KR20090036296A - Dual tuner and method for receiving the same channel there of - Google Patents

Dual tuner and method for receiving the same channel there of Download PDF

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Publication number
KR20090036296A
KR20090036296A KR1020070101388A KR20070101388A KR20090036296A KR 20090036296 A KR20090036296 A KR 20090036296A KR 1020070101388 A KR1020070101388 A KR 1020070101388A KR 20070101388 A KR20070101388 A KR 20070101388A KR 20090036296 A KR20090036296 A KR 20090036296A
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KR
South Korea
Prior art keywords
tuner
tuner unit
intermediate frequency
channel
unit
Prior art date
Application number
KR1020070101388A
Other languages
Korean (ko)
Inventor
방승인
Original Assignee
엘지이노텍 주식회사
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 엘지이노텍 주식회사 filed Critical 엘지이노텍 주식회사
Priority to KR1020070101388A priority Critical patent/KR20090036296A/en
Publication of KR20090036296A publication Critical patent/KR20090036296A/en

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/005—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission adapting radio receivers, transmitters andtransceivers for operation on two or more bands, i.e. frequency ranges
    • H04B1/0067—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission adapting radio receivers, transmitters andtransceivers for operation on two or more bands, i.e. frequency ranges with one or more circuit blocks in common for different bands
    • H04B1/0075—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission adapting radio receivers, transmitters andtransceivers for operation on two or more bands, i.e. frequency ranges with one or more circuit blocks in common for different bands using different intermediate frequencied for the different bands
    • 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
    • H04N21/42607—Internal components of the client ; Characteristics thereof for processing the incoming bitstream
    • H04N21/4263—Internal components of the client ; Characteristics thereof for processing the incoming bitstream involving specific tuning arrangements, e.g. two tuners
    • 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
    • H04N21/43—Processing of content or additional data, e.g. demultiplexing additional data from a digital video stream; Elementary client operations, e.g. monitoring of home network or synchronising decoder's clock; Client middleware
    • H04N21/438—Interfacing the downstream path of the transmission network originating from a server, e.g. retrieving encoded video stream packets from an IP network
    • H04N21/4382—Demodulation or channel decoding, e.g. QPSK demodulation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/76—Television signal recording

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  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Multimedia (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Two-Way Televisions, Distribution Of Moving Picture Or The Like (AREA)
  • Superheterodyne Receivers (AREA)

Abstract

The present invention relates to a dual tuner and its co-channel receiving method.

According to the present invention, when receiving a high frequency signal received through one tuner unit and recording through another tuner unit, by setting different intermediate frequencies between the tuner units and demodulating to different intermediate frequencies, the same oscillation frequency is generated by the same intermediate frequency. Since it is not interfered with, the tuner unit is not affected by the oscillation frequency, thereby preventing degradation of tuner reception performance and sensitivity.

Description

Dual tuner and same channel reception method {DUAL TUNER AND METHOD FOR RECEIVING THE SAME CHANNEL THERE OF}

1 is a noise waveform diagram of the same oscillation frequency of a conventional dual tuner

Figure 2 is a block diagram of a dual tuner showing an embodiment of the present invention

3 is a noise waveform diagram of another oscillation frequency according to an embodiment of FIG.

4 is a flowchart illustrating a method of receiving a co-channel of a dual tuner according to an embodiment of the present invention.

* Description of the symbols for the main parts of the drawings *

21; Distributor 22; 1st tuner part

23; Second tuner portion 24; First demodulator

25; Second demodulator

The present invention relates to a dual tuner and its co-channel receiving method.

In general, a dual tuner simultaneously receives two different digital broadcast signals from a digital broadcast receiver such as a digital TV (D-TV) or a set-top box (STB) and selects two broadcast channels from one digital broadcast signal or mutually. It is a receiver that can tune each broadcasting channel from another digital broadcasting signal.

