WO1999046931A1 - Digital signal processor for multistandard television reception - Google Patents
Digital signal processor for multistandard television reception Download PDFInfo
- Publication number
- WO1999046931A1 WO1999046931A1 PCT/US1999/004370 US9904370W WO9946931A1 WO 1999046931 A1 WO1999046931 A1 WO 1999046931A1 US 9904370 W US9904370 W US 9904370W WO 9946931 A1 WO9946931 A1 WO 9946931A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- audio
- signal
- video
- demodulator
- modulated
- Prior art date
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/44—Receiver circuitry for the reception of television signals according to analogue transmission standards
- H04N5/455—Demodulation-circuits
-
- 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
-
- 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
- H04N21/42638—Internal components of the client ; Characteristics thereof for processing the incoming bitstream involving specific tuning arrangements, e.g. two tuners involving a hybrid front-end, e.g. analog and digital 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 MPEG 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
- H04N5/44—Receiver circuitry for the reception of television signals according to analogue transmission standards
- H04N5/46—Receiver circuitry for the reception of television signals according to analogue transmission standards for receiving on more than one standard at will
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/44—Receiver circuitry for the reception of television signals according to analogue transmission standards
- H04N5/60—Receiver circuitry for the reception of television signals according to analogue transmission standards for the sound signals
Definitions
- the present invention relates to television systems, and more particularly to a digital signal processing (DSP) implementation for the video, audio, and data demodulators/receiver of a cable television (CATV) converter, satellite television receiver, multichannel multipoint distribution service (MMDS), or the like.
- DSP digital signal processing
- Cable television services are communicated from a headend via a cable distribution system to subscriber residences.
- the drop cable which carries the signals from, e.g., a telephone pole, connects the cable television signals either directly to the subscriber's television set or couples the signals through a converter and/or other subscriber electronics.
- a converter is necessary if the cable system supplies more than television channels 2 to 13. Only “cable- ready" television sets can tune the higher frequency cable channels above VHF broadcast channel 13. If additional channels, such as pay channels are supplied by the cable operator, they must be translated in frequency down to the frequencies employed by one or more channels to which conventional television sets can be tuned.
- a cable television converter will typically output the selected cable television channel on the frequency used by broadcast channel 3 or 4, to which the subscriber television will be tuned as long as it is receiving signals from the converter.
- Addressable converters are converters that can make channels available or unavailable in accordance with instructions sent in data packets from the cable headend.
- the converter includes a tuner controlled by the subscriber in order to pick out a specific channel. If a selected service is a premium service, it is scrambled and can be unscrambled only under control of data sent from the headend.
- Each subscriber has a unique electronic address, so that the cable headend is able to provide viewing authorizations to each addressable converter.
- a typical cable television converter will include a frequency converter and filter (for allowing subscribers to tune to desired channels) , a local oscillator, control circuits, a data receiver for authorizations, and a descrambler. It should be appreciated that receivers for satellite television and MMDS will contain comparable components . Where digital television signals are to be received in addition to analog signals, appropriate digital components must also be provided, generally including a downconverter for the transmitted digital signals, an analog-to-digital converter, a digital demodulator such as a QAM demodulator, a digital television' decoder such as an MPEG decoder, onscreen display circuitry and a video encoder to provide the recovered television signals in an analog format for output to a conventional television.
- a downconverter for the transmitted digital signals
- an analog-to-digital converter an analog-to-digital converter
- a digital demodulator such as a QAM demodulator
- a digital television' decoder such as an MPEG decoder
- onscreen display circuitry
- NTSC National Television Systems Committee
- PAL phase alternating line
- SECAM SECAM
- NTSC National Television Systems Committee
- PAL phase alternating line
- SECAM SECAM
- NTSC National Television Systems Committee
- PAL phase alternating line
- SECAM SECAM
- NTSC National Television Systems Committee
- PAL phase alternating line
- SECAM SECAM
- NTSC National Television Systems Committee
- PAL phase alternating line
- SECAM SECAM
- NTSC National Television Systems Committee
- PAL phase alternating line
- SECAM SECAM
- Table 1 A summary of the different NTSC and PAL television broadcast standards is set forth in Table 1.
- VLSI very large scale integration
- ASIC application specific integrated circuit
- a digital signal processor for recovering video and audio signals according to different analog and digital television standards.
- the signal processor comprises a video demodulator having a first path for coupling a modulated video signal to a mixer via a Nyquist filter, and a second path for coupling the modulated video signal to a carrier recovery circuit without passing through the Nyquist filter.
- the modulated video signal conforms to a particular television standard, such as any of the standards set forth in Table 1.
- the carrier recovery circuit (i) recovers a carrier frequency signal for use by the mixer in providing a baseband video signal and (ii) detects an audio intercarrier present in the modulated video signal.
- a programmable sound strip filter is provided to filter audio components from the baseband video signal in accordance with the particular television standard to provide a demodulated video output .
- the audio intercarrier is provided as an output from the carrier recovery circuit for subsequent recovery of audio in accordance with the particular television standard.
- the digital signal processor receives the modulated video signal at an intermediate frequency (IF) .
- An analog-to- digital converter is provided for sampling the IF modulated signal at a sampling frequency F s to digitize the signal for input to the video demodulator.
- the sampling frequency F s is an integer multiple of the intermediate frequency.
- the sampling frequency F s can be 27 MHz with the intermediate frequency either 6.75 MHz or 9.0 MHz. This arrangement is advantageous since both 6.75 MHz and and 9 MHz divide evenly into the sampling frequency of 27 MHz.
- the demodulated video output can be a digital signal sampled at a frequency F s of 13.5 MHz.
- the sampling frequency can be phase locked to a horizontal synchronization component of the baseband video signal.
- the digital signal processor can further comprise a tuner for retrieving the modulated video signal from a band of signals.
- the particular television standard to which the modulated video signal corresponds may be identified by a channel map responsive to the tuner.
- the modulated video signal can carry tag data indicative of the particular television standard to which the modulated video signal corresponds.
- the digital signal processor can further comprise means for delaying the carrier frequency signal prior to the mixer to compensate for a delay introduced by the Nyquist filter.
- An audio demodulator is provided in the digital signal processor for processing the audio intercarrier.
- the audio demodulator comprises a first synchronous demodulator for selectively demodulating a first FM modulated audio signal or a QPSK modulated audio signal carried by the audio intercarrier.
