KR20070081277A - Digital broadcasting receiver and processing method - Google Patents

Abstract

A digital broadcasting receiving system and a digital broadcasting processing method are provided to transmit and process additional data and improve receiving performance by using known data for channel equalization. A digital broadcasting processing method includes a step of receiving general data in which a known data stream is periodically embedded and converting the received data to data in a frequency domain, a step of estimating a channel impulse response by using data received in a known data period and known data, a step of obtaining an average of channel impulse responses of known data periods located before and after the general data, converting the average into data in a frequency domain and calculating an equalization coefficient, and a step of multiplying the data in the frequency domain by the equalization coefficient to compensate channel distortion and converting the data into data in a time domain.

Description

Digital broadcasting receiver and processing method

1 illustrates an example of a data frame structure after data interleaving in a digital broadcast transmission system according to the present invention.

2 is a diagram illustrating an example in which known data are periodically transmitted according to the present invention.

3 is a block diagram of a channel equalizer according to an embodiment of the present invention;

4 is a block diagram illustrating a configuration of a channel equalizer according to another embodiment of the present invention.

5 is a block diagram illustrating a configuration of a channel equalizer according to another embodiment of the present invention.

6 is a block diagram illustrating a configuration of a channel equalizer according to another embodiment of the present invention.

7 is a diagram illustrating an example of linear interpolation of the interpolator of FIG. 6.

8A and 8B illustrate embodiments of overlap & save according to the present invention.

9 is a block diagram illustrating a channel equalizer according to another embodiment of the present invention.

10 is a block diagram of a channel equalizer according to another embodiment of the present invention

11 is a block diagram illustrating a channel equalizer according to another embodiment of the present invention.

12 is a block diagram illustrating a digital broadcast receiving system according to an embodiment of the present invention.

Explanation of symbols for main parts of the drawings

301,402,502: FFT unit 302,403,503: distortion compensation unit

303,404: channel estimator 304,405,510: FFT unit

305,406: coefficient calculation unit 306,407,504: IFFT unit

307: average calculation unit 401,501: overlap

408,505: save part 409: interpolation part

506: decision unit 507: selection unit

508: subtractor 509: zero padding

511: coefficient updater 512: delay

610,710: frequency domain transform unit 620,720: distortion compensation unit

630,730: time domain converter 640,740: first coefficient calculator

650,750: second coefficient calculation unit 660,760: coefficient selection unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital communication system, and more particularly, to a digital broadcasting system and a processing method for modulating and transmitting and receiving a modulation in a VSB (Vestigial Side Band) scheme.

The 8T-VSB transmission system, adopted as a digital broadcasting standard in North America and Korea, is a system developed for transmission of MPEG video / audio data. However, with the rapid development of digital signal processing technology and the widespread use of the Internet, digital home appliances, computers, and the Internet are being integrated into one big framework. Therefore, in order to meet various needs of users, it is necessary to develop a system capable of transmitting various additional data in addition to video / audio data through a digital broadcasting channel.

Some users of supplementary data broadcasting are expected to use supplementary data broadcasting by using PC card or portable device equipped with simple indoor antenna. Due to the effects of ghosts and noise caused by reflected waves, broadcast reception performance may deteriorate. However, unlike general video / audio data, the additional data transmission should have a lower error rate. In the case of video / audio data, errors that the human eye and ears cannot detect are not a problem, while in the case of additional data (eg program executables, stock information, etc.), a bit error may cause serious problems. It can cause problems. therefore There is a need to develop a system that is more resistant to ghosting and noise in the channel.

The transmission of additional data will usually be done in a time division manner over the same channel as the MPEG video / sound. Since the beginning of digital broadcasting, however, ATSC VSB digital broadcasting receivers that receive only MPEG video / audio have been widely used in the market. Therefore, additional data transmitted on the same channel as MPEG video / audio should not affect the existing ATSC VSB-only receivers that have been used in the market. Such a situation is defined as ATSC VSB compatible, and the additional data broadcasting system should be compatible with the ATSC VSB system.

In this case, for convenience of description, the additional data having the information is called enhanced data or E-VSB data, and existing MPEG video / audio data is called main data.

In addition, in a poor channel environment, the reception performance of the conventional ATSC VSB receiving system may be degraded. Especially in the case of portable and mobile receivers, robustness against channel changes and noise is required.

Accordingly, an object of the present invention is to provide a digital broadcasting system and processing method suitable for additional data transmission and processing, and resistant to noise.

Another object of the present invention is to provide a digital broadcasting reception system and processing method for improving reception performance by using predefined known data known to the transmitting / receiving side for channel equalization.

In order to achieve the above object, the digital broadcast processing method according to an embodiment of the present invention,

(a) receiving known data strings periodically inserted into general data and transmitting them, and converting the received data into a frequency domain;

(b) estimating a channel impulse response using the data received during the known data interval and known data known to the receiver;

(c) calculating an average value of channel impulse responses of known data sections located before and after the general data section, converting the result to a frequency domain, and calculating an equalization coefficient; And

(d) multiplying the equalized coefficients by the data converted into the frequency domain to compensate for channel distortion, and converting the converted data into the time domain.

Digital broadcast processing method according to another embodiment of the present invention,

(a) receiving known data when the known data is inserted into general data and transmitting the same, and converting the received data into a frequency domain by overlapping the received data at a predetermined overlapping ratio;

(b) estimating a channel impulse response using data received during a known data interval and known data known to a receiver, converting the estimated channel impulse response into a frequency domain, and then calculating an equalization coefficient; And

(c) multiplying the equalization coefficient by the overlapping data transformed into the frequency domain to compensate for channel distortion, converting the data into a time domain, and extracting and outputting valid data from the overlapping data of the time domain. do.

The step (b) further includes the step of estimating the channel impulse response estimated in the known data interval, and converting the estimated channel impulse response in the interval without the known data into the frequency domain.

Digital broadcast processing method according to another embodiment of the present invention,

(a) receiving known data when the known data is inserted into general data and transmitting the same, and converting the received data into a frequency domain by overlapping the received data at a predetermined overlapping ratio;

(b) compensating for channel distortion by multiplying the overlapped data transformed into the frequency domain by an equalization coefficient, converting the data into a time domain, and extracting and outputting valid data from the overlapped data of the time domain; And

(c) an error is obtained by using the determined value of the equalized valid data and known data known to the receiving side, and zeros are added to the error according to the overlapping ratio, converted to the frequency domain, and the previous equalization coefficient is updated. And outputting to the step (b).

Digital broadcast processing method according to another embodiment of the present invention,

(a) When a plurality of enhanced data packets having known data inserted therein are divided into N layered sections and transmitted, the input data is converted into a frequency domain according to the layer section information, or the input data is overlapped at a predetermined overlapping ratio. Converting to the frequency domain;

(b) compensating for channel distortion by multiplying the data converted to the frequency domain by an equalization coefficient, and then converting the data to the time domain, and outputting the data of the time domain as equalized data as it is or according to the layer section information Extracting valid data and outputting the equalized data;

(c) estimating a channel impulse response using data received during the known data period and known data known to the receiver, converting the estimated channel impulse response into a frequency domain, and then calculating an equalization coefficient;

(d) obtaining an error using the determined value of the equalized data and known data known to the receiver, adding zeros to the error according to the overlap ratio, converting the frequency into a frequency domain, and updating a previous equalization coefficient. ; And

(e) selecting one of the equalization coefficients calculated in step (c) and the equalization coefficients updated in step (d) according to the hierarchical section information, and providing the same to the step (b). do.