The dual tuner tunes two broadcast channels from one digital broadcast signal to watch one broadcast channel and performs a PVR function to record another broadcast channel, or a digital broadcast receiver having a PIP function. In this case, one broadcast channel may be displayed as a main screen, and the other broadcast channel may be displayed as a sub screen.

A conventional dual tuner for performing such a function includes a divider for distributing a received high frequency signal; The high frequency signal distributed through the distributor is composed of two tuner units which receive through one channel and record through another channel.

In order to select the desired channel from the two tuners, the intermediate frequency (F IF ) = oscillation frequency (F OSC ) High Frequency Signals (F RF) ).

Therefore, when a channel to be received and a channel to be recorded in one broadcast channel are the same, the two tuners select a channel using the same intermediate frequency (F IF ).

Therefore, one tuner intermediate frequency (F IF1 ) = oscillation frequency (F OSC1 ) in the two tuner units. -High frequency signal (F RF1 ), other tuner intermediate frequency (F IF2 ) = oscillation frequency (F OSC2 ) By the high frequency signal F RF2 , the high frequency signals F RF1 and F RF2 have the same frequency, and the oscillation frequencies F OSC1 and F OSC2 also oscillate at the same frequency.

Therefore, the one tuner unit and the other tuner unit are influenced by the same frequency which is not desired. As shown in FIG. 1, the noise generated by the oscillation frequency F OSC2 of the other tuner unit is selected in the selected channel band of the tuner. There exists a problem of deteriorating tuner reception performance and sensitivity by the noise.

The present invention eliminates the influence of noise due to the oscillation frequency when receiving the same broadcast channel.

The present invention includes a first tuner unit and a second tuner unit for converting each input signal into an intermediate frequency; A controller configured to set an intermediate frequency of the second tuner different from an intermediate frequency of the first tuner when the channel selected by the first tuner is received by the second tuner; And a demodulator for demodulating the intermediate frequency converted by the first tuner and the second tuner.

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

FIG. 2 is a block diagram of a dual tuner showing an embodiment of the present invention, and FIG. 3 is a noise waveform diagram of another oscillation frequency according to the embodiment of FIG.

The divider 21 separates the input high frequency signal into each tuner, and the divider 21 is configured as a 1: 1 balun.

The first tuner unit 22 converts and outputs a high frequency signal distributed by the distributor 21 to an intermediate frequency corresponding to the selected channel signal, and the first tuner unit 22 is distributed by the distributor 21. An amplifier AMP1 for amplifying a high frequency signal and a mixer MIX1 for mixing the amplified high frequency signal with the oscillation frequency of the oscillator OSC1 and converting the intermediate frequency IF1 into an output frequency.

The second tuner unit 23 converts and outputs the high frequency signal distributed by the distributor 21 to an intermediate frequency corresponding to the selected channel signal, and the second tuner unit 23 is distributed by the distributor 21. An amplifier AMP2 for amplifying a high frequency signal, and a mixer MIX2 for mixing the amplified high frequency signal with the oscillation frequency of the oscillator OSC2 and converting the converted high frequency signal to an intermediate frequency IF2.

The control unit 30 outputs a channel selection signal to each of the first tuner unit 22 and the second tuner unit 23, and the control unit 30 selects the channel signal selected by the first tuner unit 22. Is received by the second tuner unit 23, for example, the selected channel is received through the first tuner unit 22, and the same channel as the channel selected by the second tuner unit 23 is recorded. In the case of PVR, the second tuner unit 23 is configured such that the oscillation frequency of the oscillator OSC2 does not affect the intermediate frequency of the selected channel of the first tuner unit 22. The intermediate frequency IF1 is set to another intermediate frequency IF2.

The control unit 30 determines that the same channel is received when a signal for performing the same channel recording (PVR) function is input, and receives another channel when another channel selection signal is input to the second tuner unit 23. You will be judged.

