CN1210421A - Method for rejecting NTSC interference and NTST interference rejection filter circuit using 3-stage notch filter - Google Patents
Method for rejecting NTSC interference and NTST interference rejection filter circuit using 3-stage notch filter Download PDFInfo
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- CN1210421A CN1210421A CN97109383A CN97109383A CN1210421A CN 1210421 A CN1210421 A CN 1210421A CN 97109383 A CN97109383 A CN 97109383A CN 97109383 A CN97109383 A CN 97109383A CN 1210421 A CN1210421 A CN 1210421A
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- ntsc
- energy
- signal
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/14—Picture signal circuitry for video frequency region
- H04N5/21—Circuitry for suppressing or minimising disturbance, e.g. moiré or halo
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
- H04N21/40—Client devices specifically adapted for the reception of or interaction with content, e.g. set-top-box [STB]; Operations thereof
- H04N21/41—Structure of client; Structure of client peripherals
- H04N21/426—Internal components of the client ; Characteristics thereof
Abstract
A technique for rejecting NTSC co-channel interference uses a NTSC interference rejector circuit provided with 3-stage notch filters. Using a voltage difference signal between the I-channel data symbols and data segment synchronous reference mode received by 3-stage notch filters before and after, to generate two energy signals and compare the two signals for judging and output one of the energy with lower NTSC common-channel interference in the I-channel data symbols of 3-stage notch filters before and after. Consequently, a received digital TV signal which does not contain frequency components of the three carriers causing NTSC co-channel interference is outputted.
Description
The present invention relates to Advanced Television (ATV) service, particularly in the ground digital television signal receiver, be used for the improvement technology of the common news road interference of filtering NTSC (NTSC) standard.
ATV is the service of calculated U.S. terrestrial broadcast television, is used for launching by standard 6MHz TV news road the digital television signal of a high definition TV (HDTV) digital signal or some low resolution.The video of TV signal and audio frequency composition utilize respectively as MPEG-2 and Doby AC-3 compression method and compress, and are combined into single transmission bit stream by multichannel, to utilize a plurality of N level data of residual sideband (VSB) modulation transmissions symbol.
The original original news road broadcasting of ATV in the given area, promptly so-called taboo (taboo) news road, and on some period, must share with the NTSC broadcast service.For providing the ATV service to utilize widely used NTSC receiver again, on each 6MHz TV news road, to transmit simultaneously same program material with two kinds of encoded in different formats.For this reason, in given NTSC coverage, consider with additional 6MHz TV news road transmission ATV code signal, and some additional news roads that are used for this purpose generally are general that certain part in these news roads probably are allocated for the NTSC transmission in the proximate television coverage at least.This has just caused common news road interference problem, and is promptly interfering with each other by the ATV and the NTSC of the transmission of identical news road in the proximate television coverage.Excessive NTSC interrogates the interference meeting reduces signal reproduction in the ATV receiver ability altogether in the ATV signal that is received.Therefore, NTSC must be interrogated altogether interference minimum is reduced in the influence of the ATV signal of reception.
For satisfying the demand, filtering NTSC interrogates existing two inventions in the prior art of disturbing altogether in the ATV receiver, first is that name is called " reducing the NTSC VSB HDTV transmission system (VSB HDTV TRANSMISSION SYSTEM WITH REDUCED NTSC CO-CHANNEL INTERFERENCE) of road interference altogether ", the patent No. is 5,087,975 United States Patent (USP), and second be that name is called " reducing the altogether NTSC band stop filter with the inferior precoder of switchable Tom woods (NTSC REJECTION FILTER WITHSWITCHED TOMLINSON PRECODER FOR REDUCING NTSC CO-CHANNEL INTERFERENCE IN ATV RECEIVERS) that disturbs of road of NTSC in the ATV receiver ", the patent No. is 5,602,583 United States Patent (USP), these two is presented to Richard W.Citta.In addition, also has another correlation technique, promptly be by the name that Samir N.Hulyalkar proposes be called " the inhibition NTSC method and apparatus (METHOD AND APPARATUS FORCOMBATING CO-CHANNEL NTSC INTERFERENCE FOR DIGITAL TVTRANSMISSION HAVING A SIMPLIFIED REJECTION FILTER) that disturbs of road altogether that having of being used for that Digital Television transmits simplified band stop filter ", the patent No. is 5,606,602 United States Patent (USP).