Digital broadcast processing method according to another embodiment of the present invention,

(a) converting the input data into a frequency domain by overlapping the input data at a predetermined overlapping rate when the plurality of enhanced data packets having known data inserted therein are divided into N layered sections and transmitted;

(b) compensating for channel distortion by multiplying the data converted into the frequency domain by an equalization coefficient, converting the data into a time domain, and extracting and outputting valid data from overlapping data of the time domain;

(c) estimating a channel impulse response using data received during the known data period and known data known to the receiver, converting the estimated channel impulse response into a frequency domain, and then calculating an equalization coefficient;

(d) obtaining an error using the determined value of the equalized data and known data known to the receiver, adding zeros to the error according to the overlap ratio, converting the frequency into a frequency domain, and updating a previous equalization coefficient. ; And

(e) selecting one of the equalization coefficients calculated in step (c) and the equalization coefficients updated in step (d) according to the hierarchical section information, and providing the same to the step (b). do.

A channel equalizer in a digital broadcast reception system according to an embodiment of the present invention includes: a frequency domain converter for receiving a known data string periodically inserted into and transmitted from general data, and converting the received data into a frequency domain; The channel impulse response is estimated using the data received during the known data interval and known data known to the receiver, and the average value of the channel impulse responses of the known data intervals located before and after the general data interval is obtained and converted into the frequency domain. A channel estimation and coefficient calculation unit for calculating and outputting a post equalization coefficient; A distortion compensator for compensating for channel distortion by multiplying the equalized coefficient by data converted from the frequency domain converter to the frequency domain; And a time domain converter configured to convert data of the frequency domain compensated for the channel distortion into a time domain and output the converted data.

The channel equalizer of the digital broadcasting reception system according to another embodiment of the present invention receives the known data when the known data is inserted into the general data and transmitted, and converts the received data into the frequency domain by superimposing the received data at a preset overlapping ratio. part; A channel estimation and coefficient calculation unit for estimating a channel impulse response using the received data during the known data interval and known data known to the receiver, converting the estimated channel impulse response into a frequency domain, and calculating and outputting an equalization coefficient. ; A distortion compensator for compensating for channel distortion by multiplying the equalization coefficient by the overlapping data converted from the frequency domain converter to the frequency domain; And a time domain transform unit for converting the overlapped data of the frequency domain compensated for the channel distortion into a time domain, and extracting and outputting valid data from the overlapped data.

The channel estimating and coefficient calculating unit interpolates the channel impulse response estimated in the known data interval, estimates the channel impulse response in the section without known data, and converts the frequency into the frequency domain.

The channel equalizer of the digital broadcasting reception system according to another embodiment of the present invention receives a known data when it is inserted into general data and is transmitted, and converts the received data into a frequency domain by overlapping the received data with a preset overlapping ratio. A conversion unit; A distortion compensator for compensating for channel distortion by multiplying an equalization coefficient by the overlapping data transformed into the frequency domain; A time domain converter configured to convert the overlapped data compensated for the channel distortion into a time domain, and extract and output valid data from the overlapped data of the time domain; And calculating an error using the determined value of the equalized valid data and known data known to the receiver, adding zero to the error according to the overlap ratio, converting the frequency into a frequency domain, and updating the previous equalization coefficient to perform the distortion. And a coefficient updater for outputting to the compensator.

The channel equalizer of the digital broadcasting reception system according to another embodiment of the present invention is configured to receive input data according to the hierarchical interval information when a plurality of enhanced data packets including known data are divided and transmitted into N hierarchical sections. A frequency domain converter for converting a frequency domain or converting the input data into a frequency domain by overlapping input data at a preset overlap ratio; A distortion compensator for compensating for channel distortion by multiplying data converted into the frequency domain by an equalization coefficient; Converting the data compensated for the channel distortion into a time domain and outputting the data in the time domain as equalized data according to the hierarchical section information or extracting valid data from the overlapping data in the time domain as equalized data A time domain converter; A first coefficient calculator for estimating a channel impulse response using data received during a known data interval and known data known to a receiver, converting the estimated channel impulse response into a frequency domain, and calculating an equalization coefficient; A second coefficient calculating unit which obtains an error using the determined value of the equalized data and known data known to the receiver, adds zero to the error according to an overlap ratio, converts the frequency into a frequency domain, and then updates a previous equalization coefficient. ; And a coefficient selector for selecting one of the equalization coefficient calculated by the first coefficient calculator and the equalized coefficient updated by the second coefficient calculator and outputting the equalized coefficient to the distortion compensation unit.

The channel equalizer of the digital broadcast reception system according to another embodiment of the present invention superimposes the input data at a predetermined overlapping rate when a plurality of enhanced data packets having known data inserted therein are divided and transmitted into N layered sections. A frequency domain converter for converting the frequency domain into a frequency domain; A distortion compensator for compensating for channel distortion by multiplying data converted into the frequency domain by an equalization coefficient; A time domain converter configured to convert the overlapped data compensated for the channel distortion into a time domain, and extract and output valid data from the overlapped data of the time domain; A first coefficient calculator for estimating a channel impulse response using data received during a known data interval and known data known to a receiver, converting the estimated channel impulse response into a frequency domain, and calculating an equalization coefficient; A second coefficient calculating unit which obtains an error using the determined value of the equalized data and known data known to the receiver, adds zero to the error according to an overlap ratio, converts the frequency into a frequency domain, and then updates a previous equalization coefficient. ; And a coefficient selector which selects one of the equalization coefficient calculated by the first coefficient calculator and the equalized coefficient updated by the second coefficient calculator and outputs the equalization coefficient to the distortion compensator according to the hierarchical section information. .

Other objects, features and advantages of the present invention will become apparent from the following detailed description of embodiments taken in conjunction with the accompanying drawings.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention that can specifically realize the above object will be described. At this time, the configuration and operation of the present invention shown in the drawings and described by it will be described as at least one embodiment, by which the technical spirit of the present invention and its core configuration and operation is not limited.

In addition, the terminology used in the present invention is a general term that is currently widely used as much as possible, but in certain cases, the term is arbitrarily selected by the applicant. In this case, since the meaning is described in detail in the description of the present invention, It is intended that the present invention be understood as the meaning of the term rather than the name.

The present invention is to perform channel equalization in the frequency domain using known data known to the transmitting and receiving side.

That is, in a digital broadcast transmission system in which an enhanced data packet including information is multiplexed with main data and transmitted, known data known from the transmitting / receiving side may be inserted into the enhanced data packet section and transmitted. Data transmitted in the enhanced data packet section is applied with an error correction code having better performance than the main data section in order to improve reception performance.

In this case, the known data may be inserted and transmitted in various forms in the enhanced data packet section. The known data may be used for carrier synchronization recovery, frame synchronization recovery and channel equalization in a digital broadcast reception system.

FIG. 1 shows one embodiment of the data frame structure of a data interleaver (not shown) output in a digital broadcast transmission system.

