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Digital signal reception device

A technology for digital signals and receivers, applied in the field of digital signal receivers, can solve the problems of signal interference characteristics (unstable cross-talk modulation characteristics, difficult to receive stable digital playback signals, etc.), and achieve the effect of stable reception.

Inactive Publication Date: 2008-08-13
PANASONIC CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Therefore, the interference characteristics (interference modulation characteristics) from the adjacent channel signal are unstable, and as a result, there is a problem that it is difficult to stably receive digital broadcasting signals.

Method used

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  • Digital signal reception device
  • Digital signal reception device
  • Digital signal reception device

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Experimental program
Comparison scheme
Effect test

Embodiment approach 1

[0018] use figure 1 ~ Fig. 3 illustrates the first embodiment. figure 1 It is a block diagram showing the configuration of the digital signal receiver of the first embodiment.

[0019] Through the channel selection instruction from the main system 11, the microcomputer 10 sets the channel selection data in the tuner 1. The tuner 1 is provided with a terminal 1a for inputting a reception signal, and the reception signal input from an antenna (not shown) or the like is input to the RFAGC amplifier (not shown) hidden in the tuner 1 through this terminal. The received signal is selected by the tuner 1 as the target channel, and is input to the demodulator 6 through the filter 2, the IFAGC amplifier 3, and the mixer 4. The demodulator 6 performs digital demodulation, and the demodulated signal is It is output to the main system 11 as reproduced data. The local oscillator 5 is connected to the aforementioned mixer 4, and the IF signal amplified by the IFAGC amplifier 3 and a certain f...

Embodiment approach 2

[0023] Secondly, use Figure 5 The second embodiment will be described.

[0024] Figure 5 Is in figure 1 In the block diagram, a modulation state detector 8 that detects the modulation method of each transmission layer is provided as a block diagram of a digital signal receiver constructed by inputting the output of the modulation state detector 8 to the microcomputer 10. The digital terrestrial wave broadcast channel is modulated by multiple modulation methods with different transmission levels, and the main system 11 performs level separation and selects one of the levels for reproduction. If the modulation method is different, the required C / N (carrier / noise ratio) is different. Therefore, the required C / N level becomes higher by multi-valued modulation methods in the order of QPSK, 16QAM, and 64QAM. If the delay point is set in the direction of a stronger electric field, it becomes a receiver state favorable for C / N noise characteristics. It is necessary for the receiver to...

Embodiment approach 3

[0026] Secondly, use Figure 7 , Figure 8 The third embodiment will be described.

[0027] The so-called use of receiving ground wave broadcasting while moving will be more extensive in the future. In the case of receiving while moving, unique attenuation interference occurs. The amount of attenuation interference is usually expressed by Doppler frequency. The higher the Doppler frequency, the greater the degree of interference.

[0028] Here, let the moving speed be Vs (km / h), the receiving channel frequency is Fch (MHz), and the Doppler frequency is Fdopp (Hz), then formula 1 holds

[0029] Fdopp = ( Fch × 10 6 ) × ( Vs × 10 3 ) ...

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Abstract

A digital signal reception device includes: a tuner (1) having a terminal (1a) and an RFAGC amplifier; a filter (2); an IFAGC amplifier (3) for amplifying the signal which has passed through the filter (2); a mixer (4) for converting the signal amplified by the IFAGC amplifier (3) to a signal of lower frequency; a local oscillator (5); a demodulator (6); a level detector (7) for detecting the level of an output signal from the mixer (4); a gain controller (9) which receives the signal from the level detector (7) and controls the gain of the RFAGC amplifier and the gain of the IFAGC amplifier (3) independently from each other; and a microcomputer (10) which receives the signal from the level detector (7) and outputs channel selection data of the target channel to the tuner (1) by a channel selection instruction issued from a host system (11) and a signal of the reproduction transmission hierarchy. Thus, it is possible to stably receive a digital broadcast signal.

Description

Technical field [0001] The invention relates to a digital signal receiver for receiving digitally modulated broadcast signals. Background technique [0002] In recent years, the digitization of TV broadcasting is in progress. The digitized broadcast signal is modulated by various modulation methods, so that the broadcast signal is multiplexed. According to this, multiple programs can be broadcast on channel 1. [0003] As a receiver that receives the digitized broadcast signal, it is usually called a single tuner. The single tuner has a local oscillator, which can convert the high-frequency signal (hereinafter referred to as RF signal) as the aforementioned broadcast signal into an intermediate frequency signal (hereinafter referred to as IF signal). The advantage of a single tuner is that unlike a double tuner with two local oscillators, no phase noise leaks from the two local oscillators is generated, so the bit error rate of the received signal remains unchanged. That is, it i...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H04B1/16H03G3/20H03G3/30H04N5/44
CPCH03G3/3068
Inventor 泷川雅巳尾关浩明大内英树伊藤明
Owner PANASONIC CORP