On the other hand, a kind of technology of utilizing comb filter filtering NTSC to interrogate altogether and disturb of advanced television system committee (ATSC) suggestion, promptly the exercise question of issuing in October 4 nineteen ninety-five is the technical specification of " ATSC digital television standard guide for use (GUIDE TO THE USE OF THE ATSC DIGITALTELEVISION STANDARD) ".Utilize the interference filtering characteristic of the VSB transmission system of comb filter to depend on that the NTSC in 6MHz TV news road interrogates the fundamental component of interference signal and the zero frequency location relation of cycle of vsb receiver base band comb filter altogether.
Fig. 2 A illustrates the position and the approximate range of 3 basic NTSC compositions, that is: video carrier (V) is positioned at the 1.25MHz place of low side band edge genesis; (2) chrominance carrier (C) is positioned at the 3.58MHz place higher than video carrier; And (3) sound carrier (A), be positioned at the 4.5MHz place higher than video carrier frequency.
In this technical specification, show bright filter circuit among Fig. 1 of ATSC suggestion, be used for filtering NTSC and disturb.It is a comb filter that this NTSC disturbs band stop filter, i.e. a tap feedforward filter.Can detect NTSC by circuit shown in Figure 1 and disturb, wherein, measure the binary data section signal/interference-to-noise ratio of (Field Sync) synchronously in the input and output of comb filter 10 and 20, and compare mutually.This can finish by setting up two error signals.Compare with the section synchronous base of storage by the signal that will receive and to set up first error signal, set up second error signal by the output of band stop filter is compared with the signal after the benchmark section of storage inside is passed through this filter synchronously.These errors are by the quadratic sum integration.Reach predetermined put the letter grade after, have maximum in the system and believe/make an uproar than the path of (lowest interference energy) and chosen automatically.
Frequency response characteristic is shown bright at Fig. 2 B and its periodic spectral null interval 57*fH (10.762MHz/12 or 896.85KHz).Wherein, fH is a NTSC horizontal line speed.In 6MHz news road, 7 zero-bits are arranged.The ntsc video carrier frequency is approached second zero-bit from lower band edge landing.From the 6th zero-bit at lower band edge just corresponding to the NTSC chrominance carrier, and from the 7th zero-bit at lower band edge near the NTSC sound carrier.
Yet, part as the frequency response characteristic of comb filter, and the NTSC that has earlier shown in Figure 1 disturbs the rejector circuit filtering to cause NTSC to interrogate the video carrier that disturbs altogether, chrominance carrier and sound carrier, this filter circuit also filtering should be by the digital composition of the 1st, the 3rd, the 4th and the 5th zero-bit of filtering.So the problem that this filter circuit exists is that the unnecessary loss of interrogating track data owing to the I that is received degenerates the reproducing characteristic of received signal.
The present invention will overcome above-mentioned shortcoming exactly.Thereby, one object of the present invention just provides a kind of filtering NTSC that is used for and interrogates the apparatus and method of disturbing altogether, the filtering radio-frequency component that causes NTSC to interrogate altogether disturbing selectively wherein, i.e. video carrier, chrominance carrier and sound carrier and can not cause the loss of unnecessary digital signal to the signal of desired reception.
For realizing above-mentioned purpose of the present invention, provide a kind of NTSC of 3 stage notch filters that utilizes to disturb band stop filter, include: (ⅰ) NTSC filtering device, it is after receiving I news track data symbol and data segment sync reference mode, the radio-frequency component of ntsc video carrier wave, NTSC chrominance carrier and the NTSC sound carrier that utilizes 3 stage notch filter filterings to cause NTSC to interrogate altogether to disturb produces and does not comprise and cause that NTSC interrogates the I news track data symbol and the data segment sync reference mode of the radio-frequency component that disturbs altogether; (ⅱ) the first energy apparatus for establishing was used for before 3 stage notch filtering, utilized first error signal between I news track data symbol that receives and data segment sync reference mode, produced first energy of receiving digital signals; (ⅲ) the second energy apparatus for establishing, be used for after 3 stage notch filtering, utilization was carried out the I that the is received news track data symbol of 3 stage notch filtering and second error signal between the data segment sync reference mode by described NTSC filtering device, produced second energy of the digital signal that receives; (ⅳ) least energy checkout gear, be used for detecting NTSC and interrogate interference altogether by first energy is compared with second energy, and be used to produce the selection signal that is used to control output channel, have the signal that low NTSC interrogates interfering energy altogether so that can export selectively in the I news track data symbol of I news track data symbol and 3 stage notch filtering; (ⅴ) select output device, be used to control output channel, so that at the I news track data symbol of selecting to export selectively under the signal controlling I news track data symbol and 3 stage notch filtering.
