KR102600547B1 - Apparatus for analyzing transmitter identification signal and method using the same - Google Patents

Abstract

A transmission identifier signal analysis device and method using the same are disclosed. A transmission identifier signal analysis device according to an embodiment of the present invention includes a demodulator for decoding a bootstrap corresponding to a received signal; a cancellation unit that performs a host signal cancellation process on the received signal to generate a canceled received signal; a correlator that calculates a correlation value between a signal corresponding to the canceled received signal and a sequence corresponding to a transmitter identification (TxID) signal; and a TxID profile analyzer that generates channel information between a transmitter and a receiver corresponding to the transmission identifier signal using the correlation value.

Description

Transmission identifier signal analysis device and method using the same {APPARATUS FOR ANALYZING TRANSMITTER IDENTIFICATION SIGNAL AND METHOD USING THE SAME}

The present invention relates to transmission/reception technology for transmission identifier signals in broadcasting systems, and particularly to a transmission/reception system for transmission identifier signals suitable for next-generation broadcast communication systems.

First-generation digital terrestrial TV broadcasting generates co-channel interference three times the service radius, so the same frequency cannot be reused in areas within three times the service radius.

Like this, the area where the same frequency cannot be reused is called white space, and the occurrence of white space greatly reduces spectral efficiency.

Therefore, in order to improve spectral efficiency, there is a need to develop transmission technology that can guarantee reception robustness while increasing transmission capacity. Recently, the ATSC 3.0 physical layer standard (A/322) was established, which facilitates frequency reuse, does not generate white space, and makes it easy to build and operate a single frequency network.

The ATSC 3.0 physical layer standard defines a transmitter identification (TxID) technology to identify each transmitter in a single frequency network. Using this TxID technology, signals from each transmitter can be distinguished in a single frequency network, and through this, detailed information about the channel profile for building an optimal single frequency network can be obtained.

The purpose of the present invention is to enable a receiver to identify a transmitter using a transmitter identification (TxID) signal transmitted by the transmitter in a next-generation broadcasting system.

Additionally, the purpose of the present invention is to provide a transmission identifier reception technology suitable for next-generation standards such as ATSC 3.0.

Additionally, the purpose of the present invention is to efficiently detect a transmission identifier signal injected into a host broadcast signal such as a host ATSC 3.0 signal and obtain accurate network configuration information by precisely analyzing the detected transmission identifier signal.

A transmission identifier signal analysis device according to the present invention for achieving the above object includes a demodulator for decoding a bootstrap corresponding to a received signal; a cancellation unit that performs a host signal cancellation process on the received signal to generate a canceled received signal; a correlator that calculates a correlation value between a signal corresponding to the canceled received signal and a sequence corresponding to a transmitter identification (TxID) signal; and a TxID profile analyzer that generates channel information between a transmitter and a receiver corresponding to the transmission identifier signal using the correlation value.

At this time, the transmission identifier signal analysis device may further include an ensemble averaging unit that performs averaging on frame signals corresponding to the canceled received signal.

At this time, the host signal cancellation process may cancel the cancellation signal corresponding to the preamble pilot included in the host broadcast signal from the received signal.

At this time, the host signal cancellation process may cancel the cancellation signal corresponding to the entire host broadcast signal from the received signal.

At this time, the cancellation signal may be generated using at least a portion of the preamble restored through preamble decoding including channel decoding, and a preamble pilot regenerated using the bootstrap.

At this time, the cancellation signal may be generated using a hard decision restoration signal generated by re-modulating the restoration bits restored through hard decision and a preamble pilot regenerated using the bootstrap.

At this time, the modulation may be QPSK (Quadrature Phase Shift Keying).

At this time, averaging is performed using the correlation value, and the signal corresponding to the canceled received signal may be the canceled received signal.

At this time, averaging is performed using the canceled received signal, and a signal corresponding to the canceled received signal may be a signal generated through the averaging.

At this time, the preamble pilot can be generated using the preamble_structure field included in the bootstrap.

In addition, a method for analyzing a transmission identifier signal according to an embodiment of the present invention includes the steps of decoding a bootstrap corresponding to a received signal; generating a canceled received signal by performing a host signal cancellation process on the received signal; calculating a correlation value between a signal corresponding to the canceled received signal and a sequence corresponding to a transmitter identification (TxID) signal; and generating channel information between a transmitter and a receiver corresponding to the transmission identifier signal using the correlation value.

At this time, the transmission identifier signal analysis method may further include performing averaging on frame signals corresponding to the canceled received signal.

At this time, the host signal cancellation process may cancel the cancellation signal corresponding to the preamble pilot included in the host broadcast signal from the received signal.

At this time, the host signal cancellation process may cancel the cancellation signal corresponding to the entire host broadcast signal from the received signal.

At this time, the cancellation signal may be generated using at least a portion of the preamble restored through preamble decoding including channel decoding, and a preamble pilot regenerated using the bootstrap.

At this time, the cancellation signal may be generated using a hard decision restoration signal generated by re-modulating the restoration bits restored through hard decision and a preamble pilot regenerated using the bootstrap.

At this time, the modulation may be QPSK (Quadrature Phase Shift Keying).

At this time, averaging is performed using the correlation value, and the signal corresponding to the canceled received signal may be the canceled received signal.

At this time, averaging is performed using the canceled received signal, and a signal corresponding to the canceled received signal may be a signal generated through the averaging.

At this time, the preamble pilot can be generated using the preamble_structure field included in the bootstrap.

According to the present invention, a receiver can identify a transmitter using a transmitter identification (TxID) signal transmitted by the transmitter in a next-generation broadcasting system.

Additionally, the present invention can provide transmission identifier reception technology suitable for next-generation standards such as ATSC 3.0.

In addition, the present invention can efficiently detect a transmission identifier signal injected into a host broadcast signal such as a host ATSC 3.0 signal and obtain accurate network configuration information by precisely analyzing the detected transmission identifier signal.

In addition, the present invention detects a transmission identifier signal for identifying each transmitter in a single frequency network, and can determine the optimal degree of adjustment for transmission power and transmission time for configuring a single frequency network.

Figure 1 is a block diagram showing an example of a broadcast signal transmission device using a transmission identifier signal according to an embodiment of the present invention.
Figures 2 to 4 are diagrams showing examples of transmission identifier signals inserted into the first preamble symbol period.
Figure 5 is a block diagram showing an example of a TxID code generator for generating a transmission identifier signal according to an embodiment of the present invention.
Figure 6 is a block diagram showing an example of a transmission identifier signal analysis device according to an embodiment of the present invention.
Figure 7 is a block diagram showing an example of a TxID transmission system considering the characteristics of the preamble signal.
Figure 8 is a graph showing TxID detection performance according to the randomness of the host broadcast signal.
Figure 9 is a block diagram showing another example of a transmission identifier signal analysis device according to an embodiment of the present invention.
Figure 10 is a block diagram showing another example of a transmission identifier signal analysis device according to an embodiment of the present invention.
FIG. 11 is a block diagram showing an example of the cancellation unit shown in FIGS. 9 and 10.
Figure 12 is a block diagram showing another example of the cancellation unit shown in Figures 9 and 10.
Figure 13 is a block diagram showing another example of the cancellation unit shown in Figures 9 and 10.
Figure 14 is an operation flowchart showing an example of a transmission identifier signal analysis method according to an embodiment of the present invention.
Figure 15 is a diagram showing an example of a plurality of ATSC 3.0 received signals including different TxID signals.
Figure 16 is a diagram showing an example of ATSC 3.0 pilot-based channel estimation.
Figure 17 is a diagram showing an example of a received signal after host broadcast signal cancellation is applied.
Figure 18 is a diagram showing an example of channel estimation using the target TxID signal remaining after applying host broadcast signal preamble cancellation.
Figure 19 is a graph showing the TxID signal detection performance of the transmission identifier signal analysis device according to an embodiment of the present invention.
Figure 20 is a diagram showing a computer system according to an embodiment of the present invention.

