CN101325669A - Method for blind scanning digital television broadcast receiving system using frequency spectrum analysis - Google Patents
Method for blind scanning digital television broadcast receiving system using frequency spectrum analysis Download PDFInfo
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- CN101325669A CN101325669A CNA2007101111919A CN200710111191A CN101325669A CN 101325669 A CN101325669 A CN 101325669A CN A2007101111919 A CNA2007101111919 A CN A2007101111919A CN 200710111191 A CN200710111191 A CN 200710111191A CN 101325669 A CN101325669 A CN 101325669A
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Abstract
A method of digital television broadcast receiving system blind search utilizing spectral analysis is characterized in that it comprises the following steps: receiving a television broadcast signal displayed in time domain signal; converting the television broadcast signal from time domain signal into frequency domain signal; analyzing the frequency spectrum signature of the frequency domain signal to rapidly judge whether the received television broadcast is available and distinguishing the television broadcast signal is digital television signal or analog television signal; and if the signal is digital television signal, estimating system modulating signal band width parameter directly according to the frequency spectrum signature. Thereby, the invention can distinguish the received television broadcast signal type rapidly and deals with respectively to speed up the blind search.
Description
Technical field
The present invention relates to a kind of method of blind scanning digital television broadcast receiving system, be meant a kind of method of utilizing spectrum analysis as blind scanning digital television broadcast receiving system especially.
Background technology
Because radiovision begins to enter digital Age at present, the program signal of broadcasting enters simulation and digital synchronous transfer phase from analog signal.This is that own television broadcasting is gone through in half a century, and relay is looked colorize another major transformation afterwards.
Along with digital times is arrived, television broadcasting also converts digital system to from traditional analog system gradually.Receive phenomenon bad or that signal is dynamic owing to analogue system is had by the terrain and its features factor affecting often, the digital video broadcast system then can overcome this type of to be disturbed, and more high image quality and the more program of good news matter are provided.Simultaneously, can be more efficient in the use of frequency spectrum, for example on the use frequency range identical, can transmit more program with simulated television.More prior is that digital video broadcasting can also provide the data broadcasting various value added service that (Data Broadcasting) derived.
Television broadcast medium mainly comprises: mode such as wired, satellite, microwave, ground.And in Digital TV broadcasting standard for terrestrial, mainly include the ATSC (Advanced TelevisionSystems Committee) of U.S. rule, the DVB-T (Digital VideoBroadcasting-Terrestrial) of Europe rule, and the ISDB-T (Integrated Services DigitalBroadcasting-Terrestrial) of Japan.In addition, at present ground TV broadcast system, wherein coexistence has analog-and digital-two kinds of different standard TV signal, therefore in digital television receiver, there is so-called blind sweeping (Blind Search) function in the capital, it is a kind of optionally initializing set function, can provide by hardware or software, mainly be the usefulness that is used for the scanning digital program, use digital television receiver to carry out the receiving digital television program for the first time the user, when the user does not know program frequency point (Frequency) and signal modulation parameter, all be to see through this function to seek out present all frequencies and the program that can receive perhaps.Blind effect of sweeping of known techniques at present and method have following two kinds: the one, the local program data of having announced is preset in the digital television receiver, and when blind sweeping, just in order to reaffirm that presetting program can normally receive; Another kind is real blind sweeping, because in advance and do not know any program frequency point and the signal modulation parameter information in this reception place, the TV signal that comprises a certain frequency is analog signal or digital signal, must suppose at the beginning that this received signal is a digital signal, adopt software that parameter combinations is inputed to demodulator (Demodulator) then, reexamine its state, changing one group of parameter after the overtime again attempts, after according to this all parameters being attempted, abandon search at last, to enter the search of next frequency.When running into anolog TV signals, if can not quick identification, demodulator just must be attempted multiple modulation parameter combination, reach hundreds of more than, therefore can waste long blind flyback time.And when at receiving digital signals,, also can waste a lot of times if during the poor quality of received signal.