- a second synchronous demodulator demodulates a second FM modulated audio signal carried by the audio intercarrier.
- the first and second synchronous demodulators can comprise linear phase locked loops that enable demodulation of the audio intercarrier with preliminary bandpass filtering.
- the video demodulator, carrier recovery circuit, programmable sound strip filter and audio demodulator can all be implemented on a single integrated circuit chip.
- the first synchronous demodulator is responsive to the channel map for selectively demodulating either the first FM modulated audio signal or the QPSK modulated audio signal .
- the first synchronous demodulator is responsive to the tag data for selectively demodulating either the first FM modulated audio signal or the QPSK modulated audio signal .
- the present invention also contemplates a digital signal processor for recovering video and audio signals according to different analog and digital television standards in which an audio demodulator is provided for processing an audio intercarrier.
- the audio demodulator includes a first synchronous demodulator for selectively demodulating a first FM modulated audio signal or a QPSK modulated audio signal carried by the audio intercarrier.
- a second synchronous demodulator in the audio demodulator is provided for demodulating a second FM modulated audio signal carried by the audio intercarrier.
- the first and second demodulators can comprise linear phase locked loops that enable the modulation of the audio intercarrier with preliminary bandpass filtering.
- the first synchronous demodulator can comprise a QPSK demodulator having first and second output stages.
- One of the output stages is an I output stage and the other is a Q output stage, where I and
- Q are QPSK constellation axes that are offset by 90 degrees .
- a variable oscillator provides first and second phase shifted oscillator outputs having a frequency dictated by a demodulation control signal . The first oscillator output is associated with the first output stage and the second oscillator output is associated with the second output stage of the QPSK demodulator.
- a phase locked loop controls the variable oscillator in response to an output from a particular one of the first and second output 10
- a selector is provided for selectively outputting a QPSK signal from the particular one of the first and second output stages or an FM signal from the phase locked loop.
- Apparatus is provided for recovering video and audio signals according to different analog and digital television standards.
- the apparatus includes a tuner for selecting a TV channel signal.
- the TV channel signal conforms to a particular television standard.
- Means are provided for digitizing the television channel IF signal. Intermediate frequency digitization is effective for demodulating both analog and digital modulation formats.
- Means are provided for identifying the particular television standard to which the TV channel signal conforms .
- a video digital signal processor (DSP) responsive to the identifying means demodulates the selected digitized TV channel signal to provide a video output signal.
- DSP video digital signal processor
- An audio DSP responsive to the identifying means demodulates the selected digitized TV channel signal to provide a video output signal.
- An audio DSP responsive to the identifying means demodulates the selected digitized TV channel signal to provide an audio output signal.
- the identifying means, digitizing means, video DSP and audio DSP reside together on a integrated circuit chip.
- a data DSP can be provided on the integrated circuit chip for demodulating auxiliary data carried in the TV channel signal to provide an auxiliary 11
- the apparatus can further comprise a data modulator on the integrated circuit chip.
- the data modulator modulates return path data to be communicated from the apparatus to a remote location.
- Figure 1 is a block diagram of a digital signal processing implementation of a baseband television converter in accordance with the present invention
- Figure 2 is a more detailed block diagram of the video demodulator section of the video DSP portion of Figure 1;
- FIG. 3 is a more detailed block diagram of the FM and QPSK/FM demodulators used in the audio DSP portion of Figure 1.
- the present invention combines the video, audio and data demodulator/receiver functions of a television converter into an economical package .
- these functions are implemented in a single integrated circuit such as an ASIC.
- the inventive implementation of the television converter functions using DSP techniques eliminates the need for a plurality of fixed bandpass filters and discriminators to do ultistandard processing. In this manner, a plurality of different television standards can be accommodated by a single converter.
- Sampling frequencies are chosen in a manner which enables the simple and cost effective use of a standard master clock frequency, such as the 27 MHz clock used by the Motion Picture Experts Group (MPEG) standard and as specified in ITU-R BT.601.
- Hardware requirements are significantly reduced by using, for example, one demodulator for both FM and/or QPSK signals.
- the converter includes a video DSP 12, audio DSP 26, and timing and data recovery circuitry 24.
- the video DSP demodulates and unscrambles video from an intermediate frequency (IF) carrier.
- IF intermediate frequency
- the video DSP can comprise, for example, a low IF frequency carrier such as a carrier centered at 9 MHz plus or minus 100 KHz.
- the video DSP consists of an analog- to-digital (A/D) converter 14, video demodulator 16, and a video descrambler 18.
- the low IF input via terminal 10 is sampled by the A/D converter 14.
- the sampling rate F s can be, for example, 27 MHz. Such a rate is advantageous because it conforms with the master clock rate used in the MPEG standard and ITU- R BT.601.
- the video demodulator 16 receives the sampled video from A/D converter 14 and provides various outputs.
- a baseband video output without sound carriers is provided to video descrambler 18.
- the baseband video may be advantageously provided at a 13.5 MHz sampling rate.
- the video descrambler 18 descrambles the baseband video in accordance with well known techniques to provide an unscrambled baseband video output on line 22 at the sampling frequency F s of, e.g., 13.5 MHz.
- RF and IF automatic gain control (AGC) voltages are also output from the video DSP 12 via line 20.
- video demodulator 16 In addition to the baseband video, video demodulator 16 outputs an automatic fine tune (AFT) control voltage on line 108 and an audio intercarrier on line 100. Before outputting the audio intercarrier, a mixer/phase detector 94 ( Figure 2) cancels the AM modulated video 15
- the audio intercarrier can be provided, for example, at a 27 MHz sampling rate.
- the video descrambler 18 also outputs a synchronization detection signal on line 19 which is derived from the recovered video. This signal is input to a Gen-Lock Timing & Clock Recovery circuit 28, which is part of the timing and data recovery block 24. Circuit 28 recovers the horizontal sync, vertical sync, blanking, and inversion restore timing (used for descrambling video inverted signals) which are forwarded back to the video descrambler via line 29 for use in descrambling the video output by video demodulator 16. Circuit 28 also outputs a Gen-Lock timing signal on line 34 for use by the onscreen display circuitry of the converter. The onscreen display circuitry provides text and graphics for display on the subscriber's television in a conventional manner.
- the timing and data recovery block 24 also includes a tag color burst decoder 30 which outputs tag data and a clock on line 36.
- Tag data is data that is encoded onto the color burst of the video signal and used for various converter control functions, including descrambling.