The first demodulator 24 and the second demodulator 25 digitally demodulate respective intermediate frequencies output from the first and second tuner units 22 and 23 to transport stream data TS1 (TS2). Is output to

According to the present invention configured as described above, the high frequency signal received through the antenna is distributed 1: 1 by the 1: 1 balun of the splitter 21 to output to the first tuner unit 22 and the second tuner unit 23. In this case, when receiving a selected channel through the first tuner unit 22 in the high frequency signal and recording (PVR) through the second tuner unit 23, the first tuner unit 22 is used. The high frequency signal F RF1 input to the amplifier is amplified by the amplifier AMP1 and mixed with the oscillation frequency F OSC1 of the oscillator OSC1 in the mixer MIX1, so that the intermediate frequency F IF1 = oscillation frequency F OSC1 . The high frequency signal F RF2 is output as the high frequency signal F RF1 , and the high frequency signal F RF2 input to the second tuner unit 23 is amplified by the amplifier AMP2, and the oscillator OSC2 is oscillated in the mixer MIX2. frequency (F OSC2) and a mixture of an intermediate frequency (F IF2) = oscillation frequency (F OSC2) -It outputs high frequency signal (F RF2 ).

As described above, when the respective intermediate frequencies F IF1 and F IF2 are output from the first tuner unit 22 and the second tuner unit 23, the controller 30 controls the intermediate frequency of the second tuner unit 23. F IF2 ) is set differently from the intermediate frequency F IF1 of the first tuner unit 22.

That is, in the control unit 30 with respect to the high frequency signals F RF1 and F RF2 126MHZ, the intermediate frequency F IF1 of the first tuner unit 22 is 36MHZ and the middle of the second tuner unit 23. The frequency F IF2 is set differently to 43MHZ.

Therefore, since the oscillation frequency F OSC1 of the first tuner unit 22 becomes a high frequency signal F RF1 + an intermediate frequency F IF1 , the oscillation frequency F OSC1 of the first tuner unit 22 is 126MHZ. + 36MHZ = 162MHZ, and the oscillation frequency F OSC2 of the second tuner unit 23 becomes a high frequency signal F RF2 + an intermediate frequency F IF2 , so that the oscillation frequency of the second tuner unit 23 is obtained. (F OSC2 ) = 126MHZ + 43MHZ = 169MHZ, the oscillator OSC1 of the first tuner section 22 oscillates at the oscillation frequency F OSC1 = 162MHZ, while the second tuner section 23 Oscillator (OSC2) of the oscillation frequency (F OSC2 ) = 169MHZ oscillates differently.

Accordingly, the first tuner unit 22 receives a selection channel with respect to the input high frequency signals F RF1 and F RF2 , and records the selection channel with the second tuner unit 23. When performing, the first tuner unit 22 and the second tuner unit 23 may have different intermediate frequencies F IF1 (F IF2 ) by different oscillation frequencies F OSC1 (F OSC2 ). As shown in FIG. 3, the first tuner 22 has an oscillation frequency F OSC2 of the second tuner 23 in a selected channel band of the first tuner 22. Outputs the intermediate frequency (F IF1 ) without noise by 169MHZ.

Therefore, the first tuner unit 22 and the second tuner unit 23 each have different intermediate frequencies F IF1 (F IF2 ) which are not affected by the noise caused by the oscillation frequency. And demodulate through the second demodulator 25 and output to the transport stream data TS1 (TS2), so that the selected channel is received through the first tuner 22 and the second tuner 23 is received. Will record the selected channel.

In addition, referring to the flowchart of FIG. 4, the dual tuner according to the present exemplary embodiment sets the intermediate frequencies of the first tuner unit 22 and the second tuner unit 23 differently when receiving the same channel. As follows.

When a channel selection signal is input to the first tuner unit 22 and the second tuner unit 23 from the control unit 30 through I2C communication (step 41), the first tuner unit 22 and the second tuner unit 22 are connected. The tuner unit 23 converts the high frequency signal into an intermediate frequency corresponding to the selected channel and outputs the converted high frequency signal (step 42).

