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CN100499615C - Residual side-band receiver and carrier releaser - Google Patents

Residual side-band receiver and carrier releaser Download PDF

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CN100499615C
CN100499615C CNB2004100845803A CN200410084580A CN100499615C CN 100499615 C CN100499615 C CN 100499615C CN B2004100845803 A CNB2004100845803 A CN B2004100845803A CN 200410084580 A CN200410084580 A CN 200410084580A CN 100499615 C CN100499615 C CN 100499615C
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frequency
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baseband
carrier
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CN1780275A (en
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金德�
金埈台
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Shanghai LG Electronics Co Ltd
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Abstract

本发明涉及接收以残留边带方式调制并发射的信号并还原载波的残留边带接收机及其载波还原器,包括:在通过天线选择所要频道的频率并向中频转换之后,仅使中频的一定带宽通过并进行数字化的数字处理单元;将不需要的信号的低通滤波器的输出信号的功率值与所设置的标准值或临界值进行比较,根据比较结果,将经过数字化的通带信号中的导频成分调节为想要的大小并还原基带的载波还原单元;在基带信号中去除导频信号并提取同步信号的同步解调单元;利用同步信号去除基带信号的线形噪音及残留相位噪音的杂音去除单元;对经过噪音去除的基带信号进行解码的解码单元。其在导频变弱的频道状态下,也能够更为稳定地进行载波还原。

Figure 200410084580

The present invention relates to a vestigial sideband receiver which receives a signal modulated and transmitted in a vestigial sideband manner and restores a carrier wave and a carrier restorer thereof, including: after selecting the frequency of a desired channel through an antenna and converting it to an intermediate frequency, only a certain frequency of the intermediate frequency A digital processing unit that passes through and digitizes the bandwidth; compares the power value of the output signal of the low-pass filter of the unwanted signal with the set standard value or critical value, and converts the digitized passband signal into the The carrier restoration unit that adjusts the pilot frequency component to the desired size and restores the baseband; removes the pilot signal from the baseband signal and extracts the synchronous demodulation unit of the synchronous signal; uses the synchronous signal to remove the linear noise and residual phase noise of the baseband signal Noise removal unit; a decoding unit for decoding the baseband signal after noise removal. It can also restore the carrier more stably in the channel state where the pilot frequency becomes weaker.

Figure 200410084580

Description

残留边带接收机及其载波还原器 Vestigial Sideband Receiver and Its Carrier Restorer

技术领域 technical field

本发明涉及到数字电视,特别涉及到接收以残留边带(VestigialSide Band:VSB)方式调制并传送的信号还原载波的残留边带接收机及其载波还原器。The present invention relates to digital television, in particular to a vestigial sideband receiver and a carrier restorer for receiving a signal modulated and transmitted in a vestigial sideband (VestigialSide Band: VSB) manner to restore a carrier.

背景技术 Background technique

一般而言,在美国及韩国国内,总联盟(Grand Alliance)的残留边带方式被采用为数字电视(如:HDTV)传送方式的标准,其在对信号进行振幅调制时,在以载波为中心向上下方向生成的两个边带中,仅对使其中一个方向的边带信号大幅衰减时的剩余部分进行调制的方式。即,通过仅取用基带的一个方向边带的频谱向通带转换并传送的方式,是有效地使用频带区域的方式之一。Generally speaking, in the United States and South Korea, the Vestigial Sideband method of the Grand Alliance is adopted as the standard for digital TV (such as: HDTV) transmission. Of the two sidebands generated in the up and down directions, only the remaining part after greatly attenuating the sideband signal in one direction is modulated. That is, the method of converting and transmitting the frequency spectrum of the sideband in only one direction of the baseband to the passband is one of the methods of effectively using the frequency band area.

此时,如果上述VSB调制器基带(base band)的DC频谱向通带(pass band)转移,则改变成音调频谱,该信号常常被称作导频信号。即,在电视台进行VSB调制时,为了在接收机中对信号进行精确的解调,而载入导频信号向空中发射。At this time, if the DC spectrum of the base band of the VSB modulator is shifted to the pass band, it is changed into a tone spectrum, and this signal is often called a pilot signal. That is, when a TV station performs VSB modulation, a pilot signal is loaded and transmitted in the air in order to accurately demodulate the signal in a receiver.

图1为普通数字电视的传送系统的简略结构图。随机函数发生器(Randomizer)101使输入数据随机产生并向里德所罗门RS解码器102输出,RS解码器102在对为进行内侧和外侧频道编码而随机输入的数据进行R-S解码并赋加20字节的奇偶代码之后,输出至数字复用器103。FIG. 1 is a schematic structural diagram of a common digital television transmission system. The random function generator (Randomizer) 101 randomly generates the input data and outputs it to the Reed-Solomon RS decoder 102, and the RS decoder 102 performs R-S decoding on the randomly input data for encoding the inner and outer channels and adds 20 words After the parity code of the section, it is output to the digital multiplexer 103.

数字复用器103根据已确定的规则使经R-S解码的数据交叉并向格码解码器104输出,格码解码器104在将经交叉的数据从字节转化为代码并进行格码解码之后向多路复用器105输出。多路复用器105在经格码解码的代码列上,对每个程序段及每个字段都混合程序段同步信号及字段同步信号并制作成帧之后输出至导频插入单元106。导频插入单元106在经帧化处理的发射代码上插入DC值-导频信号并输出至VSB调制单元107,VSB调制单元107以VSB方式对插入了导频信号的代码列进行调制并输出至RF升频器108,RF升频器108为能通过天线有效地传送经调制的基带的VSB信号而转换为RF通带信号之后,通过天线传送。The digital multiplexer 103 interleaves the R-S decoded data according to the determined rules and outputs to the trellis code decoder 104, and the trellis code decoder 104 converts the interleaved data from bytes to codes and performs trellis code decoding to multiplexer 105 output. The multiplexer 105 mixes the block sync signal and the field sync signal for each block and each field on the trellis-decoded code string, creates a frame, and outputs it to the pilot insertion unit 106 . The pilot insertion unit 106 inserts a DC value-pilot signal on the framed transmission code and outputs it to the VSB modulation unit 107, and the VSB modulation unit 107 modulates the code column inserted with the pilot signal in a VSB manner and outputs it to RF upconverter 108. The RF upconverter 108 can effectively transmit the modulated baseband VSB signal through the antenna, convert it into an RF passband signal, and transmit it through the antenna.