- Inband data (IBD) carried on the luminance portion of the video signal is decoded by an IBD luminance decoder 32, and output via line 38 together with an associated clock signal.
- IBD Inband data
- the clock signals provided with the tag data and IBD data will 16
- the master clock frequency of, e.g. , 27 MHz.
- the audio DSP portion 26 of the converter includes an audio demodulator and baseband processing functions .
- the audio portion of a video signal may be composed of one or two carriers.
- the carrier may have one or more subcarriers .
- FM demodulator 40 When a single FM carrier is present, it is demodulated by an FM demodulator 40.
- the capability of demodulating a second FM carrier is provided by a combined QPSK/FM demodulator 44. If one QPSK and one FM channel are provided, FM demodulator 40 will be used to demodulate the FM channel and QPSK/FM demodulator 44 will be used to demodulate the QPSK channel .
- the demodulated signals are decoded in a dual FM decoder 42 to provide a digital output to a stereo digital audio MUX/volume control circuit 56.
- This circuit processes the decoded signals to provide left and right stereo channel outputs for input to a digital interface circuit 58 (e.g., a Sony-Phillips Digital Interface - "SPDIF") and a high fidelity digital-to-analog converter 60.
- Circuit 58 outputs a digital audio (e.g., SPDIF) signal.
- Digital-to- analog converter 60 outputs analog left and right audio signals for input to a conventional audio amplifier .
- BTSC Systems Committee
- the subcarrier is decoded in decoder 50 for input to circuit 56.
- a NICAM audio signal is recovered by the demodulator 44, it is decoded in a decoder 52.
- a Dolby AC1 audio signal recovered by demodulator 44 when present, is decoded by decoder 54.
- any NICAM or Dolby AC1 signal is sliced in a slicer 46 and demultiplexed in a bitstream demultiplexer 48 to recover the digital data provided by the NICAM or Dolby AC1 signals.
- the audio DSP 26 is capable of processing various audio modes.
- Table 2 sets forth the various types of audio carriers that can be processed.
- various modes including the private BTSC, German DIN, Korean DIN, PAL I and PAL B modes include a primary carrier as well as a secondary carrier.
- two FM carriers are provided, as in the private BTSC, German DIN and Korean DIN modes, one will be processed by FM demodulator 40 and the other by demodulator 44.
- All QPSK demodulation is provided by the QPSK/FM demodulator 44.
- the QPSK modulation provided in the secondary carrier of the two PAL modes represents a NICAM digital audio signal which is subsequently processed by NICAM decoder 52.
- the QPSK modulation of the primary carrier provides a Dolby AC1 digital audio signal, 19
- FIG. 2 illustrates the video demodulator 16 in greater detail .
- This demodulator can process both amplitude modulated (vestigial sideband - "VSB") large carrier and amplitude modulated suppressed carrier with pilot AM signals.
- the only difference between the two demodulation systems is in the carrier recovery block 74.
- the mixer/phase detector 94 provided in the carrier recovery block may be implemented either as a Costas loop or a quadrature phase lock loop, both of which are well known in the art.
- a Costas loop is capable of recovering the carrier from both AM (vestigial sideband) large carrier and suppressed carrier with pilot AM signal sources.
- the quadrature phase lock loop (QPLL) is only capable of demodulating large carrier signals.
- the input to the video demodulator is a video IF signal that may be sampled, for example, at 27 MHz.
- This is the signal output from A/D converter 14 of Figure 1, and is input to the video demodulator via terminal 70 illustrated in Figure 2.
- This signal is input both to a mixer and Nyquist filter block 72 and the carrier recovery block 74.
- the video IF is first Nyquist filtered via Nyquist filter 80 20
- the recovered carrier is first passed through a Nyquist delay 84 which compensates for the delay of the Nyquist filter 80.
- the Nyquist filter is a lowpass filter that provides additional adjacent channel filtering as well as VSB double- single sideband magnitude equalization.
- the double sideband component is from 0-0.75 MHz and the single sideband component is from 0.75-4.2 MHz.
- the Nyquist filter 80 can be implemented as a finite impulse response (FIR) lowpass filter having, for example, a sampling frequency of 27 MHz, passband edge of 7.75 MHz, passband attenuation of 0.5 dB, stopband edge of 10.25 MHz, stopband attenuation of 40 dB, beta of 3.3953 and -6 dB cutoff frequency of 9 MHz.
- the FIR filter can be implemented as a 27 tap filter with fixed coefficients .
- the output of mixer 82 is input to a sound strip filter 76.
- a baseband video output (e.g., having a sampling frequency f B of 13.5 MHz) is generated from the demodulated video by removing the audio signal components .
- the audio components are removed by the sound strip filter. Filtering is performed in a two- stage filtering process using a downconverter lowpass filter 86 and a sound removal lowpass filter 92.
- a decimate by two circuit 90 is provided between the two lowpass filters. 21
- the use of a two-stage filtering process in the sound strip filter 76 reduces hardware requirements.
- the first stage provided by LPF 86 and decimator 90 decimates by two the 27 MHz sample modulated video to 13.5 MHz.
- Filter 86 is an anti-aliasing lowpass filter which may comprise, for example, an FIR half- band lowpass filter.
- the desampling frequency of the filter 86 can be 27 MHz with an operating frequency of 13.5 MHz, passband edge of 5.5 MHz, passband attenuation of 0.5 dB, stop band edge of 8 MHz, stop band attenuation of 60 dB, and the filter can have, e.g., 37 taps with fixed coefficients.
- a half band filter is utilized to reduce gate count.
- this filter operates at 13.5 MHz since every other sample is ignored. Since a half-band filter is used, the passband and stop band are centered around one- fourth the sampling frequency (27 MHz) or 6.75 MHz.
- the last stage of the sound strip filter 76 is an FIR lowpass filter 92.
- This filter can be designed, for example, to provide the sound carrier at 50 dB below the video at the sound carrier, and 25 dB below video at the sound carrier ⁇ 50 KHz.
- the coefficients of this filter are programmable to accommodate all of the different video standards capable of being processed by the television converter. The number of taps of the filter can be determined by the video standard with the smallest 22
- NTSC pass-to-stop transition bandwidth.
- NTSC has the smallest transition bandwidth, which is 696 KHz.
- carrier recovery is provided by block 74.
- the video IF from terminal 70 is input to a mixer/phase detector 94, the output of which is filtered through a loop filter 96 that controls a numerically controlled oscillator (NCO) 98.