FIG. 1 shows an example in which a predetermined number of data packets are collected and divided into a head, a body, and a tail section. The head, body, and tail sections are divided in 52 packet units. This is an example in which each section is configured in 52 packet units because the data interleaver operates periodically in 52 packet units.

That is, based on the data interleaver output, the body section in the data frame is allocated to include at least a part or the whole of the section in which the enhanced data is continuously output, and known data is periodically included in the body section. Is inserted constantly. The head section is located before the body section and the tail section is located after the body section. In FIG. 1, the main section is not included in the body section, the known data is inserted every 6 packet (or segment) periods, and the known data is additionally inserted at the beginning of the body section.

In the case of FIG. 1, the body section is a section which can show more robust reception performance because there is no interference of main data in the middle, and the enhanced data of the head and tail sections is mixed between the main data and the interleaver output order. This is a section in which the reception performance can be lower than the section.

Therefore, when inserting known data into the enhanced data and transmitting it, when a long known data is inserted periodically into the enhanced data, the body section in which the enhanced data is not mixed with the main data based on the order of the data interleaver output terminals. It is possible to insert in. In this case, it is possible to periodically insert known data of a predetermined length into the body section. However, it is difficult to periodically insert known data into the head and tail sections, and it is impossible to insert long known data continuously. Accordingly, FIG. 1 shows an example in which a short known data string is inserted into the head and tail sections at frequent intervals.

2 shows an example of a data structure in which known data strings of the same pattern are periodically inserted and transmitted. In FIG. 2, the data may be enhanced data, main data, or a mixture of enhanced data and main data. In the present invention, this data is referred to as general data to distinguish it from known data.

When the same known data is periodically inserted, the known data section may be used as a guard interval in the channel equalizer according to the present invention. That is, since the same known data appears repeatedly, this known data interval can be used as a guard. The guard interval serves to prevent interference between blocks generated by the multipath channel.

This structure is also called a cyclic prefix, and this structure allows the impulse response of data blocks and channels transmitted in a digital broadcast transmission system to be circularly convolutional in the time domain. Therefore, it is easy to perform channel equalization in the frequency domain using fast fourier transform (FFT) and inverse FFT (IFFT) in the channel equalizer of the digital broadcasting reception system. That is, since the data block received by the digital broadcasting reception system is expressed as the product of the data block and the channel impulse response in the frequency domain, the channel equalization can be performed simply by multiplying the inverse of the channel in the frequency domain during channel equalization.

In the channel equalizer of the present invention, an indirect equalization method of estimating a channel impulse response (CIR) using a known data sequence arranged at predetermined intervals and using the same may be used. Here, the indirect equalization method means performing channel equalization after estimating the impulse response of the channel to obtain the equalization coefficient, and the direct equalization method performing channel equalization after updating the equalization coefficient by obtaining an error from the channel equalized signal. it means.

3 is a block diagram illustrating an embodiment of an indirect equalization frequency domain channel equalizer according to the present invention.

3 illustrates a first fast Fourier transform (FFT) unit (FFT1,301), a distortion compensator (302), a channel estimator (303), a second FFT unit (FFT2, 304), and a coefficient calculator ( 305, and an IFFT unit 306.

The distortion compensator 302 may be any element that performs a complex multiplication role.

In FIG. 3 configured as described above, the first FFT unit 301 converts the received data into a frequency domain by FFT and outputs the transformed data to the distortion compensator 302. At this time, when the known data string of the same pattern is periodically inserted into the general data string and transmitted, the first FFT unit 301 converts the received data into FFT block units and converts the received data into data in the frequency domain.

The distortion compensator 302 complexes the equalization coefficient calculated by the coefficient calculator 305 with the data in the frequency domain output from the first FFT unit 301 and outputs the data from the first FFT unit 301. After compensating for the channel distortion, the output to the IFFT unit 306. The IFFT unit 306 IFFTs the data of which the distortion of the channel is compensated and converts the data into a time domain.

Meanwhile, the channel estimator 303 estimates a channel impulse response (CIR) by using the data received during the known data interval and the known data of the known data interval known to the receiver by an appointment of the transmitting / receiving side. After that, output to the second FFT unit 304. For example, the channel estimator 304 estimates an impulse response of a discrete equivalent channel that is likely to have passed by a signal transmitted from a transmitter during a known data interval, and outputs the result to the second FFT unit 304.

The second FFT unit 304 performs an FFT on the estimated CIR, converts the estimated CIR into a frequency domain, and outputs the converted FIR to the coefficient calculator 305. The coefficient calculator 305 calculates an equalization coefficient using the estimated CIR of the frequency domain and outputs the equalization coefficient to the distortion compensator 302. In this example, the coefficient calculating unit 305 obtains an equalization coefficient of a frequency domain that minimizes a mean square error (MMSE) from the estimated CIR of the frequency domain to the distortion compensation unit 302. Output

Meanwhile, as described above, when the first FFT unit 301 converts the input data into the frequency domain, as shown in FIG. 2, a part of the known data of the known data section is located before and after the general data section as shown in FIG. 2. In order to achieve correct channel equalization, the influence of the channel appears in the form of circular convolution.

However, when using the CIR at the point A or the point B of FIG. 2 when performing the equalization in the channel equalizer of FIG. 3, the view point of the general data to which the real equalization is applied and the point of view of the CIR used for equalization are different. Performance degradation occurs. This is because the CIR is a value obtained from the known data section, and the channel equalization of the general data section is performed using the CIR obtained from the known data section.

4 is a block diagram illustrating an embodiment of a frequency domain channel equalizer according to the present invention in consideration of such a problem, and uses an average value of the CIR for channel equalization of general data. That is, when performing equalization, the equalization performance can be improved by performing channel equalization of a general data section between A and B points using average values of CIR and A B points.

To this end, FIG. 4 is a structure further including an average calculating unit 307 between the channel estimating unit 303 and the second FFT unit 304 of FIG. 3.

That is, the CIR estimated using the data received during the known data period and the known data by the channel estimator 303 are output to the average calculating unit 307.

The average calculator 307 outputs the average value of successive CIRs to the second FFT unit 304. For example, an average value of the CIR value estimated at A and B is output to the second FFT unit 304 for use in channel equalization of general data between A and B. .

The second FFT unit 304 converts the input CIR into a frequency domain and outputs the converted CIR to the coefficient calculator 305.

The coefficient calculator 305 calculates a frequency domain equalization coefficient that satisfies the condition of minimizing the mean square error using the average CIR of the frequency domain and outputs the same to the distortion compensator 302. Subsequent operations may be omitted by referring to FIG. 3 described above.

FIG. 5 is a block diagram illustrating another embodiment of an indirect equalization frequency domain channel equalizer according to the present invention, and performs a linear weaving operation in the frequency domain using an overlap & save method.

5, the overlapping unit 401, the first FFT unit 402, the distortion compensating unit 403, the channel estimating unit 404, the second FFT unit 405, the coefficient calculating unit 406, and the IFFT unit 407, and a save unit 408.

The distortion compensator 403 may be any element that performs a complex multiplication role.

In FIG. 5 configured as described above, the received data is superimposed by the overlapping unit 401 and output to the first FFT unit 402. The first FFT unit 402 converts the overlapped data in the time domain into overlapped data in the frequency domain through an FFT and outputs the overlapped data to the distortion compensator 403.