图2是图1所示的数字电视的发射装置的VSB调制单元的详细构成的结构图。FIG. 2 is a block diagram showing a detailed configuration of a VSB modulation unit of the digital television transmitter shown in FIG. 1 .

通过由图1所示的随机函数发生器101、RS解码器102、数字复用器103、格码解码器104、多路复用器105、导频插入单元106构成的频道解码器(Channel Encoder)201的信号,为进行VSB调制而通过由合成滤波器202和中频调制器203构成的VSB调制单元。首先,通过频道解码器201的信号为进行VSB调制而通过合成滤波器(Complex filter)202。此时,如果被解码的数字信号通过合成滤波器202,则凭借希尔伯特(Hilbert)转换器和SRC将I&Q信号的频率形态转换成能够进行VSB调制的形态。Through the channel decoder (Channel Encoder) that is made of random function generator 101 shown in Fig. ) 201, to perform VSB modulation, it passes through a VSB modulation unit composed of a synthesis filter 202 and an intermediate frequency modulator 203. First, the signal passing through the channel decoder 201 passes through a complex filter (Complex filter) 202 for VSB modulation. At this time, when the decoded digital signal passes through the synthesis filter 202, the frequency form of the I&Q signal is converted into a form capable of VSB modulation by means of a Hilbert converter and an SRC.

对于合成滤波器202输出的各个I&Q信号,如果在中频调制器203中进行中频调制之后,在减法器204中将两个信号减去,则可以获得所必需的带宽的VSB中频信号。如上生成的VSB中频信号,为了以空中波进行传送,在经由RF升频器205转换成旨在进行有效传送的无线频率(RF)通带信号之后,通过天线206传送。For each I&Q signal output by the synthesis filter 202, if the IF modulation is performed in the IF modulator 203, and the two signals are subtracted in the subtractor 204, the VSB IF signal of the necessary bandwidth can be obtained. The VSB intermediate frequency signal generated as above is converted into a radio frequency (RF) passband signal for efficient transmission by the RF upconverter 205 for transmission over the air, and then transmitted through the antenna 206 .

图3是普通的数字电视的接收装置的构成的结构图。FIG. 3 is a block diagram showing the configuration of a general digital television receiver.

图3是ATSC规格的数字电视接收装置的构成的结构图。通过调谐器提取特定频道的通带信号,在利用插入边带的导频信号进行载波还原之后,从所还原的基带信号中进行代码时钟还原及频道补偿并提取发射信号。FIG. 3 is a block diagram showing the configuration of a digital television receiving apparatus of the ATSC standard. The passband signal of a specific channel is extracted through the tuner, and after the carrier is restored by using the pilot signal inserted into the sideband, code clock restoration and channel compensation are performed from the restored baseband signal to extract the transmitted signal.

上述现有技术设计的数字电视的接收装置包括:在通过天线301选择想要的频道频率之后,将上述频道频率上所负载的RF频带的VSB信号向容易在普通电路中使用的频率频带-IF频带进行第1次向下转换的调谐器302;仅使从调谐器302中输出的IF信号的一定频带通过的声表面滤波器303;将声表面滤波器303的输出频带在A/D转换器305中向想要的信号进行第2次向下转换的中频处理单元304;对中频处理单元304中的模拟输出信号进行数字化的A/D转换单元305;将A/D转换单元305的数字信号转换为基带信号的载波还原单元306;在载波还原单元306的输出信号中去除导频信号的DC去除器307;在DC去除器307的输出信号中提取同步信号并还原代码时钟的同步化单元308;在去除了DC成分的传送信号中去除线形杂音的频道均衡器309;在去除了线形杂音的传送信号中去除残留相位杂音的相位追踪器310;对传送信号执行与发射端的数字频道编码相反的解码过程的FEC单元311。The receiving device of the digital television of above-mentioned prior art design comprises: After selecting the desired channel frequency by antenna 301, the VSB signal of the RF frequency band loaded on the above-mentioned channel frequency is transmitted to the frequency frequency band-IF which is easy to use in common circuits. The tuner 302 that performs the first down-conversion of the frequency band; the surface acoustic filter 303 that only passes a certain frequency band of the IF signal output from the tuner 302; the output frequency band of the surface acoustic filter 303 in the A/D converter In 305, the intermediate frequency processing unit 304 that performs the second down-conversion to the desired signal; the A/D conversion unit 305 that digitizes the analog output signal in the intermediate frequency processing unit 304; the digital signal of the A/D conversion unit 305 The carrier recovery unit 306 converted into a baseband signal; the DC remover 307 that removes the pilot signal from the output signal of the carrier recovery unit 306; the synchronization unit 308 that extracts the synchronization signal from the output signal of the DC remover 307 and restores the code clock ; The channel equalizer 309 that removes the linear noise in the transmission signal that has removed the DC component; The phase tracker 310 that removes the residual phase noise in the transmission signal that has removed the linear noise; Carry out the opposite of the digital channel encoding at the transmitting end to the transmission signal The FEC unit 311 of the decoding process.

在此,调谐器302、声表面滤波器303和中频处理单元304可以称作模拟处理单元,可以将对属于模拟处理单元的中频处理单元304中的模拟输出信号进行数字化的A/D转换单元305和模拟处理单元合起来称作数字处理单元。而且,DC去除器307和同步化单元308可以称作同步解调单元,频道均衡器309和相位追踪器310可以称作噪音去除单元。Here, the tuner 302, the surface acoustic filter 303, and the intermediate frequency processing unit 304 can be referred to as an analog processing unit, and the A/D conversion unit 305 that can digitize the analog output signal in the intermediate frequency processing unit 304 belonging to the analog processing unit Together with the analog processing unit, it is called the digital processing unit. Also, the DC remover 307 and the synchronization unit 308 may be called a synchronous demodulation unit, and the channel equalizer 309 and the phase tracker 310 may be called a noise removal unit.

