KR0140600B1 - A method and apparatus for discriminating sound modes in television - Google Patents

Abstract

The present invention relates to a sound mode discrimination method and apparatus of a television. The sound mode discrimination method of a television according to the present invention is a case in which a signal of a D / K, B / G, and I systems is to be simultaneously received in Europe. It is advantageous to implement the part that determines the sound mode by receiving the voice intermediate frequency signals of each method in software, which is more effective and economical than the hardware implementation (represented in FIG. 5), and also the sound mode of the television. The discriminating device has an advantage of eliminating noise generated when switching channels by discriminating the sound mode by installing the microcomputer 10 and the memory 20 in the audio intermediate frequency receiving section of the television.

Description

Method and apparatus for sound mode determination of television

(A) of FIG. 1 shows a frequency spectrum of a two carrier system, (b) shows a frequency spectrum of a voice multiplex method in Japan (FM-FM), and (c) a US voice multiplex method (AM). -FM method: a diagram showing the frequency spectrum of the Zenith method),

2 is a diagram showing a frequency spectrum of the NICAM (Near Instantaneous Companded Audio Multiplex) scheme, (a) is a diagram showing the frequency spectrum of the I scheme, (b) is a diagram showing the frequency spectrum of the B scheme, (c) is G Diagram showing the frequency spectrum of the scheme,

(A) of FIG. 3 shows the characteristics of pre-emphasis and de-emphasis, (b) shows the standard characteristics of pre-emphasis,

4 is a block diagram of a conventional television reception system in which hardware capable of simultaneously receiving signals of D / K, B / G, and I systems is implemented in hardware;

5 is a flowchart of a sound mode determination method of a television according to the present invention;

6 is a block diagram of the sound mode discrimination apparatus of the television according to the present invention.

* Explanation of symbols for main parts of the drawings

10: microcomputer 20: memory

30: sound processor 40: amplifier

The present invention relates to a method and apparatus for determining the sound mode of a television, and in particular, when receiving signals of D / K, B / G, and I modes simultaneously in Europe, The sound mode discrimination method is more effective and economical than the hardware implementation by implementing the part of sound mode discrimination in software, and additionally, a microcom 10 and a memory 20 are additionally installed in the audio intermediate frequency receiver of the television. The present invention relates to a sound mode discrimination apparatus of a television for removing noise generated during channel switching by discriminating a sound mode.

The terrestrial broadcasting television transmission system is classified into M, B / G, D / K, I, L system according to the characteristics of the synchronization signal, and also NTSC system (NATIONAL TELEVISION SYSTEM COMMITTEE) and PAL system (PHASE ALTERNATION) according to the color system. BY LINE) and SECAM method (SEQUENTIEL COULEUR A MEMOIRE).

Therefore, countries around the world are doing television broadcasting using a combination of a television transmission system and a television color system. For example, the United States, Japan, and Korea employ the NTSC-M method, and in Western Europe such as Germany, Spain, Italy and Sweden, the PAL-B / G method is adopted. In China and Romania, the PAL-D / K method is adopted. PAL-I is adopted in the UK, Ireland and South Africa, SECAM-L is adopted in France and Luxembourg, and SECAM-D / K is adopted in Eastern Europe such as the Commonwealth of Independent States.

Television audio multicasting is a system in which stereo audio or bilingual broadcasting is simultaneously broadcasted by superimposing another audio signal on a radio wave of a television broadcast simultaneously.

In the voice multiplexing method, a second carrier is provided in addition to the existing voice carrier, and a subcarrier system is used to multi-modulate a subcarrier modulated by a dual carrier system and a sub-voice to a conventional voice carrier. Subdivided into two categories, the analog two-carrier method (Korea, Germany), FM-FM (Japan), AM-FM (US), and Digital Phase Shift Keying (DPSK) have.