The distortion compensator 403 multiplies the equalization coefficient calculated by the coefficient calculator 406 with the overlapping data of the frequency domain output from the first FFT unit 402 and is output from the first FFT unit 402. The channel distortion of the overlapped data is compensated and then output to the IFFT unit 407. The IFFT unit 407 IFFTs the overlapped data whose channel distortion is compensated, converts the data into a time domain, and outputs the data to the save unit 408. The save unit 408 extracts and outputs only valid data from overlapping data of the channel equalized time domain.

Meanwhile, the channel estimator 404 estimates a channel impulse response (CIR) using data received during a known data interval and known data of the known data interval known to a receiver by an appointment of the transmitter / receiver side. After that, output to the second FFT unit 405.

The second FFT unit 405 converts the estimated CIR of the time domain to the CIR of the frequency domain, and outputs the CIR to the coefficient calculator 406. The coefficient calculator 406 calculates an equalization coefficient by using the estimated CIR of the frequency domain and outputs the equalization coefficient to the distortion compensator 403. In this example, the coefficient calculator 406 obtains an equalization coefficient of a frequency domain that minimizes a mean square error (MMSE) from the estimated CIR of the frequency domain to the distortion compensation unit 403. Output

That is, the frequency domain channel equalizer of FIG. 3 performs channel equalization by performing a circular convolutional operation in the frequency domain, and the frequency domain channel equalizer of FIG. 5 performs a channel equalization by performing a linear convolutional operation in the frequency domain. The rest of the operation is the same.

However, unlike the channel equalizer of FIG. 3, the frequency domain channel equalizer of FIG. 5 does not use the characteristics of the guard interval, and thus, there is no restriction in setting the FFT block interval. That is, the known data may not be located at the front and rear portions of the general data section input to the first FFT unit FFT1.

In this case, since the channel equalizers estimate CIR using periodically transmitted known data and calculate equalization coefficients using the CIR, the rate at which the equalization coefficient is updated depends on the period in which known data is transmitted. Therefore, in a dynamic channel, that is, a channel whose characteristics change over time, the equalization performance may be degraded if the channel change rate is faster than the transmission period of the known data. At this time, if the frequent data is frequently transmitted to compensate for the rapidly changing channel, the transmission efficiency of general data to which actual useful content is transmitted decreases, and thus there is a limit to reducing the transmission period of the known data.

FIG. 6 is a block diagram illustrating an embodiment of a frequency domain channel equalizer according to the present invention in consideration of such a problem. Instead of frequently transmitting known data, FIG. 6 illustrates interpolation of estimated CIRs in known data intervals to obtain general data. Used for channel equalization.

To this end, FIG. 6 further includes an interpolator 409 between the channel estimator 404 and the second FFT unit 405 of FIG. 5.

That is, the CIR estimated using the data received during the known data period and the known data by the channel estimator 404 is output to the interpolator 409.

The interpolator 409 estimates the CIRs of the section without known data by using a preset interpolation method and outputs the CIRs to the second FFT unit 405. The second FFT unit 405 converts the input CIR into a frequency domain and outputs the converted CIR to the coefficient calculator 406. The coefficient calculator 406 calculates a frequency domain equalization coefficient that satisfies the condition of minimizing the mean square error using the interpolated CIR of the frequency domain and outputs the same to the distortion compensator 403. Subsequent operations may be omitted by referring to FIG. 5 described above.

In this case, the interpolation method of the interpolator 409 is a method of estimating data at an unknown point using known data in a function. The simplest example is linear interpolation. 7 is an example of linear interpolation.

는 다음의 수학식 1과 같이 추정할 수 있다.In other words, given a function value F (A) of x = A and a function value F (B) of x = B in any function F (x), the estimate of the function value at x = P

Can be estimated as in Equation 1 below.

When the known data string is periodically inserted and transmitted as shown in FIG. 2, the present invention provides, according to an embodiment, a single period between two known data sections located before and after the general data section, and the data of the one period. Divide the interval into multiple intervals. In each section, the CIR may be estimated using the same interpolation method as described above, and channel equalization may be performed on the data of the section using the estimated CIR.

However, when the data of one period is divided into several sections, the known data cannot be located at the front and the rear of the FFT block section in all the FFT block sections as shown in FIG. 2, and thus the interpolation method described above is used in the frequency domain channel equalizer using the cyclic prefix. Cannot be used. However, the above-described interpolation method may be used in the case of the overlapped & save type frequency domain channel equalizer as shown in FIG.

8 shows an example of data division to be processed by the frequency domain channel equalizer of the overlap & save method when linearly interpolating the CIR.

FIG. 8A illustrates a case in which data is overlapped so that a ratio of overlapping data between a current FFT block and a previous FFT block is 50%, and a period between two known data sections located before and after a general data section is divided into four sections. to be. At this time, in an embodiment of the present invention, the size and the number of each section are set such that at least one section within a period includes a known data string. This is because the FFT block data of the section including the known data string is used for channel equalization using the CIR estimated in the section as it is. In addition, the CIR obtained in the section is used for CIR interpolation in a section without a known data string.

In this case, the data input to the first FFT unit 402 is input in the order of FFT blocks 1 to 5 with reference to FIG. 8A. These data are input to the distortion compensator 403, equalized in the frequency domain, and then converted into the time domain by the IFFT unit 407, and only the valid data portion is extracted from the save unit 408 and finally output.

In FIG. 8A, intervals 1 to 5 represent valid data intervals for each FFT block. In this case, since the FFT block 1 includes the known data string, the CIR B can be estimated. In addition, the FFT block 5 includes a known data string, so that the CIR C can be estimated. In other words, the data of the FFT block 1 may perform channel equalization using the estimated CIR B, and the data of the FFT block 5 may use the estimated CIR C. However, in the case of FFT blocks 2-4, since there is no known data string, the interpolator 409 may estimate CIRs to be used in FFT blocks 2-4 by interpolating CIR B and CIR C. In this case, if linear interpolation is used, the estimated CIR in FFT blocks 2 to 4 is expressed by Equation 2 below.

FFT Block 2: 0.75B + 0.25C

FFT block 3: 0.5B + 0.5C

FFT Block 4: 0.25B + 0.75C

FIG. 8B is a case where data is overlapped so that the ratio of overlapping data between the current FFT block and the previous FFT block is 75%, and one period between two known data sections located before and after the general data section is divided into four sections. to be. Similarly, in an embodiment of the present invention, the size and number of each section are set such that at least one section in one period includes a known data string. In addition, the CIR estimated by interpolation is the same as that of FIG. 8A, except that the size of the FFT block is twice that of FIG. 8A.

8A and 8B are examples, and the order of the interpolation method and the size of the algorithm and the FFT block may be variously selected as necessary.

On the other hand, as shown in FIG. 1, since the long enough known data is periodically transmitted in the body section, an indirect equalization method using the CIR can be used. However, in the head / tail section, not only the known data can be transmitted long enough but also periodically transmitted regularly. It is not suitable for estimating CIR using known data. Therefore, in the head / tail section, the direct equalization method should be used to obtain the error from the output of the equalizer and update the coefficients.

9 is a block diagram showing an embodiment of a frequency domain channel equalizer of the direct equalization method according to the present invention.

