KR20100071874A - Terrestrial digital multimedia broadcasting software baseband receiver and the method for excuting the receiver - Google Patents

Abstract

PURPOSE: A T-DMB receiving device of the software base and a parallel data processing method of the receiving device are provided to improve the processing speed. CONSTITUTION: A digital signal processor traces the transmission mode information of the input signal. The digital signal processor processes the input signal according to the transmission mode information. The digital signal processor demodulates the input signal into the OFDM signal. An auxiliary processor performs time deinterleaving of the demodulated OFDM signal according to the transmission mode information of the input signal. A channel decoding unit(400) decodes the channel of the OFDM signal deinterleavered the time. The channel decoding revises an error.

Description

Software-based T-DM receiver and its operation method {TERRESTRIAL DIGITAL MULTIMEDIA BROADCASTING SOFTWARE BASEBAND RECEIVER AND THE METHOD FOR EXCUTING THE RECEIVER}

The present invention relates to a T-DMB receiving apparatus and a method of operating the same.

Terrestrial-Digital Multimedia Broadcasting (T-DMB) is a terrestrial digital multimedia broadcasting developed in Korea based on ITU-R's DSB System A (Eureka-147). By using the VHF band having a bandwidth of about 1.5 MHZ, a receiver traveling at a high speed of 200 km / h can receive video CD quality and CD quality stereo sound quality. T-DMB uses MPEG-4 AVC (Advanced Video Coding) video compressed data and MPEG-4 Bit-Sliced Audio Coding (BSAC) audio compression through the stream mode defined by the European Digital Audio Broadcasting (DAB) standard. MPEG-4 BIFS (Binary Format for Scenes) data for broadcasting data and interactive data is multiplexed into MPEG-4 SL (Sync Layer) and MPEG-2 Transport Stream (TS), and then added by RS and convolutional fitting. Send the stream with the error protection mechanism applied.

The T-DMB transmission frame is largely composed of a synchronization channel, a fast information channel (FIC), and a main service channel (MSC). The synchronization channel is an information channel field for transmission frame synchronization and includes a null symbol and a phase reference symbol (PRS). The null symbol is a section in which no data exists and distinguishes between a frame and a frame. PRS is a symbol that is a phase reference of the DQPSK method used in T-DMB, and plays a role of pilot data.

The receiver synchronizes the input OFDM signal using the null symbol and the PRS.

The fast information channel (FIC) is a channel including information for decoding frame data, and includes three OFDM symbols (information such as coding rate, data bit rate, and data position).

The main service channel (MSC) is a section in which a signal of an actual broadcast channel, that is, a video / audio / data channel is transmitted, and decodes desired data using a coding result of the FIC. Each MSC is composed of four CIFs, and one common interleaved frame (CIF) is composed of 18 OFDM symbols.

Among the terms used below, “ARM” is a general-purpose CPU that is suitable for processing general instructions such as a computer CPU.

1 is a block diagram showing the structure of a conventional T-DMB receiver.

As shown in FIG. 1, the T-DMB receiving apparatus 1000 includes an input terminal 100 and a DSP 200.

The input terminal 100 converts the RF signal received from the antenna into a baseband digital signal. To this end, the input stage 100 includes an RF tuner 110 and an ADC 120.

The RF tuner 110 receives an RF signal transmitted through a wireless channel through an antenna. The RF tuner 110 converts only an RF signal of a desired frequency band among the received RF signals into a signal of an intermediate frequency (IF) band.

The ADC 120 converts a signal of the intermediate frequency (IF) band into a baseband digital signal.

The DSP 200 processes the OFDM symbols of the T-DMB transmission frame and outputs them to the reproduction unit. It is stored in the common memory buffer 410 of the ARM 400. As another example, the DSP 200 processes an OFDM symbol of a T-DMB transmission frame and stores the OFDM symbol in an ARM common memory buffer, and stores the data stored in the ARM common memory buffer as a video / audio signal using a codec. Restore and play through the player.

To this end, the DSP 200 includes an input buffer 210, an initial synchronization unit 220, a synchronization tracking unit 230, a symbol demodulation unit 240, a time deinterleaver 250, an ARM 260, and a codec unit ( 270).

The input buffer 210 stores the digital signal input from the ADC 120.