Summary of the invention
In view of this, technical problem to be solved by this invention, be to provide a kind of method of utilizing spectrum analysis as blind scanning digital television broadcast receiving system, it is to utilize spectrum signature to judge whether the terrestrial television broadcast signal of reception is useful signal, and differentiation is to belong to digital tv ground broadcasting or simulated television terrestrial broadcast system apace.
In order to address the above problem, according to a kind of scheme proposed by the invention, a kind of method of utilizing spectrum analysis as blind scanning digital television broadcast receiving system is provided, its step comprises: at first receive a terrestrial television broadcast signal that presents with time domain (Time Domain) signal kenel, and to change this time-domain signal be a frequency domain (Frequency Domain) signal, and this frequency-region signal forms a frequency spectrum pattern; And confirm that the broadcast singal that is received is a useful signal.Then, judge whether this frequency spectrum pattern satisfies a left and right sides sideband symmetry and the smooth graphic feature of bandwidth, when if this frequency spectrum pattern comprises above-mentioned graphic feature, represent that then this terrestrial television broadcast signal is a digital television signal, and then demodulation and to note down this terrestrial television broadcast signal be a program frequency point, can estimate the bandwidth of this digital television signal at the same time, with required times of action such as saving rear end demodulation.In addition, when this frequency spectrum pattern is non-when comprising the smooth graphic feature of this left and right sides sideband symmetry and bandwidth, represent that then this terrestrial television broadcast signal is anolog TV signals, and then abandon search, and enter next frequency search to continue to receive other terrestrial television broadcast signal at this frequency.
In order to address the above problem, according to another kind of scheme proposed by the invention, a kind of method of utilizing spectrum analysis as blind scanning digital television broadcast receiving system is provided, its step comprises: at first receive a terrestrial television broadcast signal that presents with the time-domain signal kenel, and to change this time-domain signal be a frequency-region signal, and this frequency-region signal can form a frequency spectrum pattern; And confirm that the broadcast singal that is received is a useful signal.Then, judge whether this frequency spectrum pattern comprises the graphic feature that an image carrier or a sound carrier were fixed and included to a spectrum position, when if this frequency spectrum pattern comprises above-mentioned graphic feature, represent that then this terrestrial television broadcast signal is anolog TV signals, and then abandon the search of this terrestrial television broadcast signal.And when if this frequency spectrum pattern does not comprise that spectrum position is fixed and do not contain the graphic feature of this image carrier and this sound carrier, represent that then this terrestrial television broadcast signal is a digital television signal, and then demodulation and to note down this terrestrial television broadcast signal be a program frequency point.
Above general introduction and ensuing detailed description and accompanying drawing all are to reach mode, means and the effect that predetermined purpose is taked in order to further specify the present invention.And relevant other purpose of the present invention and advantage, will follow-up explanation and graphic in set forth.
Description of drawings
Fig. 1 is the spectrum analysis figure of the present invention about anolog TV signals;
Fig. 2 is the spectrum analysis figure of the present invention about a digital television signal;
Fig. 3 is a kind of method embodiment flow chart that utilizes spectrum analysis as blind scanning digital television broadcast receiving system of the present invention; And
Fig. 4 utilizes the method embodiment flow chart of spectrum analysis as blind scanning digital television broadcast receiving system for another kind of the present invention.
The diagrammatical symbol explanation
Image carrier (Picture carrier) a
Sound carrier (Audio carrier) b
Embodiment
Please also refer to Fig. 1 and Fig. 2, it is that the present invention is in order to describe the spectrum analysis figure of anolog TV signals and a digital television signal respectively.In this explanation earlier be, the present invention is with the DVB-T (DigitalVideoBroadcasting-Terrestrial) of the Europe rule preferable implementation as following Digital TV broadcasting standard for terrestrial, and with the NTSC (National Television System Committee) of the PAL (Phase Alternating Line) of Europe rule and the U.S. rule preferable implementation as following simulated television terrestrial broadcasting standard.