NTSC according to use 3 stage notch filters of the present invention disturbs rejector circuit, because the phenomenon of ATV digital broadcast signal that overcome when using comb filter filtering NTSC interference signal also filtering is so the quality that digital broadcast signal receives is improved.
By the detailed specific embodiments of the invention of reference accompanying drawing, purpose of the present invention, characteristics and other advantage will become more obvious.In the accompanying drawing:
Fig. 1 is to use the NTSC that has earlier of common comb filter to disturb rejector circuit figure;
Fig. 2 A be one in the news road frequency spectrum and the spectrogram of the position of NTSC carrier wave;
Fig. 2 B is the spectrogram that the character of frequency response of comb filter is arranged earlier;
Fig. 2 C is the spectrogram that the present invention uses the NTSC interference fringe resistance filter frequency characteristic of 3 stage notch filters;
Fig. 3 is the circuit diagram that uses the NTSC interference band stop filter of 3 stage notch filters according to an embodiment of the invention;
Fig. 4 is used to illustrate that the NTSC that utilizes 3 stage notch filters shown in Figure 3 disturbs the flow chart of the operating principle of rejector circuit;
Fig. 5 A is 8 level symbol mapping tables of the I news track data symbol that received;
Fig. 5 B is the routine oscillogram by the I that the is received news track data symbol of map table conversion shown in Fig. 5 A; With
Fig. 5 C is the oscillogram of expression data segment sync reference mode.
Below with reference to accompanying drawings, more detailed description the present invention according to a particular embodiment of the invention.
Fig. 3 is the NTSC interference rejector circuit figure according to the use 3 stage notch filters of first embodiment of the invention.
As shown in Figure 3, use the NTSC of 3 stage notch filters to disturb rejector circuit to comprise that a NTSC filtering unit 100, the first energy set up unit 200, the second energy and set up unit 300, least energy detector 400 and output unit 500.
First energy is set up unit 200 and is comprised first adder 210, the first squaring devices 220 and first integrator 230.Two inputs of first adder 210 are connected respectively to the source 101 of reception I news track data symbol 103 and the source 102 of data segment sync reference mode 104, and the output of first adder 210 has connected first squaring device 220 and first integrator 230 successively
Second energy is set up unit 300 and is comprised second adder 310, the second squaring devices 320 and second integral device 330.Two inputs of second adder 310 are connected to the output of first 3 stage notch filter and second 3 stage notch filter, and second squaring device 320 and second integral device 330 are connected to the output of second adder 310 successively.
Multiplexer has constituted output unit 500.Multiplexer 500 is got two signals, promptly receive I news track data symbol 103 and from the output of first 3 stage notch filter 120, with this as input, and receive from the output of least energy detector 400, and on the basis of selecting control signal 301, export in two input signals 103 and 121 one as wherein selection control signal.
Then, operation is according to an embodiment of the invention described with reference to the accompanying drawings.
In receiving I news track data symbol 103, a symbol of Miao Shuing is made up of 3 numerical datas shown in Fig. 5 B as an example, and each symbol mapping is in 8 kinds of varying levels by the predetermined map table shown in Fig. 5 A.Correspondingly, in data segment sync reference mode 104, shown in Fig. 5 C, a symbol is corresponding to a numerical data, and binary value " 1 " is transformed into " 5 ", and binary value " 0 " is transformed into " 5 ".As from shown in Fig. 5 B and the 5C, this reception I news track data symbol 103 and data segment sync reference mode 104 are delivered to source 101 and 102 with bit stream form.