- the NCO operates like a voltage controlled oscillator (VCO) and can be phase locked to an external clock by modulating its phase error input .
- One output of the mixer/phase detector 94 is the audio intercarrier which is carried with the video IF.
- the audio intercarrier is output via line 100 so that it can be input directly into the audio DSP 26 (see Figure 1) .
- the video demodulator is designed such that the sound takeoff point at the output of mixer/phase detector 94 does not require the sound to go through the Nyquist filter 80. Thus, there is no need for a separate sound demodulator which would render the system more expensive.
- Both the loop filter 96 and NCO 98 are programmable to enable operation with different television standards.
- the NCO output frequency is provided to an automatic fine tune circuit 78.
- the NCO frequency is compared in a frequency comparison circuit 102 with the actual frequency at which the video IF signal is received.
- a frequency lock loop 104 is controlled by the output of frequency compare 23
- circuit 102 in order to automatically fine tune the actual operating frequency.
- the output of the frequency lock loop is pulse width modulated in circuit 106 to provide an automatic fine tune (AFT) signal via line 108.
- AFT automatic fine tune
- the AFT signal is used by a conventional downconverter (not shown) in the television converter, to provide the low IF input to the video DSP via terminal 10 of Figure 1.
- FIG. 3 illustrates the FM demodulator 40 and QPSK/FM demodulator 44 of the audio DSP 26 in greater detail .
- Demodulator 44 is a synchronous demodulator that is configurable to perform either FM or QPSK demodulation.
- Demodulator 40 is a synchronous demodulator used for FM demodulation only.
- the audio intercarrier is provided on line
- the audio intercarrier is provided via a 2:1 multiplexer (used as a selector) to a mixer 152 which provides automatic gain control (AGC) .
- AGC automatic gain control
- the output of mixer 152 is input to mixers 154 and 156 where the signal is mixed with appropriate frequency outputs from a numerically controlled oscillator 158.
- the output of mixer 156 is passed through a loop filter 162 to control the frequency at which NCO 158 operates.
- the output of loop filter 162 is also passed through a lowpass filter 164 to provide the demodulated FM output.
- the output of mixer 154 is integrated in integrator 160 to provide the AGC signal .
- Multiplexer 150 provides the audio intercarrier as an output to mixer 152 when the audio mode is either a DIN mode (which requires two carriers for stereo) or PAL, in which case demodulator 40 demodulates the FM modulation of the primary carrier.
- multiplexer 150 passes the "FM1" signal from multiplexer (i.e., selector) 142 of demodulator 144 to the mixer 152 of demodulator 40.
- Synchronous FM/QPSK demodulator 44 receives a
- the audio intercarrier is input to a mixer 116 which provides an AGC signal from integrator 126.
- the output of mixer 116 is coupled to mixers 118 and 120 which receive the outputs of a programmable NCO 122.
- the NCO is programmable to accommodate the various standards capable of being processed by the converter.
- a loop filter 124 is provided to maintain the nominal frequency at which NCO 122 operates. Where a QPSK signal is being demodulated, loop filter 124 receives the "Q" phase of the QPSK signal from mixer 120 via multiplexer (i.e., selector) 130.
- the multiplexer 130 When the demodulator is demodulating an FM signal, the multiplexer 130 is actuated via the QPSK/FM select signal input at terminal 110 to pass the arc tangent (Q/I) from a rectangular to polar coordinate converter 136 to loop filter 124.
- the QPSK/FM 25 When the demodulator is demodulating an FM signal, the multiplexer 130 is actuated via the QPSK/FM select signal input at terminal 110 to pass the arc tangent (Q/I) from a rectangular to polar coordinate converter 136 to loop filter 124.
- the QPSK/FM 25 When the demodulator is demodulating an FM signal, the multiplexer 130 is actuated via the QPSK/FM select signal input at terminal 110 to pass the arc tangent (Q/I) from a rectangular to polar coordinate converter 136 to loop filter 124.
- the QPSK/FM 25 When the demodulator is demodulating an FM signal, the multiplexer 130 is actuated via the QPSK
- the QPSK/FM select signal also controls a multiplexer (selector) 128 to provide an appropriate input to integrator 126 in order to provide the necessary AGC signal.
- the QPSK/FM select signal actuates a multiplexer (selector) 142 to output either a demodulated FM signal from lowpass filter 144 or the I component of a demodulated QPSK signal from lowpass filter 134.
- Filter 132 can comprise a root raised cosine (RRC) FIR filter and adaptive equalizer, a counterpart of which is provided as filter 138 for the Q component of the demodulated QPSK signal .
- the Q component is passed through a second lowpass filter 146 (which may also be a RRC FIR filter) prior to being output from the demodulator 44.
- Both the I and Q components output from the respective lowpass filters 134 and 146 are input to the rectangular to polar coordinate converter 136, which also receives a sample symbol timing recovery output from symbol timing recovery circuit 140. This circuit outputs a
- an audio signal carried by the audio signal intercarrier can comprise either FM modulation, QPSK modulation, or 26
- any of the audio modes set forth in Table 2 can be accommodated .
- the present invention provides a reduced cost television converter implemented using digital signal processing techniques .
- a sampling frequency of 27 MHz is advantageous (but not required) in order to handle PAL 1, PAL B and NTSC television signals without aliasing during the demodulation. Such aliasing is prevented because the sum products are below the frequency where they would alias back into the DC to 7 MHz band of concern.
- a low IF input is converted from an analog signal to a digital signal, which is applied to a Nyquist filter.
- the Nyquist filter can comprise a 9 MHz, -6 dB symmetrical linear slope type filter.
- a gain control multiplier is used to restore scrambled video modes to a correct level.
- a 9 MHz NCO is phase locked to the Nyquist filtered video carrier and applied to I and Q multipliers.
- the difference product is the desired baseband video signal .
- the video signal can be decimated (e.g., down to 13.5 MHz sampling) before further processing is performed.
- the video PLL (phase lock loop) bandwidth is about 200 KHz initially during tuning and reduced to about 25 KHz after lock is detected. This multirate loop 27
- the Q multiplier is used for AFC and intercarrier generation. It is connected before the descrambling gain control stage to prevent AM modulation from being applied to the intercarrier. A delay matching the delay of the gain control multiplier must be inserted in the path before the Q multiplier in order to maintain the correct quadrature phase relationship. Connecting the Q multiplier before the Nyquist filter with appropriate delay reduces AM to PM conversion and improves suppressed carrier operation.