The present invention will be described in detail with reference to the attached drawings as follows. Here, repeated descriptions, known functions that may unnecessarily obscure the gist of the present invention, and detailed descriptions of configurations are omitted. Embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art. Accordingly, the shapes and sizes of elements in the drawings may be exaggerated for clearer explanation.

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the attached drawings.

A transmitter identification (TxID) uniquely identifies each individual transmitter transmitting a broadcast signal in a broadcasting system.

Identification is achieved by RF watermarking, enabling system monitoring, measurement, interference source determination, geolocation and other applications. One specific use of the TxID signal is to enable independent measurement of the channel impulse response components of each transmitter to support in-service system adjustments, including the power level and delay offset of each individual transmitter. will be. This channel impulse response information can be measured with special monitoring equipment, but does not need to be processed by a general broadcast communications receiver, such as an ATSC 3.0 receiver. That is, in these receivers, the TxID signal can be treated as a small amount of noise in the broadcast communication waveform.

Figure 1 is a block diagram showing an example of a broadcast signal transmission device using a transmission identifier signal according to an embodiment of the present invention.

Referring to FIG. 1, a broadcast signal transmission device using a transmission identifier signal according to an embodiment of the present invention includes an input formatting unit 110, a BICM unit 120, a frame builder 130, a waveform generator 140, and a transmission It includes an identifier signal generator 150 and a combiner 160.

The input formatting unit 110, BICM unit 120, frame builder 130, and waveform generator 140 shown in FIG. 1 may be components of a general broadcast signal transmission device. In other words, the transmission identifier signal generator 150 and the combiner 160 can be added to the components of a general broadcast signal transmission device to create a broadcast signal transmission device that transmits a transmission identifier signal.

The input formatting unit 110 performs one or more of data encapsulation, data compression, baseband formatting, and scheduling. That is, the input formatting unit 110 receives data packets and generates an output packet that conforms to a preset protocol. At this time, baseband formatting may include baseband packet construction, baseband packet header addition, and baseband packet scrambling.

The BICM unit 120 may perform BICM encoding. Generally, a BICM (Bit-Interleaved Coded Modulation) device consists of an error correction encoder, a bit interleaver, and a symbol mapper, and the BICM unit 120 may also include an error correction encoder, a bit interleaver, and a symbol mapper. In particular, the error correction encoder (CORE LAYER FEC ENCODER, ENHANCED LAYER FEC ENCODER) may be a series combination of a BCH encoder and an LDPC encoder, respectively. At this time, the input of the error correction encoder is input to the BCH encoder, the output of the BCH encoder is input to the LDPC encoder, and the output of the LDPC encoder can be the output of the error correction encoder.

The frame builder 130 can create a broadcast signal frame. At this time, the frame builder 130 may perform one or more of time interleaving and frequency interleaving.

The waveform generator 140 generates a host broadcast signal such as an ATSC 3.0 signal. At this time, the waveform generator 140 performs pilot insertion, MISO predistortion, IFFT, PAPR (Peak-to-Average-Power-Reduction), guard interval insertion, and bootstrap free. One or more of the fixings can be performed.

The transmission identifier signal generator 150 generates a transmission identifier signal to identify the transmitter. At this time, the transmission identifier signal generator 350 may be scaled using an injection level code.

At this time, the injection level code consists of 4 bits and can be assigned to injection level values set at 3dB intervals.

At this time, the injection level values cover the range from 9.0 dB to 45.0 dB and may include a value corresponding to the case where the transmission identifier signal is not output.

At this time, the injection level code may be assigned “0000” in case the transmission identifier signal is not output.

At this time, the injection level code lowers the power of the transmission identifier signal compared to the host broadcast signal by the first level than the injection level value corresponding to lowering the power of the transmission identifier signal compared to the host broadcast signal by the first level. When lowering the second level higher than the level, the injection level value may be preferentially assigned.

The combiner 160 injects the transmission identifier signal into the host broadcasting signal in the time domain, so that the transmission identifier signal is transmitted in synchronization with the host broadcasting signal.

Accordingly, the broadcast signal transmission device shown in FIG. 1 is transmitted over-the-air (OTA) including a TxID that identifies the transmitter. At this time, the transmission identifier signal may be a Direct Sequence Buried Spread Spectrum (DSBSS) RF watermark signal that carries a unique Gold code sequence.

Each transmission identifier signal (TxID signal) is inserted into the host broadcast signal in the time domain and transmitted in synchronization with the host broadcast signal.

The transmit identifier signal carries a gold code sequence that is unique to each transmitter on a given RF channel within the largest possible geographic region and is transmitted only within the first preamble symbol period. .

The TxID signal is a signal generated based on the gold code sequence and can be uniquely assigned to each transmitter.

Figures 2 to 4 are diagrams showing examples of transmission identifier signals inserted into the first preamble symbol period.

2 to 4, the transmission identifier signal is added at a reduced level compared to emissions from the particular transmitter.

At this time, the transmission identifier signal may be transmitted in the first preamble symbol period including the guard interval after bootstrapping of the host broadcast signal. In this case, since the transmission identifier signal is not added to the bootstrap, the detection performance of the bootstrap is not deteriorated.

The signal corresponding to the first bit of the transmission identifier (sequence or pattern) is output in synchronization with the first sample of the first preamble symbol including that symbol's guard interval. , the second bit of the transmission identifier signal may be output in synchronization with the second sample of the first preamble symbol including the guard interval. At this time, the bits of the transmission identifier signal may be modulated.

Referring to FIG. 2, when an 8K FFT preamble symbol is used, a transmission identifier sequence with a length of 8191 bits can be output once per frame.

Referring to FIG. 3, when a 16K FFT preamble symbol is used, a transmission identifier sequence with a length of 8191 bits may be repeated twice within the first preamble symbol period to output a sequence with a total length of 16382 bits.

At this time, in order to average out DC components, the second transmission identifier sequence may have an opposite polarity to the first transmission identifier sequence.

Referring to FIG. 4, when a 32K FFT preamble symbol is used, a transmission identifier sequence with a length of 8191 bits may be repeated four times within the first preamble symbol period to output a sequence with a total length of 32764 bits.

At this time, the second and fourth transmission identifier sequences may have opposite polarities to the first transmission identifier sequence, and the third transmission identifier sequence may have the same polarity as the first transmission identifier sequence.

That is, when the transmission identifier sequence is repeated, the even-numbered sequence may have an opposite polarity to the odd-numbered sequence.