即,如果通过天线301接收以VSB方式调制的RF信号,调谐器302则在使用外差法调制方式选择想要的频道频率之后,将上述频道频率上负载的RF频带的VSB信号降至经锁定的中频频带(IF:一般广泛使用44MRHz或43.75MHz),适当地过滤掉其它频道信号。That is, if an RF signal modulated in a VSB manner is received through the antenna 301, the tuner 302, after selecting a desired channel frequency using a heterodyne modulation method, reduces the VSB signal of the RF band loaded on the channel frequency to a locked frequency. The intermediate frequency band (IF: generally widely used 44MRHz or 43.75MHz), properly filter out other channel signals.

而且,将任意频道的频谱转移至锁定的IF频带并进行输出的调谐器302的输出信号,通过采用了去除其它频带信号、去除噪音信号以及模拟整合滤波器的功能的声表面(Surface Acoustic Wave:SAW)滤波器303。Furthermore, the output signal of the tuner 302, which shifts the frequency spectrum of an arbitrary channel to the locked IF band and outputs it, passes through a surface acoustic wave (Surface Acoustic Wave: SAW) filter 303.

此时,数字广播信号,举一例,因为在44MHz的中频到6MHz的频带以内存在所有信息,所以在声表面滤波器303仅留存从调谐器302输出的存在信息的6MHz的频带并去除剩余的区间之后,输出至中频处理单元304。At this time, for the digital broadcasting signal, for example, since all information exists in the frequency band from the intermediate frequency of 44 MHz to 6 MHz, only the 6 MHz frequency band in which the information output from the tuner 302 exists is retained in the surface acoustic filter 303 and the remaining interval is removed. After that, it is output to the intermediate frequency processing unit 304 .

中频处理单元304凭借A/D转换单元305变换成想要的信号,A/D转换单元305将所输入的模拟信号转换成数字信号。The intermediate frequency processing unit 304 converts the desired signal by means of the A/D conversion unit 305, and the A/D conversion unit 305 converts the input analog signal into a digital signal.

被转换成数字信号的通带信号在载波还原单元(Carrier Recovery)306被解调成基带信号(BaseBand),在被解调成基带信号的信号上,在发射端为进行载波解调而插入的导频信号的频率则转换成0Hz的DC成分。The passband signal converted into a digital signal is demodulated into a baseband signal (BaseBand) in the carrier recovery unit (Carrier Recovery) 306, and on the signal demodulated into a baseband signal, the carrier wave is inserted at the transmitting end for carrier demodulation. The frequency of the pilot signal is converted to a DC component of 0 Hz.

在此,所生成的DC成分的作用已经被执行,因此通过对其进行去除的DC去除器307。Here, the action of the generated DC component has already been performed, thus by the DC remover 307 which removes it.

从DC去除器307的输出中提取传送信号中存在的同步信号,在还原代码时钟的同步化单元308中提取同步信号区间的信息。此时,所生成的同步信号的区间的信息在后端的频道均衡器309、相位追踪器310及FEC单元311中进行使用。The synchronizing signal present in the transmission signal is extracted from the output of the DC remover 307, and the information of the synchronizing signal interval is extracted in the synchronizing unit 308 which restores the code clock. At this time, the information on the interval of the generated synchronization signal is used in the channel equalizer 309 , the phase tracker 310 , and the FEC unit 311 at the rear end.

去除了DC成分的信号,为了去除在传送频道及接收机内的模拟单元中存在的线形噪音而通过频道均衡器309。而且,经由对在前面的阻塞中未能去除的残留相位噪音进行去除的相位追踪器310,在FEC单元311中执行与在发射单元中所使用的数字频道编码相反的解码过程。如果该项作业完毕,则数字电视内的接收单元的作用全部结束,与从发射端向接收单元输入的信号相同的传送流(Transport Stream)向视频及音频信号处理单元(未图示)传送。The signal from which the DC component has been removed passes through the channel equalizer 309 in order to remove line noise present in the transmission channel and the analog unit in the receiver. Furthermore, a decoding process is performed in the FEC unit 311 inversely to the digital channel coding used in the transmit unit, via a phase tracker 310 which removes residual phase noise not removed in the previous blocking. If the work is completed, the functions of the receiving unit in the digital TV are all over, and the same transport stream (Transport Stream) as the signal input from the transmitter to the receiving unit is transmitted to the video and audio signal processing unit (not shown).

图4是图3所示的数字电视的接收装置的载波还原单元的详细构成的结构图。FIG. 4 is a configuration diagram showing a detailed configuration of a carrier recovery unit of the digital television receiver shown in FIG. 3 .

图4作为图3的接收装置的构成的结构图中的载波还原单元306的详细结构图,是有关执行根据ATSC规格提议作为载波还原单元306的频率相位锁定环路(Frequency Phase Lock Loop)时的普通结构构成图。FIG. 4 is a detailed configuration diagram of the carrier restoration unit 306 in the configuration diagram of the receiving apparatus of FIG. 3, which is related to the implementation of the Frequency Phase Lock Loop (Frequency Phase Lock Loop) proposed as the carrier restoration unit 306 according to the ATSC standard. Common structure diagram.

数字电视接收装置的载波还原单元由以下构成:如果通带(PassBand)模拟信号被转换成数字信号并进行输出,则在使其90度倒置并转换成虚数性质的Q信号之后进行输出的希尔伯特转换器402;在延迟相当于用于将数字信号转换成希尔伯特转换器402中的Q信号的处理时间之后,输出实数性质的I信号的延迟器401;将延迟器401及希尔伯特转换器402的I、Q输出信号和电压控制振荡器410的输出信号相乘,并作为基带的I、Q信号进行合成输出的合成增效器403;以由I信号低通滤波器404、延迟器406、代码提取器407、增效器408、环路滤波器409及电压控制振荡器(VCO)410构成并用于锁定合成增效器403输出的基带的I信号的频率的频率锁定环路(Frequency LockLoop)和由Q信号低通滤波器405、增效器408、环路滤波器409及电压控制振荡器(VCO)410构成并由用于锁定合成增效器403输出的基带的Q信号的相位的相位锁定环路(Phase Lock Loop)构成的频率相位锁定环路。The carrier restoration unit of the digital TV receiving device is composed of the following: If the passband (PassBand) analog signal is converted into a digital signal and output, then it is inverted by 90 degrees and converted into an imaginary Q signal and then output. Burt converter 402; After delaying the processing time equivalent to the Q signal used to convert the digital signal into the Hilbert converter 402, the delayer 401 that outputs the I signal of the real number property; the delayer 401 and the Greek The I, Q output signal of the Kalbert converter 402 and the output signal of the voltage-controlled oscillator 410 are multiplied, and as the I, Q signal of the baseband, the synthesis multiplier 403 that is synthesized and output; 404, delayer 406, code extractor 407, multiplier 408, loop filter 409 and voltage control oscillator (VCO) 410 constitute and are used for locking the frequency locking of the frequency of the I signal of the baseband output by synthesizing multiplier 403 Loop (Frequency LockLoop) and is formed by Q signal low-pass filter 405, multiplier 408, loop filter 409 and voltage control oscillator (VCO) 410 and is used for locking the baseband outputted by synthesizing multiplier 403 The phase lock loop (Phase Lock Loop) of the phase of the Q signal constitutes a frequency phase lock loop.