9, the overlapping unit 501, the first FFT unit 502, the distortion compensating unit 503, the IFFT unit 504, the save unit 505, the determination unit 506, the selection unit 507, The subtractor 508 includes a zero padding unit 509, a second FFT unit 510, a coefficient update unit 511, and a delay unit 512.

The distortion compensator 503 may be any element that performs a complex multiplication role.

In FIG. 9 configured as described above, the received data are overlapped by the overlapping unit 501 and output to the first FFT unit 502. The first FFT unit 502 converts the overlapped data of the time domain into overlapped data of the frequency domain through an FFT and is output to the distortion compensator 503 and the delayer 512.

The distortion compensator 503 complexes the equalization coefficients of the frequency domain updated by the coefficient updater 511 to the overlapping data of the frequency domain output from the first FFT unit 502, thereby generating the first FFT unit 502. After compensating for the channel distortion of the superimposed data output from the PDU, the output is output to the IFFT unit 504. The IFFT unit 504 IFFTs the overlapped data whose distortion of the channel is compensated, converts the data into a time domain, and outputs the converted data to the save unit 505. The save unit 505 extracts valid data from the overlapped data of the channel equalized time domain and outputs the data for decoding, and outputs the same to the decision unit 506 and the subtractor 508 for updating the equalization coefficient.

The determination unit 506 selects a decision value closest to the equalized data among a plurality of eight determination values and outputs the determination value to the selection unit 507. The selector 507 may be configured as a multiplexer. The selector 507 selects the determined value of the determiner 507 in the general data section and selects known data in the known data section and outputs the known data to the subtractor 508. The subtractor 508 subtracts the output of the save unit 505 from the output of the selector 507 to obtain an error and outputs the error value to the zero padding unit 509.

The zero padding unit 509 adds a zero corresponding to an amount of overlapping received data to an input error and outputs the zero padding unit 510 to the second FFT unit 510. The second FFT unit 510 converts an error in the time domain to which 0 is added to an error in the frequency domain, and outputs the error to the coefficient update unit 511. The coefficient updater 511 updates the previous equalization coefficient by using the received data of the frequency domain delayed by the delayer 512 and the error of the frequency domain, and then outputs the previous equalization coefficient to the distortion compensator 503. The updated equalization coefficient is then stored for use as a previous equalization coefficient.

In this case, in the digital broadcasting transmission system as shown in FIG. 1, both the body section and the head / tail section can be transmitted. Therefore, in order to increase the equalization efficiency, it is preferable to use an equalizer for each section.

The present invention proposes a hybrid scheme of a direct equalizer equalizer and an indirect equalizer equalizer.

FIG. 10 is a block diagram illustrating an embodiment of a hybrid frequency domain channel equalizer according to the present invention, and performs indirect equalization channel equalization using a cyclic prefix on data of a body section, and performs head / tail. The channel equalization of the direct equalization method using the overlap & save method is shown for the data of the interval.

To this end, the frequency domain channel equalizer of FIG. 10 includes a frequency domain transformer 610, a distortion compensator 620, a time domain transformer 630, a first coefficient calculator 640, a second coefficient calculator 650, and And a coefficient selector 660.

The frequency domain converter 610 includes an overlapping unit 611, a selection unit 612, and a first FFT unit 613.

The time domain converter 630 includes an IFFT unit 631, a save unit 632, and a selector 633.

The first coefficient calculator 640 includes a channel estimator 641, an average calculator 642, a second FFT unit 643, and a coefficient calculator 644.

The second coefficient calculator 650 includes a determiner 651, a selector 652, a subtractor 653, a zero padding unit 654, a third FFT unit 655, a coefficient updater 656, and a delay. And a group 657.

In this case, the selector 612 of the frequency domain converter 610, the selector 633 of the time domain converter 630, and the coefficient selector 660 may determine whether the current input data is data of a body section. It may be configured as a multiplexer (ie, mux) that selects input data depending on whether the data is tail section.

If the data input in FIG. 10 configured as described above is the data of the body section, the selecting unit 612 of the frequency domain transforming unit 610 selects the input data among the input data and the output data of the overlapping unit 611 and converts the time domain. The selecting unit 633 of the unit 630 selects the output data of the IFFT unit 631 from the output data of the IFFT unit 631 and the output data of the save unit 632. The coefficient selector 660 selects an equalization coefficient output from the first coefficient calculator 640.

Meanwhile, if the input data is data of the head / tail section, the selecting unit 612 of the frequency domain converter 610 selects the output data of the overlapping unit 611 among the input data and the output data of the overlapping unit 611, The selector 633 of the time domain converter 630 selects the output data of the save unit 632 from among the output data of the IFFT unit 631 and the output data of the save unit 632. The coefficient selector 660 selects the equalization coefficient output from the second coefficient calculator 650.

That is, the received data is input to the overlapping unit 611, the selection unit 612, and the first coefficient calculating unit 640 of the frequency domain transform unit 610. The selector 612 selects the received data and outputs the received data to the first FFT unit 613 when the input data is the data of the body section, and selects the overlapped data by the overlapping unit 611 if the data is the head / tail section. Output to the first FFT unit 613. The first FFT unit 613 converts the time domain data output from the selector 612 into a frequency domain by converting the data in the time domain into a frequency domain, and then retarders 657 of the distortion compensator 620 and the second coefficient calculator 650. )

The distortion compensator 620 complexes the equalization coefficient output from the coefficient selector 660 with the data in the frequency domain output from the first FFT unit 613 to output the data from the first FFT unit 613. After compensating for the channel distortion, the output signal is output to the IFFT unit 631 of the time domain transform unit 630.

The IFFT unit 631 of the time domain transform unit 630 converts the data whose channel distortion is compensated, converts the data into a time domain, and outputs the data to the save unit 632 and the selector 633. The selector 633 selects output data of the IFFT unit 631 if the input data is data of the body section, and selects valid data extracted from the save unit 632 if data of the head / tail section is used to perform data decoding. Output to the second coefficient calculating unit 650 at the same time.

The channel estimator 641 of the first coefficient calculating unit 640 uses the data received during the known data interval and the known data of the known data interval known to the receiver by an appointment of the transmitting / receiving side. After estimating, the result is output to the average calculating unit 642.

The average calculating unit 642 obtains an average value of successive CIRs which are input, and outputs the average value to the second FFT unit 643. For example, the second FFT unit 643 may use the average value of the CIR value estimated at time A and the CIR value estimated at time B of FIG. Is output.

The second FFT unit 643 converts the input CIR of the time domain into a frequency domain and outputs the FIR to the coefficient calculator 644.

The coefficient calculator 644 calculates a frequency domain equalization coefficient that satisfies a condition of minimizing the mean square error using the CIR of the frequency domain and outputs the calculated frequency domain equalization coefficient to the coefficient selector 660.

The determination unit 651 of the second coefficient calculating unit 650 selects a determination value closest to the equalized data among the eight determination values and outputs the determination value to the selection unit 652. The selector 652 selects the determined value of the determiner 651 in the general data section, selects known data in the known data section, and outputs the known data to the subtractor 653. The subtractor 653 subtracts the output of the selector 633 of the time domain converter 630 from the output of the selector 652 to obtain an error and outputs the error value to the zero padding unit 654.