At this time, the FFT size can be identified by the preamble_structure of the bootstrap.

That is, in a situation where the length of the preamble symbol is different for each FFT size, TxID can be inserted repeatedly in a long FFT size in order to insert as much TxID signal as possible into the first preamble.

Figure 5 is a block diagram showing an example of a TxID code generator for generating a transmission identifier signal according to an embodiment of the present invention.

Referring to FIG. 5, the TxID code generator for generating a transmission identifier signal according to an embodiment of the present invention includes a pair of shift register units that have specific feedback arrangements and are set to a preset value at a specific time. You can see that a code sequence is created using . That is, the TxID code generator shown in FIG. 5 can be viewed as a gold sequence generator. At this time, the gold sequence may be a type of pseudo random noise (PN) sequence.

Two shift register units (Tier 1 and Tier 2) used to generate a transmission identifier sequence transmitted by a transmission identifier signal may be preloaded during a specific setup interval. The combined output of the two shift register units can be sent to the BPSK modulator for insertion and transmission into the host broadcast signal.

As shown in FIG. 5, the two shift register units can be defined by the following generator polynomial.

- Tier 1 Generator Polynomial: x ¹³ + x ⁴ + x ³ + x + 1

- Tier 2 Generator Polynomial: x ¹³ + x ¹² + x ¹⁰ + x ⁹ + x ⁷ + x ⁶ + x ⁵ + x + 1

Each of the two shift register units must be preloaded prior to generating the transmission identifier sequence for each frame.

At this time, the registers of the Tier 1 register unit may be preloaded with only the x stage as 1, and all other stages may be preloaded with 0.

At this time, the registers of the Tier 2 register unit can be preloaded by the 13-bit value txid_address corresponding to the transmitter. That is, a 13-bit txid_address can be preloaded from the x ¹³ to x ¹ stages of the tier 2 shift register unit. At this time, msb of txid_address may correspond to the x ¹³ register of the tier 2 register part, and lsb of txid_address may correspond to the x register of the tier 2 register part.

The txid_address value is uniquely assigned to each transmitter in a given RF channel and can be used by the scheduler that controls each transmitter.

Table 1 below is a table showing preloading values of registers of the TxID code generator shown in FIG. 5.

Tier 1 Tier 2 0 0 0 0 0 0 0 0 0 0 0 0 One

In Table 1, the values indicated by t correspond to the corresponding bits of the txid_address field, where t ¹³ represents msb and t ¹ represents lsb.

According to Table 1, the transmission identifier sequence (TxID sequence) has a length of 2 ¹³ -1 = 8191 bits, and the total number of sequences that can be assigned to each transmitter is 2 ¹³ = 8192.

The generated gold code sequence can be BPSK modulated before being inserted into the host broadcast signal symbol (ATSC 3.0 preamble). If the generated sequence bit is '0', it can be modulated to '-1', and if the generated sequence bit is '1', it can be modulated to '+1'. Because it is modulated with BPSK, the BPSK modulated transmission identifier signal (TxID signal) is inserted into the in-phase part of the host broadcast signal preamble and may not be inserted into the quadrature part.

In order to minimize performance degradation of the preamble while maintaining detection performance of the transmit identifier signal, a range of various injection levels can be used to insert the transmit identifier signal into the host broadcast signal preamble.

The insertion level of the transmit identifier signal may include turning off the transmit identifier signal output and may be provided from the controlling scheduler to the transmitter.

At this time, the insertion level of the transmission identifier signal can be defined as a dB value.

Table 2 below is a table showing injection level codes according to an embodiment of the present invention.

The transmission identifier signal scaled according to Table 2 below can be inserted into the broadcast signal preamble immediately after bootstrapping.

TxID Injection Level Code TxID Injection Level Below Preamble (dB) Scaling Factor
(Amplitude) 0000 OFF 0 0001 45.0 dB 0.0056234 0010 42.0 dB 0.0079433 0011 39.0 dB 0.0112202 0100 36.0 dB 0.0158489 0101 33.0 dB 0.0223872 0110 30.0 dB 0.0316228 0111 27.0 dB 0.0446684 1000 24.0 dB 0.0630957 1001 21.0 dB 0.0891251 1010 18.0 dB 0.1258925 1011 15.0 dB 0.1778279 1100 12.0 dB 0.2511886 1101 9.0 dB 0.3548134 1110 Reserved - 1111 Reserved -

As can be seen in Table 2, the injection level code consists of 4 bits and can be assigned to injection level values set at 3dB intervals.

At this time, the injection level values cover the range from 9.0 dB to 45.0 dB and may include a value corresponding to the case where the transmission identifier signal is not output (OFF).

At this time, the injection level code may be assigned “0000” in case the transmission identifier signal is not output.

At this time, the injection level code lowers the power of the transmission identifier signal compared to the host broadcast signal by the first level than the injection level value corresponding to lowering the power of the transmission identifier signal compared to the host broadcast signal by the first level. When lowering the second level higher than the level, the injection level value may be preferentially assigned. For example, an injection level code corresponding to 45.0 dB may be assigned preferentially over an injection level code corresponding to 42.0 dB.

The detection performance of the TxID signal (transmission identifier signal) is greatly affected by the insertion level, noise level, and receiving field strength of the TxID signal. The insertion level of the TxID signal must be appropriately selected within a range that does not affect the host broadcast signal. In particular, since there is no normalization process after insertion of the TxID signal, insertion of a high level TxID signal causes an increase in transmission power. Since the transmitter's transmission power is strictly limited and generally the actual transmission power should not exceed 1.05 times the permitted transmission power, the TxID insertion level is preferably determined within the range of 15dB to 45dB. In addition, insertion of a high-level TxID signal causes performance degradation of the preamble, which is the host broadcast signal, so the TxID signal is maintained at a signal level sufficient to detect the TxID signal while reducing the impact on the host broadcast signal to a negligible level. It is desirable to insert it.

Therefore, because the strength of the TxID signal inserted into the host broadcast signal is not large enough, it may be difficult for the receiver to detect it.

Figure 6 is a block diagram showing an example of a transmission identifier signal analysis device according to an embodiment of the present invention.

Referring to FIG. 6, the transmission identifier signal analysis device according to an embodiment of the present invention includes a pre-selector 610, a frequency down converter 620, a demodulator 630, a correlator 640, and a sequence generator 650. ), an ensemble average unit 660, and a TxID profile analyzer 670.

When an ATSC 3.0 RF broadcast signal including TxID signals transmitted from multiple transmitters is received through a receiving antenna, the pre-selector 610 leaves only the signal of the selected channel and removes signals of adjacent channels. .

The frequency down converter 620 performs frequency down conversion on the input RF (Radio Frequency) signal to generate an IF (Intermediate Frequency) signal.

The demodulator 630 receives the IF signal, restores at least one of the bootstrap and the preamble, and performs a time and frequency synchronization process on the ATSC 3.0 broadcast signal using the restored bootstrap.

The sequence generator 650 generates a TxID sequence corresponding to the object to be analyzed from the transmission identifier signal.

The correlator 640 calculates a correlation value between the signal received from the receiver and the TxID sequence generated by the sequence generator 650.