The initial synchronization unit 220 performs an initial synchronization process for the digital signal. The initial synchronizer 220 estimates and compensates for a time offset and a frequency offset of an OFDM signal input through an OFDM reception channel.

The synchronization tracking unit 230 estimates and compensates for the time change amount and the frequency change amount of the OFDM signal that change over time.

The symbol demodulator 240 demodulates the OFDM signal estimated and compensated by the sync tracker 230 and outputs the demodulated OFDM signal to the time deinterleaver 250.

The time deinterleaver 250 performs a time deinterleaving process on the OFDM signal demodulated by the symbol demodulator 240. Thus, clustering errors that can occur in a wireless channel can be avoided. The time deinterleaver 250 stores the time interleaved OFDM signal in the channel decoder buffer 410 of the channel decoding unit 300.

The ARM 260 reads data stored in the channel decoder buffer 310 and processes the OFDM signal. For this purpose, the ARM 260 includes a shared memory buffer 261. Accordingly, the DSP 200 and the ARM 260 share the data stored in the common memory buffer 261 to perform a subsequent processing for reproducing the data.

The codec unit 270 restores data stored in the common memory buffer 261 to a video / audio signal using a codec to reproduce the data through a player.

The channel decoder 300 corrects an error of the OFDM signal stored in the channel decoder buffer 310 and stores the error in the common memory buffer 410 of the DSP 200 and the ARM 400. That is, the channel decoding unit 300 decodes the reception channel of the OFDM signal and corrects an error of the OFDM signal stored in the channel decoder buffer 310, and then, in the common memory buffer 410 of the DSP 200 and the ARM 400. Save it.

The conventional T-DMB receiver processes all the above-described processes using a DSP. Therefore, there is a difficulty in improving the processing speed of the T-DMB receiving apparatus.

The present invention has been made to solve the above-described problems, and an object thereof is to improve a processing speed of a T-DMB receiving apparatus and to reduce power consumption.

In order to achieve the above object, a T-DMB receiver for performing parallel data processing using EDMA according to an example of the present invention is an input terminal for converting an RF signal input from an antenna into a baseband digital signal, which is input from an input terminal. A mode search unit for estimating transmission mode information of the first digital signal, an initial synchronizer for estimating an offset of the first digital signal according to the transmission mode information, a transmission mode information of the first digital signal, and a first digital signal A synchronization tracker for estimating the offset of the second digital signal that changes over time using the offset, the transmission mode information of the first digital signal, and the offset of the second digital signal into the OFDM signal using the offset. A symbol demodulator for demodulating, time interleaving an OFDM signal according to transmission mode information, and decoding a channel of the interleaved OFDM signal. Correcting the errors, and W, and includes a channel decoder for storing the corrected OFDM signal to the memory buffer.

The modem control unit may further include a modem control unit configured to output the frame of the OFDM signal to the EDMA according to the transmission mode information.

The mode searcher estimates transmission mode information by measuring a length of a null symbol of the first digital signal through energy detection.

The offset of the first digital signal and the offset of the second digital signal mean a time offset and a frequency offset.

According to an embodiment of the present invention, a method of operating a T-DMB receiver includes converting an RF signal input from an antenna into a baseband digital signal, estimating transmission mode information of a first digital signal input from an input terminal, and transmitting Estimating an offset of the first digital signal according to mode information, and using a transmission mode information of the first digital signal and an offset of the first digital signal, the second digital signal that changes with time. Estimating an offset, demodulating the second digital signal into an OFDM signal using the transmission mode information of the first digital signal and the offset of the second digital signal, and temporally interleaving the OFDM signal according to the transmission mode information. Time interleaving) and decoding the channel of the interleaved OFDM signal to correct an error, and storing the corrected OFDM signal in a memory buffer. And a step.

According to the present invention, there is an effect of improving the processing speed of the T-DMB receiver and also reducing power consumption.

<Hereinafter to the part shown hereafter is content of the inventor's invention proposal. Those skilled in the art will clearly understand the present invention from the following invention proposal. 1, 2, and 3 in the proposal contents refer to FIGS. 5, 6, and 7 of the present specification.>

[Brief Description of Drawings]

1 is a structural diagram of a conventional T-DMB receiver

2 is a structural diagram of a parallel data processing based T-DMB receiver using EDMA

3 is an exemplary diagram for explaining parallel data processing using EDMA.