在此,I信号低通滤波器404、延迟器406及代码提取器407检测频率误差(Error),Q信号低通滤波器405在所测出的频率误差中检测相位误差(Error)。而且,I信号低通滤波器404、延迟器406及代码提取器407的频率误差和Q信号低通滤波器405的相位误差通过增效器408相乘,最终求得频率及相位误差成分(控制电压)。Here, the I-signal low-pass filter 404, the delayer 406, and the code extractor 407 detect a frequency error (Error), and the Q-signal low-pass filter 405 detects a phase error (Error) from the measured frequency error. And, the frequency error of the I signal low-pass filter 404, the delayer 406 and the code extractor 407 and the phase error of the Q signal low-pass filter 405 are multiplied by the multiplier 408 to finally obtain the frequency and phase error components (controlling Voltage).

这样一来,环路滤波器409去除频率及相位误差成分中包含的频率成分,在电压控制振荡器410中则根据频率及相位误差成分(控制电压)改变振荡频率并进行振动。In this way, the loop filter 409 removes frequency components included in the frequency and phase error components, and the voltage controlled oscillator 410 oscillates while changing the oscillation frequency according to the frequency and phase error components (control voltage).

即,环路振荡器409仅过滤基带信号并进行输出,电压控制振荡器410根据环路滤波器409的输出信号输出经改变的振荡频率。而且,如此根据电压控制振荡器410中经改变的振荡频率改变载波的频率及相位并去除成拍(beat)频率(即差频或拍频)。That is, the loop oscillator 409 only filters and outputs the baseband signal, and the voltage controlled oscillator 410 outputs the changed oscillation frequency according to the output signal of the loop filter 409 . Moreover, the frequency and phase of the carrier wave are changed according to the changed oscillation frequency of the VCO 410 and the beat frequency (ie, the difference frequency or beat frequency) is removed.

即,在载波还原单元306中,从声表面滤波器303的输出信号中分离相位,对基带的I、Q信号进行解调并且锁定(locking)频率和相位。电压控制振荡器(VCO)410的中心频率被锁定为中频(例如:46.690559MHz),VCO410的输出在合成增效器403中与声表面滤波器303的输出相乘并被解调成基带的I、Q频道信号(i(t),q(t))。That is, in the carrier restoration unit 306, the phase is separated from the output signal of the surface acoustic filter 303, the baseband I and Q signals are demodulated, and the frequency and phase are locked. The center frequency of the voltage-controlled oscillator (VCO) 410 is locked to an intermediate frequency (for example: 46.690559MHz), and the output of the VCO 410 is multiplied with the output of the surface acoustic filter 303 in the synthesis multiplier 403 and demodulated into a baseband I , Q channel signal (i(t), q(t)).

此时,发射装置中插入的导频频率必须在声表面滤波器303的输出中精确地存在于中频(例如:46.690559MHz)之上,其余的接收装置才正常地执行动作。一般情况下,不是46.690559MHz的时候很多。At this time, the pilot frequency inserted in the transmitting device must exist precisely above the intermediate frequency (for example: 46.690559MHz) in the output of the surface acoustic filter 303, and the rest of the receiving devices can perform normal operations. In general, there are many times when it is not 46.690559MHz.

然而,由于电压控制振荡器410的输出频率被锁定在46.690559MHz,所以在声表面滤波器303中导频的输出频率并非是46.690559MHz的情况下,则存在相当于合成增效器403中输出的两个频率的差异的成拍(beat)频率。为了去除上述成拍频率,使用频率相位锁定环路。即,通过使电压控制振荡器410的振荡频率改变,使载波的频率及相位改变并去除成拍频率。因而,找出使电压控制振荡器410的振荡频率变化和大小则是频率相位锁定环路的目的。However, since the output frequency of the voltage-controlled oscillator 410 is locked at 46.690559MHz, in the case where the output frequency of the pilot in the SAW filter 303 is not 46.690559MHz, there is The beat frequency of the difference between two frequencies. In order to remove the above beat frequency, a frequency phase locked loop is used. That is, by changing the oscillation frequency of the voltage controlled oscillator 410 , the frequency and phase of the carrier wave are changed and the beat frequency is removed. Therefore, finding out the variation and size of the oscillation frequency of the voltage controlled oscillator 410 is the purpose of the frequency phase locked loop.

FPLL具备由用于使频率锁定的环路(loop)和用于使相位(phase)锁定的环路相结合的形态。The FPLL has a combination of a loop for frequency locking and a loop for phase locking.

在图4中,由低通滤波器404、延迟器406实现的自动频率调节滤波器(AFC Filter:Auto Frequency Control Filter)和由代码检测器407、增效器408、环路滤波器409、电压控制振荡器410及合成增效器403构成的环路成为用于使频率锁定环路(FLL),由Q信号低通滤波器405、增效器408、环路滤波器409、电压控制振荡器410及合成增效器403构成的环路成为用于使相位锁定环路(PLL)。In Fig. 4, the automatic frequency adjustment filter (AFC Filter: Auto Frequency Control Filter) realized by low-pass filter 404, delayer 406 and code detector 407, multiplier 408, loop filter 409, voltage The loop formed by the control oscillator 410 and the synthesizing multiplier 403 becomes a frequency locked loop (FLL), which is composed of a Q signal low-pass filter 405, a multiplier 408, a loop filter 409, and a voltage controlled oscillator. The loop formed by 410 and synthesizing multiplier 403 becomes a phase-locked loop (PLL).