The ensemble averaging unit 660 improves TxID detection performance by frame averaging (or ensemble averaging) correlation values for multiple frames.

In the embodiment shown in FIG. 6, the ensemble averaging unit 660 operates by receiving the output of the correlator 640 as an example. However, the ensemble averaging unit 660 operates by receiving the output of the demodulator 630. And, the correlator 640 may operate by receiving the output of the ensemble average unit 660. At this time, the output of the correlator 640 can be directly provided to the TxID profile analyzer 670.

That is, the ensemble average unit 660 may average the correlation values for several frame signals, or may first average several frame signals and then generate a correlation value using the averaged value. there is.

At this time, the operation of the ensemble average unit 660 can be viewed as reducing the noise component. In other words, by collecting multiple frames and performing averaging, TxID detection performance can be improved by lowering the noise level while maintaining the strength of the desired signal (TxID signal).

The TxID profile analyzer 670 can obtain channel information between a desired transmitter and receiver using the correlation value.

When frame averaging (or ensemble averaging) is performed by the ensemble averaging unit shown in FIG. 6, the fact that the host broadcast signal continues to randomly change every frame improves the detection performance of the TxID signal. If the host broadcast signal remains the same for all frames, there may be no gain through frame averaging.

Looking at the preamble of the ATSC 3.0 host broadcast signal in the frequency domain, some subcarriers into which pilots are inserted do not change even when the frame changes, and the remaining subcarriers into which data is inserted change every frame depending on the inserted data. Since the TxID signal is inserted into the preamble in the time domain after the ATSC 3.0 host broadcast signal passes through the OFDM modulator block, the TxID signal transmission system considering the randomness of the host broadcast signal and TxID signal insertion is expressed as shown in Figure 7. It can be.

Figure 7 is a block diagram showing an example of a TxID transmission system considering the characteristics of the preamble signal.

Referring to FIG. 7, the preamble of the ATSC 3.0 host broadcast signal into which the TxID signal is inserted is generated by inputting two parts, a pilot (constant data) and randomly changing data (variable data), into an OFDM modulator. Able to know.

When averaging multiple frames at the receiver, the effect of the randomness of the host broadcast signal on TxID detection performance is as follows.

Hereinafter, the signal-to-DTV noise ratio (SDR) is used as an indicator of TxID detection performance.

Figure 8 is a graph showing TxID detection performance according to the randomness of the host broadcast signal.

Referring to FIG. 8, it can be seen that the randomness of the host broadcast signal affects TxID detection performance. At this time, the randomness of the host broadcast signal was defined as VARIABLE DATA / (VARIABLE DATA + CONSTANT DATA), and experiments were conducted on randomness at 10% intervals from 0% to 100% to examine TxID detection performance according to randomness. You can see that this has been done.

As shown in FIG. 8, when only one frame is used, the randomness of the host broadcast signal does not affect TxID detection performance, but as the number of averaging frames increases, the randomness of the host broadcast signal significantly affects performance. It affects. In the example shown in FIG. 8, when the randomness is 80% or less, it can be seen that performance saturates when the number of averaging frames is about 30, which means that under that condition, the TxID signal analysis device averages 30 frames. This means that sufficient performance can be provided through leasing alone.

The randomness of the preamble signal, which is the host broadcast signal, is determined by the FFT size of the preamble and the guard interval (GI). Table 3 below shows the randomness of the preamble signal according to the combination of FFT sizes and guard intervals.

GI Pattern 8K FFTs 16K FFTs 32K FFTs GI1_192 74.16% 76.65% 76.65% GI2_384 69.18% 74.16% 76.65% GI3_512 65.86% 72.50% 75.82% GI4_768 59.22% 69.18% 74.16% GI5_1024 52.58% 52.58% 65.86% GI6_1536 59.22% 59.22% 69.18% GI7_2048 52.58% 52.58% 65.86% GI8_2432 N/A 52.58% 65.86% GI9_3072 N/A 59.22% 52.58% GI10_3648 N/A 59.22% 52.58% GI11_4096 N/A 52.58% 52.58% GI12_4864 N/A N/A 52.58%

In Table 3, GI represents the guard interval and the number after the underbar represents the guard interval length. For example, GI12_4864 indicates the 12th guard interval and its length is 4864.

When configuring a single frequency network, the guard interval is set considering the distance between transmissions. In the case of T-DMB built in Korea, a single frequency network (SFN) was designed considering the transmission time distance of about 73.75km. Considering the Korean situation in the single frequency network configuration using ATSC 3.0, it may be necessary to set the guard interval value to GI6 or GI7 or higher listed in Table 3 above. If a broadcaster considers only values greater than GI6, the randomness of the preamble will have a value of less than 70%. In this case, as shown in FIG. 8, in the randomness, the gain decreases rapidly from the number of frames averaged from 10. It decreases and from 20 onwards, you can have almost the same performance.

In this way, the minimum number of averaging frames for optimal detection performance in the TxID detection device can be derived based on the FFT size and guard interval value of the preamble signal constituting the single frequency network.

The transmission identifier signal analysis device can further improve the detection performance of TxID performance by canceling at least part of the host broadcast signal from the received signal.

Figure 9 is a block diagram showing another example of a transmission identifier signal analysis device according to an embodiment of the present invention.

Referring to FIG. 9, the transmission identifier signal analysis device according to an embodiment of the present invention includes a pre-selector 610, a frequency down converter 620, a demodulator 630, a cancellation unit 910, and a correlator ( 640), a sequence generator 650, an ensemble average unit 660, and a TxID profile analyzer 670.

The pre-selector 610, frequency down converter 620, demodulator 630, correlator 640, sequence generator 650, ensemble average unit 660, and TxID profile analyzer 670 shown in FIG. may be the same as or similar to the components described through FIG. 6.

When an ATSC 3.0 RF broadcast signal including TxID signals transmitted from multiple transmitters is received through a receiving antenna, the pre-selector 610 leaves only the signal of the selected channel and removes signals of adjacent channels. .

The frequency down converter 620 performs frequency down conversion on the input RF (Radio Frequency) signal to generate an IF (Intermediate Frequency) signal.

The demodulator 630 receives the IF signal, converts it into a baseband signal, and then decodes the bootstrap signal. At this time, the demodulator 630 can decode the first preamble symbol. The receiver can use the bootstrap signal to find ATSC 3.0 broadcast signals even in poor channel environments and synchronize to ATSC 3.0 frames.