<Description of the symbols for the main parts of the drawings>

201: RF Tuner 202: Analog-to-Digital Converter (ADC)

203: input buffer 204: initial synchronization unit

205: mode search unit 206: synchronization tracking unit

207: modem control unit 208: symbol demodulation unit

209: time deinterleaving 210: channel decoding unit

Detailed description of the invention

[Purpose of invention]

        The present invention is a technique for improving the processing speed and reducing the amount of power consumed by changing the data processing structure to a parallel structure by performing a time-deinterleaving process of T-DMB implemented on a software basis using an auxiliary processor.

[Technical Field to which the Invention belongs and Prior Art in the Field]

      The present invention relates to a TDMB receiver structure for improving the processing speed by performing a time deinterleaving process using a sentry processor called EDMA (Enhanced Direct Memory Access).

      The existing receiver structure used in the T-DMB system is shown in FIG. In the conventional TDMB receiver structure, a radio signal transmitted through a radio channel is received using an antenna. The received RF data is converted into an intermediate frequency (IF) band only by a signal of a desired frequency band through the RF tuner 101 and converted into a baseband digital signal by the ADC 102. The digital signal is stored in the input buffer 103 and the initial synchronization unit 104 performs an initial synchronization process using the digital signal stored in the modem processor to estimate and compensate for the time and frequency offset by the wireless channel. The signal compensated for the time and frequency offset is estimated and compensated for the amount of change in time and frequency offset that changes over time through the sync tracker 105, and the data is demodulated through the OFDM signal demodulation process in the symbol demodulator 106. Is done. The demodulated data performs a time deinterleaving process to avoid clustering errors that may occur in a wireless channel in the time deinterleaver 107 and performs channel coding 108 to correct an error of the data. As such, the existing software-based TDMB receiver structure has all the processing in the DSP because the modem processing is performed through a series of processing, and it is difficult to improve the processing speed.

[Technical problem to be achieved]

In the present invention, by using the auxiliary processor to implement the time deinterleaving function of the TDMB receiver to reduce the calculation process that must be processed in the DSP. It also improves the processing speed by converting the processing process into a parallel structure so that the data of the transmission frame can be simultaneously processed by the coprocessor and the DSP.

   [Configuration of Invention]

Figure 2 is a diagram showing the structure of the TDMB receiver proposed in the present invention. Data received via the RF tuner 201 is converted into a digital signal through the ADC 202 and stored in the input buffer 203. The DSP estimates and compensates the time and frequency offsets in the initial synchronizer 204 using the stored input signal, and estimates and compensates the time and frequency offsets that change over time in the sync tracker 206. The signal demodulated with the time and frequency offset performs an OFDM data demodulation process in the symbol demodulator 208. The mode search unit 205 searches for the transmission mode of the currently input signal and informs the modem controller 207 of the transmission mode information of the input signal. The modem control unit 207 changes the modem's processing structure according to the retrieved transmission mode. There are three transmission modes in TDMB system. Frame length and composition vary according to transmission mode. In one frame, there are four CIFs in transmission mode 1, one CIF in transmission mode 2, and two CIFs in transmission mode 4. And one CIF has 24ms of data. (Transmission mode 3 is a transmission frame mode for satellite DMB.) Accordingly, the modem control unit 207 collects one frame in transmission mode 1, 4 frames in 2, and 2 frames in 4 to time dinterlaver 209. Put it as input. The reason why the modem controller 207 changes the input of the time deinterleaver 209 according to the transmission mode is that preparation time for initialization and configuration is required to perform an arbitrary function block using EDMA. Therefore, if the time deinterleaver (209) is called too frequently, it takes more time to prepare than the amount of improving the processing time using EDMA. Therefore, even if the transmission mode is changed, the time deinterleaver (209) is always called once every 4 CIF. To be possible. When the time deinterleaving process is completed using the EDMA, the channel decoding unit 210 performs the remaining channel coding process to end the modem processing.