Wherein, distinguish the graphic feature of digital spectrum and analog spectrum, the most important thing is to judge whether left-right symmetric of frequency spectrum.By the simulated television frequency spectrum of Fig. 1 as can be seen, its irregular pattern that shows shaded side is to be its real graphical distribution, wherein the scope that is begun by its top comprises two parts, be respectively the 4MHz and the 1.25MHz that extends to left side X-axis Frequency that extends to the right X-axis Frequency, the dotted line that extends to 4MHz place, the left side is then represented if this graphical distribution is to present symmetrical words, it is the most long-range that the shaded side on the left side should extend to dotted line, but truth is non-right, and the television spectrum of simulation is to belong to the asymmetric graphic feature in the left and right sides as can be known by this.Then, again with reference to figure 2, begin to find out bandwidth (about Frequency (4) HMz～of its right and left 4HMz) for being evenly distributed by X-axis Frequency 0MHz, and the more long-range angle that also can find out its inclination of looking also identical toward both sides again, and the Digital Television frequency spectrum of finding out that therefore can be very definite is to belong to symmetrical graphic feature.
The foundation of other judgement then comprises, (about Frequency (4) HMz～4HMz), except left-right symmetric, it is to present smooth bell to distribute to the bandwidth of Digital Television frequency spectrum, is not that bell as the massif shape as the simulated television frequency spectrum distributes.Moreover the video carrier of simulated television frequency spectrum and the relative position of sound carrier are fixed, and the simulated television frequency spectrum can include a high-octane image carrier (Picture carrier) a and sound carrier (Audio carrier) b, and the Digital Television frequency spectrum does not then have.
With reference to the above, can find has very big obvious differentiation between Digital Television frequency spectrum and the simulated television frequency spectrum, blind sweeping (Blind Search) method that therefore disclosed Fig. 3 and Fig. 4 can be used as digital television broadcast receiving system according to above-mentioned frequency spectrum difference.
Please refer to Fig. 3, be a kind of method embodiment flow chart that utilizes spectrum analysis as blind scanning digital television broadcast receiving system of the present invention, comprise: at first, on present frequency, whether detecting has a terrestrial television broadcast signal input (S301) that presents with time domain (Time Domain) signal kenel, if the result is for being in detecting, then receive, and this time-domain signal is converted to a frequency domain (Frequency Domain) signal (S303), wherein this frequency-region signal can form as the simulation of Fig. 1 or the digital spectrum pattern of Fig. 2, and its conversion method is the operation method with a fast fourier transform, and the operation method of this fast fourier transform can for example be to provide calculation process by fourier transform arithmetic element or software program in the demodulator of digital television receiver, to change this time-domain signal is frequency-region signal, shown quality that comprises this frequency-region signal and the strength information of this frequency spectrum pattern in addition, whether with the terrestrial television broadcast signal that further judgement was received is useful signal, and the lock-out state that also can for example see through automatic gain control (AGC) circuit on the hardware is in addition judged; And if the detecting result of step (S301) for not, then finishes the search (S302) of this present frequency.
Then, if frequency-region signal is a useful signal, judge then whether this frequency spectrum pattern comprises a left-right symmetric and the smooth graphic feature (S305) of bandwidth, when if this frequency spectrum pattern comprises above-mentioned graphic feature, then represent this terrestrial television broadcast signal be a digital television signal (as shown in Figure 2) (S307), and then to carry out demodulation and note down this terrestrial television broadcast signal be a program frequency point (S309), simultaneously the bandwidth that more can estimate this digital television signal according to this frequency spectrum pattern is 6MHz, one of them of 7MHz or 8MHz system makes and is used for saving time to offer related procedure such as rear end demodulation.
In addition, if the judged result of step (S305) is not for the time, just this frequency spectrum pattern is non-when comprising the smooth graphic feature of this left-right symmetric and bandwidth, represent that then this terrestrial television broadcast signal is anolog TV signals (S311) or other interference, and then to abandon this terrestrial television broadcast signal be program frequency point (S313).And reach (S313) afterwards at step (S302), (S309), just switch to next frequency (S314) again, and get back to (S301) and detect the input whether terrestrial television broadcast signal is arranged at this frequency to continue carrying out this blind method of sweeping.By repeating above-mentioned steps, just all terrestrial television broadcast signal can be judged, and tell digital television signal apace, and then demodulation and record are program frequency point.
