KR20130073033A - Apparatus for receiving a broadcast signal and method for transmitting/receiving a broadcast signal - Google Patents

Abstract

PURPOSE: A broadcast signal reception device and a broadcast signal transceiving method are provided to be able to identify a cell in a multi-frequency network environment. CONSTITUTION: A broadcast transmission side output a broadcast signal in which program table information with pre-set identifier information of a cell, which is a radio range of a broadcast signal, and broadcast data are multiplexed and modulated (S10). The broadcast transmission side transmits the broadcast signal including the identifier information of cell (S20). A broadcast receipt side receives the broadcast signal including the identifier information of cell, which is a radio range of the broadcast signal (S30). The broadcast receipt side demodulates the received broadcast signal, and parses the program table information from the demodulated signal to obtain the identifier information (S40). [Reference numerals] (AA) Start; (BB) End; (S10) Output a broadcast signal in which program table information with pre-set identifier information of a cell, which is a radio range of a broadcast signal, and broadcast data are multiplexed and modulated; (S20) Transmit the broadcast signal including the identifier information of cell; (S30) Receive the broadcast signal including the identifier information of cell, which is a radio range of the broadcast signal; (S40) Demodulate the received broadcast signal, and parse the program table information from the demodulated signal to obtain the identifier information

Description

Apparatus for receiving a broadcast signal and method for transmitting / receiving a broadcast signal}

The present invention relates to a broadcast signal reception apparatus and a broadcast signal transmission and reception method, and more particularly, to a broadcast signal reception apparatus and a broadcast signal transmission and reception method capable of mobile reception of a broadcast in a multi-frequency network environment.

Digital broadcasting systems that can transmit and receive broadcasts are being developed or are commercially available. However, such a digital broadcast system for mobile reception has a problem in that it is not compatible with the conventional broadcast system for fixed reception by designing a broadcast system separate from the broadcast system for fixed reception.

For example, the transmission system according to the VSB (vestigial sideband) method defined by the Advanced Television System Committee (ATSC) is designed without considering mobility due to the characteristics of the terrestrial wave. The broadcast system according to the ATSC is suitable for a multi-frequency network environment, and it is inconvenient to rescan the channel even when the same broadcast channel is moved to an area broadcasted at a different frequency.

An object of the present invention is to provide a broadcast signal reception apparatus and a broadcast signal transmission and reception method capable of mobile reception in a multi-frequency network environment.

Another object of the present invention is to provide a broadcast signal reception apparatus and a broadcast signal transmission / reception method according to a mobile reception broadcast system compatible with a fixed reception broadcast system.

It is still another object of the present invention to provide a broadcast signal receiving apparatus and a broadcast signal transmitting / receiving method for allowing a user to watch the same broadcast program without inconvenience even in a multi-frequency network environment. It is.

A broadcast signal receiver according to an embodiment of the present invention is a tuner for receiving a broadcast signal, wherein the broadcast signal is identified by a transport stream ID field, and the broadcast signal includes a cell information table (CIT), and the CIT Includes a cell identifier field for identifying a cell according to a transmission area in which the broadcast signal is transmitted, a demodulator for demodulating the received broadcast signal, and a table information storage unit for extracting the CIT from the demodulated broadcast signal; The CIT further includes a service ID field and a cell number field, wherein the service ID identifies a broadcast service in the broadcast signal, and the cell number field is the same or similar to a broadcast service identified by the service ID. Indicates the number of adjacent cells according to the transmission region to be transmitted, and uses the extracted CIT. And a decoder for acquiring the broadcast service and decoding the obtained broadcast service.

The effects of the apparatus for receiving broadcast signals and the method for transmitting and receiving broadcast signals according to the present invention described above are as follows.

First, according to the present invention, a cell can be identified in a multi-frequency network environment, and thus mobile reception of a broadcast is possible. Second, according to the present invention, it is possible to provide a mobile reception broadcast system compatible with a fixed reception broadcast system. Third, according to the present invention, even if a user moves to a region broadcasting at a different frequency in a multi-frequency network environment, the same broadcast program can be viewed without inconvenience.

1 is a flow chart illustrating an embodiment of a broadcast signal transmission and reception method according to the present invention.
2 is a flowchart for explaining another embodiment of a broadcast signal transmission / reception method according to the present invention.
3 is a flowchart for explaining another embodiment of a broadcast signal transmission / reception method according to the present invention.
4 is a diagram schematically illustrating a broadcast system according to ATSC for easily explaining the present invention.
5 is a view briefly illustrating a concept of an apparatus for transmitting and receiving a broadcast signal according to the present invention;
6 is a diagram illustrating an embodiment of a service multiplexer disclosed in FIG. 4.
FIG. 7 is a diagram illustrating a concept of receiving broadcast data when handover is performed according to an embodiment of the broadcast signal transmission and reception method according to the present invention.
FIG. 8 is a diagram illustrating an embodiment of a mobile service multiplexer among the service multiplexers disclosed in FIG. 6; FIG.
FIG. 9 illustrates an embodiment of the transmitter disclosed in FIG. 4. FIG.
FIG. 10 is a diagram illustrating an embodiment of a preprocessor shown in FIG. 9.
11 is a diagram illustrating a table type value defined in MGT which is program table information having cell information.
12 illustrates a cell information table (CIT) including cell information.
13 is a view showing an example of an MGT for explaining an embodiment of a broadcast signal transmission and reception method according to the present invention;
14 illustrates an example of a descriptor for explaining another embodiment of a broadcast signal transmission / reception method according to the present invention.
15 is a flowchart for explaining another embodiment of a broadcast signal transmission / reception method according to the present invention.
16 is a flowchart illustrating an embodiment in which the same program can be continuously displayed during handover.
17 illustrates an embodiment of a broadcast signal receiving apparatus according to the present invention.
18 is a diagram illustrating an embodiment of a demodulator in a broadcast signal receiving apparatus according to the present invention.
19 illustrates another embodiment of a broadcast signal receiving apparatus according to the present invention.
20 is a view showing another embodiment of a broadcast signal receiving apparatus according to the present invention

Hereinafter, with reference to the accompanying drawings an embodiment of the present invention that can be specifically realized the present invention.

1 is a flowchart illustrating an embodiment of a broadcast signal transmission and reception method according to the present invention. An embodiment of a broadcast signal transmission and reception method according to the present invention will be described with reference to FIG. 1.

First, the broadcast transmitter outputs a broadcast signal obtained by multiplexing and modulating program table information and broadcast data in which identifier information of a cell, which is a propagation region of a broadcast signal, is broadcast (S10).

Then, the broadcast signal including the identifier information of the cell is transmitted (S20).

The broadcast receiving side receives a broadcast signal including identifier information of a cell which is a propagation area of the broadcast signal (S30).

The received broadcast signal is demodulated, and program table information is parsed from the demodulated signal to obtain identifier information of the cell (S40).

In particular, the present embodiment may identify a propagation region of a broadcast signal transmitted at any one of multiple frequencies when the broadcast signal is moved while receiving the broadcast signal in a multi-frequency network environment (MFN).

2 is a flowchart illustrating another embodiment of a broadcast signal transmission and reception method according to the present invention. Referring to FIG. 2, another embodiment of the broadcast signal transmission / reception method according to the present invention will be described.

The broadcast transmission side outputs program table information in which transmission channel information in each cell is set for broadcast data identified by broadcast stream identifier, program table information in which cell identifier information is set, and a broadcast signal multiplexed with the broadcast data (S110). ).

The multiplexed broadcast signal is modulated (S120), and the modulated broadcast signal is transmitted (S130).

When receiving a broadcast, the receiving side multiplexes the first program table information in which transmission channel information in each cell is set for the broadcast data identified by the broadcast stream identifier, the second program table information in which identifier information of a cell is set, and the broadcast data are multiplexed. The received broadcast signal is received (S140).

The first program table information may include information on which channel a broadcast program transmitted by any broadcaster in the first cell is transmitted in another cell. The first program table information may deliver channel information on broadcast data according to an identifier of each broadcast stream.

When the identifier information of the cell in the second program table information is changed, channel information in which the broadcast data in the cell according to the changed identifier is transmitted is obtained from the first program table information (S150).

Then, the obtained channel information is tuned to receive and display the broadcast data of the changed cell (S160).

3 is a flowchart for explaining another embodiment of a broadcast signal transmission / reception method according to the present invention. Referring to FIG. 3, another embodiment of a broadcast signal transmission / reception method according to the present invention will be described.

The broadcast transmission side outputs program table information in which transmission channel information in each cell for broadcast data identified by the broadcast stream identifier is set, and a broadcast signal multiplexed with the broadcast data (S210).

In addition, the signaling signal in which the transmission parameter including the identifier information of the cell is set is added to the output broadcast signal and modulated (S220).

The modulated signal is then transmitted (S230).

The broadcast receiving side receives a broadcast signal including program table information in which transmission channel information in each cell for broadcast data identified by the broadcast stream identifier is set and identifier information of the first cell (S240).

When the power of the received broadcast signal is smaller than the first threshold, the signal transmitted from the second cell is received to obtain identifier information of the second cell set in the signaling information of the received signal of the second cell (S250).

The program table information is tuned to a channel of the second cell for the broadcast data, and a broadcast signal is received from the tuned channel and displayed.

In order to easily describe the present invention, a broadcast system according to ATSC having a multi-frequency network environment will be described as an example, but the present invention is not necessarily limited thereto.