3 is an exemplary diagram for explaining a data parallel processing structure using EDMA. EDMA is Enhanced Direct Memory Access, a device that reads or writes data directly to memory on behalf of a DSP. In addition, time deinterleaving is a process of mixing data in the time domain in order to avoid cluster error, and thus it is easy to implement using EDMA. In case of transmission mode 1, when the DSP completes the symbol demodulation process 301 of four CIFs of the current frame, the result is stored in the time deinterleaver buffer 302. In the meantime, the EDMA completes the initialization and configuration and performs the time deinterlaving process 303 using the data stored in the buffer. At the same time, the DSP starts modem processing of the next frame. When the EDMA completes the time deinterleaving process while processing the data of the next frame in the DSP, the result is stored in the channel decoding buffer 304 and the DSP performs the symbol demodulation process and then the channel decoding process using the output of the time deinterleaver (305). EDMA performs the time deinterleaving process of the next frame using the data stored in the time deinterleaver buffer. Therefore, unlike the existing TDMB receiver, the TDMB receiver structure proposed in the present invention does not need to perform a time deinterleaving process in the DSP, and the time waiting for the initialization and configuration of the auxiliary processing apparatus also uses a parallel structure to the next frame. By allowing the data to be preprocessed, it also reduces the processing time of the entire system and reduces the power consumed by the DSP.

   [Effects of the Invention]

        The TDMB receiver structure proposed by the present invention performs a time deinterleaver process using an auxiliary processing apparatus called EDMA and changes the data processing structure to a parallel structure, which reduces the computational complexity and reduces power consumption of the DSP, unlike a conventional TDMB receiver.

[Claims]

[Claim 1]

A structure and method for improving processing time and reducing power consumption by using an auxiliary processor in a T-DMB receiver structure implemented using a DSP.

[Claim 2]

A structure and method for implementing a time deinterleaver function block using a coprocessor in a T-DMB receiver structure implemented using a DSP.

[Claim 3]

In the T-DMB receiver structure implemented using DSP, a structure and method for processing data in parallel in order to implement a time deinterleaver function block using an auxiliary processor and to efficiently process it.

[Claim 4]

In the parallel processing of data using an auxiliary processor in a T-DMB receiver structure implemented using a DSP, a structure and a method for processing differently depending on a transmission mode through a modem controller.

Supplementary explanation for the contents of the proposal

<This is the content of the proposal.

<The following is a detailed description of the present invention made based on the foregoing invention proposal. Those skilled in the art will be able to understand the spirit of the present invention comprehensively from the above description and the following description.

The present invention implements a time deinterleaver using a sentry processor called Enhanced Direct Memory Access (EDMA). EDMA (Enhanced Direct Memory Access) is a device that reads or writes data directly to memory on behalf of a digital signal processor (DSP). Through this, the data processing structure is implemented in parallel so that the digital signal processor (DSP) processes the OFDM symbols of the next T-DMB transmission frame while performing the time deinterleaving process in the EDMA. Therefore, the digital signal processor (DSP) reduces the process of processing OFDM symbols of the T-DMB transmission frame, thereby improving processing speed and greatly reducing the amount of power consumed in processing the OFDM symbol.

Hereinafter, a software-based T-DMB receiver and an operation method thereof according to an example of the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram showing the structure of a T-DMB receiving apparatus according to an example of the present invention.

As shown in FIG. 2, the T-DMB receiver 1000 according to the present invention includes an input terminal 100, a DSP 200, an EDMA 300, and a channel decoding unit 400.

The input terminal 100 converts the RF signal received from the antenna into a baseband digital signal. To this end, the input stage 100 includes an RF tuner 110 and an ADC 120.

The RF tuner 110 receives the RF signal of the radio channel. The RF tuner 110 converts only an RF signal of a desired frequency band among the received RF signals into a signal of an intermediate frequency (IF) band.

The ADC 120 converts a signal of the intermediate frequency (IF) band into a baseband digital signal.

The DSP 200 processes the OFDM symbols of the T-DMB transmission frame and stores the OFDM symbols in the common memory buffer 271 of the DSP 200 and the ARM 270. In addition, the DSP 200 reconstructs the data stored in the common memory buffer 271 to a video / audio signal using a codec and reproduces the data through a player as a subsequent process.

To this end, the DSP 200 includes an input buffer 210, an initial synchronizer 220, a sync tracker 230, a symbol demodulator 240, a mode search unit 250, a modem controller 260, and an ARM ( 270 and a codec unit 280.

The input buffer 210 stores the digital signal input from the ADC 120.