(A) of FIG. 1 is a diagram showing a frequency spectrum of a two-carrier scheme. The two-carrier scheme is used in Korea, Germany, China, and the like. In addition to the conventional voice carrier (channel 1), a second voice carrier (channel 2) From Channel 1, Korea is added 14.25fh (fh = 15.7342㎑), while Germany and China are 15.5fh (fh = 15.625㎑). The pilot signal used to discriminate the speech content from the receiver is a control signal obtained by modulating the 3.5fh subcarrier at 50% AM. The modulation frequency is 149.85 Hz in Korea, 117.5 Hz in Germany and China when the modulation frequency is stereo. Silver 276.04Hz, Germany and China use 274.1Hz, when mono is unmodulated. The two-carrier type has better left and right separation in stereo than the FM-FM method, and crosstalk and signal-to-noise ratio in two languages.

FIG. 1 (b) is a diagram showing the frequency spectrum of the Japanese multiplex method (FM-FM). The Japanese multiplex method is an FM-FM method in which 2fh is a subcarrier. L + R, subchannel signal consists of stereo LR, bilingual and pilot signal. For better separation of the two languages, the frequency shift of the sub-signals is set to 15KHz and 20KHz for stereo, and the pilot signal with 60% AM modulation of the 3.5fh subcarrier is 982.5Hz, bilingual for the modulation frequency. Is using 922.5Hz.

Analyzing the frequency spectrum of the Japanese multiplexed signal, the 4.5MHz carrier of the FM FM wave is FM-modulated at 25KHz with the baseband of the unmodulated baseband, the FM-modulated sub-signal, and the AM-modulated pilot signal combined. do. In this case, the sub-signal is an FM-FM wave that modulates FM twice, and the control signal is an AM-FM wave. In this way, the Japanese multiplexing method is called the FM-FM method based on the modulation method of the sub-signals. In the case of stereo broadcasting, the receiver detects the LR signal through a band pass filter, which limits the bandwidth required to transmit the signal to prevent interference with the main channel or control channel and to prevent noise. Since the s delay occurs and the stereo separation becomes worse due to the time difference with the L + R signal, the transmitter compensates the time difference with the LR signal by delaying the L + R signal by 0.00002 s and removes the noise of the high frequency component. In order to transmit high frequency components, the pre-emphasis is emphasized, and de-emphasis is performed to demodulate the original signal in the receiver.

(C) of FIG. 1 is a diagram showing the frequency spectrum of the US voice multiplex method (AM-FM method: Zenith method). Zenith dbx system is adopted by the Federal Communications Commission (FCC) for US voice multicasting. The stereo system of this method is compared to the FM-FM method of the AM-FM method, which uses 2fh as a subcarrier and fh as a pilot signal, so that it is more susceptible to the effects of the buzz generated in the receiver. The reduction circuit is used to improve the signal-to-noise ratio. Bilingual broadcasting is the second sub-channel of FM-modulated second carrier 5fh called SAP (Second Audio Program), which also employs dbx noise reduction circuit to improve signal-to-noise ratio. The main channel (L + R) contains a filter to compensate for the delay caused by the noise reduction circuit of the subchannel, which improves the signal-to-noise ratio and prevents deterioration of the separation of the stereo signal. The FM maximum frequency shift set by the Federal Communications Commission (FCC) of 73 KHz is the first sub-signal (LR) + pilot signal + second sub-signal + Telemetry = 50K + 5K + 15K + 3K = 73KHz when L = -R This is the maximum deviation when modulating a transmitting device. The noise reduction system employed by the Federal Communications Commission's television voice multiplexing scheme is a circuit inserted to obtain a high noise reduction effect on a channel having a bad signal-to-noise ratio.

2 is a diagram illustrating a frequency spectrum of a NICAM (Near Instantaneous Companded Audio Multiplex) scheme, (a) in FIG. 1, (b) in FIG. B, and (c) in FIG. The digital method is divided into English (I) voice multiplexing and Swedish (or Scandinavian, B / G) voice multiplexing. Voice multiplexing in English (I) or Suweden (or Scandinavian, B / G) is a system that adds a second carrier to I, B / G television modulation and adds a second carrier. And digitalize the data signal, and in the British method (I method), transmit a second carrier of 6.552 MHz by 4-phase DPSK (Differential Phase Shift Keying) modulation, and use the Swedish method (or Scandinavian method or B / G method). In the present invention, a second carrier of 5.58 MHz is modulated and transmitted by four-phase Differential Phase Shift Keying (DPSK).