- the I multiplier is decimated by two and FIR filtered to remove the sound carrier(s).
- the FIR filter is coefficient programmable to the video standard in use.
- the converter enables the reception of digital audio independent of video (for example, for an audio only digital music channel) .
- the video carrier NCO must be set to a fixed frequency mode in order to mix the desired QPSK carrier to the desired intercarrier frequency.
- the television converter can receive various modes of audio signals.
- the video demodulator quadrature output at, e.g., 27 MHz is used as the source of audio intercarriers .
- About 40 dB cancellation can be expected from the 28
- a linear PLL demodulator with AGC can be used to extract the FM modulation while providing at least 40 dB AM rejection. Due to linear down conversion, very little video AM is present on the sound carrier. Hum amplitude modulation is eliminated by the AGC loop.
- the PLL demodulator is also used for DIN applications.
- an intercarrier PLL can include a ROM lookup table for carrier recovery when used in the QPSK modes. Clock recovery is also included.
- the output of the I and Q multipliers is decimated down to a low sampling rate for efficient lowpass filtering and then interpolated back up before data sampling is applied.
- One filter can be used for PAL 1, PAL B, and AC-1. Only the NCO frequency will be changed for these various modes.
- the demodulated data is demultiplexed, decrypted if authorized, Dolby AC-1 decoded, volume controlled, and output via a digital analog converter for left and right stereo audio outputs.
- a digital audio output e.g., complying with the Sony-Phillips Digital Interface (SPDIF) , is also provided. Similar processing is provided for NICAM data when present . 29
- the video carrier phase lock loop is placed before the Nyquist for AM-VSB, and compensating delay is inserted in the NCO path to the multiplier after the Nyquist filter.
- PLL phase lock loop
- the Nyquist filter is a programmable FIR filter, either highpass or lowpass, to allow the tuner oscillator to be higher or lower than the desired channel.
- the digitized IF video carrier can be above the sound carrier or below the sound carrier.
- Example video carrier frequencies are 6.75 MHz for highpass and 9 MHz for lowpass .
Abstract
Description
Claims
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
BR9908638-7A BR9908638A (en) | 1998-03-09 | 1999-02-26 | Digital signal processor for reception of multiple television standards |
EP99908557A EP1062806A1 (en) | 1998-03-09 | 1999-02-26 | Digital signal processor for multistandard television reception |
AU27960/99A AU747600B2 (en) | 1998-03-09 | 1999-02-26 | Digital signal processor for multistandard television reception |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US09/037,292 US6147713A (en) | 1998-03-09 | 1998-03-09 | Digital signal processor for multistandard television reception |
US09/037,292 | 1998-03-09 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1999046931A1 true WO1999046931A1 (en) | 1999-09-16 |
Family
ID=21893550
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US1999/004370 WO1999046931A1 (en) | 1998-03-09 | 1999-02-26 | Digital signal processor for multistandard television reception |
Country Status (6)
Country | Link |
---|---|
US (1) | US6147713A (en) |
EP (1) | EP1062806A1 (en) |
CN (1) | CN1182706C (en) |
AU (1) | AU747600B2 (en) |
BR (1) | BR9908638A (en) |
WO (1) | WO1999046931A1 (en) |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2001028255A1 (en) * | 1999-10-13 | 2001-04-19 | Thomson Licensing S.A. | Digital and analog television signal digitization and processing device |
WO2001082612A1 (en) * | 2000-04-25 | 2001-11-01 | Koninklijke Philips Electronics N.V. | Method of masking picture display transitions upon change-over of the video playback speed |
EP1150500A3 (en) * | 2000-04-28 | 2002-01-16 | Sony Corporation | Digital demodulation circuit for television signals |
US7102692B1 (en) | 1999-10-13 | 2006-09-05 | Thomson Licensing | Digital and analog television signal digitization and processing device |
WO2009013015A2 (en) * | 2007-07-26 | 2009-01-29 | Micronas Gmbh | Multistandard receiver circuit for analogue and digital broadcasting |
EP2023623A2 (en) * | 2007-07-27 | 2009-02-11 | Realtek Semiconductor Corp. | Apparatus and method for determining the transmission standard of a sound transmission transmitted with a television broadcast |
EP2373009A3 (en) * | 2010-03-31 | 2014-05-28 | Sony Corporation | Television signal receiver apparatus with sound signal detection |
CN114554027A (en) * | 2022-03-16 | 2022-05-27 | 湖南双菱电子科技有限公司 | Audio embedding processing and video-audio synchronous output processing method |
Families Citing this family (67)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6304621B1 (en) * | 1998-05-13 | 2001-10-16 | Broadcom Corporation | Multi-mode variable rate digital cable receiver |
US6804497B2 (en) | 2001-01-12 | 2004-10-12 | Silicon Laboratories, Inc. | Partitioned radio-frequency apparatus and associated methods |
US6476878B1 (en) * | 1998-10-21 | 2002-11-05 | Scientific-Atlanta, Inc. | Method and apparatus for audio signal processing |
US7039941B1 (en) * | 1998-10-30 | 2006-05-02 | General Instrument Corporation | Low distortion passthrough circuit arrangement for cable television set top converter terminals |
EP1093652B1 (en) * | 1998-12-21 | 2004-05-12 | Roke Manor Research Limited | Acoustically activated marketing method and device |
US6263195B1 (en) * | 1999-02-12 | 2001-07-17 | Trw Inc. | Wideband parallel processing digital tuner |
EP1032200B1 (en) | 1999-02-26 | 2005-11-16 | Canon Kabushiki Kaisha | Image display apparatus control system and image display system control method |
EP1032201B1 (en) * | 1999-02-26 | 2005-11-02 | Canon Kabushiki Kaisha | Image display control system and method |