With reference to Fig. 4 flow process, disturb in the operation of band stop filter at the NTSC of use shown in Figure 33 stage notch filters, at first receive I news track data symbol 103 and data segment sync reference mode 104 (ST2) by input source end 101 and 102.Then, receive I news track data symbol 103 by first 3 stage notch filter 120 and 130 pairs in second 3 stage notch filter respectively and data segment sync reference mode 104 carries out 3 stage notch filtering (ST6).
Usually, known notch filter is the filter that given frequency is absorbed and decays.The present invention is the comb filter of using with in the 3 stage notch filters replacement prior art filter circuit.The 3 stage notch filter responses that the present invention uses show bright in Fig. 2 C.Shown in Fig. 2 C, 3 stage notch filters 120 and 130 are three characteristic frequency of filtering selectively just, promptly produce NTSC and interrogate video carrier, chrominance carrier and the sound carrier that disturbs altogether.When having been caused that by the NTSC carrier wave receiving undesirable in I news track data symbol 103 and the data segment sync reference mode 104 interrogates when disturbing altogether, this interrogates interference altogether by 3 stage notch filters 120 and 130 filterings., when such common news road not occurring and disturb, also can lose desirable digital broadcast signal.
On the other hand, before 3 stage notch filtering, first energy is set up first energy 231 (ST4) that unit 200 produces this digital broadcast signal.Be the synchronizing signal of filtering in digital broadcast signal, first adder 210 is given in the I news track data symbol 103 of reception and the voltage dimension error signal 211 between the data segment sync reference mode 104.Then, has the error signal 211 of predetermined amplitude and phase place by first squaring device, 220 parallel and first integrator 230 continuous integrals.Consequently, first integrator 230 generations do not have first energy that the preceding I of 3 stage notch filtering of synchronizing signal is interrogated the road digital signal.
In addition, second energy sets up that unit 300 produces is second energy 331 (ST8) through the digital broadcast signal of 3 stage notch filtering.Be the synchronizing signal in the filtering digital broadcast signal, after the data segment sync reference mode 131 of I news track data symbol 121 that receives 3 stage notch filtering and 3 stage notch filtering, second adder 310 produces a voltage dimension error signal 311 by the data segment sync reference mode 131 that deducts 3 stage notch filtering from the I news track data symbol 121 of 3 stage notch filtering.Then, the error signal 311 with a predetermined amplitude and phase place by second squaring device, 320 quadratic sums by second integral device 330 integration continuously.So second integral device 330 produces second energy of the filtered I news of 3 stage notch that do not have synchronizing signal road digital signal.
Receive the least energy detector 400 of first energy 231 and second energy 331, first energy 231 and second energy 331 are compared, and on basis relatively, provide a preset selection control signal 301 (ST10) to multiplexer 500.Have this moment two kinds may, a kind of situation is, first energy 231 is greater than second energy 331, illustrate that NTSC interrogates to disturb altogether to enter I and interrogate the situation of track data symbol 103 and taken place; On the contrary, another kind of situation is that first energy 231 is less than second energy 331, illustrates that NTSC interrogates the not generation of situation that interference enters I news track data symbol 103 altogether.Correspondingly, under former instance, multiplexer 500 is selected the output 121 of first 3 stage notch filter 120, produces data output 530; And under latter instance, these multiplexer 500 selections do not have the I news track data symbol 103 through the reception of 3 stage notch filtering, produce data output 530 (ST12).The selection control signal 301 that is used for the multipath conversion needs is provided by least energy detector 400.
So multiplexer 510 can provide to output port 530 has VSB (residual sideband) digital broadcast signal 513 that removes simulation NTSC composition, simulation NTSC composition includes video (V) carrier wave, colourity (C) subcarrier and sound accompaniment (A) carrier wave.
As mentioned above, the present invention is used in reception under the situation of digital ATV signal of terrestrial broadcasting, disturb rejector circuit by the NTSC that uses 3 stage notch filters, can overcome the shortcoming of the prior art of using comb filter, this shortcoming is that the digital TV broadcasting signal follows simulation NTSC to interrogate the filtering of interfering components altogether and incur loss inevitably, this interrogates interfering components altogether promptly is video carrier, chrominance carrier and sound carrier.So the present invention can provide a digital broadcast signal that improves quality.
In addition, use the NTSC of 3 stage notch filters to disturb rejector circuit to use to be used for the 8-VSB demodulation chip of the digital TV that receives terrestrial broadcasting.
