KR100320449B1 - Interference discrimination device of NCC adjacent channel in high definition receiver - Google Patents

Abstract

The present invention relates to a receiver of a high-definition TV receiver (HDTV), and more particularly, in an 8VSB GA transmission system, by determining whether there is interference in an adjacent channel of an existing NTSC broadcast, an optical path of a decoder (Viterbi Decoder) is determined. The circuit generates a signal for determining whether to use an optimal path or a partial path.

Conventional NTSC adjacent channel interference discrimination circuit uses an NTSC rejection filter, two 10-bit subtractors, two squarers, two integrators, and an energy detector to determine the presence or absence of interference in adjacent NTSC channels. Therefore, the circuit configuration has a complicated disadvantage.

The present invention provides a post comb filter (2), a multiplexer (4), a slicer (30) for determining a positive or negative number of uncompressed digital data, and a post comb filter (2). A slicer 31 for comparing the output of the output to a reference value range, an MSB rejection unit 32 for generating an absolute value of the slicer 31, an output encoder 33 of the MSB rejection unit 32, and frame synchronization Gate circuits 35 and 36 and gate circuits 35 for outputting the pattern generator 34, the output of the slicer 30, the output of the encoder 33, and the difference between the pattern generator 34, respectively. 36. The integrators 37 and 38 of the output, the subtractor 39 for subtracting the outputs of the integrators 37 and 38, and the sign of the output value of the diffuser 39 are detected to control the multiplexer 4. An interference discrimination apparatus of an NTSC adjacent channel composed of a sign detector 40,

G.A. processing using all 10-bit symbol data This circuit simplifies the circuit configuration by eliminating the method and enabling the determination of NTSC interference through 1-bit data comparison.

Description

Interference Discrimination Device of NTSC Adjacent Channel in High Definition TV Receiver (HDTV)

The present invention relates to a receiver of a high-definition TV receiver (HDTV), and is particularly present in the 8VSB Grand Alliance (GA) transmission system-a transmission system defined to use a tabo channel, which is a channel not used in NTSC broadcasting. A circuit that determines whether there is an adjacent channel of a NTSC broadcast and generates a signal for determining whether to use an optical path or a partial path for a decoder (Viterbi Decoder)- The present invention relates to an interference discrimination apparatus of an NTSC adjacent channel in a high definition TV receiver (HDTV).

1 is a block diagram showing a circuit configuration of a receiver of an HDTV, wherein an analog digital converter (1) converts a received analog broadcast signal into a digital signal, and an NTSC signal in the digital signal output from the analog digital converter (1). A post comb filter (2) for removing a carrier signal, the output of the analog digital converter (1) and the output of the comb filter (2) are input to determine the presence or absence of an NTSC adjacent channel, and the multiplexer ( 4) and the output of the analog digital converter 1 or the output of the comb filter 2 under the control of the adjacent channel interference discriminator 3 and the output of the comb filter 2 under the control of the adjacent channel interference discriminator 3. A multiplexer (4) supplied to (5), an equalizer (5) for equalizing and amplifying a signal output from the multiplexer (4), and an optical path section for performing an optical process on the signal output from the equalizer (5) ( 6) And above, etc. A partial pass unit 7 for parsing the signal output from the device 5 and the output of the optical path unit 6 or the partial path unit 7 under the control of the adjacent channel interference discriminator 3. It consists of a multiplexer 8 for selecting the output of.

The post comb filter 2 is composed of a delayer 2a for delaying the input signal by 12 symbols and a subtractor 2b for subtracting and outputting the delayed signal from the input signal to the delayer 2a.

In the receiver having the above-described configuration, when there is no NTSC adjacent channel interference, the receiver transmits a signal that does not pass through the Post Comb Filter 2 to the equalizer 5, and passes a decoder (Viterbi Decoder) to the optical path. Used as an Optimal Path (6), when there is NTSC adjacent channel interference, a carrier wave (Visual Carrier, Chrominance Sub), which is an important element of NTSC signal, is passed through the comb filter (2) from the signal output from the analog digital converter 1 The signal from which Carrier and Aural Carrier are removed is transmitted to the equalizer 5, and the decoder is used as the partial response path 7. The operation is as follows.

The analog digital converter 1 converts an input analog reception preference into a digital signal and outputs the digital signal of 10 bits, which is input to a post comb filter 2 and a multiplexer 4.