In order for the first preamble symbol to be decoded and re-encoded, preamble_structure information for decoding L1-Basic and L1-Basic Parameters for L1-Detail information may be needed to decode L1-Detail. In particular, the third symbol of the bootstrap may need to be decoded to obtain preamble_structure information. Table 4 below is a table showing the preamble_structure field and the structure of the corresponding preamble.

preamble_structure FFT Size GI Length (samples) Preamble Pilot DX L1-Basic
FEC Mode 0 8192 192 16 L1-Basic Mode 1 One 8192 192 16 L1-Basic Mode 2 2 8192 192 16 L1-Basic Mode 3 3 8192 192 16 L1-Basic Mode 4 4 8192 192 16 L1-Basic Mode 5 5 8192 384 8 L1-Basic Mode 1 6 8192 384 8 L1-Basic Mode 2 7 8192 384 8 L1-Basic Mode 3 8 8192 384 8 L1-Basic Mode 4 9 8192 384 8 L1-Basic Mode 5 10 8192 512 6 L1-Basic Mode 1 11 8192 512 6 L1-Basic Mode 2 12 8192 512 6 L1-Basic Mode 3 13 8192 512 6 L1-Basic Mode 4 14 8192 512 6 L1-Basic Mode 5 15 8192 768 4 L1-Basic Mode 1 16 8192 768 4 L1-Basic Mode 2 17 8192 768 4 L1-Basic Mode 3 18 8192 768 4 L1-Basic Mode 4 19 8192 768 4 L1-Basic Mode 5 20 8192 1024 3 L1-Basic Mode 1 21 8192 1024 3 L1-Basic Mode 2 22 8192 1024 3 L1-Basic Mode 3 23 8192 1024 3 L1-Basic Mode 4 24 8192 1024 3 L1-Basic Mode 5 25 8192 1536 4 L1-Basic Mode 1 26 8192 1536 4 L1-Basic Mode 2 27 8192 1536 4 L1-Basic Mode 3 28 8192 1536 4 L1-Basic Mode 4 29 8192 1536 4 L1-Basic Mode 5 30 8192 2048 3 L1-Basic Mode 1 31 8192 2048 3 L1-Basic Mode 2 32 8192 2048 3 L1-Basic Mode 3 33 8192 2048 3 L1-Basic Mode 4 34 8192 2048 3 L1-Basic Mode 5 35 16384 192 32 L1-Basic Mode 1 36 16384 192 32 L1-Basic Mode 2 37 16384 192 32 L1-Basic Mode 3 38 16384 192 32 L1-Basic Mode 4 39 16384 192 32 L1-Basic Mode 5 40 16384 384 16 L1-Basic Mode 1 41 16384 384 16 L1-Basic Mode 2 42 16384 384 16 L1-Basic Mode 3 43 16384 384 16 L1-Basic Mode 4 44 16384 384 16 L1-Basic Mode 5 45 16384 512 12 L1-Basic Mode 1 46 16384 512 12 L1-Basic Mode 2 47 16384 512 12 L1-Basic Mode 3 48 16384 512 12 L1-Basic Mode 4 49 16384 512 12 L1-Basic Mode 5 50 16384 768 8 L1-Basic Mode 1 51 16384 768 8 L1-Basic Mode 2 52 16384 768 8 L1-Basic Mode 3 53 16384 768 8 L1-Basic Mode 4 54 16384 768 8 L1-Basic Mode 5 55 16384 1024 6 L1-Basic Mode 1 56 16384 1024 6 L1-Basic Mode 2 57 16384 1024 6 L1-Basic Mode 3 58 16384 1024 6 L1-Basic Mode 4 59 16384 1024 6 L1-Basic Mode 5 60 16384 1536 4 L1-Basic Mode 1 61 16384 1536 4 L1-Basic Mode 2 62 16384 1536 4 L1-Basic Mode 3 63 16384 1536 4 L1-Basic Mode 4 64 16384 1536 4 L1-Basic Mode 5 65 16384 2048 3 L1-Basic Mode 1 66 16384 2048 3 L1-Basic Mode 2 67 16384 2048 3 L1-Basic Mode 3 68 16384 2048 3 L1-Basic Mode 4 69 16384 2048 3 L1-Basic Mode 5 70 16384 2432 3 L1-Basic Mode 1 71 16384 2432 3 L1-Basic Mode 2 72 16384 2432 3 L1-Basic Mode 3 73 16384 2432 3 L1-Basic Mode 4 74 16384 2432 3 L1-Basic Mode 5 75 16384 3072 4 L1-Basic Mode 1 76 16384 3072 4 L1-Basic Mode 2 77 16384 3072 4 L1-Basic Mode 3 78 16384 3072 4 L1-Basic Mode 4 79 16384 3072 4 L1-Basic Mode 5 80 16384 3648 4 L1-Basic Mode 1 81 16384 3648 4 L1-Basic Mode 2 82 16384 3648 4 L1-Basic Mode 3 83 16384 3648 4 L1-Basic Mode 4 84 16384 3648 4 L1-Basic Mode 5 85 16384 4096 3 L1-Basic Mode 1 86 16384 4096 3 L1-Basic Mode 2 87 16384 4096 3 L1-Basic Mode 3 88 16384 4096 3 L1-Basic Mode 4 89 16384 4096 3 L1-Basic Mode 5 90 32768 192 32 L1-Basic Mode 1 91 32768 192 32 L1-Basic Mode 2 92 32768 192 32 L1-Basic Mode 3 93 32768 192 32 L1-Basic Mode 4 94 32768 192 32 L1-Basic Mode 5 95 32768 384 32 L1-Basic Mode 1 96 32768 384 32 L1-Basic Mode 2 97 32768 384 32 L1-Basic Mode 3 98 32768 384 32 L1-Basic Mode 4 99 32768 384 32 L1-Basic Mode 5 100 32768 512 24 L1-Basic Mode 1 101 32768 512 24 L1-Basic Mode 2 102 32768 512 24 L1-Basic Mode 3 103 32768 512 24 L1-Basic Mode 4 104 32768 512 24 L1-Basic Mode 5 105 32768 768 16 L1-Basic Mode 1 106 32768 768 16 L1-Basic Mode 2 107 32768 768 16 L1-Basic Mode 3 108 32768 768 16 L1-Basic Mode 4 109 32768 768 16 L1-Basic Mode 5 110 32768 1024 12 L1-Basic Mode 1 111 32768 1024 12 L1-Basic Mode 2 112 32768 1024 12 L1-Basic Mode 3 113 32768 1024 12 L1-Basic Mode 4 114 32768 1024 12 L1-Basic Mode 5 115 32768 1536 8 L1-Basic Mode 1 116 32768 1536 8 L1-Basic Mode 2 117 32768 1536 8 L1-Basic Mode 3 118 32768 1536 8 L1-Basic Mode 4 119 32768 1536 8 L1-Basic Mode 5 120 32768 2048 6 L1-Basic Mode 1 121 32768 2048 6 L1-Basic Mode 2 122 32768 2048 6 L1-Basic Mode 3 123 32768 2048 6 L1-Basic Mode 4 124 32768 2048 6 L1-Basic Mode 5 125 32768 2432 6 L1-Basic Mode 1 126 32768 2432 6 L1-Basic Mode 2 127 32768 2432 6 L1-Basic Mode 3 128 32768 2432 6 L1-Basic Mode 4 129 32768 2432 6 L1-Basic Mode 5 130 32768 3072 8 L1-Basic Mode 1 131 32768 3072 8 L1-Basic Mode 2 132 32768 3072 8 L1-Basic Mode 3 133 32768 3072 8 L1-Basic Mode 4 134 32768 3072 8 L1-Basic Mode 5 135 32768 3072 3 L1-Basic Mode 1 136 32768 3072 3 L1-Basic Mode 2 137 32768 3072 3 L1-Basic Mode 3 138 32768 3072 3 L1-Basic Mode 4 139 32768 3072 3 L1-Basic Mode 5 140 32768 3648 8 L1-Basic Mode 1 141 32768 3648 8 L1-Basic Mode 2 142 32768 3648 8 L1-Basic Mode 3 143 32768 3648 8 L1-Basic Mode 4 144 32768 3648 8 L1-Basic Mode 5 145 32768 3648 3 L1-Basic Mode 1 146 32768 3648 3 L1-Basic Mode 2 147 32768 3648 3 L1-Basic Mode 3 148 32768 3648 3 L1-Basic Mode 4 149 32768 3648 3 L1-Basic Mode 5 150 32768 4096 3 L1-Basic Mode 1 151 32768 4096 3 L1-Basic Mode 2 152 32768 4096 3 L1-Basic Mode 3 153 32768 4096 3 L1-Basic Mode 4 154 32768 4096 3 L1-Basic Mode 5 155 32768 4864 3 L1-Basic Mode 1 156 32768 4864 3 L1-Basic Mode 2 157 32768 4864 3 L1-Basic Mode 3 158 32768 4864 3 L1-Basic Mode 4 159 32768 4864 3 L1-Basic Mode 5 160-255 Reserved Reserved Reserved Reserved