First, FIG. 4 is a diagram schematically illustrating a broadcast system according to ATSC in order to easily explain the present invention.

In the broadcasting system according to the ATSC, the broadcasting signal transmitting apparatus includes a service multiplexer and a transmitter.

In this case, the service multiplexer may be located in a studio of each broadcasting station, and the transmitter may be located in one or more specific sites. In addition, the plurality of transmitters may share the same frequency, in which case the plurality of transmitters all transmit the same signal. The service multiplexer multiplexes main service data for fixed reception and mobile service data for mobile reception. The transmitter modulates and transmits the multiplexed broadcast data. Hereinafter, in order to facilitate the terminology, a technique of modulating main service data for fixed reception and mobile service data for mobile reception is referred to as mobile VSB (MVSB). When the transmitter transmits broadcast data for mobile reception, the transmitter modulates the data so that the data can be stably received even with various distortions and noises that may occur in the transmission channel.

The broadcast signal receiving apparatus may restore the transmitted broadcast signal by compensating for the signal distortion. Various methods may be used for data communication between the service multiplexer and a transmitter located at a remote location, and in one embodiment, a standard such as SMPTE-310M (Synchronous Serial Interface for transport of MPEG-2 data) may be used.

5 is a diagram schematically illustrating a concept of an apparatus for transmitting and receiving broadcast signals according to the present invention. For ease of explanation, hereinafter, a range in which a transmission system according to one frequency is affected in a multi-channel network (MFN) environment is called a cell. According to an exemplary embodiment of the present invention, the broadcast signal receiving apparatus may allow a viewer to continuously watch a broadcast of a received channel even when receiving a broadcast while moving through several cells. In the following description, a broadcast signal receiving apparatus receives a broadcast from a current cell A, receives a broadcast from another cell B, and changes a broadcast receiving cell. This is called a handover.

A mobile service elementary stream (ES) for mobile reception may be transmitted through a different frequency for each region through each transmitter. When a broadcast signal for mobile reception (mobile service ES) is transmitted, physical information of a cell received by the broadcast signal receiving apparatus and a channel according to the cell is changed. However, the user can express the broadcast of the same channel without additional work such as channel search again. A cell can be identified by its cell ID. In addition, certain broadcast signals (ES) in each cell may be transmitted on different physical channels.

Table 1 is a table illustrating the location and broadcast information of the transmitter according to the identifier of the cell.

cell ID 0x0001 0x0002 location Gwanaksan Yongmunsan Broadcast information (channel name, major, physical) MBC (11, 15)
ABC1 (9,14)
ABC2 (7,13)
SBB (6,16)
ESS (10,29) MBC (11, 14)
ABC1 (9,21)
ABC2 (7,22)
SBB (6,12)
ESS (10,25)

In the example of Table 1, a cell with a cell identifier of 0x0001 is located at Gwanak Mountain and a cell with a cell identifier of 0x0002 is located at Yongmun Mountain. The same broadcast channel may be transmitted to different physical channels according to a cell.

6 is a diagram illustrating an embodiment of a service multiplexer disclosed in FIG. 4 as an embodiment of a broadcast signal transmission apparatus according to the present invention. 6 illustrates a main audio / video (A / V) system 210, a main auxiliary data system 220, a mobile A / V system 240, a mobile auxiliary data system 250, and a main service multiplexer ( 230, mobile service multiplexer 260, and transmission service multiplexer 270.

The main service data is encoded and compressed in the main A / V system 210 and output to the main service multiplexer 230. If there are a plurality of types of main service data, a plurality of main A / V systems may be provided. The main service multiplexer 230 multiplexes the output of the main A / V system 210 and various additional data 220 of the main service and outputs the multiplexed data to the transmission service multiplexer 270.

Similarly, the mobile service data is encoded and compressed in the mobile A / V system 240 and output to the mobile service multiplexer 260. Here, when there are a plurality of types of mobile service data, a plurality of mobile A / V systems may be provided. The mobile service multiplexer 260 multiplexes the output of the mobile A / V system 260 and various additional data of the mobile service and outputs the multiplexed data to the transmission service multiplexer 270.

The transmission service multiplexer 270 multiplexes the output of the main service multiplexer 230 and the output of the mobile service multiplexer 260 and outputs the multiplexed data to a transmitter. The output data of the transmission service multiplexer 270 may be in the form of an MPEG-2 Transport Stream (TS) packet.

The transmission service multiplexer 270 may transmit the service data to the transmitter at a constant data rate. When the service data transmitted from the transmission service multiplexer 270 to the transmitter includes only main service data or only main service data and mobile service data, the transmission service multiplexer 270 may transmit to the transmitter at a constant data rate. For example, if the transmission service multiplexer 270 transmits data to the transmitter at 19.39 Mbps, the mobile service data is multiplexed with the main service data within 19.39 Mbps. The mobile service data may be subjected to additional error correction encoding at the transmitter, and the mobile service data rate may be reduced in consideration of this.

If it is necessary to maintain the output of the service multiplexer at a constant data rate, for example, 19.39 Mbps, at least one of the main service multiplexer, the mobile service multiplexer, and the transmit data multiplexer may be null data ( By inserting null data or null packets, the data rate of the final output can be set to a constant data rate. Here, null data may be generated in the multiplexer or may be input from the outside.

FIG. 7 is a diagram illustrating a concept of receiving broadcast data when handover is performed according to an embodiment of the broadcast signal transmission and reception method according to the present invention. Transmission data in which the main service data M and the mobile service data E1 and E2 are multiplexed may be transmitted to each cell. The main service data and the mobile service data may be multiplexed and transmitted on a time axis in a burst form, and the reception apparatus turns on / off signal reception only at a time when desired broadcast service data is transmitted when a broadcast signal is received. By doing so, desired broadcast service data can be obtained. For example, when E1 broadcast data is obtained from cell A, a signal is received only when E1 broadcast data is transmitted. Then, the power of the receiver of the broadcast signal receiving apparatus is turned off in the section in which the main service data and the E2 broadcast data are received. When the broadcast signal receiving apparatus turns on / off to receive a signal, the tuner or the demodulator may prepare to receive a signal by turning on / off a little earlier in time than the actual data receiving section. When the broadcast signal receiving apparatus receives the E1 broadcast data in cell B, it may operate similarly to cell A.

According to an embodiment of the broadcast signal receiving apparatus according to the present invention, when receiving the E1 broadcast data while moving a plurality of cells, even if a handover occurs in the broadcast signal receiving apparatus, the broadcast signal receiving apparatus may use the same broadcast data (for example, E1). Can be constantly received.

FIG. 8 is a diagram illustrating an embodiment of a mobile service multiplexer among the service multiplexers disclosed in FIG. 6. The embodiment of the mobile service multiplexer of FIG. 8 includes a first multiplexer 311, a program table information generator 312, a second multiplexer 313, and a packet conversion buffer 314.

The first multiplexer 311 multiplexes program data such as a program map table (PMT) generated by the program table information generator 312 and mobile data in the form of MPEG-2 transport stream (TS). Output to firearm 313. The program table information generator 312 generates information according to Program Specific Information (PSI) or Program and System Information Protocol (PSIP), and the PSI generates information such as a program map table (PMT) and a program association table (PAT). The PSIP includes a system time table (STT), a rating region table (RTT), a master guide table (MGT), a virtual channel table (VCT), an event information table (ETT), and an extended text table (ETT). Hereinafter, information including information on a broadcast signal transmitted in one or more sections, such as PSI / PSIP, is called program table information. In addition, the program table information generator 312 may generate program table information for transmitting information about a channel broadcast to each cell. Hereinafter, program table information including cell information such as channel information of a cell may be converted into CIT ( cell information table).

Each broadcasting station may allocate cell information, which is an area of a signal transmitted by the broadcasting station, to the CIT and transmit the information. Since the CIT can transmit channel information according to cells identified by the broadcasting station to which the CIT is allocated, the CIT can transmit CIT having different contents for each broadcasting station.

The second multiplexer 313 multiplexes the output of the first multiplexer 311 and the output of the program table information generator 312 to the packet conversion buffer 314. The first multiplexer 311 includes a plurality of multiplexers that multiplex the plurality of mobile service data with the PMT for that data. Here, one mobile service data may be a single program. Information related to a physical layer for the real-time broadcast, that is, information such as time slicing and burst length, may be included in the program table information. The packet conversion buffer 314 adjusts the transport stream in units of 188 bytes output from the second multiplexer 313 to a block length required by the preprocessor to start thereafter.

FIG. 9 is a diagram illustrating an embodiment of a transmitter disclosed in FIG. 4.

An embodiment of the transmitter according to the present invention includes a demultiplexer (DEMUX) 331, a packet jitter reducer 332, an M-VSB preprocessor 333, a first transmit data multiplexer 334, and a data renderer. Miser 335, RS encoder / Non-systematic RS encoder 336, data interleaver 337, parity substituent 338, unstructured RS encoder 339, trellis coding A unit 340, a second transmit data multiplexer 341, a pilot inserter 342, a VSB modulator 343, and an RF up converter 344.

The demultiplexer 331 of the transmitter separates the main service data and the mobile service data through the demultiplexing from the data transmitted from the transmission service multiplexer 270, and then separates the main service data into the packet jitter reducer 332. The mobile service data is output to the M-VSB preprocessor 333, respectively.