依据相位锁定环路而生成的S-曲线(curve)如图5所示。The S-curve (curve) generated according to the phase locked loop is shown in FIG. 5 .

一方面,如前所述,频率相位锁定环路构成的载波还原算法具备将电压控制振荡器410的输出频率与导频信号的频率吻合的形式。因而,在I信号的导频信号不精确地存在于DC中的情况下,寻找导频信号的频谱上的位置是非常重要的,导频信号之外的数据成分无法给予载波解调所必需的信息。On the one hand, as described above, the carrier restoration algorithm constituted by the frequency phase locked loop has a form in which the output frequency of the voltage controlled oscillator 410 matches the frequency of the pilot signal. Therefore, in the case where the pilot signal of the I signal does not exist precisely in DC, it is very important to find the position on the frequency spectrum of the pilot signal, and the data components other than the pilot signal cannot give the carrier necessary for demodulation. information.

因而,为了去除载波解调所不必要的数据成分,使用I信号低通滤波器404。Therefore, the I signal low-pass filter 404 is used in order to remove data components unnecessary for carrier demodulation.

但是,在通过频道的同时导频信号成分被严重弱化的情况下,仅就使用低通滤波器而言,存在难以阻止使用频率相位锁定环路的载波解调系统的性能退化的问题。However, there is a problem that it is difficult to prevent performance degradation of a carrier demodulation system using a frequency-phase-locked loop only by using a low-pass filter when the simultaneous pilot signal component is severely attenuated while passing through the channel.

图6a~图6c是用于对载波还原单元的合成增效器输出信号的特性进行说明的示意图。6a to 6c are schematic diagrams for explaining the characteristics of the output signal of the synthesized multiplier of the carrier restoration unit.

图6a展示的是在导频信号被接收装置稳定地接收的情况下,基带中形成的I信号的频谱。图6b和图6c展示的是在导频信号被频道严重弱化的情况下,基带信号的频谱特性。Fig. 6a shows the frequency spectrum of the I signal formed in the baseband under the condition that the pilot signal is stably received by the receiving device. Figures 6b and 6c show the spectral characteristics of the baseband signal when the pilot signal is severely attenuated by the channel.

在载波还原未能完美地实现的情况下,导频信号也具有某种程度的频率导频,同时位于DC附近。In cases where carrier restoration is not achieved perfectly, the pilot signal also has some degree of frequency pilot while being located near DC.

因而,在导频信号被频道损伤的情况下,合成增效器的I信号的输出,其功率在DC附近变得非常弱。Therefore, when the pilot signal is corrupted by the channel, the power of the I signal output from the synthesis booster becomes very weak near DC.

另一方面,如前所述,频率相位锁定环路算法在导频信号的大小随着以导频信号为基础执行载波解调而变弱的情况下,存在因其性能退化而最终无法顺利执行载波解调的问题。On the other hand, as mentioned earlier, the frequency-phase-locked-loop algorithm cannot perform smoothly due to its performance degradation when the size of the pilot signal becomes weaker as the carrier demodulation is performed based on the pilot signal. Carrier demodulation problem.

发明内容 Contents of the invention

本发明正是为解决上述问题而设计的,其目的在于:提供在接收以残留边带方式解调并传送的信号并还原载波的情况下,在通过传送频道的导频信号成分变弱时,能够使该导频信号的大小一定的残留边带接收机。The present invention is designed to solve the above-mentioned problems, and its purpose is to provide a solution to reduce the carrier wave when the pilot signal component passing through the transmission channel becomes weak when receiving a signal demodulated and transmitted in a vestigial sideband mode. A vestigial sideband receiver capable of keeping the size of the pilot signal constant.

根据旨在实现上述目的本发明而设计的残留边带接收机,就将所接收的通带模拟信号解调成基带数字信号的数字电视的接收机而言,包括:在通过天线选择所要频道的频率并向中频转换之后,仅使上述中频的一定带宽通过并进行数字化的数字处理单元;将在经过数字化的通带信号中去除还原载波时不需要的信号的低通滤波器的输出信号的功率值与所设置的标准值或临界值进行比较,根据比较结果,将经过数字化的通带信号中的导频成分调节为想要的大小并还原基带的载波的载波还原单元;在基带信号中去除导频信号并提取同步信号的同步解调单元;利用同步信号去除基带信号的线形杂音及残留相位杂音的杂音去除单元;对经过杂音去除的基带信号进行解码的解码单元。According to the vestigial sideband receiver designed according to the present invention to achieve the above object, as far as the received passband analog signal is demodulated into the digital television receiver of the baseband digital signal, it includes: selecting the desired channel through the antenna After the frequency is converted to the intermediate frequency, only a certain bandwidth of the above-mentioned intermediate frequency is passed and digitized; the output signal power of the low-pass filter that removes the unnecessary signal when restoring the carrier in the digitized passband signal The value is compared with the set standard value or critical value. According to the comparison result, the pilot component in the digitized passband signal is adjusted to the desired size and the carrier restoration unit of the baseband carrier is restored; the baseband signal is removed. A synchronous demodulation unit that extracts the pilot signal and a synchronous signal; a noise removal unit that removes linear noise and residual phase noise of the baseband signal by using the synchronous signal; a decoding unit that decodes the noise-removed baseband signal.

一方面,上述同步解调单元包括去除导频信号的DC去除器和在去除了导频信号的信号中提取同步信号的同步化单元构成,噪音去除单元由在去除了导频信号的信号中去除线形噪音的频道均衡器和在去除了线形噪音的信号中去除残留相位噪音的相位追踪器构成,解码单元由在去除了残留相位噪音的信号对发射信号进行解码的FEC单元构成。In one aspect, the synchronous demodulation unit includes a DC remover for removing the pilot signal and a synchronization unit for extracting the synchronous signal from the signal from which the pilot signal has been removed, and the noise removal unit is composed of removing A channel equalizer for line noise and a phase tracker for removing residual phase noise from a signal from which line noise has been removed, and a decoding unit is composed of an FEC unit for decoding a transmission signal from a signal from which residual phase noise has been removed.