L1-Basic Mode 1, L1-Basic Mode 2, and L1-Basic Mode 3 listed in Table 4 may correspond to QPSK and 3/15 LDPC.

In particular, L1-Basic Mode 1 may correspond to 3/15, QPSK, parity repetition ON, and first puncturing size.

Additionally, L1-Basic Mode 2 may correspond to 3/15, QPSK, parity repetition off, and a second puncturing size larger than the first puncturing size.

Additionally, L1-Basic Mode 3 may correspond to 3/15, QPSK, parity repetition off, and a third puncturing size that is larger than the second puncturing size.

L1-Basic Mode 4 listed in Table 4 may correspond to 16-NUC (Non Uniform Constellation) and 3/15 LDPC.

L1-Basic Mode 5 listed in Table 4 may correspond to 64-NUC (Non Uniform Constellation) and 3/15 LDPC.

L1-Basic Mode 6 and L1-Basic Mode 7 listed in Table 4 may correspond to 256-NUC (Non Uniform Constellation) and 3/15 LDPC. The modulation method/code rate described below represents a combination of modulation method and code rate, such as QPSK and 3/15 LDPC.

As shown in Table 4 above, when the FFT sizes corresponding to the OFDM parameters are the same, the preamble structure corresponding to the second guard interval length shorter than the first guard interval length is preferentially allocated to the preamble structure corresponding to the first guard interval length. It can be. In addition, as shown in Table 4, for the combination of the same FFT size, guard interval length, and pilot pattern, the first mode, second mode, third mode, fourth mode, and fifth mode are in order of robustness. may be assigned.

The allocation order of the lookup table in Table 4 can greatly affect the performance of the system. In other words, since errors may occur in some bits of the signaling signal received at the receiver, signaling signal restoration performance can vary greatly depending on how the allocation order is set.

As shown in Table 4, the FFT size, guard interval length, preamble pilot Dx, and L1-Basic FEC mode are determined according to each preamble_structure value. At this time, preamble_structure can be used by the receiver to obtain necessary pilot information when estimating the channel for the first preamble symbol part.

The cancellation unit 910 performs a host signal cancellation process on the output signal of the demodulator 960 to generate a canceled received signal.

At this time, the host signal cancellation process may remove the cancellation signal corresponding to the preamble pilot included in the host broadcast signal from the received signal.

At this time, the preamble pilot may be generated using the preamble_structure field included in the bootstrap.

At this time, the host signal cancellation process may remove a cancellation signal corresponding to the entire host broadcast signal from the received signal.

At this time, the cancellation signal may be generated using at least a portion of the preamble restored through preamble decoding including channel decoding, and a preamble pilot regenerated using the bootstrap.

At this time, the cancellation signal may be generated using a hard decision restoration signal generated by re-modulating the restored bits restored through hard decision and a preamble pilot regenerated using the bootstrap.

At this time, the modulation may be QPSK (Quadrature Phase Shift Keying).

The sequence generator 650 generates a TxID sequence corresponding to the object to be analyzed from the transmission identifier signal.

The correlator 640 calculates a correlation value between the signal received from the receiver and the TxID sequence generated by the sequence generator 650. That is, the correlator 640 calculates a correlation value between a signal corresponding to the canceled received signal and a sequence corresponding to a transmitter identification (TxID) signal corresponding to the target.

The ensemble averaging unit 660 improves TxID detection performance by frame averaging (or ensemble averaging) correlation values for multiple frames. That is, the ensemble averaging unit 660 performs averaging on frame signals corresponding to the canceled received signal.

The TxID profile analyzer 670 uses the correlation value to generate channel information between a desired transmitter (corresponding to the transmission identifier signal) and a receiver.

Figure 10 is a block diagram showing another example of a transmission identifier signal analysis device according to an embodiment of the present invention.

Referring to FIG. 10, it can be seen that the ensemble averaging unit 665 may operate using the output of the correlator as shown in FIG. 9, but may also operate using the output of the cancellation unit 910. there is. At this time, the ensemble averaging unit 665 may receive the output of the cancellation unit 910 and perform averaging using the canceled received signal.

In the example shown in FIG. 10, the correlator 640 may calculate a correlation value between the output of the ensemble average unit 665 and the sequence corresponding to the target transmission identifier signal.

All of the components shown in FIG. 10 may be the same or similar to the components described in FIGS. 6 and 9 .

FIG. 11 is a block diagram showing an example of the cancellation unit shown in FIGS. 9 and 10.

Referring to FIG. 11, the cancellation unit 910 includes a pilot generator 1110, an OFDM modulator 1120, a channel compensation unit 1130, and a subtractor 1140.

In the example shown in FIG. 11, the host signal cancellation process performed by the cancellation unit may cancel the cancellation signal corresponding to the preamble pilot included in the host broadcast signal from the received signal.

That is, for the host signal cancellation process to remove the cancellation signal corresponding to the entire host broadcast signal from the received signal, decoding of the first preamble may be required, which requires complex functions such as channel decoding, bit deinterleaving, and demapping. Blocks may be needed.

In particular, channel decoding such as LDPC decoding greatly increases the complexity of the receiving device and requires a lot of memory. Therefore, in the example shown in FIG. 11, TxID detection performance can be improved by removing only the pilot signal from the received signal without performing preamble symbol decoding such as LDPC decoding. That is, the cancellation unit shown in FIG. 11 improves TxID detection performance by removing certain components such as pilot signals from the first preamble symbol.

The pilot generator 1110 generates one or more of the preamble pilot and common CP signals using the preamble_structure provided from the demodulator 630. At this time, the pilot generator 1110 may use only the FFT size and guard interval length among the preamble_structure information.

The OFDM modulator 1120 performs OFDM modulation on the input signal, similar to that performed in an ATSC 3.0 broadcast transmitter. At this time, frequency domain pilot signals may be converted into time domain signals by the OFDM modulator 1120. At this time, the OFDM modulator 1120 may generate an OFDM signal corresponding to the preamble pilot by performing guard interval insertion and IFFT.