The initial synchronizer 220 initially synchronizes the first digital signal read from the input buffer 210 using the transmission mode information of the first digital signal input from the modem controller 260. The initial synchronizer 220 estimates and compensates for a time offset amount and a frequency offset amount of the first digital signal and outputs the same to the sync tracer 230.

The synchronization tracking unit 230 may include the transmission mode information of the first digital signal estimated by the mode search unit 250 and the time offset and frequency variation amount of the first digital signal estimated by the initial synchronization unit 220. Frequency Offset is used to estimate and compensate for a time offset and a frequency offset of the second digital signal that is input differently from the input buffer 210 every time.

The symbol demodulator 240 demodulates the second digital signal input from the sync tracker 230 into an OFDM signal according to the transmission mode information of the first digital signal input from the modem controller 260. The symbol demodulator 240 stores the demodulated OFDM signal in the time deinterleaver buffer 310 of the EDMA 300.

The mode search unit 250 estimates a transmission mode using a null symbol of the first digital signal stored in the input buffer 210. The T-DMB transmission frame includes a null symbol for which no data exists. The length of the null symbol varies depending on the transmission mode of the T-DMB transmission frame input from the transmitter. Therefore, the mode search unit 250 estimates the transmission mode of the digital signal currently input to the receiver by measuring the length of the null symbol through energy detection.

The transmission mode depends on the network environment in which it is applied. Transmission mode 1 is applied in the band 375MHZ or less (Band I ~ III), transmission mode 2 is applied in the band 750MHZ or less (Band I ~ V, L Band). Transmission mode 4 is applied in the band below 1.5GHZ. Since transmission mode 3 is applied to the satellite system, it is omitted in the present invention. For reference, the transmission mode 1 is applied to the T-DMB system currently being serviced in Korea.

Looking at each transmission mode, one frame of the transmission mode 1 is composed of four CIF Common Interleaved Frame (CIF), one frame of the transmission mode 2 is composed of one CIF. In addition, one frame of transmission mode 4 is composed of two CIFs. Here, each CIF consists of an OFDM symbol of 24 ms.

The modem controller 260 controls each block to differently process the second digital signal input from the input buffer 210 according to the transmission mode information of the first digital signal estimated by the mode search unit 250. That is, the modem controller 260 outputs a transmission frame of the first digital signal input from the input buffer 210 differently according to the transmission mode information of the first digital signal estimated by the mode search unit 250 to function of each block. To control.

The modem controller 260 differently outputs the frame of the digital signal to the EDMA 300 according to the transmission mode of the digital signal estimated by the mode search unit 250. The reason for differently outputting the frame of the digital signal according to the transmission mode of the digital signal is that the EDMA 300 requires a waiting time for initialization and configuration for its processing operation. Thus, calling EDMA 300 too often takes longer than the benefit of time savings. In order to solve this problem, the present invention is implemented such that the EDMA 300 is always called once every four CIFs to operate.

The ARM 270 processes the OFDM signal by reading data stored in the channel decoder buffer 410. To this end, the ARM 270 includes a shared memory buffer 271. Accordingly, the DSP 200 and the ARM 270 share data stored in the common memory buffer 271 to perform a subsequent processing for reproducing the data.

The codec unit 280 restores data stored in the common memory buffer 271 to a video / audio signal using a codec and reproduces the data through a player.

The channel decoding unit 400 corrects an error of the OFDM signal time-deinterleaved by the EDMA 300 and stores the error in the common memory buffer 271 of the ARM 270. That is, the channel decoding unit 400 decodes the reception channel of the OFDM signal to correct an error of the OFDM signal, and stores the same in the common memory buffer 271 of the DSP 200 and the ARM 270.

The EDMA 300 reads the OFDM signal stored in the time deinterleaver buffer 310 according to the transmission mode input from the modem controller 260 and performs the time deinterleaving process. Here, time deinterleaving is a process of mixing OFDM signals in the time domain to avoid clustering errors.

The EDMA 300 stores the time interleaved OFDM signal in the channel decoding unit 400 of the channel decoding unit 400.

3 is a block diagram illustrating a process in which a T-DMB receiving apparatus performs parallel data processing using EDMA according to an embodiment of the present invention.