The zero padding unit 654 adds a zero corresponding to an amount of overlapping received data to an input error and outputs the zero padding unit 655 to the third FFT unit 655. The third FFT unit 655 converts an error in the time domain to which zero is added to an error in the frequency domain, and then outputs the error to the coefficient changer 656. The coefficient updater 656 updates the previous equalization coefficient using the data of the frequency domain and the frequency domain delayed by the delayer 657 and then outputs the same to the coefficient selector 660. The updated equalization coefficient is then stored for use as a previous equalization coefficient.

The coefficient selector 660 selects an equalization coefficient calculated by the first coefficient calculator 640 if the input data is data of a body section, and updates the equalized coefficient updated by the second coefficient calculator 650 if the data is a head / tail section. The coefficient is selected and output to the distortion compensator 620.

FIG. 11 is a block diagram illustrating another embodiment of a hybrid frequency domain channel equalizer according to the present invention, and performs indirect equalization channel equalization using an overlap & save method for data in a body section, and performs head / An example of performing channel equalization of the direct equalization method using the overlap & save method on the data of the tail section is shown.

To this end, the frequency domain channel equalizer of FIG. 11 includes a frequency domain converter 710, a distortion compensator 720, a time domain converter 730, a first coefficient calculator 740, a second coefficient calculator 750, and And a coefficient selector 760.

The frequency domain converter 710 includes an overlapping unit 711 and a first FFT unit 712.

The time domain converter 730 includes an IFFT unit 731 and a save unit 732.

The first coefficient calculator 740 includes a channel estimator 741, an interpolator 742, a second FFT unit 743, and a coefficient calculator 744.

The second coefficient calculator 750 includes a determiner 751, a selector 752, a subtractor 753, a zero padding unit 754, a third FFT unit 755, a coefficient updater 756, and a delay. And a group 757.

In this case, the coefficient selector 760 may be configured as a multiplexer (ie, mux) that selects input data according to whether current input data is data of a body section or data of a head / tail section. That is, the coefficient selector 760 selects an equalization coefficient of the first coefficient calculator 740 if the input data is data of the body section, and selects an equalization coefficient of the second coefficient calculator 750 if the data of the head / tail section is data. Choose.

In FIG. 11 configured as described above, the received data is input to the overlapping unit 711 and the first coefficient calculating unit 740 of the frequency domain transforming unit 710. The overlapping unit 711 overlaps the input data according to a preset overlap ratio and outputs the overlapped input data to the first FFT unit 712. The first FFT unit 712 converts overlapped data in the time domain into overlapped data in the frequency domain through an FFT, and is output to the delay compensator 720 and the delay unit 757 of the second coefficient calculator 750.

The distortion compensator 720 complexes an equalization coefficient output from the coefficient selector 760 with overlapping data of the frequency domain output from the first FFT unit 712, and outputs the complex equalization coefficient from the first FFT unit 712. The channel distortion of the overlapped data is compensated for and then output to the IFFT unit 731 of the time domain transform unit 730. The IFFT unit 731 IFFTs the overlapped data whose distortion of the channel is compensated, converts the data into a time domain, and outputs the converted data to the save unit 732. The save unit 732 extracts only valid data from the overlapped data of the channel equalized time domain and outputs the data for data decoding and outputs the data to the second coefficient calculator 750 for coefficient update.

The channel estimator 741 of the first coefficient calculator 740 estimates the CIR using the data and the known data received during the known data period and outputs the CIR to the interpolator 742. The interpolator 742 estimates the CIRs, ie, the CIRs in a section without known data, at a time point located between the estimated CIRs using the input CIR, and calculates the result of the second FFT unit (FIR). 743). The second FFT unit 743 converts the input CIR into a frequency domain and outputs the converted CIR to the coefficient calculator 744. The coefficient calculator 744 calculates a frequency domain equalization coefficient that satisfies the condition of minimizing the mean square error by using the CIR of the frequency domain and outputs the same to the coefficient selector 760.

Since the configuration and operation of the second coefficient calculator 750 are the same as those of the second coefficient calculator 650 of FIG. 10, detailed description thereof will be omitted.

The coefficient selector 760 selects an equalization coefficient calculated by the first coefficient calculator 740 when the input data is data of a body section, and updates the equalization updated by the second coefficient calculator 750 when the data is a head / tail section. The coefficient is selected and output to the distortion compensator 720.

FIG. 12 is a diagram illustrating an embodiment of a digital broadcast receiving system having at least one of the above-described channel equalizers, and includes a tuner 810, a demodulator 820, a channel equalizer 830, and known data. And a detection and generation unit 840 and an error correction unit 850.

The error correction unit 850 includes a Viterbi decoder 851, a data deinterleaver 852, an RS decoder / unstructured RS parity remover 853, a derandomizer 854, and a main data packet remover 855. , An E-VSB packet deformatter 856, and an E-VSB data processing unit 857.

That is, the tuner 810 digitizes the frequency of a specific channel and outputs it to the demodulator 820 and the known data detector and generator 840.

The demodulator 820 performs carrier recovery and timing recovery using the known data on the tuned channel frequency to form a baseband signal, and then, the channel equalizer 830 and the known data detection and generation unit 840. Output

The channel equalizer 830 applies the channel equalizer of any one of FIGS. 3 to 6 and 9 to 11 to compensate for the distortion on the channel included in the demodulated signal, and then corrects the error. Will output

The known data detection and generation unit 840 detects the known data inserted by the transmitting side from the input / output data of the demodulator 820, that is, the data before demodulation is performed or the data after demodulation is performed. 820 and the channel equalizer 830.

The Viterbi decoder 851 of the error correcting unit 850 performs Viterbi decoding on the data output from the channel equalizer 830 and outputs the Viterbi decoder to the deinterleaver 852. In this case, the 8-level determination value determined by the Viterbi decoder 851 may be provided to the channel equalizer 830 to improve the equalization performance. The deinterleaver 852 performs an inverse process of the data interleaver on the transmitting side with respect to the input data and outputs the RS data to an RS encoder / non-systematic RS parity remover 853. The RS decoder / unstructured RS parity removal unit 853 performs systematic RS decoding when the received packet is a main data packet, and removes an unstructured RS parity byte inserted in the packet when the received packet is an enhanced data packet. Output to derandomizer 854.

The de-randomizer 854 performs de-randomization on the output of the RS decoder / unstructured RS parity remover 853 and inserts MPEG sync bytes in front of every packet and outputs them in units of 188-byte packets. The output of the derandomizer 854 is output to the main MPEG decoder (not shown) and to the main data packet remover 855.

Meanwhile, the main data packet remover 855 removes the main data packet in units of 188 bytes from the output of the derandomizer 854 and outputs the main data packet to the E-VSB packet deformatter 856. The E-VSB packet deformatter 856 removes the MPEG header and known data inserted into the enhanced data packet at the transmitting side from the enhanced data packet output from the main data packet removing unit 855, and then E-VSB data. Output to processing unit 857. The E-VSB data processor 857 performs null data removal, additional error correction decoding, deinterleaving, and the like on the output of the E-VSB packet deformatter 856 to finally output the enhanced data.

On the other hand, the terms used in the present invention (terminology) are terms defined in consideration of the functions in the present invention, which may vary according to the intention or practice of those skilled in the art and the definitions are used throughout the present invention. It should be based on the content.

The present invention is not limited to the above-described embodiments, and can be modified by those skilled in the art as can be seen from the appended claims, and such modifications are within the scope of the present invention.