The channel compensation unit 1130 performs channel estimation and channel compensation. That is, the channel compensator 1130 can generate a signal in which the channel profile information is reflected by reflecting the channel profile information in the OFDM signal.

At this time, the channel compensator 1130 performs channel estimation based on the pilot of the ATSC 3.0 frame after ATSC 3.0 frame synchronization using the bootstrap signal is completed. At this time, channel estimation may be performed by combining multiple ATSC 3.0 signals received by the TxID analysis device. That is, since all transmitters transmit the same signal using the same pilot pattern, channel estimation for each individual transmitter is impossible using pilot-based channel estimation. Through channel estimation using pilot signals of the first preamble symbol, a channel response in the frequency domain can be obtained, which can be converted to a channel response in the time domain.

Channel profile information obtained through channel estimation can be used for channel compensation for the pilot signal. At this time, channel compensation can be performed using convolution of the modulated pilot signals and the estimated channel response.

Subtractor 1140 subtracts the channel-compensated signals from the received baseband signals so that components corresponding to the pilot signals of the first preamble symbol are removed from the received signals.

Ultimately, the output of the cancellation unit shown in FIG. 11 consists of an ATSC 3.0 signal without pilot signals of the first preamble symbol, a TxID signal, and noise.

Figure 12 is a block diagram showing another example of the cancellation unit shown in Figures 9 and 10.

Referring to FIG. 12, the cancellation unit 910 includes a preamble decoder 1210, a preamble regeneration unit 1220, a pilot generation unit 1230, an OFDM modulator 1240, a channel compensation unit 1240, and a subtractor 1260. Includes.

In the example shown in FIG. 12, the host signal cancellation process performed by the cancellation unit may remove the cancellation signal corresponding to the entire host broadcast signal from the received signal.

That is, in the example shown in FIG. 12, the entire host broadcast signal including data and pilot can be removed from the received signal by the host signal cancellation process.

The preamble decoder 1210 performs preamble decoding to restore the preamble signal. At this time, preamble decoding may be decoding a signal generated according to the ATSC 3.0 A/322 standard. To this end, the preamble decoder 1210 may include a functional block such as an LDPC decoder. At this time, the preamble decoder 1210 may receive preamble_structure from the demodulator 630 and perform preamble decoding.

The preamble regeneration unit 1220 re-encodes the decoded preamble. At this time, the preamble regeneration unit 1220 may re-encode only the portion corresponding to the first preamble symbol, or may re-encode the entire L1-Basic and L1-Detail.

The pilot generator 1230 acquires information about the pilot pattern of the preamble from preamble_structure and generates a pilot.

The OFDM modulator 1240 performs OFDM modulation on the part corresponding to the first preamble symbol. At this time, the OFDM modulator 1240 can perform IFFT and guard interval insertion.

The channel compensation unit 1250 processes the regenerated first preamble symbol using channel information about the estimated host preamble signal.

When the first preamble symbol processed through the subtractor 1260 is subtracted from the received signal, the host broadcast signal corresponding to the first preamble symbol is removed and only the TxID signal and noise are output. At this time, a portion of the host broadcast signal may remain due to inaccuracy in channel estimation.

The pilot generator 1230, OFDM modulator 1240, channel compensator 1250, and subtractor 1260 shown in FIG. 12 are the pilot generator 1110, OFDM modulator 1120, and channel compensation shown in FIG. 11. It may be the same as the unit 1130 and the subtractor 1140.

Figure 13 is a block diagram showing another example of the cancellation unit shown in Figures 9 and 10.

Referring to FIG. 13, the cancellation unit 910 includes a preamble hard decision unit 1310, a QPSK modulation unit 1320, a pilot generation unit 1330, an OFDM modulator 1340, a channel compensation unit 1350, and a subtractor 1360. ) may include.

In the example shown in FIG. 13, the host signal cancellation process performed by the cancellation unit removes the cancellation signal corresponding to the entire host broadcast signal from the received signal, but the cancellation signal is simplified compared to the example shown in FIG. 12. It can be calculated using the above method.

Implementing the preamble decoder shown in FIG. 12 can significantly increase the complexity of the TxID analysis device, especially due to its configuration as an LDPC decoder.

The preamble hard decision unit 1310 restores the restoration bits for the first symbol of the preamble through hard decision.

The QPSK modulation unit 1320 QPSK modulates the restoration bits again.

That is, LDPC decoding is not performed through the preamble hard decision unit 1310 and the QPSK modulation unit 1320, and the preamble transmission signal is restored.

At this time, the QPSK modulation unit 1320 performs QPSK (Quadrature Phase Shift Keying) because there is a high probability that the preamble was encoded using QPSK, but modulation techniques other than QPSK may be used.

In particular, L1-Basic modes 1, 2, and 3 of the ATSC 3.0 broadcasting system use QPSK, and L1-Basic mode 1 or 2 will be widely used to ensure sufficient robustness, so the embodiment of FIG. 13 is similar to that of FIG. 12. While providing performance close to the embodiment, the complexity of implementation can be much lowered.

The pilot generator 1330, OFDM modulator 1340, channel compensator 1350, and subtractor 1360 shown in FIG. 13 are the pilot generator 1230, OFDM modulator 1240, and subtractor shown in FIG. 12. It may be the same as the channel compensator 1250 and the subtractor 1260.

Figure 14 is an operation flowchart showing an example of a transmission identifier signal analysis method according to an embodiment of the present invention.

Referring to FIG. 14, when an ATSC 3.0 RF broadcast signal including TxID signals transmitted from a plurality of transmitters is received through a receiving antenna, the transmission identifier signal analysis method according to an embodiment of the present invention analyzes only the signal of the selected channel. Signals from adjacent channels are removed (S1410).

Additionally, the transmission identifier signal analysis method according to an embodiment of the present invention generates an IF signal by performing frequency down-conversion on the input RF signal (S1420).

Additionally, the transmission identifier signal analysis method according to an embodiment of the present invention performs demodulation to decode the bootstrap corresponding to the received signal (S1430).

Additionally, the transmission identifier signal analysis method according to an embodiment of the present invention generates a canceled received signal by performing a host signal cancellation process on the received signal (S1440).

At this time, the host signal cancellation process may cancel the cancellation signal corresponding to the preamble pilot included in the host broadcast signal from the received signal.

At this time, the preamble pilot can be generated using the preamble_structure field included in the bootstrap.

At this time, the host signal cancellation process may cancel the cancellation signal corresponding to the entire host broadcast signal from the received signal.

At this time, the cancellation signal may be generated using at least a portion of the preamble restored through preamble decoding including channel decoding, and a preamble pilot regenerated using the bootstrap.

At this time, the cancellation signal may be generated using a hard decision restoration signal generated by re-modulating the restoration bits restored through hard decision and a preamble pilot regenerated using the bootstrap.

At this time, the modulation may be QPSK (Quadrature Phase Shift Keying).

In addition, the transmission identifier signal analysis method according to an embodiment of the present invention calculates a correlation value between a signal corresponding to the canceled received signal and a sequence corresponding to a transmitter identification (TxID) signal ( S1450).

At this time, the signal corresponding to the canceled received signal may be a canceled received signal.

Additionally, the transmission signal identifier analysis method according to an embodiment of the present invention performs averaging on frame signals corresponding to the canceled received signal (S1460).