The Swedish method (or Scandinavian method, B / G method) modulates a second carrier at 5.85 MHz with 4-phase differential phase shift keying (DPSK) as an input signal by using a 728 KHz clock and 728 Kbit / sec data as an input signal. sec.

On the other hand, Japanese satellite voice multiplexing digitalizes two types of voice (A mode: mono, stereo and dual broadcast, B mode: stereo broadcast) and two types of independent voice (A mode), and has a signal of 5.727272 MHz. The rear side modulates a four-phase differential phase shift keying (DPSK) to add a subcarrier.

NICAM-728 (Near Instantaneous Companded Audio Multiplex-728) Digital Voice Carrier System provides two types of voice and data signals: Near Instantaneous Companding, Bit Interleaving, Energy Dispersal Scrambling, etc. After digital processing, the second voice carrier is modulated with Quadrature Differential Phase Shift Keying (QDPSK) and transmitted in a 16 frame sequence (16 Frame Sequence: 16 ms). Compressed sample coding is performed by two's complement by Near Instantaneous Companding the initial 14 bits / samples with 32 samples / ms block by sampling frequency by 10 bits / sample.

FIG. 3 is a diagram showing characteristics of pre-emphasis and de-emphasis, and (b) is a diagram showing standard characteristics of pre-emphasis. The carrier is 4.5MHz (B / G: 5.5MHz, D / K, L: 6.5MHz, I: 6.0MH) higher in NTS-M than the video carrier. FM modulation and transmission are performed at 25KHz (± 50KHz in PAL), pre-emphasis time constant 0.000075s (0.00005s in PAL), and P / S power ratio 1 / 2-1 / 10 so as not to interfere with video signal components. The FM modulated wave increases the noise component as the signal of higher frequency component deteriorates and deteriorates the signal-to-noise ratio. Therefore, the FM modulation wave is pre-emphasized at the transmitting side to emphasize the high-frequency component and de-emphasis at the receiving side to correct the frequency characteristic.

Looking at the voice carrier frequencies of D / K, B / G, and I systems classified according to the synchronization signal characteristics among the television transmission methods, the D / K method has 6.5 MHz, the B / G method has 5.5 MHz, and the I method. Has 6 MHz.

4 is a block diagram of a conventional television reception system in which a part capable of simultaneously receiving D / K, B / G, and I signals is implemented in hardware.

In Europe, the D / K, B / G, and I signals may need to be received at the same time. The conventional TV audio signal receiver receives the sound intermediate frequency signals of each system as shown in FIG. Since the discriminating part was made of hardware, there was a problem that the price was expensive and there were many coordinators.

Accordingly, the present invention determines the sound mode by receiving the voice intermediate frequency signal of each method when it is necessary to simultaneously receive the signals of the D / K, B / G, I method in order to solve the above problems The purpose of the present invention is to provide an effective and economical sound mode discrimination method by implementing the software part, and also by adding a microcomputer and a memory to the audio intermediate frequency receiver of the television and discriminating the sound mode through the above software. It is an object of the present invention to provide a sound mode discrimination apparatus for removing noise generated during channel switching.