As described above, the digital broadcasting system and the processing method according to the present invention have the advantage of being resistant to errors and compatible with existing VSB receivers when transmitting additional data through a channel. In addition, there is an advantage that the additional data can be received without error even in a ghost and noisy channel than the conventional VSB system.

In addition, the present invention constructs and transmits an enhanced data packet including at least one of enhanced data having information at the transmitting side and known data known at the transmitting / receiving side, and at the receiving side, using the known data for channel equalization. Can improve the reception performance.

In particular, in the present invention, when a plurality of enhanced data packets are divided into layered sections and transmitted, channel equalization may be improved by performing indirect equalization or direct equalization according to the characteristics of each section.

The present invention is more effective when applied to portable and mobile receivers in which channel variation is severe and robustness to noise is required.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention.

Therefore, the technical scope of the present invention should not be limited to the contents described in the embodiments, but should be defined by the claims.

Claims (35)

(a) receiving known data strings periodically inserted into general data and transmitting them, and converting the received data into a frequency domain; (b) estimating a channel impulse response using the data received during the known data interval and known data known to the receiver; (c) calculating an average value of channel impulse responses of known data sections located before and after the general data section, converting the result to a frequency domain, and calculating an equalization coefficient; And and (d) multiplying the equalized coefficients by the data converted into the frequency domain to compensate for channel distortion, and converting the converted data into the time domain. The method of claim 1, wherein step (a) And converting the received data into a frequency domain by FFTing the received data in units of FFT blocks. The method of claim 2, wherein the FFT block interval is And a part of the known data of the known data section is located both before and after general data. The method of claim 1, wherein the equalization coefficient of step (c) And an equalization coefficient in the frequency domain for minimizing the mean square error. (a) receiving known data when the known data is inserted into general data and transmitting the same, and converting the received data into a frequency domain by overlapping the received data at a predetermined overlapping ratio; (b) estimating a channel impulse response using data received during a known data interval and known data known to a receiver, converting the estimated channel impulse response into a frequency domain, and then calculating an equalization coefficient; And (c) multiplying the equalization coefficient by the overlapping data transformed into the frequency domain to compensate for channel distortion, converting the data into a time domain, and extracting and outputting valid data from the overlapping data of the time domain. Digital broadcasting processing method. 6. The method of claim 5, wherein the equalization coefficient of step (b) is And an equalization coefficient in the frequency domain for minimizing the mean square error. The method of claim 5, wherein step (b) And interpolating the channel impulse response estimated in the known data section, estimating the channel impulse response in the section without known data, and converting the channel impulse response into a frequency domain. 8. The method of claim 7, wherein step (b) A digital broadcast processing method comprising dividing a plurality of sections between two known data sections located before and after a general data section and interpolating a channel impulse response of the known data section to estimate a channel impulse response for each section. . (a) receiving known data when the known data is inserted into general data and transmitting the same, and converting the received data into a frequency domain by overlapping the received data at a predetermined overlapping ratio; (b) compensating for channel distortion by multiplying the overlapped data transformed into the frequency domain by an equalization coefficient, converting the data into a time domain, and extracting and outputting valid data from the overlapped data of the time domain; And (c) an error is obtained by using the determined value of the equalized valid data and known data known to the receiving side, and zeros are added to the error according to the overlapping ratio, converted to the frequency domain, and the previous equalization coefficient is updated. And outputting to step (b). The method of claim 9, wherein step (c) And selecting a known value of equalized valid data in a general data section, and selecting known data in a known data section, and calculating an error by calculating a difference from the equalized valid data. (a) When a plurality of enhanced data packets having known data inserted therein are divided into N layered sections and transmitted, the input data is converted into a frequency domain according to the layer section information, or the input data is overlapped at a predetermined overlapping ratio. Converting to the frequency domain; (b) compensating for channel distortion by multiplying the data converted to the frequency domain by an equalization coefficient, and then converting the data to the time domain, and outputting the data of the time domain as equalized data as it is or according to the layer section information Extracting valid data and outputting the equalized data; (c) estimating the channel impulse response using the data received during the known data interval and known data known to the receiver, and calculating the average value of the estimated channel impulse responses of at least two consecutive known data intervals to convert them into the frequency domain. Then calculating an equalization coefficient; (d) obtaining an error using the determined value of the equalized data and known data known to the receiver, adding zeros to the error according to the overlap ratio, converting the frequency into a frequency domain, and updating a previous equalization coefficient. ; And (e) selecting one of the equalization coefficients calculated in step (c) and the equalization coefficients updated in step (d) according to the hierarchical section information, and providing the same to the step (b). Digital broadcasting processing method. The method of claim 11, wherein the N layered sections are At least a part of a section in which enhanced data can be continuously continuously output based on an output order after data interleaving among a plurality of enhanced data packets, wherein the second section is divided into first, second, and third sections. The entire enhanced data packet is divided to be included, and the first interval is divided into a portion that is output before the second interval in the plurality of enhanced data packets, and the third interval is divided into a portion that is output later. Digital broadcasting processing method. The method of claim 12, And a long known data stream is assigned to the second section, and a short known data stream is assigned to the first and third sections. The method of claim 12, If the input data is data of the second section, the step (a) converts the input data into the frequency domain as it is, and the step (b) outputs the data of the time domain as equalized data, and the step (e) and selecting the equalization coefficient calculated in step (c). The method of claim 12, If the input data is data of the first and third sections, step (a) converts the overlapped data into the frequency domain, and step (b) extracts valid data from the overlapped data of the time domain and outputs the equalized data. And (e) step selects the equalization coefficient updated in step (d). (a) converting the input data into a frequency domain by overlapping the input data at a predetermined overlapping rate when the plurality of enhanced data packets having known data inserted therein are divided into N layered sections and transmitted; (b) compensating for channel distortion by multiplying the data converted into the frequency domain by an equalization coefficient, converting the data into a time domain, and extracting and outputting valid data from overlapping data of the time domain; (c) estimating a channel impulse response using data received during the known data period and known data known to the receiver, converting the estimated channel impulse response into a frequency domain, and then calculating an equalization coefficient; (d) obtaining an error using the determined value of the equalized data and known data known to the receiver, adding zeros to the error according to the overlap ratio, converting the frequency into a frequency domain, and updating a previous equalization coefficient. ; And (e) selecting one of the equalization coefficients calculated in step (c) and the equalization coefficients updated in step (d) according to the hierarchical section information, and providing the same to the step (b). Digital broadcasting processing method. The method of claim 16, wherein step (c) And interpolating the channel impulse response estimated in the known data section, estimating the channel impulse response in the section without known data, and converting the channel impulse response into a frequency domain. The method of claim 16, wherein the N layered sections are At least a part or all of the sections in which enhanced data can be continuously continuously output based on an output order after data interleaving among a plurality of enhanced data packets is divided into first, second, and third sections. The enhanced data packet is divided to include the first interval, and the first interval is divided into a portion that is output earlier than the second interval in the plurality of enhanced data packets, characterized in that the third interval is divided into parts that are output later Digital broadcast processing method. 