Subsequently, the controller 30 determines whether a signal for performing a recording (PVR) function is input to the second tuner unit 23 (step 43). If the recording signal is not input at this time, the first tuner unit (22) and the intermediate frequency converted by the second tuner unit 23 are demodulated through the first demodulator 24 and the second demodulator 25.

On the other hand, if a signal for performing a recording function is input to the second tuner unit 23, the controller 30 determines whether the recording channel is the same channel as the selected channel of the first tuner unit 22 ( Step 44), if the recording channel is the same channel as the selection channel of the first tuner unit 22, the controller 30 sets the oscillator OSC to set the intermediate frequency to another intermediate frequency in the second tuner unit 23. After the oscillation frequency is changed (step 45), the intermediate frequency of the first tuner unit 22 and the changed intermediate frequency of the second tuner unit 23 are converted to the first demodulator 24 and the second demodulator. Demodulation is performed through the grandfather 25 (step 46).

As described above, in the present invention, when receiving a high frequency signal received through one tuner unit and recording through another tuner unit, by setting different intermediate frequencies between the tuner units and demodulating to different intermediate frequencies, the same intermediate frequency is achieved. Since the interference is not affected by the same oscillation frequency, it is not affected between the tuner portions by the oscillation frequency, thereby preventing degradation of tuner reception performance and deterioration of sensitivity.

Claims (8)

 A first tuner unit and a second tuner unit which convert each input signal into an intermediate frequency; A controller configured to set an intermediate frequency of the second tuner different from an intermediate frequency of the first tuner when the channel selected by the first tuner is received by the second tuner; And a demodulator for demodulating the intermediate frequency converted by the first tuner and the second tuner. The first tuner unit of claim 1, wherein the first tuner unit and the second tuner unit convert the high frequency signals input through the divider with the oscillation frequency of each oscillator to convert to an intermediate frequency corresponding to the selected channel. And the oscillation frequency of the first tuner unit and the second tuner unit is different when the channel selected in the second tuner unit is received. The dual tuner of claim 1, wherein the controller determines that the same channel is received when a signal for performing the same channel recording function is input. The dual tuner of claim 1, wherein the demodulator comprises a first demodulator and a second demodulator configured to demodulate intermediate frequencies converted by the first tuner and the second tuner into digital signals, respectively. A first tuner unit and a second tuner unit which convert each input signal into an intermediate frequency; A first demodulator for demodulating the intermediate frequency converted by the first tuner; And a second demodulation unit for demodulating the intermediate frequency converted by the second tuner unit differently from the intermediate frequency of the first tuner unit. Converting each of the signals input to the first tuner unit and the second tuner unit into a first intermediate frequency and a second intermediate frequency; Demodulating the converted first intermediate frequency; And demodulating the converted second intermediate frequency differently from the first intermediate frequency. Converting each of the signals input to the first tuner unit and the second tuner unit into a first intermediate frequency and a second intermediate frequency; Determining whether the selected channel is the same channel in the first tuner unit and the second tuner unit; and if the selected channel is the same, demodulating the second intermediate frequency differently from the first intermediate frequency. How to receive same channel. The method of claim 7, wherein when the signal for performing the recording function is input, the channel selected by the first tuner unit and the second tuner unit is determined to be the same channel.
KR1020070101388A 2007-10-09 2007-10-09 Dual tuner and method for receiving the same channel there of KR20090036296A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR1020070101388A KR20090036296A (en) 2007-10-09 2007-10-09 Dual tuner and method for receiving the same channel there of

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1020070101388A KR20090036296A (en) 2007-10-09 2007-10-09 Dual tuner and method for receiving the same channel there of

Publications (1)

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KR20090036296A true KR20090036296A (en) 2009-04-14

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KR1020070101388A KR20090036296A (en) 2007-10-09 2007-10-09 Dual tuner and method for receiving the same channel there of

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KR (1) KR20090036296A (en)

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