When the transmission service multiplexer 270 inserts and transmits null data to match the data rate, the demultiplexer 331 discards null data by referring to the identification information transmitted together, processes only the remaining data, and then moves to the corresponding block. Alternatively, the demultiplexer 331 may set and transmit other information such as control information required for transmission to null data.

The M-VSB preprocessor 333 performs additional encoding on the mobile service data in order to respond quickly and strongly to noise and channel changes. The mobile service data separated by the demultiplexer 331 is output to the M-VSB preprocessor 333. The embodiment of the M-VSB preprocessor 333 may randomize the mobile service data and perform error correction encoding. If the M-VSB preprocessor 333 performs randomizing, the latter data randomizer 335 may omit the randomizing process for the mobile service data. The renderer for mobile service data may or may not be the same as the one specified by ATSC.

The M-VSB preprocessor 333 multiplexes the mobile service data packet and the main service data packet in units of 188 bytes according to a predefined multiplexing method and outputs the data to the data randomizer 335. The multiplexing method can be adjusted by several variables of the system design.

As a method of multiplexing the data by the first transmission data multiplexer 334, as illustrated in FIG. 7, a burst section is provided on a time axis, and a burst section transmits a plurality of data groups and not bursts. In the interval, only main service data may be transmitted. Alternatively, the main service data may be transmitted in the burst period. That is, as shown in FIG. 7, a plurality of consecutive mobile service packets are gathered to form one data group, and the plurality of data groups are mixed with main service data packets to form one burst. Mobile service data or main service data may be transmitted within one burst period.

The main service data may exist in a burst section or a non-burst section. The number of main data packets included in the main service data section in the burst section and the main service data section in the non-burst section may be different or the same.

As such, when the mobile service data is transmitted in a burst structure, the broadcast signal receiving apparatus that receives only the mobile service data turns on the power only in the burst section to receive the data, and in the other section where only the main service data is transmitted, the power is turned off. The power consumption can be reduced.

The packet jitter reducer 332 readjusts the relative position of the main service data packet so that overflow or underflow does not occur in the buffer of the decoder in the broadcast signal receiving apparatus. In the packet multiplexing process, since the mobile service data group is multiplexed between main service data, the temporal position of the main service packet moves relatively. The decoder (eg, MPEG decoder) of the apparatus for processing the main service data of the broadcast signal receiving apparatus may receive and decode only the main service data and recognize the mobile service data packet as a null packet. Therefore, packet jitter may occur when the decoder of the broadcast signal receiving apparatus receives the main service data packet multiplexed with the mobile service data group.

The first transmission data multiplexer 334 can generate packet jitter because the decoder of the receiving device has several levels of buffers for the video data and its size is quite large. Packet jitter may cause an overflow or underflow in a buffer for main service data of the broadcast signal receiving apparatus, for example, a buffer for audio data.

The packet jitter reducer 332 knows the information multiplexed by the first transmission data multiplexer 334 at the later stage. If it is assumed that the audio data packet is normally processed, the packet reducer 332 may rearrange the audio data packet of the main service as follows.

First, if there is one audio data packet in the main service data section in the burst section, for example, the main service data section located between two mobile service data groups, the audio data packet is placed in front of the main service data section. If two are present, they are arranged at the front and the rear. If there are three or more, they are placed at the front and the rear and the rest are evenly spaced therebetween. Second, in the main service data section before the start of the burst section, the audio data packet is placed at the last position. Third, the audio data packet is placed first in the main service data section after the burst section ends. Packets other than audio data are arranged in a space excluding the location of audio data packets in the order of input.

On the other hand, if the position of the main service data packet is relatively readjusted, the value of the PCR (Program Clock Reference) is modified accordingly. The PCR value is a time reference value to match the time of the MPEG decoder and is inserted into a specific area of the TS packet and transmitted. The packet jitter reducer 332 may modify the PCR value.

The output of the packet jitter reducer 332 is input to the first transmit data multiplexer 334. As described above, the first multiplexer 334 bursts the main service data output from the packet jitter reducer 332 and the mobile service data output from the M-VSB preprocessor 333 into a burst structure according to a preset multiplexing rule. Multiplexing is performed to the data randomizer 335.

If the input data is a main service data packet, the data randomizer 335 performs rendering in the same manner as the existing renderer. That is, it discards the synchronous bytes in the main service data packet and randomizes the remaining 187 bytes using internally generated pseudo random bytes, and outputs the resultant to the RS encoder / unscrambler RS encoder 336.

However, if the input data is a mobile service data packet, the data renderer 335 may discard synchronization bits of the 4-byte MPEG header included in the mobile service data packet and perform rendering for only the remaining 3 bytes. The mobile service data excluding the MPEG header is output to the RS encoder / unstructured RS encoder 336 without performing rendering. In this case, rendering is performed in advance by the M-VSB preprocessor 333. In addition, randomization may or may not be performed on the known data (or known data location holder) and the initialization data location holder included in the mobile service data packet.

The RS encoder / unstructured RS encoder 336 performs RS encoding on the data to be rendered or bypassed by the data renderer 335, adds 20 bytes of RS parity, and outputs the data to the data interleaver 337. do. In this case, when the input data is a main service data packet, the RS encoder / unstructured RS encoder 336 performs systematic RS encoding similarly to the ATSC VSB system and adds 20 bytes of RS parity to 187 bytes of data. If it is a mobile service data packet, a 20-byte RS parity obtained by performing unsystematic RS coding is inserted at a parity byte position in the packet.

The data interleaver 337 performs convolutional interleaving on a byte basis. The output of the data interleaver 337 is input to the parity substituent 338 and the unstructured RS encoder 339.

The memory in the trellis encoder 340 may be initialized first in order to make the output data of the trellis encoder 340 located at the rear end of the parity substituter 338 into known data defined by appointment on the transmitting / receiving side. have. Before the input known data string is trellis encoded, the memory of the trellis encoder 340 is initialized.

If the beginning of the input known data string is the initialization data position holder inserted by the MVSB preprocessor 333, the initialization data position is generated immediately before the input known data string is trellis encoded to generate the corresponding trellis memory initialization data position. Replace with holder.

The trellis memory initialization data is generated based on a value determined according to the memory state of the trellis encoder 340. In addition, the RS parity may be recalculated and replaced with the RS parity output from the data interleaver 337 under the influence of the replaced initialization data.

The unstructured RS encoder 339 receives a mobile service data packet including an initialization data position holder to be replaced with initialization data from the data interleaver 337, and receives initialization data from the trellis encoder 340. The initialization data position holder of the input mobile service data packet is replaced with initialization data, the RS parity data added to the mobile service data packet is removed, and a new unstructured RS parity is calculated and output to the parity substituter 338. The parity substituter 338 then selects the output of the data interleaver 337 for data in the mobile service data packet, and selects the output of the unstructured RS encoder 339 for the RS parity to the trellis encoder 340. Output

Meanwhile, when the main service data packet is input or the mobile service data packet which does not include the initialization data location holder to be replaced is input, the parity substituent 338 selects data and RS parity output from the data interleaver 337 as it is. Output to release coder 340.

The trellis encoder 340 converts the data of the byte unit into the symbol unit, performs 12-way interleaving, trellis-encodes, and outputs the trellis to the second transmission data multiplexer 341.

The second transmission data multiplexer 341 inserts the field synchronization and the segment synchronization into the output of the trellis encoder 340 and outputs them to the pilot inserter 342. Data in which the pilot is inserted in the pilot inserter 342 is VSB modulated in the VSB modulator 343 and then transmitted to the broadcast signal receiving apparatus through the RF up converter 343.

The transmitter transmits various transmission parameters for transmission signals such as main service data and mobile service data, and the broadcasting signal receiving apparatus needs to receive the transmission parameters of the transmitted signal in order to correctly receive the transmitted signal. For example, in order to transmit mobile service data, information on how signals in a symbol region are encoded is required, and information on how main service data and mobile service data are multiplexed is needed. In addition, identifier information for a cell may also be required in a multi-frequency network environment. Here, the information on this transmission parameter is called signaling information. In the embodiment of FIG. 9, such signaling information may be inserted and transmitted by the preprocessor 333 or the second transmission data multiplexer 341. The second transmission data multiplexer 341 may insert the signaling information into the field sync segment area.

FIG. 10 is a diagram illustrating an embodiment of a preprocessor shown in FIG. 9. An embodiment of the preprocessor shown in FIG. 9 includes an M-VSB data renderer 401, an RS frame encoder 402, an M-VSB block processor 403, a group formatter 404, a data deinterleaver 405, and a packet formatter. 406.

The M-VSB renderer 401 randomizes the input mobile service data and outputs it to the RS frame encoder 402 for error correction encoding. When the M-VSB renderer 401 performs the rendering on the mobile service data, the subsequent data renderer 335 may omit the rendering process on the mobile service data.

The RS frame encoder 402 performs an error correction encoding process on the rendered mobile service data. When the RS frame encoder 402 is error corrected and encoded, it provides robustness to the mobile service data while obscuring cluster errors that may occur due to changes in the radio wave environment to cope with poor and rapidly changing radio wave environments. The RS frame encoder 402 may include a process of mixing mobile service data of a certain size in units of rows of data.

Hereinafter, the error correction encoding may be performed by RS encoding, or may be accommodated or applied as cyclic redundancy check (CRC) encoding. Parity data to be used for error correction is generated when RS encoding is performed, and CRC data to be used for error detection is generated when CRC encoding is performed.