The digital signal processor (DSP) 200 reads T-DMB transmission frames stored in the input buffer. The DSP 200 demodulates OFDM symbols of four CIFs (CIF1n, CIF2n, CIF3n, and CIF4n) constituting each main service channel (MSC) of a T-DMB transmission frame, and then decodes the time deinterleaver buffer 310. ). That is, the DSP 200 demodulates the nth CIF and stores the demodulated data in the time deinterleaver buffer 310.

At this time, the EDMA 300 performs a time deinterlaving process by reading the n−1 th CIF stored in the time deinterleaver buffer 310 while the DSP 200 demodulates the n th CIF. That is, while the DSP 200 demodulates the CIF of the currently input OFDM signal, the EDMA 300 reads the CIF previously demodulated and stored in the time deinterleaver buffer 310 to perform time deinterleaving ( Time deinterlaving) process is performed.

Therefore, the CIF demodulation process in the DSP 200 and the time deinterleaving process in the EDMA 300 are simultaneously performed. That is, when the DSP 200 completes the demodulation process for the n th CIF, the n-1 th CIF in which the time deinterleaving process is completed in the EDMA 300 is stored in the channel decoder buffer 410.

The channel decoding unit 400 reads the n−1 th CIF in which the time deinterleaving process is completed from the channel decoder buffer 410 and then performs channel decoding to correct an error of the OFDM signal. The channel decoding unit 400 stores the error-corrected OFDM signal in the common memory buffer 271 of the DSP 200 and the ARM 270.

Accordingly, the T-DMB receiver according to the present invention does not need to perform a time deinterleaving process in the DSP 200 unlike the conventional T-DMB receiver. In addition, by processing the OFDM signal using the DSP 200 and the EDMA 300 simultaneously, the processing time of the T-DMB receiver is reduced, and the power consumed by the DSP is also reduced.

4 is a flowchart illustrating a process in which a T-DMB receiving apparatus performs parallel data processing using EDMA according to an embodiment of the present invention.

The input terminal 100 converts the RF signal received from the antenna into a baseband digital signal and stores it in the input buffer 210 of the DSP 200 (S401).

The mode search unit 250 estimates a transmission mode using a null symbol of the first digital signal stored in the input buffer 210 (S402). The T-DMB transmission frame includes a null symbol for which no data exists. The length of the null symbol varies depending on the transmission mode of the T-DMB transmission frame input from the transmitter. Therefore, the mode search unit 250 estimates the transmission mode of the digital signal currently input to the receiver by measuring the length of the null symbol through energy detection.

The initial synchronizer 220 initially synchronizes the first digital signal read from the input buffer 210 using the transmission mode information of the first digital signal input from the modem controller 260 (S403). The initial synchronizer 220 estimates and compensates for a time offset amount and a frequency offset amount of the first digital signal and outputs the same to the sync tracer 230.

The sync tracker 230 transmits the transmission mode information of the first digital signal estimated by the mode search unit 250 and the time offset and frequency variation of the first digital signal estimated by the initial synchronizer 220. The offset is used to estimate and compensate for a time offset amount and a frequency offset amount of the second digital signal that are input differently from the input buffer 210 at every time (S404).

The symbol demodulator 240 demodulates the second digital signal input from the synchronization tracking unit 230 into an OFDM signal according to the transmission mode information of the first digital signal input from the modem controller 260 (S405). The symbol demodulator 240 stores the demodulated OFDM signal in the time deinterleaver buffer 310 of the EDMA 300 (S406).

The EDMA 300 reads an OFDM signal stored in the time deinterleaver buffer 310 according to the transmission mode input from the modem controller 260 and performs a time deinterleaving process (S407). Here, time deinterleaving is a process of mixing OFDM signals in the time domain to avoid clustering errors. The EDMA 300 stores the time interleaved OFDM signal in the channel decoding unit 400 of the channel decoding unit 400.

The channel decoding unit 400 corrects an error of the OFDM signal time-deinterleaved by the EDMA 300 and stores the error in the common memory buffer 271 of the ARM 270 (S408). That is, the channel decoding unit 400 decodes the reception channel of the OFDM signal to correct an error of the OFDM signal, and stores the same in the common memory buffer 271 of the DSP 200 and the ARM 270.

