving only a broadcast signal desired by a mobile terminal of a cellular mobile communication system according to an embodiment of the present invention;

9 is an internal block diagram of a receiver of a mobile terminal for receiving a broadcast signal in a cellular mobile communication system according to an embodiment of the present invention;

10 is a control flowchart of receiving broadcast information in a mobile terminal of a cellular mobile communication system according to an embodiment of the present invention;

11 is a diagram illustrating another embodiment in which a broadcast information packet is transmitted according to an embodiment of the present invention.

Claims (2)

In the method for providing a broadcast service in a mobile communication system, Encoding each broadcast information to be transmitted in packet units; Interleaving and modulating the encoded broadcast information symbols; Dividing the interleaved and modulated symbols into a minimum transmission unit; And time division multiplexing the divided modulation symbols to transmit the symbols of the broadcast information in accordance with a required quality of service. An apparatus for providing a broadcast service in a mobile communication system, An encoder for encoding each broadcast information to be transmitted in packet units; An interleaver for interleaving the encoded broadcast information symbols; A modulator for modulating the interleaved symbols; A symbol divider for dividing the modulated symbols into a minimum transmission unit; And a time division multiplexer for time division multiplexing the divided modulation symbols and transmitting the symbols of the broadcast information in accordance with a required quality of service.