RS encoding may use a Forward Error Correction (FEC) structure. The CRC data generated by the CRC encoding may indicate whether the mobile service data is damaged by an error while being transmitted through the channel. The error correction encoding may use other error detection encoding methods in addition to the CRC encoding, or may increase the overall error correction capability at the receiving end by using the error correction encoding method. The mobile service data encoded by the RS frame encoder 402 is input to the M-VSB block processing unit 403.

The M-VSB block processing unit 403 encodes the input mobile service data at a G / H code rate and outputs the same to the group formatter 404. The M-VSB block processing unit 403 divides the mobile service data input in byte units into bits, encodes the divided G bits into H bits, and converts them into byte units and outputs them. For example, if one bit of input data is encoded into two bits and outputted, G = 1 and H = 2. If one bit of input data is encoded into four bits and outputted, G = 1 and H = 4. In the present invention, for convenience of description, the former is referred to as encoding at 1/2 code rate (or sometimes referred to as 1/2 encoding), and the latter is referred to as encoding at 1/4 code rate (or referred to as 1/4 encoding). do. The 1/4 encoding has a higher code rate than the 1/2 encoding and can have a high error correction capability. Accordingly, the group formatter 404 allocates data encoded at a 1/4 code rate to a region where reception performance may be deteriorated, and assigns data encoded at 1/2 code rate to an region that may have better reception performance. The allocation can also reduce the difference in reception performance.

The M-VSB block processing unit 403 may also receive signaling information including transmission parameter information. The data containing the signaling information may also use 1/2 encoding or 1/4 encoding. Can be done. The signaling information is information necessary for receiving and processing data included in the data group in the broadcast signal receiving apparatus and may include cell identifier information, data group information, multiplexing information, burst information, and the like.

The group formatter 404 inserts the mobile service data output from the M-VSB block processing unit 403 into a corresponding region in the data group formed according to a predefined rule. In addition, in relation to data deinterleaving, various position holders or known data may also be inserted into a corresponding region in the data group. The data group may be divided into at least one layered area, and the type of mobile service data inserted into each area may vary according to characteristics of each layered area. For example, each layered area may be classified based on reception performance within a data group.

In addition to the mobile service data, the group formatter 404 may also insert signaling information such as transmission parameter information into the data group. When inserting the generated known data into the corresponding region in the mobile service data group, the group formatter 404 may insert signaling information instead of the known data into at least a portion of the region into which the known data can be inserted. For example, when a long known data string is inserted at the beginning of a body region in a mobile service data group, some of the signaling information is inserted in place of the known data. In this case, some of the known data strings inserted in the remaining regions except for the region in which the signaling information is inserted may be used to capture the starting point of the mobile service data group in the receiving system, and others may be used for channel equalization in the receiving system. .

In addition to the encoded mobile service data output from the M-VSB block processing unit 403, the group formatter 404 may include an MPEG header position holder, an unstructured RS parity position holder, and a data deinterleaving. You can insert the main service data location holder.

The reason for inserting the main service data location holder is that there is an area where the mobile service data and the main service data are mixed between the data after the data interleaving. As an example, the position holder for the MPEG header is assigned to the front of each packet based on the output data after the data deinterleaving.

The group formatter 404 can also insert known data generated by a predetermined method or insert known data position holders for later inserting known data. In addition, the position holder for initializing the Trellis encoding module may be inserted into the previous region of the known data string. The mobile service data size that can be inserted into one data group may vary depending on the size of trellis initialization, known data, MPEG header, RS parity, etc., inserted into the data group.

The data deinterleaver 405 deinterleaves the data and position holders in the data group output from the group formatter 404 in a reverse process of data interleaving and outputs them to the packet formatter 406.

The packet formatter 406 removes the main service data location holder and the RS parity location holder that were allocated for deinterleaving, and adds one byte of MPEG sync byte to the three bytes of MPEG header location holder for the remaining data portions, 4 bytes of MPEG header can be inserted.

In addition, the packet formatter 406 may insert the actual known data into the known data position holder when the group formatter 404 inserts the known data position holder, or may output the known data position holder without adjustment. The packet formatter 406 then divides the data in the packet-formatted data group into mobile service data packets (ie, MPEG TS packets) in units of 188 bytes and outputs them to the multiplexer. The packet formatter 406 may insert and output signaling information in place of at least part of the known data in at least a portion of the known data area. When the known data location holder is inserted at the beginning of the body area in the mobile service data group, signaling information may be inserted in place of the known data in some of the known data location holders.

When the signaling information is inserted, the inserted signaling information may be inserted by block coding in a short period or a predetermined pattern may be inserted according to the signaling information. Body regions within a mobile service data group may have different known data patterns. Therefore, the reception system can recognize only the symbol of the promised interval from the known data sequence and recognize it as signaling information.

8 to 10 illustrate an example of transmitting a broadcast signal capable of mobile reception. Hereinafter, an example of a broadcast signal transmission / reception method when a broadcast signal reception apparatus changes a cell to receive a broadcast will be described.

In the broadcast signal transmission / reception method according to an embodiment of the present invention, the cell identifier information is transmitted and received using program table information called PSI / PSIP, or the cell identifier information is transmitted and received using signaling information including transmission parameter information. can do.

If the information about the cell changes as the receiving devices move between cells, the information about the PSI or PSIP may change, and the receiving device may obtain information about the moved cell according to the changed program table information. For example, when information on the PSI or PSIP is changed, the broadcast signal reception apparatus may know whether program table information is updated through a master guide table (MGT). The master guide table (MGT) defines the PID, version number, and table size of the PSIP table except for the system time table (STT). Therefore, when the table information in the MGT is changed, the corresponding version number in the MGT is changed, so that the changed table can be received again. The broadcast signal receiving apparatus may recognize movement between cells through the MGT when a CIT (cell information table), which is program table information having information about a cell, is changed.

11 is a diagram illustrating a table type value defined in an MGT which is program table information having cell information. The MGT delivers the packet identifier (PID) and version values of all tables except the system time table (STT). That is, the apparatus for receiving broadcast signals can check the version up of other program table information through the MGT and not check the version of each table information, thereby relieving the load on the broadcast system. One of the embodiments of the present invention defines the type of a cell information table (CIT) that delivers cell information to the MGT to determine whether the version of the CIT is updated. FIG. 11 shows an example in which table_type of the CIT is defined as 0x0022. The broadcast signal receiving apparatus may convert a channel into physical channel information of the changed cell using the CIT information, so that the user may watch the broadcast program of the channel being watched as it is.

12 is a diagram illustrating a cell information table (CIT) including cell information. Referring to FIG. 12, information about a cell is disclosed in CIT information as follows. The CIT may be transmitted and received like the PSIP table defined in the ATSC, and is a table for transmitting and receiving information on a cell whose version may be managed by the MGT. In the example of FIG. 12, the identifier (table_id) of the CIT is defined as 0xCE. Section_syntax_indicator, private_indicator, reserved (unspecified), section_length (section length), transport_stream_id (transport stream identifier), reserved (unspecified), version_number (version number), current_next_indicator, section_number (section number), last_section_number (last section number) , protocol_version (protocol version) can be defined in the same way as defined in the MEPG-2 header.

num_cells_in_section is the number of cells defined in the CIT and may match the number of transmitters. The broadcasting station may define information on all transmitters transmitting the broadcast in the CIT.

The cell_id is an identifier for identifying a cell according to a signal transmission region of each transmitter, and may be matched with a transmitter of each broadcasting station. cell_text defines the name of each transmitter. For example, it may be set as 'Yongmunsan transmitter'. cell_location defines the region where each sender is located. For example, it may be set as 'Yongmun Mountain.'

num_channels_in_cell defines the number of broadcast channels transmitted by each transmitter. num_channels_in_cell may be the total number of virtual channels for the physical channel transmitted by each transmitter.

The CIT is based on each num_channels_in_cell, major_channel_number (number of major channels), minor_channel_number (number of minor channels), modulation mode (modulation mode (eg QAM, VSB, etc), carrier_frequency (carrier frequency), program number (program number) ), reserved (unspecified) may include information.

The CIT may include a descriptor located at each channel level, a descriptor located at each cell unit level, and a descriptor located at a CIT unit level. And, it may include a code for error correction.

13 is an example of an MGT for explaining an embodiment of a broadcast signal transmission / reception method according to the present invention. An embodiment of a broadcast signal transmission and reception method according to the present invention will be described with reference to FIG. 13.

An embodiment of the broadcast signal transmission / reception method according to the present invention allows a broadcast signal reception apparatus to check a version number of an MGT when a handover to a cell occurs, so as to recognize a cell change. To this end, the example of FIG. 13 shows an example in which a cell identifier defined in the CIT is set in an unspecified area of the MGT table. In addition to the fields illustrated in FIG. 13, a cell identifier defined in the CIT may be set in various ways.

In FIG. 13, cell_id includes an index of a cell included in a CIT in an unspecified region of an MGT. MGT sets the table_type field for a defined table (table_defined). The broadcast signal receiving apparatus may check whether each program table information described in FIG. 11 is updated or changed according to table_type. And, table_type_PID is a field for setting the PID of the packet carrying the table_type.

The broadcast signal receiving apparatus may obtain channel information according to the cell_id field defined in the MGT through the CIT information illustrated in FIG. 12 of the program table information.