而且,旨在实现上述目的的本发明的载波还原器,还包括:将来自频率相位锁定环路的振荡频率与经数字转换的通带信号相乘,对基带信号的载波进行还原并输出的合成增效器;利用基带信号的导频信号使基带信号的频率和相位锁定,使振荡频率生成的频率相位锁定环路;将输入频率相位锁定环路的基带信号的功率值与所设置的标准值或临界值进行比较,将从合成增效器中输出的基带信号中所包括的导频信号调节成想要的大小并向频率相位锁定环路输出的增益控制装置。Moreover, the carrier restorer of the present invention aimed at achieving the above object further includes: multiplying the oscillation frequency from the frequency phase locked loop by the digitally converted passband signal, restoring and outputting the carrier wave of the baseband signal Multiplier; use the pilot signal of the baseband signal to lock the frequency and phase of the baseband signal, so that the frequency phase lock loop generated by the oscillation frequency; the power value of the baseband signal input into the frequency phase lock loop and the set standard value A gain control device that adjusts the pilot signal included in the baseband signal output from the synthesizing multiplier to a desired size and outputs it to the frequency phase locked loop by comparing it with a critical value.

再者,上述增益控制装置,包括:在从输入频率相位锁定环路的基带信号中去除了载波还原所不必要的数据成分的信号后,计算合成增效器的基带信号的功率的功率计算单元;将经计算的功率值与所设置的标准值或临界值进行比较并输出的比较单元;设置在合成增效器和频率相位锁定环路之间,根据比较单元的输出结果对从合成增效器中输出的基带信号的增益进行控制,来对导频信号的大小进行调节并输出经还原载波的增效调节单元。Furthermore, the above-mentioned gain control device includes: a power calculation unit that calculates the power of the baseband signal of the synthesized multiplier after removing the signal of the data component unnecessary for carrier restoration from the baseband signal input to the frequency phase locked loop. ;A comparison unit that compares the calculated power value with the set standard value or critical value and outputs it; it is set between the synthesizing booster and the frequency phase locked loop, and boosts the slave synthesizing according to the output result of the comparison unit Control the gain of the baseband signal output in the device to adjust the size of the pilot signal and output the synergy adjustment unit of the restored carrier.

而且,在上述合成增效器中,如果经数字转换的通带信号具有90度相位差的通带的I、Q信号被输入,则将其与振荡频率相乘并合成基带的I、Q信号;增效调节单元则由对基带的I、Q的信号的各自的增效进行控制的第1、第2增效调节单元构成。Also, in the synthesis multiplier described above, if the digitally-converted passband signal has a passband I, Q signal with a phase difference of 90 degrees is input, it is multiplied by the oscillation frequency and synthesized into a baseband I, Q signal The boost adjustment unit is composed of the first and second boost adjustment units that control the respective boosts of the baseband I and Q signals.

并且,上述频率相位锁定环路,包括:包括在通过增益调节单元的基带的I信号中去除不必要的数据成分之后锁定频率的第1低通滤波器、延迟器、代码提取器、增效器、环路滤波器及频率振荡器构成的频率锁定环路;包括在上述基带的Q信号中去除不必要的数据成分之后锁定相位的第2低通滤波器、增效器、环路滤波器、及频率振荡器构成的相位锁定环路。而且,上述功率计算单元对通过第1低通滤波器的基带I信号的功率进行计算。And, the above-mentioned frequency-phase-locked loop includes: a first low-pass filter, a delayer, a code extractor, and a multiplier that lock the frequency after removing unnecessary data components from the baseband I signal passing through the gain adjustment unit. , a frequency locked loop composed of a loop filter and a frequency oscillator; including a second low-pass filter, a multiplier, a loop filter, and a phase-locked loop composed of a frequency oscillator. Furthermore, the power calculation unit calculates the power of the baseband I signal that has passed through the first low-pass filter.

再者,上述增益控制装置,包括:在从输入频率相位锁定环路的基带信号中去除了载波还原所不必要的数据成分的信号后,对合成增效器的信号的功率进行计算的功率计算单元;将所计算的功率值与所设置的标准值或临界值进行比较并输出的比较单元;设置在频率相位锁定环路的频率及相位误差检测单元与环路滤波器之间,根据依据比较单元中的输出结果对从频率及相位误差检测单元中输出基带信号的增益进行控制来调节导频信号的大小并输出至环路滤波器的增益调节单元。Furthermore, the above-mentioned gain control device includes: after removing the signal of the data component unnecessary for carrier restoration from the baseband signal input to the frequency phase locked loop, and then calculating the power of the signal synthesized by the multiplier Unit; a comparison unit that compares the calculated power value with a set standard value or critical value and outputs it; it is set between the frequency and phase error detection unit and the loop filter of the frequency phase locked loop, and compares according to the basis The output result in the unit controls the gain of the baseband signal output from the frequency and phase error detection unit to adjust the size of the pilot signal and outputs it to the gain adjustment unit of the loop filter.

本发明的另一目的、特性及优点,可通过参照附图对实施例所做的详细说明得到了解。Another object, characteristics and advantages of the present invention can be understood through the detailed description of the embodiments with reference to the accompanying drawings.

本发明具有以下效果:使得能够在导频信号的大小变弱的情况下自动对频率相位锁定环路环路的增益进行调节,即使在导频信号的大小变弱的频道情况下,也能够更为稳定地执行载波还原。The present invention has the effect of enabling automatic adjustment of the gain of the frequency-phase-locked loop loop when the magnitude of the pilot signal becomes weaker, and even in the case of a channel where the magnitude of the pilot signal becomes weaker. To perform carrier restoration stably.

附图说明 Description of drawings

图1是普通的数字电视的发射装置的构成的结构图。FIG. 1 is a block diagram showing the configuration of a common digital television transmitter.

图2是图1所示的数字电视的发射装置的VSB调制单元的详细构成的结构图。FIG. 2 is a block diagram showing a detailed configuration of a VSB modulation unit of the digital television transmitter shown in FIG. 1 .

图3是普通的数字电视的接收装置的构成的结构图。FIG. 3 is a block diagram showing the configuration of a general digital television receiver.

图4是图3所示的数字电视的接收装置的载波还原单元的详细构成的结构图。FIG. 4 is a configuration diagram showing a detailed configuration of a carrier recovery unit of the digital television receiver shown in FIG. 3 .

图5是根据相位同步环路而形成的S-曲线特性的示意图。FIG. 5 is a schematic diagram of an S-curve characteristic formed according to a phase synchronous loop.