The sound mode determination method of the television according to the present invention for achieving the above object is a channel for determining the sound mode at the time of tuning when the signal of the D / K, B / G, I method should be received at the same time A first step of starting tuning; A second step of continuing channel tuning; Determining whether channel tuning is terminated and, if terminated, moving to the next step; if not, moving to the second step and continuing channel tuning; A fourth step of starting sound mode determination when channel tuning is completed in the third step; A fifth step of continuing the sound mode determination; A sixth step of determining whether the sound mode determination is terminated and moving to the next step if it is terminated, and if not, going to the fifth step to continue the sound mode determination; A seventh step of storing sound mode data in a memory when sound mode determination is terminated in the sixth system; An eighth step of repeating the sixth step from the first step to determine a sound mode by tuning a next channel when the sound mode determination is terminated in the sixth step; A ninth step of determining whether the channel is switched at the time of switching and repeating if the channel is not switched, and proceeding to the next step if the channel is switched; A tenth step of reading sound mode data from the memory when it is determined that the channel is switched in the ninth step; And an eleventh step of transmitting the sound mode data read from the memory in the tenth step to the sound processor through a bus line.

The sound mode determination apparatus of the television according to the present invention for achieving the above object, and tunes the channel according to the remote control signal of the remote control and determines the sound mode to transmit the sound mode data to another device via the bus line A micom for importing sound mode data stored at the time of channel switching; A memory for storing sound mode data determined by the micom; A sound processor for obtaining a low frequency signal from a voice intermediate frequency signal according to the sound mode data determined by the microcomputer; And an amplifier for amplifying the weak low frequency signal from the sound processor to increase the volume.

Hereinafter, with reference to the accompanying drawings will be described in detail with respect to the present invention.

5 is a flowchart of a sound mode determination method of a television according to the present invention, in which a channel tuning is started to determine a sound mode at the time of tuning when signals of the D / K, B / G, and I systems should be received simultaneously. First step (S1) to perform; A second step S2 of continuing channel tuning; A third step (S3) of continuing to tune to the second step (S2) if it is terminated after determining whether the channel tuning is terminated and moving to the next step if it is not terminated; A fourth step (S4) of starting sound mode determination when the channel tuning is completed in the third step (S3); a fifth step (S5) of continuing sound mode determination; determining whether the sound mode determination is terminated A sixth step (S6) for moving to the next step if it is terminated afterwards, and continuing to go to the fifth step (S5) to continue sound mode discrimination if it is not terminated; A seventh step S7 of storing sound mode data in a memory when the sound mode determination is terminated in the sixth step S6; When the sound mode determination is terminated in the sixth step S6, an eighth step S8 for repeating the sixth step S6 from the first step S1 to determine the sound mode by tuning the next channel. ); Determining whether the channel is switched at the time of channel switching, if the channel is not switched, and repeatedly performing the step; if the channel is switched, a ninth step (S9); A tenth step (S10) of reading sound mode data from a memory when it is determined that the channel is switched in the ninth step (S9); And an eleventh step S11 of transmitting sound mode data read from the memory in the tenth step S10 to the sound processor through a bus line.

Referring to the operation and effects of the sound mode determination method of the television according to the present invention configured as described above are as follows.

In the first step S1, when it is necessary to simultaneously receive signals of the D / K, B / G, and I methods, channel tuning is started to determine the sound mode at the time of tuning.

In the second step S2, channel tuning continues.

In the third step (S3), it is determined whether the channel tuning is terminated, and if it is terminated, moves to the next step, and if it is not terminated, goes to the second step (S2) and continues channel tuning.

In the fourth step S4, when the channel tuning is terminated in the third step S3, sound mode determination is started.

In the fifth step S5, sound mode determination is continued.

In the sixth step S6, after determining whether the sound mode determination is terminated, if it is terminated, go to the next step. If not, go to the fifth step S5 to continue the sound mode determination.

In the seventh step S7, when the sound mode determination is terminated in the sixth step S6, the sound mode data is stored in the memory.

In the eighth step S8, when the sound mode determination is terminated in the sixth step S6, the sixth step S6 is repeated from the first step S1 to tune the next channel to determine the sound mode. do.

In the ninth step S9, it is determined whether the channel is switched at the time of channel switching, and if the channel is not switched, the process is repeated. If the channel is switched, the process proceeds to the next step.

In the tenth step S10, when it is determined that the channel is switched in the ninth step S9, the sound mode data is read from the memory.