The broadcast signal receiving apparatus parses an MGT, which is one of program table information, obtains a current cell ID value, and channel information of a cell handed over through a cell ID of a CIT having a cell ID equal to the cell ID value of the MGT. Can be obtained. When the broadcast signal reception apparatus moves to another cell, the MGT receives the MGT again and updates the transport stream information of the CIT using the cell ID of the MGT as an index. Therefore, major_channel_number (number of major channels), minor_channel_number (number of minor channels), modulation mode (modulation mode, ex) QAM, VSB, etc), carrier_frequency (carrier frequency), and program number (program number) set in the CIT Channel information can be obtained.

14 is an example of a descriptor for explaining another embodiment of a broadcast signal transmission / reception method according to the present invention. Referring to FIG. 14, another embodiment of a broadcast signal transmission / reception method according to the present invention will be described.

In the example of FIG. 14, cell_id set in the MGT is transmitted through the descriptor. In FIG. 14, a descriptor for parsing cell_id from MGT is called cell_link_descriptor. The descriptor illustrated in FIG. 14 may be parsed from the descriptor of the MGT shown in FIG. 13. The descriptor for parsing cell_id illustrated in FIG. 14 may include descriptor_tag as 0xAB, descriptor_length in byte units, cell_id, and unspecified region.

The broadcast signal reception apparatus may obtain channel information of the changed cell by using the same cell_id included in the CIT when cell_id is parsed from the descriptor of the updated MGT during handover.

15 is a flowchart for explaining another embodiment of a broadcast signal transmission / reception method according to the present invention. FIG. 15 is useful when the same broadcast as the channel of the cell before the movement is not broadcast in the cell after the movement, compared to the embodiments described with reference to FIGS. 13 and 14. If the same cell as the cell before the movement is not broadcast in the moved cell, the MGT version update cannot be checked. The broadcast signal receiving apparatus cannot detect the handover because the version of the MGT is not updated even if the signal of the cell before the movement is lowered, and thus receives the broadcast signal before the movement. Therefore, in this case, the handover can be detected using the received power.

In the present embodiment, first, a broadcast signal is received from a cell that receives program table information such as PSI / PSIP, and the broadcast is expressed (S310). The broadcast signal according to the example disclosed above includes mobile service data in addition to the main service data. In addition, the broadcast signal receiving apparatus may receive a signal in a burst period of the signal as illustrated in FIG. 6.

Receives whether the cell has changed during the reception off period of the broadcast signal in order to receive the broadcast signal of E1 in the burst period in the cell A before the handover, and to continuously receive E1 in the burst period of the broadcast signal in the cell B after the handover. It may be determined by the magnitude of the power of the signal (S320). That is, if the power of the received signal of the cell A during the broadcast signal reception off period is less than the first threshold value, it is determined that the handover is performed (Y in S320). Otherwise, the broadcast signal is continuously received from the cell A (S320). N).

If the magnitude of the power of the received signal is smaller than the first threshold (Y in S320), at least one cell identifier included in the cell candidate group is obtained to find a cell that can be handed over, and cell B according to the cell identifier. Tuning the channel of the cell B using the channel information of (S330). Cell identifier information for a candidate group of cells that can be handed over may be obtained from signaling information of a received signal. That is, when cell identifier information about neighbor cells can be obtained from signaling information, channel tuning may be attempted to the neighbor cells, respectively.

If the signal can be received from the channel of the cell B, it is determined whether the power of the signal received from the cell B is greater than the second threshold (S340). The second threshold may be the same value as the first threshold. Steps S320, S330, and S340 may be performed in a reception off period of the broadcast signal received from the cell A.

As a result of the determination, when the received signal is larger than the second threshold (Y in S340), the broadcast signal may be received from the cell B, and cell identifier information may be extracted from the signaling information of the signal received from the cell B (S350). . Alternatively, the identifier of cell B may be obtained from program table information of cell B.

If the received signal is smaller than the second threshold (Y in S340) as a result of the determination in S340, the signal of cell A, which is the original cell, is continuously received (S345), or S330 for a third cell other than cell A and cell B The process may be repeated (dashed line at S345). That is, when the reception off period of the broadcast signal received from the cell A is long, step S330 may be performed again.

16 is a flowchart illustrating an embodiment in which the same program can be continuously expressed during handover according to an embodiment of a broadcast signal transmission and reception method according to the present invention.

Powered on from a cell (S410), the broadcast signal receiving apparatus may receive a user's request to change the physical channel (S415). The frequency may be tuned to the changed channel (S420), and program table information such as VCT, PAT, and PMT may be received from the tuned channel (S430).

Demultiplex program table information to receive a table related to a channel, either PSIP or PSI. For example, the VCT may be parsed from the PSIP in the received signal, or, if there is PSI information, the PAT or PMT may be parsed (S440).

The A / V PID of the virtual channel information selected by the user is detected using the program table information (S450).

It is determined whether a broadcast signal according to the detected PID is received from a valid channel (S460). That is, when no broadcast is received on the channel, without displaying any broadcast information on the screen (S465), to go to step S430 to receive the program table information for a valid channel.

If the selected channel is a valid channel, it decodes an elementary stream (ES) according to the A / V PID of the corresponding channel (S470) and expresses the decoded broadcast (S480). In this case, additional information such as channel number and channel information may also be decoded and displayed together.

It is determined whether there is a channel change during broadcast presentation (S490). If the physical channel is changed to step S470, if the virtual channel is changed to go to step S480 to perform the above-described process it can represent the broadcast of the changed channel.

It is assumed that channel information of a cell is transmitted through an MGT as in the above-described embodiment. If there is no channel change request, but there is a cell change, it is checked whether the MGT is changed (S510). The broadcast station may transmit updated information of the program table information using the version number field of the program table information, and the broadcast signal receiving apparatus may determine whether the program table information is updated.

If the version of the MGT is changed, it is checked whether the cell ID information is changed from the MGT in order to determine whether the handover is performed (S520). As a result, when the cell ID is changed (S520 Y), the channel information changed in the CIT is detected using the new cell ID obtained from the MGT (S550).

If the MGT is changed and the cell ID information is not changed (N in S520), the program table information in the same cell is updated, so the program table information in step S430 is received.

If the MGT is not changed, the cell ID is extracted from the signaling information by determining the power of the received signal (S530). If the cell ID is changed, the changed channel information is detected according to the changed cell ID (S550). ). When the program of the cell before the change in the changed cell is broadcast on another channel, that is, when the physical channel information in the changed cell is changed, the step after step S415 is performed.

17 is a diagram illustrating an embodiment of a broadcast signal receiving apparatus according to the present invention. An embodiment of the broadcast signal receiving apparatus illustrated in FIG. 17 includes a tuner 510, a demodulator 520, a demultiplexer 530, a decoder 540, a display 550, a controller 560, and a memory. A unit 570 and a program table information decoding unit 580 are included.

Referring to FIG. 17, an operation of an embodiment of a broadcast signal receiving apparatus according to the present invention will be described.

The tuner 510 receives a broadcast signal including cell information, and selects and outputs a broadcast signal of a channel according to a control signal of the controller 560 among broadcast signals received from the current cell.

The demodulator 520 may demodulate and output the received signal. The demodulator 520 may output signaling information including cell information and transmit the demodulated signal to the controller 560. A detailed description of the demodulator 520 is illustrated in FIG.

The demultiplexer 530 may demultiplex the information about the program table information (PSI / PSIP) and the audio / video information among the received signals. Alternatively, a broadcast stream for recording or playing back a broadcast stream may be received from the digital recording device. In this case, the input signal according to IEEE1394 can be directly received without going through a tuner.

The decoder 540 may decode the audio / video broadcast signals demultiplexed by the demultiplexer 530, respectively. The decoder 540 decodes the audio / video elementary stream packet and outputs it to the display unit 550.

The display unit 550 receives and expresses an audio / video signal decoded by the decoder 540. The display unit 550 includes an OSD (on screen display) unit for displaying a graphic signal displayed on the display screen.

The program table information decoding unit 580 may decode the program table information demultiplexed by the demultiplexing unit 530 and temporarily store the decoded table information. The program table information decoder may extract a cell information by parsing a table including cell information, according to the above example, and output the obtained cell information to the controller 540.

The controller 560 includes an interface unit that receives a control signal from a user. The controller 560 may store channel map information in which physical channels and virtual channels are mapped so that the tuner 510 selects a channel, and control the decoder 540 to display a broadcast according to a channel request of the user. . The control unit 560 stores the updated channel information in the channel map when the program table information decoding unit 580 parses the updated table information. In addition, the controller 560 may store, in the memory unit 570, other control information such as information required for handover of the broadcast signal receiving apparatus, information on an application, and user request information.

 When the program table information decoding 580 extracts cell information, the controller 560 may obtain channel information on the handed-over cell by using the CIT information decoded by the program table information decoding 580. In addition, the controller 560 uses the channel information of the handed-over cell to adjust the tuner 510, the demodulator 520, the demultiplexer 530, and the decoder to express the broadcast of the channel received from the cell before the handover. The unit 540 may be controlled.

When the demodulator 520 extracts the cell identifier included in the signaling signal, the controller 560 determines whether the demodulator 520 has received the handover. After the program table information is decoded (580), the CIT information can be parsed using the cell identifier corresponding to the signaling signal included in the handover-related broadcast signal. The controller 560 may control the tuner 510, the demodulator 520, the demultiplexer 530, the decoder 540, and the like to process the broadcast signal of the cell handed over from the parsed information.