At this time, averaging can be performed using a correlation value.

Additionally, the transmission signal identifier analysis method according to an embodiment of the present invention uses the correlation value to generate channel information between a transmitter and a receiver corresponding to the transmission identifier signal (S1470).

Steps S1450 and S1460 shown in FIG. 14 may be reversed in order. That is, after the step (S1460) shown in FIG. 14 is first performed and averaging is performed on the frame signals corresponding to the canceled received signal, the step (S1450) is performed with the result to change the correlation value. may be calculated. At this time, averaging is performed using the canceled received signal, and the signal corresponding to the canceled received signal in step S1450 may be a signal generated through averaging in step S1460.

Figure 15 is a diagram showing an example of a plurality of ATSC 3.0 received signals including different TxID signals.

Referring to FIG. 15, it can be seen that in a single frequency network environment with two transmitters, each transmitter transmits a broadcast signal by inserting a TxID signal. The signal received by the receiver is the sum of signals from each transmitter, and without analyzing the TxID, the receiver cannot distinguish which transmitter the received signal is from.

Figure 16 is a diagram showing an example of ATSC 3.0 pilot-based channel estimation.

Referring to FIG. 16, it can be seen that when a receiver performs channel estimation using a pilot signal, channel information for all host broadcast signals is estimated.

In order to generate channel information between each transmitter and receiver in a single frequency network, channel estimation using the TxID signal is essential. To this end, if the host broadcast signal is removed from the received signal, a signal as shown in FIG. 17 can be detected.

Figure 17 is a diagram showing an example of a received signal after host broadcast signal cancellation is applied.

Additionally, by taking correlation with the desired TxID signal, channel information for the desired transmitter can be generated as shown in FIG. 18.

Figure 18 is a diagram showing an example of channel estimation using the target TxID signal remaining after applying host broadcast signal preamble cancellation.

Figure 19 is a graph showing the TxID signal detection performance of the transmission identifier signal analysis device according to an embodiment of the present invention.

Referring to FIG. 19, it can be seen that when the host signal cancellation process is not performed (ORIGINAL), the performance gain is not significant even if multiple frames are averaged.

As shown in the example shown in FIG. 12, when cancellation is performed on the entire host broadcast signal (WHOLE HOST CANCELLATION), high performance gains are shown even when frame averaging is not performed, and performance gains due to frame averaging are maximized. Know what you can do.

As in the example shown in FIG. 11, when cancellation for the pilot is performed (ONLY PILOT CANCELLATION), performance is similar to when frame averaging is not performed, but performance is similar to when the host cancellation process is not performed, but frame averaging When applied, it can be seen that a performance gain of 11dB can be obtained compared to ORIGINAL by eliminating the randomness degradation phenomenon caused by pilot.

Although not shown in FIG. 19, when cancellation of the entire host broadcast signal is performed briefly through hard-decision as in the example of FIG. 13, performance is close to that of WHOLE HOST CANCELLATION in FIG. 19. It can be displayed, and at least it can display higher performance than ONLY PILOT CANCELLATION.

Figure 20 is a diagram showing a computer system according to an embodiment of the present invention.

Referring to FIG. 20, the transmission identifier signal analysis device according to an embodiment of the present invention may be implemented in a computer system 2000 such as a computer-readable recording medium. As shown in FIG. 20, the computer system 2000 includes one or more processors 2010, a memory 2030, a user interface input device 2040, and a user interface output device 2050 that communicate with each other through a bus 2020. and storage 2060. Additionally, the computer system 2000 may further include a network interface 2070 connected to the network 2080. The processor 2010 may be a central processing unit or a semiconductor device that executes processing instructions stored in the memory 2030 or storage 2060. Memory 2030 and storage 2060 may be various types of volatile or non-volatile storage media. For example, the memory may include ROM (2031) or RAM (2032).

As described above, the transmission identifier signal analysis device and method according to the present invention are not limited to the configuration and method of the embodiments described above, but the embodiments are each embodiment so that various modifications can be made. All or part of them may be selectively combined.

Claims (20)

a demodulator that decodes the bootstrap corresponding to the received signal;
a cancellation unit that performs a host signal cancellation process on the received signal to generate a canceled received signal;
an ensemble averaging unit that performs averaging on frame signals corresponding to the canceled received signal to improve detection performance of a transmitter identification (TxID) signal;
a correlator that calculates a correlation value between a signal corresponding to the canceled received signal and a sequence corresponding to the transmission identifier signal; and
A TxID profile analyzer that generates channel information between a transmitter and a receiver corresponding to the transmission identifier signal using the correlation value,
The insertion level of the transmission identifier signal is
Corresponds to a 4-bit injection level code,
The 4-bit injection level code is
In case the transmission identifier signal is not output, it is assigned “0000”,
The 4-bit injection level code is
Bits to which '0' is assigned in the case corresponding to 39.0dB, the case corresponding to 33.0dB, the case corresponding to 30.0dB, the case corresponding to 21.0dB, the case corresponding to 18.0dB, and the case corresponding to 12.0dB The number and the number of bits to which '1' is assigned are both the same, and
The host signal cancellation process is
A transmission identifier signal analysis device characterized in that a cancellation signal corresponding to a preamble pilot included in a host broadcast signal is removed from the received signal. delete delete delete delete delete delete In claim 1,
The averaging is performed using the correlation value, and the signal corresponding to the canceled received signal is the canceled received signal. In claim 1,
The averaging is performed using the canceled received signal, and the signal corresponding to the canceled received signal is a signal generated through the averaging. In claim 1,
The preamble pilot is
A transmission identifier signal analysis device, characterized in that generated using the preamble_structure field included in the bootstrap. Decoding the bootstrap corresponding to the received signal;
generating a canceled received signal by performing a host signal cancellation process on the received signal;
performing averaging on frame signals corresponding to the canceled received signal to improve detection performance of a transmitter identification (TxID) signal;
calculating a correlation value between a signal corresponding to the canceled received signal and a sequence corresponding to the transmission identifier signal; and
Generating channel information between a transmitter and a receiver corresponding to the transmission identifier signal using the correlation value,
The insertion level of the transmission identifier signal is
Corresponds to a 4-bit injection level code,
The 4-bit injection level code is
In case the transmission identifier signal is not output, it is assigned “0000”,
The 4-bit injection level code is
Bits to which '0' is assigned in the case corresponding to 39.0dB, the case corresponding to 33.0dB, the case corresponding to 30.0dB, the case corresponding to 21.0dB, the case corresponding to 18.0dB, and the case corresponding to 12.0dB The number and the number of bits to which '1' is assigned are both the same, and
The host signal cancellation process is
A transmission identifier signal analysis method comprising canceling a cancellation signal corresponding to a preamble pilot included in a host broadcast signal from the received signal. delete delete delete delete delete delete In claim 11,
The averaging is performed using the correlation value, and the signal corresponding to the canceled received signal is the canceled received signal. In claim 11,
The averaging is performed using the canceled received signal, and the signal corresponding to the canceled received signal is a signal generated through the averaging. In claim 11,
The preamble pilot is
A transmission identifier signal analysis method, characterized in that generated using the preamble_structure field included in the bootstrap.

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