In the eleventh step S11, the sound mode data read from the memory in the tenth step S10 is transmitted to the sound processor through a bus line.

As described above, in the sound mode determination method of the television according to the present invention, when the signals of the D / K method, the B / G method, and the I method should be received simultaneously, the sound mode is received by receiving the audio intermediate frequency signals of each method. It is effective and economical to implement the discriminating part in software.

6 is a block diagram of a sound mode discriminating apparatus for a television according to the present invention for achieving the above object, and tunes a channel according to a remote control signal of a remote controller and determines a sound mode to bus the sound mode data. A microcomputer 10 for transmitting the stored sound mode data to another device through the device; A memory 20 for storing sound mode data determined by the microcomputer 10; A sound processor (30) for obtaining a low frequency signal from the voice intermediate frequency signal according to the sound mode data determined by the microcomputer (10); And an amplifier 40 for amplifying the weak low frequency signal from the sound processor 30 to increase the volume.

Referring to the operation and effect of the sound mode determination device of the television according to the present invention configured as described above are as follows.

In the microcomputer 10, the channel is tuned according to the remote control signal of the remote controller, the sound mode is determined, and the sound mode data is transmitted to another device through the bus line, and the sound mode data is stored when the channel is switched. The memory 20 functions to store sound mode data determined by the microcomputer 10. Noise is generated during channel switching from the B / G channel to the D / K channel. In order to eliminate such noise, the sound mode is determined during channel tuning, and the sound mode data is stored in the memory. When the channel is switched, the sound mode data of the corresponding channel is read from the memory. In this case, it is not necessary to discriminate the sound mode at the time of channel switching, thereby preventing noise generated during the channel switching.

The sound processor 30 functions to obtain a low frequency signal from the voice intermediate frequency signal according to the sound mode data determined by the microcomputer 10. The amplifier 40 amplifies the weak low frequency signal from the sound processor 30 to increase the volume.

As described above, the apparatus for discriminating sound mode of a television according to the present invention has an effect of eliminating noise generated when switching channels by determining a sound mode by installing a microcomputer and a memory in an audio intermediate frequency receiver of a television. have.

Claims (2)

A first step (S1) of starting channel tuning to determine the sound mode at the time of tuning when signals of the D / K, B / G, and I modes are to be received simultaneously; A second step S2 of continuing channel tuning; A third step (S3) of continuing to tune to the second step (S2) if it is terminated after determining whether the channel tuning is terminated and moving to the next step if it is not terminated; A fourth step (S4) of starting sound mode determination when channel tuning is completed in the third step (S3); A fifth step S5 of continuing the sound mode determination; A sixth step S6 of determining whether the sound mode determination is terminated and moving to the next step if it is terminated, and if not, going to the fifth step S5 to continue the sound mode determination; A seventh step (S7) of storing sound mode data in a memory when sound mode determination is terminated in the sixth step (S6); When the sound mode determination is terminated in the sixth step S6, an eighth step S8 for repeating the sixth step S6 from the first step S1 to determine the sound mode by tuning the next channel. ); Determining whether the channel is switched at the time of channel switching, if the channel is not switched, and repeatedly performing the step; if the channel is switched, a ninth step (S9); A tenth step (S10) of reading sound mode data from the memory when it is determined that the channel is switched in the ninth step (S9); and a sound mode read from the memory in the tenth step (S10). A sound mode discrimination method of a television operating sequentially in an eleventh step (S11) of transmitting data through a bus line to a sound processor. A microcomputer 10 for tuning a channel according to a remote control signal of a remote controller, determining a sound mode, transmitting sound mode data to another device through a bus line, and importing stored sound mode data when switching channels; A memory 20 for storing sound mode data determined by the microcomputer 10; A sound processor 30 for obtaining a low frequency signal from the voice intermediate frequency signal according to the sound mode data determined by the microcomputer 10; and for amplifying a weak low frequency signal from the sound processor 30 to increase the volume. Sound mode discrimination apparatus of a television comprising an amplifier (40).