18 is a diagram illustrating an embodiment of a demodulator in the broadcast signal receiving apparatus according to the present invention. FIG. 18 illustrates a component that demodulates a broadcast signal when it is transmitted as shown in FIGS. 8 to 10. Referring to FIG. 18, a detailed embodiment of a demodulator is as follows.

The broadcast signal receiving apparatus may improve reception performance by performing carrier synchronization recovery, frame synchronization recovery, channel equalization, etc. using known data information inserted into a mobile service data section in a transmission system.

The broadcast signal receiving apparatus includes a VSB demodulator 702, an equalizer 703, a known data detector 704, an M-VSB block decoder 705, an M-VSB data deformatter 706, and an RS frame decoder 707. , An M-VSB derandomizer 708, a data deinterleaver 709, an RS decoder 710, a data derandomizer 711, and a signaling information decoder 712. For convenience of description in FIG. 18, the M-VSB data deformatter 706, the RS frame decoder 707, and the M-VSB derandomizer 708 are referred to as mobile service data processing units, and a data deinterleaver 709 is provided. The RS decoder 710 and the data derandomizer 711 will be referred to as a main service data processor.

The VSB demodulator 702 and the known data detector 704 each receive a signal down-converted to an intermediate frequency (IF) signal by tuning a frequency at the tuner.

The VSB demodulator 702 converts the IF signal into an automatic gain control, carrier recovery, and timing recovery into a baseband signal in consideration of the VSB scheme and outputs the same to the equalizer 703 and the known data detector 704. .

The equalizer 703 compensates for the distortion on the channel included in the demodulated signal and outputs it to the M-VSB block decoder 705.

At this time, the known data detector 704 detects the known data position inserted by the transmitting side from the input / output data of the VSB demodulator 702, that is, data before VSB demodulation is performed or data after demodulation is performed. The known data detector 704 then outputs the symbol sequence of the known data generated at the position to the VSB demodulator 702 and the equalizer 703 together with the position information. In addition, the known data detection unit 704 may provide information for allowing the M-VSB block decoder 705 to distinguish between mobile service data that has undergone additional error correction encoding and main service data that does not undergo additional error correction encoding. Output to the VSB block decoder 705. Although the connection state is not illustrated in the diagram of FIG. 18, the information detected by the known data detector 704 may be generally used in the receiving apparatus, and the M-VSB data deformatter 706 and the RS frame decoder 707 may be used. It can also be used.

The VSB demodulation unit 702 can improve demodulation performance by using the known data symbol string at the time of timing recovery or carrier recovery, and the equalizer 703 can also improve the equalization performance by using the known data. . In addition, the equalization performance may be improved by feeding back the decoding result of the M-VSB block decoder 705 to the equalizer 703.

If the data received from the equalizer 703 is mobile service data in which both additional error correction encoding and trellis encoding are performed at the transmitting side, the M-VSB block decoder 705 reverses trellis decoding and additionally. Error correction decoding is performed. If no additional encoding is performed at the transmitting side, only trellis decoding is performed if the trellis encoding is main service data.

The data group decoded by the M-VSB block decoder 705 is input to the M-VSB data deformatter 706, and the main service data packet is input to the data deinterleaver 709.

If the input data is main service data, the M-VSB block decoder 705 performs a Viterbi decoding on the input data and outputs a hard decision value or hard-soft decision value. The determination result can also be output.

On the other hand, if the input data is mobile service data, the M-VSB block decoder 705 outputs a hard decision value or a soft decision value with respect to the input mobile service data. If the input data is mobile service data, the M-VSB block decoder 705 performs decoding on the data encoded by the M-VSB block processor and the trellis encoder of the transmission system. At this time, the RS frame coder of the M-VSB preprocessor of the transmitting side may be an outer code, and the M-VSB block processor and the trellis coder may be an inner code. The decoder of the inner code can output the soft decision value so as to maximize the performance of the outer code at the time of decoding the concatenated code.

Therefore, the M-VSB block decoder 705 may output a hard decision value for the mobile service data, but it may be better to output a soft decision value if necessary.

Meanwhile, the data deinterleaver 709, the RS decoder 710, and the derandomizer 711 receive and process main service data. The data deinterleaver 709 deinterleaves the main service data output from the M-VSB block decoder 705 in the reverse process of the data interleaver on the transmitting side, and outputs the deinterleaver to the RS decoder 710.

The RS decoder 710 performs systematic RS decoding on the deinterleaved data and outputs the deserializer 711. The derandomizer 711 receives the output of the RS decoder 710 to generate the same pseudo random bytes as the transmitter's renderer, bitwise XOR (exclusive OR operation) the MPEG sync byte to Insert before and output in 188 byte main service data packet unit.

On the other hand, the form of data output from the M-VSB block decoder 705 to the M-VSB data deformatter 706 is data of a group form. At this time, since the M-VSB data deformatter 706 already knows the configuration of the input data group, the signaling information having system information and the mobile service data can be distinguished from each other in the data group. The signaling information is information for transmitting system information and may carry information on a transmission parameter including cell identifier information.

The mobile service data is output to the RS frame decoder 707. The M-VSB data deformatter 706 stores the base data, trellis initialization data, MPEG header, and RS encoder of the transmission system, which have been inserted into the main service data and the data group. Removes the added RS parity from the unstructured RS encoder or the unstructured RS encoder and outputs the RS parity decoder 707.

That is, the RS frame decoder 707 receives only RS coded and / or CRC coded mobile service data from the M-VSB data deformatter 706.

The RS frame decoder 707 performs an inverse process in the RS frame encoder of the transmission system to correct errors in the RS frame, and then 1-byte MPEG sync byte removed in the RS frame encoding process to the error corrected mobile service data packet. Is added to the M-VSB de-randomizer 708.

The M-VSB derandomizer 708 performs derandering corresponding to the inverse process of the M-VSB renderer of the transmission system with respect to the received mobile service data, thereby outputting the mobile service data transmitted from the transmission system .

The signaling information decoding unit 712 can decode the signaling information included in the received signal. The example of FIG. 18 shows an example of decoding signaling information including cell identifier information and the like from the equalizer 703 or the M-VSB data deformatter 706 according to the position on the signal carrying the signaling information.

19 is a view showing another embodiment of a broadcast signal receiving apparatus according to the present invention. An operation of an embodiment of the broadcast signal receiving apparatus according to the present invention will be described with reference to FIG. 19 as follows.

Another embodiment of the broadcast signal receiving apparatus according to the present invention is to control the second memory unit 620 and the second memory unit capable of storing a program other than the memory unit 570 of the embodiment of the broadcast signal receiving apparatus disclosed in FIG. It further includes a memory controller 610.

The broadcast service data demultiplexed by the demultiplexer 530 may be decoded and output to the decoder 540 and may be output by the memory controller 610 that controls the second memory 620. ) Can be entered or read. The demultiplexer 530 may store the main service data or the mobile service data demodulated by the demodulator 520 in the second memory unit 620, respectively.

The controller 560 may allow the demultiplexer 530 to immediately record, schedule, and time shift the broadcast service data demultiplexed through the memory controller 610. In addition, the controller 560 may reproduce broadcast service data already stored in the second memory unit 620 through the memory controller 610 and the demultiplexer 540.

The second memory unit 620 may be divided into a temporary storage area for storing data according to a time shift and / or a permanent storage area for permanently storing data according to a user selection.

The memory controller 610 controls the play, fast forward, rewind, slow motion, instant replay, etc. of data stored in the second memory unit 620. Control may be performed according to the control signal of 560. In this case, the instant replay is a function that can repeatedly view scenes to be viewed again. In addition to the stored data, data currently received in real time can be instantly replayed in conjunction with a time shift function.

The memory controller 610 may scramble and store the input data in order to prevent illegal copying of the data input and stored in the second memory unit 620. Conversely, the memory controller 610 may read, descramble, and store data scrambled and stored in the second memory unit 620.

The program table information decoder 580 may decode the broadcast data when the broadcast data for data broadcast is included in the main service data or the mobile service data. Data for data broadcasting may be decoded from the program table information decoder 580 and stored in the data storage 630.

When the controller 560 drives a data broadcasting application according to a user's request, the program table information decoder 580 decodes and outputs broadcast data for data broadcasting. The application driven by the controller 560 may implement data broadcasting output by the program table information decoder 580 and output the data broadcast to the display unit 550.

The program table information decoder 580 may decode broadcast data according to PSI or PSIP or service information such as DVB-SI as an example. The broadcast data for data broadcast may be a packetized elementary stream (PES) type or a section type. That is, data for data broadcasting includes data of PES type or data of section type.

For example, data for data broadcasting may be included in a digital storage media command and control (DSM-CC) section, and the DSM-CC section may be composed of TS packets in units of 188 bytes. The identifier of the TS packet included in the DSM-CC section is included in program table information which is a data service table (DST). If DST is transmitted, 0x95 is allocated as the stream_type field value in the service location descriptor of PMT or VCT. The broadcast signal reception apparatus determines that data for data broadcast is received when the stream_type field value of the PMT or VCT is 0x95. Data for data broadcasting may be transmitted in a data carousel manner.