Though show and described the present invention that with reference to specific embodiments of the invention these those skilled in the art should understand according to the scope of the invention of appended claim defined can make various changes and modification.
Claims (10)
1. use 3 stage notch filtering filtering NTSC interrogate the method for disturbing altogether, comprise step:
(ⅰ) after receiving I news track data symbol and data segment sync reference mode, carry out 3 stage notch filtering, cause wherein that to produce NTSC interrogates the radio-frequency component that disturbs altogether by the I of filtering news track data symbol and data segment sync reference mode causing radio-frequency component that NTSC interrogates the ntsc video carrier wave, NTSC chrominance carrier and the NTSC sound carrier that disturb altogether;
(ⅱ) before 3 stage notch filtering, from first error signal between I news track data symbol that receives and data segment sync reference mode, produce first energy of the digital signal that receives;
(ⅲ) after 3 stage notch filtering, from described step (ⅰ) through in second error signal between the reception I of 3 stage notch filtering news track data symbol and the data segment sync reference mode, produce second energy of the digital signal that receives;
(ⅳ) detect NTSC and interrogate interference altogether by first energy is compared with second energy, and produce the selection signal that is used to control output channel, make from the I news track data symbol of I news track data symbol and 3 stage notch filtering, to export selectively to have the signal that low NTSC interrogates interfering energy altogether;
(ⅴ) selecting to control output channel under the signal controlling, so that can export a signal in the I news track data symbol of I news track data symbol and 3 stage notch filtering selectively, wherein, interrogate altogether at NTSC and to disturb under the situation not have generation, the signal of selecting output is the I news track data symbol of the reception before 3 stage notch filtering, and interrogate altogether under the situation of disturbing generation at NTSC, the signal of selecting output is the I news track data symbol of the reception after 3 stage notch filtering.
2. method according to claim 1, the step that wherein said step (ⅱ) comprises has:
By from the I news track data symbol that receives, deducting the data segment sync reference mode, with generation a kind of second error signal of voltage dimension signal;
Produce first power signal by square first error signal; With
Produce first energy by integration first power signal.
3. method according to claim 1, the step that wherein said step (ⅲ) comprises has:
By from I news track data symbol, deducting data segment sync reference mode, be a kind of first error signal of voltage dimension signal with generation through 3 stage notch filtering through the reception of 3 stage notch filtering;
Produce second power signal by square second error signal; With
Produce second energy by integration second power signal.
4. method according to claim 1, wherein, be less than at first energy under the situation of second energy, carry out not producing the detection that NTSC interrogates disturbed condition altogether, and under the situation of first energy, carry out producing the detection that NTSC interrogates disturbed condition altogether greater than second energy.
5. one kind is used the NTSC of 3 stage notch filters to disturb rejector circuit, comprising:
(ⅰ) NTSC filtering device, be used for after receiving I news track data symbol and data segment sync reference mode, to causing that the radio-frequency component that NTSC interrogates the ntsc video carrier wave, NTSC chrominance carrier and the NTSC sound carrier that disturb altogether carries out 3 stage notch filtering, do not comprise and cause that NTSC interrogates the I news track data symbol and the data segment sync reference mode of the radio-frequency component that disturbs altogether to produce;
(ⅱ) the first energy apparatus for establishing was used for before 3 stage notch filtering, from receive first error signal between I news track data symbol and the data segment sync reference mode, produced first energy of the digital signal that receives;
(ⅲ) the second energy apparatus for establishing, be used for after 3 stage notch filtering, from the reception I news track data symbol and second error signal between the data segment sync reference mode that carried out 3 stage notch filtering by described NTSC filtering device, produce second energy of the digital signal that receives;
(ⅳ) least energy checkout gear, be used for detecting NTSC and interrogate interference altogether by first energy is compared with second energy, and produce the selection signal that is used to control output channel, have the signal that low NTSC interrogates interfering energy altogether so that can from the I news track data symbol of I news track data symbol and 3 stage notch filtering, export selectively; With
(ⅴ) select output device, be used for selecting to control output channel under the signal controlling, so that can export a signal in the I news track data symbol of I news track data symbol and 3 stage notch filtering selectively.