The post comb filter 2 removes an important component of the NTSC signal (Visual Carrier, Chrominance Sub Carrier, Aural Carrier) and inputs the multiplexer (4) and the adjacent channel interference discriminator (3).

That is, the post comb filter 2 receives a 10-bit input and inputs a signal delayed by 12 symbols from the l2 symbol delayer 2a to the 10-bit subtractor 2b, and the subtractor 2b is currently input. By subtracting the signal before 12 symbols from the signal, only the MSB 10 bits are output from the 11-bit value.

The adjacent channel interference discriminator 3 determines whether there is interference in the NTSC neighbor channel and, when there is no interference, outputs a control signal as '0' to select a signal that the multiplexer 4 does not pass through the comb filter 2. To the equalizer 5 and to supply the control signal to the multiplexer 8 as a '0' so that the multiplexer 8 outputs the signal passed through the equalizer 5 and the optical path part 6. do.

However, if there is adjacent channel interference, the discriminator 3 outputs the control signal as '1' so that the multiplexer 4 selects the signal passed through the post comb filter 2 and transmits it to the equalizer 5. In addition, the control signal is also supplied to the multiplexer 8 so that the multiplexer 8 outputs the signal passed through the equalizer 5 and the partial response path unit 7.

2 shows a circuit configuration of the adjacent channel interference discriminator 3.

As shown in FIG. 2, the conventional circuit for determining the presence or absence of NTSC adjacent channel interference includes a subtractor 3a which subtracts a reference pattern from a received 1 channel data signal and squares the output of the subtractor 3a. A squarer 3b, an integrator 3c that integrates the output of the squarer 3b, an NTSC rejection filter 3d that removes channel noise from the reference pattern signal, and the post comb filter 2 A subtractor 3e that subtracts the output of the filter 3d from the output of a squarer, a squarer 3f that squares the output of the subtractor 3e, and an integrator 3g that integrates the output of the squarer 3f. ) And an energy detector (3h) for outputting a control signal to the multiplexer (4) (8) to compare the output of the integrator (3c) (3g) to select the one with the smallest energy. Same as

The received subchannel 3a subtracts the received subchannel data signal from the subchannel received by the subtractor 3a by generating a reference pattern in the data field sync from the receiving end with the same data as the transmitting end. The difference between the reference signals generated at < RTI ID = 0.0 >, < / RTI >

The NTSC rejection filter 3a removes the channel noise from the reference pattern signal, outputs a signal to which the channel noise is not added, and inputs it to the subtractor 3e, and the subtractor 3e is a post comb filter ( The output of the filter 3a is subtracted from the output of 2) and input to the squarer 3f.

The squarer 3f squares the output of the subtractor 3e, and the integrator 3g adds the output of the squarer 3f for one period and inputs it to the energy detector 3h.

The minimum energy detector 3h compares the outputs of the two integrators 3c and 3g and outputs a control signal of '0' or '1' so that the multiplexer 4 or 8 selects the one with the lowest energy. Thus, the receiver signal processing path as described in FIG. 1 is appropriately selected.

However, the method proposed by the GA determines the presence or absence of interference in the NTSC adjacent channel, since it uses the NTSC rejection filter, two 10-bit subtractors, two squarers, two integrators, and an energy detector. This is a complex disadvantage.

The present invention deals with G.A. processing using all 10-bit symbol data. The purpose of this invention is to provide interference discrimination apparatus for NTSC adjacent channels in high definition TV receivers (HDTV), which simplifies the circuit configuration by eliminating the method and enabling the determination of the presence of NTSC interference through 1-bit data comparison. do.

Figure 3 shows the circuit arrangement of the interference discrimination apparatus of the present invention.