In order to process data for data broadcasting, the demultiplexer 530 performs section filtering under the control of the program table information decoder 580 to discard the overlapping sections, and the non-overlapping sections are the program table information decoder 580. The program table information decoder 580 may determine whether data for data broadcasting is received in a data signal in a broadcast signal according to the PID of the VCT. The PID of the VCT may be set in the MGT or have a fixed value.

The demultiplexer 530 may output only the application information table (AIT) to the program table information decoder 580 through section filtering. The AIT includes information on an application driven in the broadcast signal receiving apparatus for data service.

The AIT contains information about the application, such as the name of the application, the version of the application, the priority of the application, the ID of the application, the state of the application (auto-start, user operable, kill, etc.), the type of application ( Java or HTML), the location of the stream including the classes and data files of the application, the base directory of the application, the location of the icon of the application, and the like. Therefore, by using this information, information necessary for driving the application may be stored in the data storage unit 630.

The application driven by the controller 560 may be received and updated together with the broadcast data. The data broadcast application manager executed by the controller 560 to drive the application may include a platform for executing the application program. The platform may be, for example, a Java virtual machine for executing a Java program.

Assuming that the data broadcasting service is a traffic information service, the broadcast signal receiving apparatus may provide the user with at least one of text, voice, graphics, still images, and video even without an electronic map or a global positioning system (GPS). have. If the broadcast signal receiving apparatus includes a GPS module, the GPS module extracts current location information (longitude, latitude, and altitude) received from the satellite, and then may implement a data broadcasting application. The data storage unit 630 of the broadcast signal receiving apparatus may store an electronic map including information on each link and node and various graphic information.

20 is a view showing another embodiment of a broadcast signal receiving apparatus according to the present invention. An operation of an embodiment of the broadcast signal receiving apparatus according to the present invention will be described with reference to FIG. 20 as follows. The embodiment of FIG. 20 may process the scrambled received signal.

20 may further include a first descrambler 640, a second descrambler 650, and an authenticator 660 in the embodiment of FIG. 19. Alternatively, in the embodiment of FIG. 20, only one of the first descrambler 640 and the second descrambler 650 may be provided. The first descrambler 640 receives and descrambles the demultiplexed signal from the demultiplexer 530. In this case, the first descrambler 640 may receive the authentication result or data necessary for descramble from the authenticator 660 and use the descrambler. The decoder 540 receives the descrambled signal from the first descrambler 640, decodes the signal, and outputs the descrambled signal. When the embodiment of FIG. 20 does not include the first descrambler 640, the signal output by the decoder 540 may be descrambled by the second descrambler 650.

The apparatus for transmitting a broadcast signal may scramble and transmit broadcast content to provide a service for preventing illegal copying or illegal viewing of the transmitted main service data or mobile service data, or a paid broadcast service.

The broadcast signal receiving apparatus descrambles the scrambled broadcast content to display the broadcast content, which may be subjected to an authentication procedure by the authentication means before descramble. In the example of FIG. 20, the first scram part 640, the second scram part 650, and the authentication part 660 may be attached to or detached from the broadcast signal receiving apparatus in the form of a slot or a memory stick.

When the scrambled broadcast content is received through the tuner 510 and the demodulator 520, the controller 560 may determine whether the received broadcast content is scrambled. If the received broadcast content is scrambled, the authenticator 660 operates the authentication means.

The authenticator 660 performs an authentication procedure to determine whether the broadcast signal receiving apparatus is a legitimate host (broadcast signal receiving apparatus) qualified to receive the paid broadcast content. Various authentication procedures may be performed. For example, the authenticator 660 may perform authentication by comparing an IP address of an IP datagram in the broadcast content with a unique address of the corresponding broadcast signal receiving apparatus. The unique address of the broadcast signal receiving apparatus may be a media access control (MAC) address. The authenticator 660 extracts an IP address from the decapsulated IP datagram and obtains information on a received device mapped to the address. The authenticator 660 may include information (for example, a table format) capable of mapping the IP address and the information of the receiving apparatus in advance, and compare the same to determine whether the information is the same.

In another authentication embodiment, the transmitting and receiving side defines the standardized identification information in advance, and transmits the identification information of the receiving apparatus applying for the pay broadcasting service at the transmitting side, and the receiving apparatus performs the authentication procedure after determining the identity with its own identification number. can do. The transmitter generates and stores a unique identification information of the receiving apparatus that has applied for the pay broadcast service, and transmits the identification information in the Entitlement Management Message (EMM) when scrambled the broadcast content. When the broadcast content is scrambled, a message (eg, ECM, EMM) such as conditional access system (CAS) information, mode information, and message location information applied to the scramble may be transmitted through a corresponding data header or another packet. .

The Entitlement Control Message (ECM) may include a control word (CW) used for scramble. In this case, the control word may be encrypted with an authentication key. The EMM may include an authentication key and entitlement information of the data. The authentication key may be encrypted with the recipient's own distribution key. If broadcast data is scrambled using the control word (CW) and information for authentication and information for descrambling are transmitted from the transmitting side, the transmitting side encrypts the CW with an authentication key and then transmits it in the entitlement control message (ECM). Can be.

In addition, the transmitting side transmits the authentication key used to encrypt the CW and the reception qualification of the broadcast signal reception apparatus (eg, a standardized serial number of the broadcast signal reception apparatus having the reception qualification) in the EMM.

Therefore, the authentication unit 660 of the broadcast signal receiving apparatus extracts the unique identification information of the apparatus, extracts the identification information included in the EMM of the receiving broadcast service, determines whether the two identification information is the same, and performs the authentication procedure. Perform. If the two pieces of information are the same as the result of the authentication unit 660, the broadcast signal receiving apparatus may determine that the broadcast signal receiving apparatus is a legitimate broadcast signal receiving apparatus.

In another authentication embodiment, the apparatus for receiving broadcast signals may include authentication means 3008 in a detachable external module. In this case, the broadcast signal receiving apparatus and the external module interface with each other through a common interface (CI). The external module may perform descrambling by receiving scrambled data from the receiving device through a common interface, and may transmit only information necessary for descrambling to the receiving device.

In addition, the common interface includes a physical layer and one or more protocol layers, and the protocol layer may have a structure including one or more layers that provide independent functions in consideration of scalability in the future.

The external module may be a memory or a card that stores key information and authentication information used for scramble and does not have a descramble function, or a card including a descramble function. That is, the module may include a descrambling function in the form of hardware, middleware or software.

At this time, the receiving device and the external module must be authenticated to provide the user with the pay broadcasting service provided by the transmitter. Therefore, the transmitting side may provide the pay broadcasting service only to the receiving device and the module pair which have been authenticated.

In addition, the receiving device and the external module may mutually authenticate each other through a common interface. The external module may communicate with the control unit 560 of the receiving device through the common interface to authenticate the receiving device. The broadcast signal receiving apparatus may authenticate a module through a common interface. The module may extract the unique ID and the unique ID of the apparatus for receiving a broadcast signal in a mutual authentication process and transmit the extracted unique ID to the transmitting side. If necessary, the controller 560 may transmit the charging information to the transmitting side of the remote place through the communication module 670.

The authenticator 660 authenticates the receiving device and / or the external module, and recognizes the receiving device as a legitimate receiving device that is entitled to receive the paid broadcasting service of the receiving device when the authentication process is completed and succeeds. Also, the authenticator 660 may receive authentication-related data from a mobile communication company subscribed to by a user of a receiving apparatus other than the transmitting side providing the broadcast content. In this case, the authentication-related data may be scrambled by the transmitting side providing the broadcast content through the mobile telecommunication company or scrambled by the mobile telecommunication company.

When the authentication procedure of the authenticator 660 is successfully completed, the receiving device may scramble and descramble the received broadcast content. The descrambler is performed by the descramblers 640 and 650, and the descramblers 640 and 650 may be provided in an internal or external module of the receiving device. Also, the broadcast signal receiving apparatus may have a common interface and communicate with an external module including the descramblers 640 and 650 to descramble the received signal.

If the descramblers 640 and 650 are provided inside the receiving apparatus, the transmitting side (including at least one of a service provider and a broadcasting station) may scramble and transmit data using the same scramble method. Meanwhile, if the descramblers 640 and 650 are included in an external module, data may be scrambled and transmitted by different scramble methods for each transmitting side.

The controller 560 may communicate with the descramblers 640 and 650 in a predetermined interface format. The common interface protocol between the receiving device and the external module includes a function of periodically checking the state of the other party to maintain normal communication with each other. The receiving device and the module use this function to manage the status of the other party and include a function of reporting and attempting recovery to the user or the sending side if one malfunctions.

In another embodiment of authentication, the authentication procedure may be performed in software without being dependent on hardware.

That is, the broadcast signal receiving apparatus receives the CAS software from the memory card, loads it, and performs an authentication procedure when the memory card in which the software is stored in advance is inserted by downloading the CAS software. According to an embodiment of the present invention, the CAS software read from the memory card is stored in the memory units 570 and 620 in the broadcast signal receiving apparatus and driven as one application on the middleware. The middleware will be described using JAVA middleware as an example.

To this end, the broadcast signal reception apparatus may include a common interface for connecting to a memory card, and the first memory unit 570 may be a volatile memory, a nonvolatile memory, and a flash memory (or referred to as a flash ROM). Memory cards mainly use flash memory or small hard disks. The memory card may be used in at least one broadcast signal receiving apparatus according to contents, authentication, scramble, billing method, etc. of stored CAS software. However, CAS software contains at least the information needed for authentication and the information needed for descramble.