Please refer to Fig. 4, for another kind of the present invention utilizes the method embodiment flow chart of spectrum analysis as blind scanning digital television broadcast receiving system, comprise: at first, on present frequency, whether detecting has a terrestrial television broadcast signal input (S401) that presents with the time-domain signal kenel, if the result is for being in detecting, then receive, and this time-domain signal is converted to a frequency-region signal (S403), wherein this frequency-region signal can form as the simulation of Fig. 1 or the digital spectrum pattern of Fig. 2, and its conversion method is the operation method with a fast fourier transform, and the operation method of this fast fourier transform can for example be to provide calculation process by fourier transform arithmetic element or software program in the demodulator of digital television receiver, to change this time-domain signal is this frequency-region signal, shown quality that comprises this frequency-region signal and the intensity of this frequency spectrum pattern in addition, whether with the terrestrial television broadcast signal that further judgement was received is useful signal, and the lock-out state that also can for example see through automatic gain control (AGC) circuit on the hardware is in addition judged; And if the detecting result of step (S401) for not, then finishes the search (S402) of this present frequency.Then, judge whether a spectrum position that is comprised in this frequency spectrum pattern fixes and include the graphic feature (S405) of an image carrier or a sound carrier, if judged result is for being, represent that then this terrestrial television broadcast signal is anolog TV signals (S407), and then to abandon this terrestrial television broadcast signal be program frequency point (S409).
Otherwise, if the judged result of step (S405) is for denying, when just this frequency spectrum pattern does not comprise that spectrum position is fixed and does not contain the graphic feature of this image carrier and this sound carrier, represent that then this terrestrial television broadcast signal is a digital television signal (S411), and then demodulation and to note down this terrestrial television broadcast signal be a program frequency point (S413).And reach (S413) afterwards at step (S402), (S409), just switch to next frequency (S414) again, and get back to (S401) and detect the input whether terrestrial television broadcast signal is arranged at this frequency to continue carrying out this blind method of sweeping.
In sum, the present invention is that the terrestrial television broadcast signal of utilizing the difference of spectrum signature to distinguish reception is to belong to digital tv ground broadcasting or simulated television terrestrial broadcast system, need not all carry out parameter at every turn and receive trial, also need not in receiving cut-and-try process, to wait for the time-consuming time each terrestrial television broadcast signal.In addition, owing to itself the fourier transform arithmetic element is arranged promptly in the demodulator of digital television receiver, therefore can promptly carry out the conversion of time-domain signal at an easy rate, also can judge very soon and have or not digital signal or analog signal on this frequency actually, carry out efficient with the initialization that improves Digital Television by this.
But, the above, it only is the detailed description of specific embodiments of the invention and graphic, be not in order to restriction the present invention, all scopes of the present invention should be as the criterion with claim, anyly be familiar with this skill person in the field of the invention, can think easily and variation or modify and all can be encompassed in the claim that the present invention defines.
Claims (13)
1, a kind of method of blind scanning digital television broadcast receiving system is characterized in that, step comprises:
Receive a television broadcasting signal, wherein this television broadcasting signal is to present with time-domain signal;
Changing this television broadcasting signal is a frequency-region signal;
Whether the frequency spectrum pattern of analyzing this frequency-region signal comprises a left-right symmetric and the smooth graphic feature of bandwidth; And
When the frequency spectrum pattern of this frequency-region signal comprises the smooth graphic feature of this left-right symmetric and bandwidth, then be expressed as a digital television signal, and note down this television broadcasting signal.
2, the method for blind scanning digital television broadcast receiving system as claimed in claim 1 is characterized in that: described television broadcasting signal is a terrestrial television broadcast signal.