JP3647305B2 (en) | 1999-02-26 | 2005-05-11 | キヤノン株式会社 | Image display device control system and image display system control method |
DE19948745A1 (en) * | 1999-10-09 | 2001-04-12 | Philips Corp Intellectual Pty | Circuit arrangement for demodulating an intermediate frequency video signal |
US7106388B2 (en) * | 1999-12-15 | 2006-09-12 | Broadcom Corporation | Digital IF demodulator for video applications |
DE10006701C2 (en) * | 2000-02-16 | 2002-04-11 | Harman Becker Automotive Sys | receiver |
US7149223B2 (en) * | 2000-03-06 | 2006-12-12 | Juniper Networks, Inc. | Enhanced fiber nodes with CMTS capability |
US20020056135A1 (en) * | 2000-03-06 | 2002-05-09 | Alok Sharma | Transceiver channel bank with reduced connector density |
US7099340B2 (en) * | 2000-03-06 | 2006-08-29 | Juniper Networks, Inc. | Enhanced CMTS for reliability, availability, and serviceability |
JP2002044557A (en) * | 2000-07-19 | 2002-02-08 | Sony Corp | Television receiver |
JP4484355B2 (en) * | 2000-11-22 | 2010-06-16 | 富士通マイクロエレクトロニクス株式会社 | Demodulator, broadcast system and broadcast receiver |
US7477326B2 (en) * | 2000-12-15 | 2009-01-13 | Broadcom Corporation | HDTV chip with a single IF strip for handling analog and digital reception |
US7352411B2 (en) | 2000-12-15 | 2008-04-01 | Broadcom Corporation | Digital IF demodulator |
US7239357B2 (en) * | 2000-12-15 | 2007-07-03 | Broadcom Corporation | Digital IF demodulator with carrier recovery |
FR2824986B1 (en) * | 2001-05-18 | 2003-10-31 | St Microelectronics Sa | ELECTRONIC COMPONENT FOR THE DECODING OF A RADIO FREQUENCY TRANSMISSION CHANNEL CARRYING ENCODED DIGITAL INFORMATION, PARTICULARLY FOR DIGITAL SATELLITE BROADCASTING |
CN1233156C (en) * | 2001-05-29 | 2005-12-21 | 索尼公司 | Analog television signal receiving method and device |
CN1572107A (en) * | 2001-10-16 | 2005-01-26 | Rf信息公司 | Methods and apparatus for implementing a receiver on a monolithic integrated circuit |
US7019791B2 (en) * | 2001-11-09 | 2006-03-28 | Hitachi, Ltd. | Video processing device |
US7847864B1 (en) * | 2002-03-01 | 2010-12-07 | Broadcom Corporation | All digital radio frequency modulator |
JP2004015129A (en) * | 2002-06-03 | 2004-01-15 | Toshiba Corp | Trap circuit and television receiver |
US7199843B2 (en) * | 2002-09-30 | 2007-04-03 | Lsi Logic Corporation | Spectral translation for VSB compensation |
GB2394373B (en) * | 2002-10-19 | 2005-12-14 | Zarlink Semiconductor Ltd | Radio frequency tuner |
US20050036357A1 (en) * | 2003-08-15 | 2005-02-17 | Broadcom Corporation | Digital signal processor having a programmable address generator, and applications thereof |
US7489362B2 (en) | 2003-03-04 | 2009-02-10 | Broadcom Corporation | Television functionality on a chip |
FR2853487A1 (en) * | 2003-04-01 | 2004-10-08 | St Microelectronics Sa | ELECTRONIC COMPONENT FOR DECODING DIGITAL SATELLITE TELEVISION SIGNALS |
FR2853486B1 (en) * | 2003-04-03 | 2005-08-05 | St Microelectronics Sa | ELECTRONIC COMPONENT FOR DECODING DIGITAL OR CABLE TELEVISION SIGNALS |
FR2853796B1 (en) | 2003-04-11 | 2005-07-01 | St Microelectronics Sa | ELECTRONIC COMPONENT FOR DECODING TERRESTRIAL OR CABLE DIGITAL TELEVISION SIGNALS. |
FR2853795B1 (en) * | 2003-04-11 | 2005-07-01 | St Microelectronics Sa | ELECTRONIC COMPONENT WITH INTEGRATED TUNING DEVICE FOR DECODING TERRESTRIAL OR CABLE DIGITAL TELEVISION SIGNALS. |
BRPI0412547A (en) * | 2003-07-14 | 2006-09-19 | Thomson Licensing | apparatus and method for processing analogue and digital signals from multiple signal sources |
CN1665279B (en) * | 2004-03-04 | 2010-06-23 | 亚洲光学股份有限公司 | Signal integration device and communication system |
TWI312615B (en) * | 2004-03-19 | 2009-07-21 | Mediatek Inc | Decording apparatus and decording method for multiple audio standards |
WO2005109866A1 (en) * | 2004-04-30 | 2005-11-17 | Telegent Systems, Inc. | Fft-based multichannel video receiver |
CA2580613A1 (en) * | 2004-09-17 | 2006-03-30 | That Corporation | Direct digital encoding and radio frequency mod elation for broadcast tele vision application |
US7653447B2 (en) | 2004-12-30 | 2010-01-26 | Mondo Systems, Inc. | Integrated audio video signal processing system using centralized processing of signals |
US7825986B2 (en) | 2004-12-30 | 2010-11-02 | Mondo Systems, Inc. | Integrated multimedia signal processing system using centralized processing of signals and other peripheral device |
US8880205B2 (en) * | 2004-12-30 | 2014-11-04 | Mondo Systems, Inc. | Integrated multimedia signal processing system using centralized processing of signals |
US8015590B2 (en) * | 2004-12-30 | 2011-09-06 | Mondo Systems, Inc. | Integrated multimedia signal processing system using centralized processing of signals |
US7692726B1 (en) * | 2005-05-17 | 2010-04-06 | Pixelworks, Inc. | Video decoder with integrated audio IF demodulation |
US7483085B2 (en) * | 2005-07-11 | 2009-01-27 | Sandbridge Technologies, Inc. | Digital implementation of analog TV receiver |
JP4066269B2 (en) * | 2005-08-24 | 2008-03-26 | シャープ株式会社 | Receiving device, receiving system |
JP4063841B2 (en) * | 2005-09-09 | 2008-03-19 | シャープ株式会社 | Receiving device, receiving system |
US7518661B2 (en) * | 2005-09-30 | 2009-04-14 | Sigmatel, Inc. | System and method of audio detection |
JP4350084B2 (en) * | 2005-11-07 | 2009-10-21 | シャープ株式会社 | Receiver and receiver system |
JP2007165943A (en) * | 2005-12-09 | 2007-06-28 | Funai Electric Co Ltd | Digital television receiver |
JP2007251446A (en) * | 2006-03-15 | 2007-09-27 | Sharp Corp | Receiving apparatus, and receiving system |
JP2007251702A (en) * | 2006-03-17 | 2007-09-27 | Sharp Corp | Receiving apparatus, receiving system |
JP4338710B2 (en) * | 2006-03-27 | 2009-10-07 | シャープ株式会社 | Receiver and receiver system |