Therefore, the authenticator 660 performs an authentication procedure between the transmitting side and the broadcast signal receiving apparatus or the broadcast signal receiving apparatus and the memory card. The memory card may include information on a normal broadcast signal receiving apparatus that can be authenticated as being eligible for reception. For example, the information on the broadcast signal receiving apparatus includes unique information such as a standardized serial number for the broadcast signal receiving apparatus. Accordingly, the authenticator 660 may perform authentication between the memory card and the broadcast signal receiving apparatus by comparing the unique information such as a standardized serial number included in the memory card with the unique information of the corresponding broadcast signal receiving apparatus.

CAS software operates based on Java middleware to perform authentication between a broadcast signal receiving device and a memory card. For example, it is checked whether the unique number of the broadcast signal receiving apparatus included in the CAS software is the same as the unique number of the broadcast signal receiving apparatus read through the controller 560 of the broadcast signal receiving apparatus. If the result is the same, the memory card is identified as a normal memory card that can be used in the broadcast signal receiving apparatus. At this time, the CAS software may be embedded in the memory units 570 and 620 at the time of shipment of the broadcast signal receiving apparatus. Alternatively, the data may be stored in the memory units 570 and 620 from a transmitting side or a module or a memory card. The descramble function may operate in the form of one application by the data broadcast application.

The CAS software parses the EMM / ECM packet output from the demultiplexer 530, checks whether the corresponding receiving device is eligible for reception, obtains information necessary for descramble (ie, CW), and provides it to the descrambler 640 and 650. can do. CAS software operating on Java middleware reads the unique number of the broadcast signal receiver from the broadcast signal receiver and compares the unique number of the broadcast signal receiver transmitted to the EMM to check the current broadcast signal receiver. do.

When the reception qualification of the broadcast signal reception apparatus is confirmed, the broadcast signal reception apparatus checks whether the broadcast signal reception apparatus is entitled to receive the broadcast service by using the broadcast service information transmitted to the ECM and the reception qualification of the broadcast service. When the qualification to receive the broadcast service is confirmed, the encrypted CW transmitted to the ECM is decrypted using the authentication key transmitted to the EMM and then output to the descramblers 640 and 650. The descramblers 640 and 650 descramble a broadcast service using the CW.

On the other hand, CAS software stored in the memory card can be expanded according to the paid service to be provided by the broadcasting station. The CAS software may also include other additional information as well as information related to authentication and descramble. In addition, the broadcast signal receiving apparatus may download CAS software from the transmitter and upgrade the CAS software stored in the memory card.

The descramblers 640 and 650 may be included in a module in hardware or software form. In this case, the scrambled and received data may be descrambled in the module and then decoded.

When the scrambled and received data are stored in the second memory unit 620, the scrambled data may be descrambled and stored, or the scrambled data may be stored as it is and then descrambled during playback. In addition, when the scramble / descramble algorithm is provided in the memory controller 610, the memory controller 610 may scramble the received scrambled data once again and store the scrambled data in the second memory unit 620.

In another embodiment, the descrambled (receive limited) broadcast content is transmitted through a broadcasting network, and the authentication, descrambling related information, etc. for removing the reception restriction is transmitted and received through the communication module 670 to receive a broadcast signal. It is possible to enable bidirectional communication in.

The broadcast signal receiving apparatus may transmit unique information such as serial number or MAC address of the corresponding broadcast signal receiving apparatus so that the transmitting side can recognize the broadcast data desired to be transmitted / received with the transmitter located at a remote site and the broadcast signal receiving apparatus transmitting the broadcast data. ID) is transmitted to or received from the communication module 670 in the transmission side.

The communication module 670 in the broadcast signal receiving apparatus may support a protocol required for performing bidirectional communication with the communication module 670 in the transmitting side in the broadcast signal receiving apparatus that does not support the bidirectional communication function. The broadcast signal receiving apparatus configures a Protocol Data Unit (PDU) using a Tag-Length-Value (TLV) coding method including data to be transmitted and unique information (ID). The tag field includes indexing of the corresponding PDU, the length field includes the length of the value field, and the value field includes actual data to be transmitted and a unique number (ID) of the broadcast signal receiving apparatus.

If the broadcast signal receiving apparatus is equipped with a Java platform (Java Platform) and the Java application (Java Application) of the transmitting side can be configured to operate after downloading the network application through the network to the broadcast signal receiving apparatus. In this case, a PDU including a tag field arbitrarily defined by the transmitter may be downloaded from a storage medium or the like in the broadcast signal receiving apparatus and then transmitted to the communication module 670.

At this time, the broadcast signal receiving apparatus transmits and receives through a wireless data network, and has a common interface and can be connected through a mobile communication base station such as CDMA, GSM, WAP, CDMA 1x EV-DO, and a wireless LAN accessible through an access point. , Mobile Internet, WiBro, WiMAX, and the like.

It is easy for a person skilled in the art to change or modify the present invention from the present specification. Therefore, although an embodiment of the present invention has been described above clearly, various modifications thereof should be made without departing from the spirit and the scope of the present invention.

Claims (14)

Receiving a broadcast signal, wherein the broadcast signal is identified by a transport stream ID field, the broadcast signal includes a cell information table (CIT), and the CIT indicates a cell according to a transmission area in which the broadcast signal is transmitted. A cell identifier field for identifying;
Demodulating the received broadcast signal;
Extracting the CIT from the demodulated broadcast signal, wherein the CIT further includes a service ID field and a cell number field, the service ID identifies a broadcast service in the broadcast signal, and the cell number field Indicate a number of adjacent cells according to a transmission area in which a broadcast service identical or similar to a broadcast service identified by a service ID is transmitted;
Acquiring the broadcast service using the extracted CIT; And
And decoding the obtained broadcast service. The method of claim 1, wherein the CIT further includes a table ID field, and the table ID field identifies the CIT. The method as claimed in claim 1, wherein the step of acquiring the broadcast service using the extracted CIT comprises:
Identifying a cell using the cell identifier field;
Identifying a broadcast service transmitted through a transmission area according to the identified cell using the service ID field; And
And acquiring the broadcast service transmitted through the adjacent cells by using the cell number field. The method of claim 1, wherein the broadcast signal comprises a multiplexed mobile broadcast service and a main broadcast service. 4. The method of claim 3, wherein the mobile broadcast service comprises error correction encoding. A tuner for receiving a broadcast signal, wherein the broadcast signal is identified by a transport stream ID field, and the broadcast signal includes a cell information table (CIT), and the CIT indicates a cell according to a transmission area in which the broadcast signal is transmitted. A cell identifier field for identifying;
A demodulator for demodulating the received broadcast signal;
A table information storage unit for extracting the CIT from the demodulated broadcast signal, wherein the CIT further includes a service ID field and a cell number field, wherein the service ID identifies a broadcast service in the broadcast signal, respectively, A field indicates the number of adjacent cells according to a transmission area in which a broadcast service identical or similar to a broadcast service identified by the service ID is transmitted;
And a decoder for obtaining the broadcast service using the extracted CIT and decoding the obtained broadcast service. 7. The broadcast signal receiver of claim 6, wherein the CIT further comprises a table ID field, wherein the table ID field identifies the CIT. The mobile station of claim 6, wherein the decoder identifies a cell using the cell identifier field, identifies a broadcast service transmitted through a transmission area according to the identified cell using the service ID field, and transmits the cell number. And acquiring the broadcast service transmitted through the adjacent cells using a field. The broadcast signal receiver of claim 6, wherein the broadcast signal includes a multiplexed mobile broadcast service and a main broadcast service. The broadcast signal receiver of claim 9, wherein the mobile broadcast service includes error correction coding. Error correction coding of a mobile broadcast service;
Multiplexing the error-correction-coded mobile broadcast service and the main broadcast service; And
Transmitting a broadcast signal including the multiplexed broadcast service, wherein the broadcast signal is identified by a transport stream ID field, and the broadcast signal includes a cell information table (CIT), wherein the CIT indicates that the broadcast signal is And a cell identifier field for identifying a cell according to a transmission area to be transmitted, wherein the CIT further includes a service ID field and a cell number field, wherein the service ID identifies a broadcast service in the broadcast signal, respectively, And a number field indicates the number of adjacent cells according to a transmission area in which a broadcast service identical or similar to the broadcast service identified by the service ID is transmitted. 12. The method of claim 11, wherein the CIT further comprises a table ID field, wherein the table ID field identifies the CIT. An error correction coder for error correction encoding the mobile broadcast service;
A multiplexer which multiplexes the error correction coded mobile broadcast service and a main broadcast service; And
A transmitter for transmitting a broadcast signal including the multiplexed broadcast service, the broadcast signal is identified by a transport stream ID field, the broadcast signal includes a cell information table (CIT), and the CIT is the broadcast signal. And a cell identifier field for identifying a cell according to a transmission area to which the CTL is transmitted, wherein the CIT further includes a service ID field and a cell number field, wherein the service ID identifies a broadcast service in the broadcast signal, respectively, And a cell number field indicates the number of adjacent cells according to a transmission area in which a broadcast service identical or similar to a broadcast service identified by the service ID is transmitted. 14. The broadcast signal transmitter of claim 13, wherein the CIT further comprises a table ID field, wherein the table ID field identifies the CIT.

Images