图6a~图6c是用于说明合成增效器输出信号的特性的示意图。6a to 6c are schematic diagrams for explaining the characteristics of the output signal of the composite multiplier.

图7是本发明的第1实施例的数字电视的接收装置的载波还原单元的详细构成的结构图。FIG. 7 is a block diagram showing a detailed configuration of a carrier recovery unit of the digital television receiver according to the first embodiment of the present invention.

图8是本发明的第2实施例的数字电视的接收装置的载波还原单元的详细构成的结构图。FIG. 8 is a block diagram showing a detailed configuration of a carrier recovery unit of a digital television receiver according to a second embodiment of the present invention.

附图主要部分符号说明Explanation of symbols in main parts of drawings

701、801:合成增效器             702:第1增益调节单元701, 801: Synthetic multiplier 702: The first gain adjustment unit

703:第2增益调节单元             809:增益调节单元703: The second gain adjustment unit 809: Gain adjustment unit

704、802:第1低通滤波器          705、803:第2低通滤波器704, 802: 1st low-pass filter 705, 803: 2nd low-pass filter

706、804:延迟器                 707、805:代码提取器706, 804: delayer 707, 805: code extractor

708、806:增效器                 709、807:功率计算单元708, 806: Amplifier 709, 807: Power calculation unit

710、810:环路滤波器             711、811:电压控制振荡器710, 810: Loop Filter 711, 811: Voltage Controlled Oscillator

712、808:比较单元               720、820:增益控制装置712, 808: comparison unit 720, 820: gain control device

730、830:频率相位锁定环路730, 830: frequency phase locked loop

具体实施方式 Detailed ways

以下,参照附图对本发明的残留边带接收机及载波还原器进行详细说明。Hereinafter, the vestigial sideband receiver and carrier restorer of the present invention will be described in detail with reference to the accompanying drawings.

图7是第1实施例的数字电视的接收装置的载波还原单元的详细构成的结构图。FIG. 7 is a block diagram showing a detailed configuration of a carrier recovery unit of the digital television receiver of the first embodiment.

本发明的第1实施例的数字电视的接收装置的载波还原单元,包括:如果通带(PassBand)模拟信号被转换成数字信号并进行输出,则在使其90度倒置并转换成虚数性质的Q信号之后进行输出的希尔伯特转换器(未图示);在延迟相当于用于将数字信号转换成希尔伯特转换器中的Q信号的处理时间之后,将输出实数性质的I信号的延迟器(未图示)中的I、Q输出信号与电压控制振荡器711的输出信号相乘并合成输出基带的I、Q信号(载波)的合成增效器701;以由第1低通滤波器704、延迟器706、代码提取器707、增效器708、环路滤波器710及电压控制振荡器(VCO)711构成并对基带的I信号的频率进行锁定的频率锁定环路(Frequency Locked Loop)和由第2低通滤波器705、环路滤波器710及电压控制振荡器(VCO)711构成并对Q信号的相位进行锁定的相位锁定环路(Phase Locked Loop)构成的频率相位锁定环路730;由对从第1低通滤波器704中输出的I信号的导频功率进行计算的功率计算单元709、将功率计算单元709中计算出的导频功率与事先设置的临界值或标准值进行比较的比较单元712和分别设置在合成增效器701与第1、第2低通滤波器704、705之间,由根据依据比较单元712的输出结果对合成增效器701中输出的I、Q输出信号的增益进行调节来将用于还原载波的导频信号的大小调节成想要的大小并向频率相位锁定环路730的第1、第2低通滤波器704、705进行输出的第1、第2增益调节单元702、703构成的增益控制装置720。The carrier recovery unit of the digital television receiving device of the first embodiment of the present invention includes: if the passband (PassBand) analog signal is converted into a digital signal and output, then make it 90 degrees inverted and converted into an imaginary number A Hilbert converter (not shown) that outputs after the Q signal; after a delay equivalent to the processing time used to convert the digital signal to the Q signal in the Hilbert converter, an I of a real nature will be output The I, Q output signal in the delayer (not shown) of the signal is multiplied by the output signal of the voltage control oscillator 711 and synthesizes the I, Q signal (carrier) of the output baseband to synthesize the multiplier 701; Low-pass filter 704, delayer 706, code extractor 707, multiplier 708, loop filter 710, and voltage-controlled oscillator (VCO) 711 form a frequency-locked loop that locks the frequency of the baseband I signal (Frequency Locked Loop) and a Phase Locked Loop (Phase Locked Loop) which is composed of a second low-pass filter 705, a loop filter 710, and a voltage-controlled oscillator (VCO) 711 to lock the phase of the Q signal Frequency-phase-locked loop 730; by the power calculation unit 709 that calculates the pilot power of the I signal output from the first low-pass filter 704, the pilot power calculated in the power calculation unit 709 and the preset The comparison unit 712 that critical value or standard value compares is respectively arranged between the synthesizing multiplier 701 and the 1st, the 2nd low-pass filter 704,705, by according to the output result of comparing unit 712 to synthesize multiplier The gain of the I and Q output signals output in 701 is adjusted to adjust the size of the pilot signal used to restore the carrier to the desired size and to the first and second low-pass filters 704 of the frequency phase locked loop 730 , 705 to output the first and second gain adjustment units 702, 703 to form a gain control device 720.

本发明的数字电视接收装置的基本构成与图3所示的数字电视接收装置类似,只是就载波还原单元对载波进行还原而言,如果在普通的数字处理单元中,在通过天线选择想要的频道频率并转换成中频之后,仅使中频的一定频带通过并进行数字化,则将从通带信号中去除载波还原所不必要的信号的第1低通滤波器704的输出信号的功率值与所设置的标准值或临界值进行比较,根据比较结果将经数字化的通带信号的导频成分的大小调节成想要的大小并对载波进行还原。其去除另外的导频信号并提取同步信号的同步解调单元和利用上述同步信号去除基带信号的线形噪音及残留相位噪音的噪音去除单元以及对去除了噪音的基带信号进行解码的解码单元(例如:FEC单元)的构成与普通的构成相同,因此略去对其的详细说明。The basic structure of the digital television receiving device of the present invention is similar to the digital television receiving device shown in Fig. 3, but with respect to the carrier wave restoration unit restores the carrier wave, if in a common digital processing unit, the desired signal is selected through the antenna After the channel frequency is converted into an intermediate frequency, only a certain frequency band of the intermediate frequency is passed and digitized, and the power value of the output signal of the first low-pass filter 704 that removes unnecessary signals for carrier restoration from the passband signal is compared with the specified Compared with the set standard value or critical value, according to the comparison result, the size of the pilot component of the digitized passband signal is adjusted to the desired size and the carrier is restored. It is a synchronous demodulation unit that removes another pilot signal and extracts a synchronous signal, a noise removal unit that removes linear noise and residual phase noise of a baseband signal using the synchronous signal, and a decoding unit that decodes the noise-removed baseband signal (e.g. : FEC unit) has the same configuration as a general configuration, and therefore a detailed description thereof will be omitted.