19. The method of claim 18, wherein step (e) If the input data is data of the second section, the equalization coefficient calculated in step (c) is selected, and if the data of the first and third sections is selected, the equalization coefficient updated in step (d) is selected. Broadcast processing method. A frequency domain converter which receives the known data string periodically inserted into the general data and transmits the received data stream, and converts the received data into the frequency domain; The channel impulse response is estimated using the data received during the known data interval and known data known to the receiver, and the average value of the channel impulse responses of the known data intervals located before and after the general data interval is obtained and converted into the frequency domain. A channel estimation and coefficient calculation unit for calculating and outputting a post equalization coefficient; A distortion compensator for compensating for channel distortion by multiplying the equalized coefficient by data converted from the frequency domain converter to the frequency domain; And And a time domain converter for converting data of the frequency domain compensated for the channel distortion into a time domain and outputting the data. 21. The apparatus of claim 20, wherein the channel estimation and coefficient calculation unit A channel equalizer of a digital broadcast receiving system, characterized in that it calculates an equalization coefficient in the frequency domain that minimizes the mean square error from the channel impulse response. A frequency domain converter which receives the known data after being inserted into the general data and transmits the received data, and converts the received data into a frequency domain by overlapping the received data at a preset overlap ratio; A channel estimation and coefficient calculation unit for estimating a channel impulse response using the received data during the known data interval and known data known to the receiver, converting the estimated channel impulse response into a frequency domain, and calculating and outputting an equalization coefficient. ; A distortion compensator for compensating for channel distortion by multiplying the equalization coefficient by the overlapping data converted from the frequency domain converter to the frequency domain; And And a time domain converter configured to convert overlapped data of the frequency domain compensated for the channel distortion into a time domain, and extract and output valid data from the overlapped data. 2. 23. The apparatus of claim 22, wherein the channel estimation and coefficient calculation unit A channel equalizer of a digital broadcasting reception system, characterized by interpolating a channel impulse response estimated in a known data section, estimating a channel impulse response in a section in which there is no known data, and converting it into a frequency domain. 24. The apparatus of claim 23, wherein the channel estimation and coefficient calculation unit A digital broadcast reception system comprising dividing a plurality of sections between two known data sections located before and after a general data section and interpolating a channel impulse response of the known data section to estimate a channel impulse response for each section. Channel equalizer. A frequency domain converter which receives the known data when inserted into the general data and transmits the received data, and converts the received data into a frequency domain by overlapping the received data at a preset overlap ratio; A distortion compensator for compensating for channel distortion by multiplying an equalization coefficient by the overlapping data transformed into the frequency domain; A time domain converter configured to convert the overlapped data compensated for the channel distortion into a time domain, and extract and output valid data from the overlapped data of the time domain; And The error is obtained by using the determined value of the equalized valid data and known data known to the receiving end, and the zero is added to the error according to the overlapping ratio, converted to the frequency domain, and the previous equalization coefficient is updated to compensate for the distortion. And a coefficient updating unit for outputting to a negative unit. The method of claim 25, wherein the coefficient update unit The channel equalizer of the digital broadcasting receiver system selects a determined value of equalized valid data in a general data section, and selects known data in a known data section, and calculates an error by calculating a difference from the equalized valid data. . When a plurality of enhanced data packets having known data inserted therein are divided into N layered sections and transmitted, the input data is transformed into a frequency domain according to the layer section information, or the input data is overlapped at a predetermined overlapping rate, thereby transmitting the frequency domain. A frequency domain converter for converting the frequency into a frequency band; A distortion compensator for compensating for channel distortion by multiplying data converted into the frequency domain by an equalization coefficient; The time for converting the data compensated for the channel distortion into the time domain, and outputting the data in the time domain as equalized data according to the hierarchical section information or extracting valid data from the overlapping data in the time domain as equalized data. A region converter; The channel impulse response is estimated using the data received during the known data interval and the known data known to the receiver. A first coefficient calculating unit for calculating a coefficient; A second coefficient calculating unit which obtains an error using the determined value of the equalized data and known data known to the receiver, adds zero to the error according to an overlap ratio, converts the frequency into a frequency domain, and then updates a previous equalization coefficient. ; And And a coefficient selector for selecting one of the equalization coefficient calculated by the first coefficient calculator and the equalized coefficient updated by the second coefficient calculator and outputting the equalization coefficient to the distortion compensator according to the hierarchical section information. Channel equalizer of the receiving system. 28. The method of claim 27, wherein the N layered sections are At least a part or all of the sections in which enhanced data can be continuously continuously output based on an output order after data interleaving among a plurality of enhanced data packets is divided into first, second, and third sections. The enhanced data packet is divided to include the first interval, and the first interval is divided into a portion that is output earlier than the second interval in the plurality of enhanced data packets, characterized in that the third interval is divided into parts that are output later Channel equalizer in digital broadcast reception systems. The method of claim 28, The long known data stream is assigned to the second section, and the short known data stream is assigned to the first and third sections. The method of claim 28, If the input data is data of the second section, the frequency domain converter converts the input data into the frequency domain, the time domain converter outputs the data of the time domain as equalized data, and the coefficient selector is calculated by the first coefficient calculator. Selecting the equalized coefficients. The method of claim 28, If the input data is data of the first and third sections, the frequency domain converter converts the overlapped data into the frequency domain, and the time domain converter extracts valid data from the overlapped data of the time domain and outputs the equalized data. The coefficient selector selects an equalization coefficient updated by the second coefficient calculator. A plurality of enhanced data packets having known data inserted therein, divided into N layered sections and transmitted, the frequency domain converting unit converting the input data into a frequency domain by overlapping the input data at a preset overlap ratio; A distortion compensator for compensating for channel distortion by multiplying data converted into the frequency domain by an equalization coefficient; A time domain converter configured to convert the overlapped data compensated for the channel distortion into a time domain, and extract and output valid data from the overlapped data of the time domain; A first coefficient calculator for estimating a channel impulse response using the data received during the known data interval and known data known to the receiver, converting the estimated channel impulse response into a frequency domain, and calculating an equalization coefficient; A second coefficient calculating unit which obtains an error using the determined value of the equalized data and known data known to the receiver, adds zero to the error according to an overlap ratio, converts the frequency into a frequency domain, and then updates a previous equalization coefficient. ; And And a coefficient selector which selects one of the equalization coefficient calculated by the first coefficient calculator and the equalized coefficient updated by the second coefficient calculator and outputs the equalization coefficient to the distortion compensator according to the hierarchical section information. Channel equalizer in broadcast reception system. 33. The apparatus of claim 32, wherein the first coefficient calculating unit A channel equalizer of a digital broadcasting reception system, characterized by interpolating a channel impulse response estimated in a known data section, estimating a channel impulse response in a section in which there is no known data, and converting it into a frequency domain. 33. The method of claim 32, wherein the N layered sections are At least a part or all of the sections in which enhanced data can be continuously continuously output based on an output order after data interleaving among a plurality of enhanced data packets is divided into first, second, and third sections. The enhanced data packet is divided to include the first interval, and the first interval is divided into a portion that is output earlier than the second interval in the plurality of enhanced data packets, characterized in that the third interval is divided into parts that are output later Channel equalizer in digital broadcast reception systems. The method of claim 34, wherein the coefficient selector If the input data is data of the second interval, the equalization coefficient calculated by the first coefficient calculation unit is selected, and if the data of the first and third intervals, the equalization coefficient updated by the second coefficient calculator is selected. Channel equalizer in broadcast reception system.

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