As shown in FIG. 3, in the high definition TV receiver (HDTV) of the present invention, an interference discrimination apparatus of an adjacent channel of NTSC (NTSC),

An optical path or partial response path is selected by selecting a post comb filter (2) for removing and outputting an NTSC carrier from digital data of a reception channel, and receiving data not passing through the comb filter (2) or a signal passing through the comb filter (2). A multiplexer (4) for outputting a signal, a first slicer (30) for comparing and determining whether the digital data of the reception channel is positive (+) or negative (-), and the post comb filter ( A second slicer 31 for comparing the output data of 2) with a predetermined reference value range and outputting a comparison result, and an MSB rejection unit for converting the output of the second slicer 31 to an absolute value and outputting the absolute value; 32, an encoder 33 for encoding the output of the MSB rejection unit 32, a pattern generator 34 for generating a frame synchronization pattern, and the first slicer 30 And the output pattern of the pattern generator 34 In contrast, the first gate circuit 35 outputting the difference, the second gate circuit 36 comparing the output pattern of the pattern generator 34 and the output of the encoder 33, and outputting the difference; A first integrator 37 for adding an output of the first gate circuit 35, a second integrator 38 for adding an output of the second gate circuit 36, and an output of the second integrator 38. A subtractor 39 for subtracting the output of the first integrator 37 and a sign detector 40 for detecting the sign of the output value of the subtractor 39 to control the multiplexer 4 Looking at it as follows.

The post comb filter 2 removes and outputs a carrier (Visual Carrier, Chrominance Sub Carrier, Aural Carrier), which is an important element, among the NTSC signals of the digital reception signal output from the analog digital converter (1).

The multiplexer 4 selects a signal passing through the post comb filter 2 or a signal not passing through the post comb filter 2 according to the presence or absence of interference of the NTSC neighboring channel, and thus, an optical path part 6 or a partial response path part of the rear stage. Supply appropriately to (7) (refer to the drawing and operation description of FIG. 1 above).

The appropriate selection of the receiver signal processing path is performed by the interference discrimination apparatus of the NTSC adjacent channel in the high definition TV receiver (HDTV) of the present invention as follows.

First, the first slicer 30 receives a digital signal of a reception channel and outputs '1' if the input signal is greater than '0' (positive) and outputs '0' if less than '0' (negative). do.

That is, the result of the comparison judgment is output to the input (x) and the output (y) of the first slicer (30) with y = 1 if x> 0 and y = 0 if x <0, so that the first gate circuit 35 Enter on one side of).

On the other hand, the second slicer 31 receives the data signal output from the post comb filter 2 and compares the data value with a predetermined reference range value and outputs a comparison result.

That is, with respect to the input (x) and the output (y) of the second slicer (31), y = 1 for 90 <x, y = 0 for -90 <x <90, and y = -1 for x <-90. Output the result of the comparison judgment.

The signal output from the second slicer 31 is input to the MSB rejection unit 32, and the MSB rejection unit 32 is y = 1 when x = + 1 with respect to the input (x) and the output (y). If x = -1, y = 1, and if x = 0, y = 0, and this output value is input to the encoder 33.

However, since the output of the MSB rejection unit 32 has the same effect as the differential decoding after passing the received signal through the first slicer 30, it is necessary to offset the effect of the decoding. Pass the Encoder (33).

The encoder 33 inputs the output of the MSB rejection unit 32 to the Modulo 2 adder 33a, inputs the output of the Modulo 2 adder 33a to the second gate circuit 36, In addition, the output of the modulo 2 adder 33a is input to the l2 symbol delayer 33b, and the signal delayed by the l2 symbol by the delayer 33b is input to the modulo 2 adder 33a. To the output of.

On the other hand, the same pattern as that used for frame synchronization of the transmitter is generated by the pattern generator 34 and input to the first gate circuit 35 and the second gate circuit 36.

The first gate circuit 35 and the second gate circuit 36 are configured as an exclusive OR gate so that the first gate circuit 35 generates an output and a pattern of the first slicer 30. The difference between the reference pattern signal and the output of the first slicer 30 is obtained by logically receiving the reference pattern signal of the unit 34 and inputs the difference value to the first integrator 37.

The second gate circuit 36 receives a logic combination of the output of the encoder 33 and the reference pattern signal of the pattern generator 34 to obtain a difference between the reference pattern signal and the output of the encoder 33. Input to second integrator 38.

The first integrator 37 adds the output of the first gate circuit 35 to the subtractor 39, and the second integrator 38 adds the output of the second gate circuit 36 to the subtractor 39. do.

That is, the first integrator 37 is input to the 9-bit adder 37a, the output (9-bit) of the adder 37a is input to the subtractor 39, and is input to the 1-symbol delayer 37b. The symbol retarder 37b delays the output of the adder 37a by one symbol and inputs it to the adder 37a, so that the 9-bit adder 37a inputs the output of the first gate circuit 35 to one data signal before one symbol. And the added result is supplied to the subtractor 39.