US8502920B2 (en) * | 2007-03-14 | 2013-08-06 | Vyacheslav Shyshkin | Method and apparatus for extracting a desired television signal from a wideband IF input |
US8902365B2 (en) * | 2007-03-14 | 2014-12-02 | Lance Greggain | Interference avoidance in a television receiver |
US8184201B2 (en) * | 2007-11-04 | 2012-05-22 | Analog Devices, Inc. | Method and apparatus for automatic audio standard detection in terrestrial broadcast signals employing frequency scanning |
US8090110B2 (en) * | 2008-04-21 | 2012-01-03 | Himax Technologies Limited | Method and apparatus for determining sound standard for input sound signal |
US8565324B2 (en) * | 2008-09-17 | 2013-10-22 | Harris Corporation | Communications device using measured signal-to-noise ratio to adjust phase and frequency tracking |
CN101547362B (en) * | 2009-05-06 | 2010-11-24 | 天津大学 | Compatible transmission method for wide-gamut digital TV signals |
US10521250B2 (en) * | 2012-09-12 | 2019-12-31 | The Directv Group, Inc. | Method and system for communicating between a host device and user device through an intermediate device using a composite video signal |
CN105577237B (en) * | 2015-12-18 | 2019-03-12 | 国网河南省电力公司安阳供电公司 | A kind of modulation-demo-demodulation method and chip for low-voltage power line carrier communication system |
JP6604213B2 (en) * | 2016-01-20 | 2019-11-13 | ティアック株式会社 | Control equipment |
JP6682871B2 (en) * | 2016-01-20 | 2020-04-15 | ティアック株式会社 | Control equipment |
JP6686461B2 (en) * | 2016-01-20 | 2020-04-22 | ティアック株式会社 | Control equipment |
US9992049B1 (en) * | 2016-06-17 | 2018-06-05 | Xilinx, Inc. | Numerically controlled oscillator for fractional burst clock data recovery applications |
CN108376538B (en) * | 2018-04-27 | 2020-05-29 | 京东方科技集团股份有限公司 | Connector for display device and display device |
US11212072B1 (en) | 2020-12-22 | 2021-12-28 | Xilinx, Inc. | Circuit for and method of processing a data stream |
Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0574273A1 (en) * | 1992-06-12 | 1993-12-15 | Kabushiki Kaisha Toshiba | A receiver compriser a combined AM-FM demodulator |
US5357284A (en) * | 1990-03-29 | 1994-10-18 | Dolby Laboratories Licensing Corporation | Compatible digital audio for NTSC television |
EP0664645A2 (en) * | 1994-01-24 | 1995-07-26 | Kabushiki Kaisha Toshiba | Broadcasting system discriminating television receiver |
US5506636A (en) * | 1994-06-28 | 1996-04-09 | Samsung Electronics Co., Ltd. | HDTV signal receiver with imaginary-sample-presence detector for QAM/VSB mode selection |
EP0753945A2 (en) * | 1995-07-14 | 1997-01-15 | General Instrument Corporation | Apparatus integrating digital audio and analog video reception in a single receiver |
EP0769873A1 (en) * | 1995-10-17 | 1997-04-23 | Paradyne Corporation | Radio frequency receiver adapted to receive one or more modulated signals |
WO1998014005A1 (en) * | 1996-09-27 | 1998-04-02 | Sarnoff Corporation | Multiple modulation format television signal receiver system |
US5835131A (en) * | 1997-04-15 | 1998-11-10 | Samsung Electronics Co., Ltd. | Digital television receiver with adaptive filter circuitry for suppressing NTSC co-channel interference |
Family Cites Families (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3784946D1 (en) * | 1987-11-06 | 1993-04-22 | Itt Ind Gmbh Deutsche | SOUND CHANNEL CIRCUIT FOR DIGITAL TELEVISION RECEIVERS. |
US5038402A (en) * | 1988-12-06 | 1991-08-06 | General Instrument Corporation | Apparatus and method for providing digital audio in the FM broadcast band |
US4962427A (en) * | 1989-04-20 | 1990-10-09 | Motorola Inc. | TV receiver including multistandard OSD |
US5029003A (en) * | 1989-12-18 | 1991-07-02 | General Electric Company | Apparatus for incorporating digital signals with a standard TV signal |
DE69306330T2 (en) * | 1992-02-20 | 1997-06-05 | Motorola Inc | MODULATOR CIRCUIT |
DE4315128A1 (en) * | 1993-05-07 | 1994-11-10 | Philips Patentverwaltung | Circuit arrangement for demodulating the audio signals in a television signal |
US5355162A (en) * | 1993-07-13 | 1994-10-11 | Pacific Ray Video Limited | Multi-standard cable television system |
DE4417724A1 (en) * | 1994-05-20 | 1995-11-23 | Ant Nachrichtentech | Device for digitally demodulating the picture and sound components of a television signal |
DE4417723A1 (en) * | 1994-05-20 | 1995-11-23 | Ant Nachrichtentech | Device for processing a modulated real-valued analog television signal |
KR970007887B1 (en) * | 1994-11-30 | 1997-05-17 | Samsung Electronics Co Ltd | Tuner device for multi broadcasting receiver |
US5737035A (en) * | 1995-04-21 | 1998-04-07 | Microtune, Inc. | Highly integrated television tuner on a single microcircuit |
JP3364098B2 (en) * | 1995-12-04 | 2003-01-08 | シャープ株式会社 | Satellite tuner |
-
1998
- 1998-03-09 US US09/037,292 patent/US6147713A/en not_active Expired - Fee Related
-
1999
- 1999-02-26 EP EP99908557A patent/EP1062806A1/en not_active Withdrawn
- 1999-02-26 WO PCT/US1999/004370 patent/WO1999046931A1/en not_active Application Discontinuation
- 1999-02-26 CN CNB998052523A patent/CN1182706C/en not_active Expired - Fee Related
- 1999-02-26 BR BR9908638-7A patent/BR9908638A/en not_active IP Right Cessation
- 1999-02-26 AU AU27960/99A patent/AU747600B2/en not_active Ceased
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5357284A (en) * | 1990-03-29 | 1994-10-18 | Dolby Laboratories Licensing Corporation | Compatible digital audio for NTSC television |
EP0574273A1 (en) * | 1992-06-12 | 1993-12-15 | Kabushiki Kaisha Toshiba | A receiver compriser a combined AM-FM demodulator |
EP0664645A2 (en) * | 1994-01-24 | 1995-07-26 | Kabushiki Kaisha Toshiba | Broadcasting system discriminating television receiver |
US5506636A (en) * | 1994-06-28 | 1996-04-09 | Samsung Electronics Co., Ltd. | HDTV signal receiver with imaginary-sample-presence detector for QAM/VSB mode selection |