6. NTSC according to claim 5 disturbs rejector circuit, and wherein said NTSC filtering device comprises:
The one 3 stage notch filter, be used for after being provided the I news track data symbol that receives, to causing that the radio-frequency component that NTSC interrogates the ntsc video carrier wave, NTSC chrominance carrier and the NTSC sound carrier that disturb altogether carries out 3 stage notch filtering, do not comprise and cause that NTSC interrogates the I news track data symbol and the data segment sync reference mode of the radio-frequency component that disturbs altogether to produce; With
The 23 stage notch filter, be used for after being provided the I news track data symbol that receives, to causing that the radio-frequency component that NTSC interrogates the ntsc video carrier wave, NTSC chrominance carrier and the NTSC sound carrier that disturb altogether carries out 3 stage notch filtering, do not comprise and cause that NTSC interrogates the I news track data symbol and the data segment sync reference mode of the radio-frequency component that disturbs altogether to produce.
7. NTSC according to claim 5 disturbs rejector circuit, and the wherein said first energy apparatus for establishing comprises:
First error signal generation device is used for by deducting the data segment sync reference mode from the I news track data symbol that receives, and generation is a kind of first error signal of voltage dimension signal;
The first power signal generation device is used for producing first power signal by square first error signal; With
First energy producing unit is used for producing first energy by integration first power signal.
8. NTSC according to claim 5 disturbs rejector circuit, and the wherein said second energy apparatus for establishing comprises:
Second error signal generation device is used for by deduct the data segment sync reference mode through 3 stage notch filtering from the reception I news track data symbol through 3 stage notch filtering, and generation is second error signal of a voltage dimension signal;
The second power signal generation device, be used for by square second error signal produce second power signal and
Second energy producing unit is used for producing second energy by integration second power signal.
9. NTSC according to claim 5 disturbs rejector circuit, wherein, interrogate altogether under the situation about disturbing not producing NTSC, the output signal of selecting from described selected output signal is the I news track data symbol of the reception before 3 stage notch filtering, and interrogate altogether under the situation of disturbing generation at NTSC, the output signal of selection is the I news track data symbol of the reception after 3 stage notch filtering.
10. NTSC according to claim 5 disturbs rejector circuit, wherein said least energy checkout gear, when first energy is less than second energy, what detect is that NTSC interrogates the situation that does not have generation of disturbing altogether, and when first energy during greater than second energy, detection be that NTSC interrogates the situation about producing of disturbing altogether.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR44660/97 | 1997-08-30 | ||
| KR1019970044660A KR100256449B1 (en) | 1997-08-30 | 1997-08-30 | Method for rejecting ntsc interference for using 3 step notch filter and a ntsc interference rejection filter circuit for reproming the same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1210421A true CN1210421A (en) | 1999-03-10 |
Family
ID=19520294
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN97109383A Pending CN1210421A (en) | 1997-08-30 | 1997-12-25 | Method for rejecting NTSC interference and NTST interference rejection filter circuit using 3-stage notch filter |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JPH1175133A (en) |
| KR (1) | KR100256449B1 (en) |
| CN (1) | CN1210421A (en) |
| GB (1) | GB2328822B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20040096319A (en) * | 2003-05-09 | 2004-11-16 | 삼성전자주식회사 | Device remove a characteristic different interference signal and a method removing thereof |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5282023A (en) * | 1992-05-14 | 1994-01-25 | Hitachi America, Ltd. | Apparatus for NTSC signal interference cancellation through the use of digital recursive notch filters |
| KR0151529B1 (en) * | 1995-10-31 | 1998-10-15 | 김광호 | Apparatus and method for controlling the operation selection of ntsc rejection filter |
-
1997
- 1997-08-30 KR KR1019970044660A patent/KR100256449B1/en not_active IP Right Cessation
- 1997-12-11 GB GB9726243A patent/GB2328822B/en not_active Expired - Fee Related
- 1997-12-17 JP JP9347513A patent/JPH1175133A/en active Pending
- 1997-12-25 CN CN97109383A patent/CN1210421A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| GB2328822A (en) | 1999-03-03 |
| JPH1175133A (en) | 1999-03-16 |
| GB2328822B (en) | 1999-07-14 |
| GB9726243D0 (en) | 1998-02-11 |
| KR19990021153A (en) | 1999-03-25 |
| KR100256449B1 (en) | 2000-05-15 |
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