The second integrator 38 is input to the 9-bit adder 38a, the output (9-bit) of the adder 38a is input to the subtractor 39, and is input to the 1-symbol delayer 38b. The symbol retarder 38b delays the output of the adder 38a by one symbol and inputs it to the adder 38a, so that the 9-bit adder 38a sends the output of the second gate circuit 36 to the data signal before one symbol. And the added result is supplied to the subtractor 39.

The subtractor 39 subtracts the output of the first integrator 37 from the output of the second integrator 38 and inputs the subtracted result to the sign detector 40.

From this subtraction result, it is possible to determine the presence or absence of NTSC neighbor channel interference.

That is, if the output of the second integrator 38 is greater than the output of the first integrator 37, the subtraction result will be positive, and the second slicer 31-MSB rejection unit 32-encoder ( 33)-Since the intensity of the signal passing through the post comb filter 2 passing through the second gate circuit 36 is greater than that of the non-com comfiltered signal, in this case, there is a case where there is interference of an adjacent NTSC channel. Will be

If the output of the first integrator 37 is greater than the output of the second integrator 38, the subtraction result will be negative, and the post comb will pass through the first slicer 30-the first gate circuit 35. Since the strength of the signal not passing through the filter 2 is greater than that of the signal passing through the post comb filter 2, in this case, there is no interference of the adjacent NTSC channel.

The sign detector 40 outputs '1' if the output of the subtractor 38 is a positive sign, and outputs '0' if a negative sign is output, and outputs the multiplexer 4 to the output '1' or '0' signal. ).

That is, the sign detector 40 outputs y = 1 to the input x by determining that the output y has an interference of the NTSC neighboring channel when x> 0, and outputs y = 1 to thereby output the multiplexer 4 to the post comb. By controlling to select the signal passing through the filter (2), and if x <0, it is determined that there is no interference of the NTSC adjacent channel, and outputs y = 0, so that the multiplexer (4) does not go through the post comb filter (2). And control the multiplexer 8 in FIG. 1 in the same manner so that the decoder (Viterbi Decoder) is used as the optical path if there is no channel interference, and if there is channel interference To use it as a response path.

As described above, in the high definition TV receiver (HDTV) of the present invention, the interference discrimination apparatus of the NTSC neighbor channel slices 10-bit symbol data into 1-bit binary data and processes the circuit. The configuration will be simple to implement.

1 is a block diagram of the HDTV receiver

2 is a block diagram of a circuit for determining a conventional NTSC neighbor channel interference.

3 is a block diagram showing the circuit configuration of the device of the present invention.

Explanation of symbols for main parts of the drawings

2 ; Post comb filters 4,8; Multiplexer

30,31; Slicer 32; MSB Rejection Section

33; Encoder 34; Pattern generator

35,36; Gate circuits 37,38; integrator

39; Subtractor 40; Sign detector

Claims (1)

An optical path or partial response path is selected by selecting a post comb filter (2) for removing and outputting an NTSC carrier from digital data of a reception channel, and receiving data not passing through the comb filter (2) or a signal passing through the comb filter (2). A multiplexer (4) for outputting a signal, a first slicer (30) for comparing and determining whether the digital data of the reception channel is positive (+) or negative (-), and the post comb filter ( A second slicer 31 for comparing the output data of 2) with a predetermined reference value range and outputting a comparison result, and an MSB rejection unit for converting the output of the second slicer 31 to an absolute value and outputting the absolute value; 32, an encoder 33 for encoding the output of the MSB rejection unit 32, a pattern generator 34 for generating a frame synchronization pattern, and the first slicer 30 And the output pattern of the pattern generator 34 In contrast, the first gate circuit 35 outputting the difference, the second gate circuit 36 comparing the output pattern of the pattern generator 34 and the output of the encoder 33, and outputting the difference; A first integrator 37 for adding an output of the first gate circuit 35, a second integrator 38 for adding an output of the second gate circuit 36, and an output of the second integrator 38. A subtractor 39 for subtracting the output of the first integrator 37 and a sign detector 40 for detecting the sign of the output value of the subtractor 39 to control the multiplexer 4. Interference discrimination apparatus of NTSC adjacent channel in high definition TV receiver (HDTV).