EP0753945A2 (en) * | 1995-07-14 | 1997-01-15 | General Instrument Corporation | Apparatus integrating digital audio and analog video reception in a single receiver |
EP0769873A1 (en) * | 1995-10-17 | 1997-04-23 | Paradyne Corporation | Radio frequency receiver adapted to receive one or more modulated signals |
WO1998014005A1 (en) * | 1996-09-27 | 1998-04-02 | Sarnoff Corporation | Multiple modulation format television signal receiver system |
US5835131A (en) * | 1997-04-15 | 1998-11-10 | Samsung Electronics Co., Ltd. | Digital television receiver with adaptive filter circuitry for suppressing NTSC co-channel interference |
Cited By (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2001028255A1 (en) * | 1999-10-13 | 2001-04-19 | Thomson Licensing S.A. | Digital and analog television signal digitization and processing device |
US7102692B1 (en) | 1999-10-13 | 2006-09-05 | Thomson Licensing | Digital and analog television signal digitization and processing device |
WO2001082612A1 (en) * | 2000-04-25 | 2001-11-01 | Koninklijke Philips Electronics N.V. | Method of masking picture display transitions upon change-over of the video playback speed |
EP1150500A3 (en) * | 2000-04-28 | 2002-01-16 | Sony Corporation | Digital demodulation circuit for television signals |
US6678011B2 (en) | 2000-04-28 | 2004-01-13 | Sony Corporation | Fronted circuit |
WO2009013015A2 (en) * | 2007-07-26 | 2009-01-29 | Micronas Gmbh | Multistandard receiver circuit for analogue and digital broadcasting |
WO2009013015A3 (en) * | 2007-07-26 | 2010-05-14 | Trident Microsystems (Far East) Ltd. | Multistandard receiver circuit for analogue and digital broadcasting |
US8373803B2 (en) | 2007-07-26 | 2013-02-12 | Entropic Communications, Inc. | Multistandard receiver circuit for analogue and digital broadcasting |
EP2023623A2 (en) * | 2007-07-27 | 2009-02-11 | Realtek Semiconductor Corp. | Apparatus and method for determining the transmission standard of a sound transmission transmitted with a television broadcast |
EP2023623A3 (en) * | 2007-07-27 | 2010-03-17 | Realtek Semiconductor Corp. | Apparatus and method for determining the transmission standard of a sound transmission transmitted with a television broadcast |
EP2373009A3 (en) * | 2010-03-31 | 2014-05-28 | Sony Corporation | Television signal receiver apparatus with sound signal detection |
CN114554027A (en) * | 2022-03-16 | 2022-05-27 | 湖南双菱电子科技有限公司 | Audio embedding processing and video-audio synchronous output processing method |
Also Published As
Publication number | Publication date |
---|---|
AU747600B2 (en) | 2002-05-16 |
US6147713A (en) | 2000-11-14 |
BR9908638A (en) | 2001-12-18 |
CN1182706C (en) | 2004-12-29 |
CN1298605A (en) | 2001-06-06 |
EP1062806A1 (en) | 2000-12-27 |
AU2796099A (en) | 1999-09-27 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6147713A (en) | Digital signal processor for multistandard television reception | |
US7239357B2 (en) | Digital IF demodulator with carrier recovery | |
US7075585B2 (en) | Broadband receiver having a multistandard channel filter | |
US7265792B2 (en) | Television receiver for digital and analog television signals | |
US7834937B2 (en) | Digital IF demodulator | |
US7477326B2 (en) | HDTV chip with a single IF strip for handling analog and digital reception | |
KR920000580B1 (en) | Digital tv receivers | |
EP0769873A1 (en) | Radio frequency receiver adapted to receive one or more modulated signals | |
EP1681873A1 (en) | A single integrated high definition television (HDTV) chip for analog and digital reception | |
EP1635560A2 (en) | World wide analog television signal receiver | |
GB2343815A (en) | Digital receiver | |
JP4677159B2 (en) | Digitization / processing device for digital television signals and analog television signals | |
WO2005081519A1 (en) | Broadband receiver having a multistandard channel filter | |
MXPA00008840A (en) | Digital signal processor for multistandard television reception | |
KR100195710B1 (en) | A demodlation for vsb, qam and ntsc signals | |
KR19990060510A (en) | Digital residual sideband demodulation device | |
Weltersbach | System and realization aspects of multistandard TV receivers |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WWE | Wipo information: entry into national phase |
Ref document number: 99805252.3 Country of ref document: CN |
|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): AL AM AT AU AZ BA BB BG BR BY CA CH CN CU CZ DE DK EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MD MG MK MN MW MX NO NZ PL PT RO RU SD SE SG SI SK SL TJ TM TR TT UA UG UZ VN YU ZW |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): GH GM KE LS MW SD SL SZ UG ZW AM AZ BY KG KZ MD RU TJ TM AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE BF BJ CF CG CI CM GA GN GW ML MR NE SN TD TG |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
DFPE | Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101) | ||
WWE | Wipo information: entry into national phase |
Ref document number: PA/a/2000/008840 Country of ref document: MX |
|
NENP | Non-entry into the national phase |
Ref country code: KR |
|
WWE | Wipo information: entry into national phase |
Ref document number: 27960/99 Country of ref document: AU |
|
WWE | Wipo information: entry into national phase |
Ref document number: 1999908557 Country of ref document: EP |
|
WWE | Wipo information: entry into national phase |
Ref document number: IN/PCT/2000/478/CHE Country of ref document: IN |
|
WWP | Wipo information: published in national office |
Ref document number: 1999908557 Country of ref document: EP |
|
REG | Reference to national code |
Ref country code: DE Ref legal event code: 8642 |
|
WWG | Wipo information: grant in national office |
Ref document number: 27960/99 Country of ref document: AU |
|
WWW | Wipo information: withdrawn in national office |
Ref document number: 1999908557 Country of ref document: EP |