The parallel data processing method of the T-DMB receiving apparatus using the EDMA according to the present invention can be implemented in the form of program instructions that can be executed by various computer means and recorded in a computer readable medium. The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. Program instructions recorded on the media may be those specially designed and constructed for the purposes of the present invention, or they may be of the kind well-known and available to those having skill in the computer software arts. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tape, optical media such as CD-ROMs, DVDs, and magnetic disks, such as floppy disks. Magneto-optical media, and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include machine code, such as that produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter. The hardware device described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

In the present invention as described above has been described by the specific embodiments, such as specific components and limited embodiments and drawings, but this is provided to help a more general understanding of the present invention, the present invention is not limited to the above embodiments. For those skilled in the art, various modifications and variations are possible from such description.

Therefore, the spirit of the present invention should not be limited to the described embodiments, and all of the equivalents or equivalents of the claims as well as the claims to be described later will belong to the scope of the present invention. .

The invention described above can be represented in the form of claims as follows. In the future, claims will be added by amendment based on the invention proposal contents and the detailed description of the invention.

[Patent Claims]

[Claim 1]

An input stage for converting an RF signal input from an antenna into a baseband digital signal;

A mode searching unit estimating transmission mode information of a first digital signal input from the input terminal;

An initial synchronizer for estimating an offset of the first digital signal according to the transmission mode information;

A synchronization tracking unit estimating an offset of a second digital signal that changes over time using transmission mode information of the first digital signal and an offset of the first digital signal;

A symbol demodulator for demodulating the second digital signal into an OFDM signal using transmission mode information of the first digital signal and an offset of the second digital signal;

Enhanced Direct Memory Access (EDMA) for time interleaving the OFDM signal according to the transmission mode information; And

A channel decoding unit to correct an error by decoding the channel of the interleaved OFDM signal, and to store the corrected OFDM signal in a memory buffer

T-DMB receiver comprising a.

[Claim 2]

The method of claim 1,

A modem control unit for controlling the EDMA to process the frame of the OFDM signal according to the transmission mode information

T-DMB receiver further comprising.

[Claim 3]

The method of claim 1,

The mode search unit,

And a T-DMB receiving apparatus for estimating the transmission mode information by measuring a length of a null symbol of the first digital signal through energy detection.

[Claim 4]

The method of claim 1,

The offset of the first digital signal and the offset of the second digital signal is a time offset and a frequency offset (Frequency Offset).

[Claim 5]

Converting an RF signal input from an antenna into a baseband digital signal;

Estimating transmission mode information of a first digital signal input from the input terminal;

Estimating an offset of the first digital signal according to the transmission mode information;

Estimating an offset of a second digital signal that changes over time using transmission mode information of the first digital signal and an offset of the first digital signal;

Demodulating the second digital signal into an OFDM signal using transmission mode information of the first digital signal and an offset of the second digital signal;

Time interleaving the OFDM signal according to the transmission mode information; And

Decoding the channel of the interleaved OFDM signal to correct an error and storing the corrected OFDM signal in a memory buffer

Operation method of the T-DMB receiving apparatus comprising a.

[Claim 6]

A computer-readable recording medium having recorded thereon a computer program for executing each step of the method of operating a T-DMB receiving apparatus according to claim 5 on a computer.

1 is a block diagram showing the structure of a conventional T-DMB receiver.

2 is a block diagram showing the structure of a T-DMB receiving apparatus according to an example of the present invention.

3 is a block diagram illustrating a process in which a T-DMB receiving apparatus performs parallel data processing using EDMA according to an embodiment of the present invention.

4 is a flowchart illustrating a process in which a T-DMB receiving apparatus performs parallel data processing using EDMA according to an embodiment of the present invention.

<Explanation of symbols on main parts of the drawings>

110: RF tuner, 240: mode search unit

120: ADC 250: modem control unit

130: input buffer, 270: ARM

210: initial synchronization unit, 280: codec unit

220: synchronization tracking unit 300: EDMA

230: symbol demodulation unit 400: channel decoding unit

Claims (17)