3, the method for blind scanning digital television broadcast receiving system as claimed in claim 1 is characterized in that: changing this time-domain signal is that (Fast FourierTransforms, operation method FFT) is carried out with a fast fourier transform for this frequency-region signal.
4, the method for blind scanning digital television broadcast receiving system as claimed in claim 3 is characterized in that: the operation method of described fast fourier transform is to provide calculation process by the fourier transform arithmetic element in the demodulator of digital television receiver.
5, the method for blind scanning digital television broadcast receiving system as claimed in claim 1 is characterized in that: but analyze the quality and the intensity of the frequency spectrum pattern picked up signal of this frequency-region signal.
6, the method for blind scanning digital television broadcast receiving system as claimed in claim 1 is characterized in that: the bandwidth that more can estimate this digital television signal according to the frequency spectrum pattern of this frequency-region signal.
7, the method for blind scanning digital television broadcast receiving system as claimed in claim 1, it is characterized in that: further comprise: when the frequency spectrum pattern of this frequency-region signal does not comprise the smooth graphic feature of this left-right symmetric and bandwidth, then be expressed as anolog TV signals, and abandon noting down this television broadcasting signal.
8, a kind of method of blind scanning digital television broadcast receiving system is characterized in that, step comprises:
Receive a television broadcasting signal, wherein this television broadcasting signal is to present with time-domain signal;
Changing this television broadcasting signal is a frequency-region signal;
Whether the frequency spectrum pattern of analyzing this frequency-region signal comprises the graphic feature that an image carrier or a sound carrier were fixed and included to a spectrum position; And
When the frequency spectrum pattern of this frequency-region signal does not comprise that this spectrum position is fixed and when not containing the graphic feature of this image carrier or this sound carrier, then is expressed as a digital television signal, and notes down this television broadcasting signal.
9, the method for blind scanning digital television broadcast receiving system as claimed in claim 8 is characterized in that: described television broadcasting signal is a terrestrial television broadcast signal.
10, the method for blind scanning digital television broadcast receiving system as claimed in claim 8 is characterized in that: changing this time-domain signal is that (FastFourier Transforms, operation method FFT) is carried out with a fast fourier transform for this frequency-region signal.
11, the method for blind scanning digital television broadcast receiving system as claimed in claim 10 is characterized in that: the operation method of described fast fourier transform is to provide calculation process by the fourier transform arithmetic element in the demodulator of digital television receiver.
12, the method for blind scanning digital television broadcast receiving system as claimed in claim 8 is characterized in that: but analyze the quality and the intensity of the frequency spectrum pattern picked up signal of this frequency-region signal.
13, the method for blind scanning digital television broadcast receiving system as claimed in claim 8, it is characterized in that: further comprise: when the frequency spectrum pattern of this frequency-region signal comprises this spectrum position and fixes and include the graphic feature of this image carrier or this sound carrier, then be expressed as anolog TV signals, and abandon noting down this television broadcasting signal.
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| Application Number | Priority Date | Filing Date | Title |
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| CNA2007101111919A CN101325669A (en) | 2007-06-14 | 2007-06-14 | Method for blind scanning digital television broadcast receiving system using frequency spectrum analysis |
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| CNA2007101111919A CN101325669A (en) | 2007-06-14 | 2007-06-14 | Method for blind scanning digital television broadcast receiving system using frequency spectrum analysis |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101909183B (en) * | 2009-06-04 | 2012-11-21 | 联发科技股份有限公司 | Multi-channel broadcasting program receiver and channel scanning method |
| CN106507002A (en) * | 2016-10-10 | 2017-03-15 | 广州视源电子科技股份有限公司 | Television channel searching method and digital-analog integrated television |
-
2007
- 2007-06-14 CN CNA2007101111919A patent/CN101325669A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101909183B (en) * | 2009-06-04 | 2012-11-21 | 联发科技股份有限公司 | Multi-channel broadcasting program receiver and channel scanning method |
| CN106507002A (en) * | 2016-10-10 | 2017-03-15 | 广州视源电子科技股份有限公司 | Television channel searching method and digital-analog integrated television |
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Open date: 20081217 |