An input stage for converting an input signal received from an antenna into a baseband digital signal and storing the input signal in an input buffer; A digital signal processor for tracking transmission mode information of the input signal and processing the input signal according to the transmission mode information to demodulate an OFDM signal; An auxiliary processor for time deinterleaving the demodulated OFDM signal according to the transmission mode information of the input signal; And A channel decoding unit to correct an error by decoding the channel of the time deinterleaved OFDM signal T-DMB receiver comprising a. The method of claim 1, The digital signal processor, An input buffer for storing an input signal received from the input terminal; A modem controller for estimating transmission mode information of an input signal stored in the input buffer; An initial synchronizer configured to estimate and compensate for a time variation amount and a frequency variation amount of the input signal according to the transmission mode information of the input signal; A synchronization tracking unit for tracking and compensating for a time variation amount and a frequency variation amount of the input signal that change as time passes by using transmission mode information of the input signal; And A symbol demodulator for demodulating the input signal into an OFDM signal according to the transmission mode information of the input signal T-DMB receiver comprising a. The method of claim 2, The modem control unit, And a T-DMB receiver which estimates the transmission mode information by measuring a length of a null symbol of the input signal using an energy detection algorithm. The method of claim 2, The modem control unit, And an initial synchronization unit, the synchronization tracking unit, and the symbol demodulator to process the input signal in units of predetermined transmission frames according to the transmission mode information of the input signal. The method of claim 2, The modem control unit, T-DMB receiving apparatus for controlling the sub-processor to time-deinterleaving the demodulated OFDM signal in units of a predetermined transmission frame according to the transmission mode information of the input signal. The method of claim 2, The modem control unit, T-DMB receiving apparatus for controlling the auxiliary processor to bundle and process the transmission frame of the input signal in a predetermined Common Interleaved Frame (CIF) unit according to the transmission mode information of the input signal. The method of claim 5, The auxiliary processor, The OFDM signal input from the symbol demodulator is stored in a time deinterleaver buffer, And a digital signal processor for processing a current input signal stored in an input buffer while the digital signal processor reads an input signal previously processed from the time deinterleaver buffer. The method of claim 5, The digital signal processor stores the OFDM signal processed by the channel decoding unit in a common memory buffer of the ARM, The ARM is a T-DMB receiver which is a general purpose CPU (central processing unit). The method of claim 8, The ARM, And a post-processing process for reproducing the OFDM signal stored in the common memory buffer. (a) converting an input signal received from the antenna into a baseband digital signal and storing it in an input buffer; (b) tracking transmission mode information of the input signal, processing the input signal according to the transmission mode information, and demodulating the OFDM signal into an OFDM signal; (c) time deinterleaving the demodulated OFDM signal according to the transmission mode information of the input signal; And (d) correcting an error by decoding a channel of the time deinterleaved OFDM signal Parallel data processing method of the T-DMB receiving apparatus comprising a. The method of claim 10, In step (b), (a ”) storing the input signal received from the antenna; (b ”) estimating a transmission mode of the input signal stored in the input buffer; estimating and compensating for the time variation and the frequency variation of the input signal according to the transmission mode of the input signal; (d ”) tracking and compensating for a time variation amount and a frequency variation amount of the input signal that change with time according to the transmission mode of the input signal; And (e ”) demodulating the input signal into an OFDM signal according to the transmission mode of the input signal Parallel data processing method of the T-DMB receiving apparatus comprising a. The method of claim 11, Step (b ”), And a method of estimating the transmission mode information by measuring a length of a null symbol of the input signal using an energy detection algorithm. The method of claim 11, Step (b ”), A step of controlling the steps (c ”), (d”) and (e ”) to process the input signal in units of predetermined transmission frames according to the transmission mode information of the input signal. Parallel data processing. The method of claim 11, Step (b ”), And controlling step (c) to time-deinterleave the demodulated OFDM signal in units of predetermined transmission frames according to the transmission mode information of the input signal. The method of claim 11, Step (b ”), And (c) controlling step (c) to bundle and process a transmission frame of the input signal in a predetermined Common Interleaved Frame (CIF) unit according to the transmission mode information of the input signal. The method of claim 14, Step (c) is, Storing the OFDM signal input in the step (e ”) in a time deinterleaver buffer; And While the current input signal stored in the input buffer is processed in step (c), the input signal previously processed in step (c) is read from the time deinterleaver buffer and processed. Parallel data processing method of the T-DMB receiving apparatus comprising a. A computer-readable recording medium having recorded thereon a computer program for executing each step of a parallel data processing method of a T-DMB receiving apparatus according to any one of claims 10 to 16.

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