如前所述,频率相位锁定环路算法根据导频信号执行载波还原。因而,为了去除载波还原所不必要的数据成分而使用第1低通滤波器704,功率计算单元709则对第1低通滤波器704输出信号的功率进行计算。As mentioned earlier, the frequency phase locked loop algorithm performs carrier recovery from the pilot signal. Therefore, the first low-pass filter 704 is used to remove data components unnecessary for carrier restoration, and the power calculation unit 709 calculates the power of the output signal of the first low-pass filter 704 .

而且,第1、第2增益调节单元702、703利用功率计算单元709中计算出的功率值,对第1、第2低通滤波器704、705输入信号,即载波还原单元的I、Q输出信号的增益(gain)进行调节。Moreover, the first and second gain adjustment units 702 and 703 use the power values calculated in the power calculation unit 709 to input signals to the first and second low-pass filters 704 and 705, that is, the I and Q outputs of the carrier recovery unit Signal gain (gain) to adjust.

因而,可以根据随着导频信号的大小变弱而减小的第1、第2低通滤波器704、705的输出信号的程度,对滤波器输入信号的大小进行调节。在将输入第1、第2低通滤波器704、705的输入信号的功率(power)标准化(normalization)的情况下,存在线形噪音,因此即使在导频信号的功率变弱的情况下,也可以使具有一定功率的导频信号输入第1、第2低通滤波器704、705。这就意味着,以上是在通过在导频信号的大小相对变弱的情况下扩大的,因此即使在导频信号变弱的情况下,也能够扩大整个频率相位锁定环路的增益。Therefore, the size of the filter input signal can be adjusted according to the degree of output signals of the first and second low-pass filters 704 and 705 that decrease as the size of the pilot signal becomes weaker. When the power (power) of the input signal input to the first and second low-pass filters 704 and 705 is normalized (normalization), there is line noise, so even when the power of the pilot signal becomes weak, the A pilot signal having a certain power can be input to the first and second low-pass filters 704 and 705 . This means that the above is expanded when the magnitude of the pilot signal is relatively weak, so even when the pilot signal is weak, the gain of the entire frequency-phase locked loop can be expanded.

图8是本发明的第2实施例的数字电视的接收装置的载波还原单元的详细构成的结构图。FIG. 8 is a block diagram showing a detailed configuration of a carrier recovery unit of a digital television receiver according to a second embodiment of the present invention.

在本发明的第2实施例中包括:如果通带模拟信号被转换成数字信号并进行输出,则在使其90度倒置并转换成虚数性质的Q信号之后进行输出的希尔伯特转换器(未图示);在延迟相当于用于将数字信号转换成希尔伯特转换器中的Q信号的处理时间之后,输出实数性质的I信号的延迟器(未图示);将上述延迟器及希尔伯特转换器的I、Q输出信号与电压控制振荡器811的输出信号相乘并合成输出基带的I、Q信号(载波)的合成增效器801;以由第1低通滤波器802、延迟器804、代码提取器805、增效器806、环路滤波器810及电压控制振荡器811构成并对基带的I信号的频率进行锁定的频率锁定环路(和由第2低通滤波器803、增效器806、环路滤波器810及电压控制振荡器811构成并对基带的Q信号的相位进行锁定的相位锁定环路构成的频率相位锁定环路830;由对从第2低通滤波器803的I输出信号的功率进行计算的功率计算单元807、将在功率计算单元807中计算出的I输出信号的功率与事先设置的临界值或标准值进行比较的比较单元808和由接收上述增效器806的输出值和比较单元808的输出结果并对合成增效器801中输出的I、Q输出信号的增益进行调节,据此将导频信号的大小调节成想要的大小并输出至频率相位锁定环路830的增益调节单元809构成的增益控制装置820。In the second embodiment of the present invention, if the passband analog signal is converted into a digital signal and output, it is inverted by 90 degrees and converted into an imaginary Q signal and then output. (not shown); after the delay is equivalent to the processing time for converting the digital signal into the Q signal in the Hilbert converter, the delay device (not shown) that outputs the I signal of the real number nature; the above-mentioned delay The I, Q output signals of the device and the Hilbert converter are multiplied by the output signal of the voltage-controlled oscillator 811 and synthesized to output the baseband I, the Q signal (carrier) of the synthesizer 801; Filter 802, delayer 804, code extractor 805, multiplier 806, loop filter 810, and voltage-controlled oscillator 811 constitute a frequency-locked loop that locks the frequency of the baseband I signal (and is composed of the second Low-pass filter 803, multiplier 806, loop filter 810 and voltage-controlled oscillator 811 constitute and the phase-locked loop 830 that the phase-locked loop that the phase of the Q signal of baseband is locked constitutes; The power calculation unit 807 for calculating the power of the I output signal of the second low-pass filter 803, and the comparison unit for comparing the power of the I output signal calculated in the power calculation unit 807 with a preset critical value or standard value 808 and by receiving the output value of the multiplier 806 and the output result of the comparison unit 808 and adjusting the gain of the I and Q output signals output in the synthesizing multiplier 801, thereby adjusting the size of the pilot signal to the desired The desired magnitude is output to the gain control device 820 constituted by the gain adjustment unit 809 of the frequency phase locked loop 830 .

在本发明的第2实施例中,从合成增效器801中实际输出载波还原单元的I、Q信号。In the second embodiment of the present invention, the I and Q signals of the carrier recovery unit are actually output from the synthesizer 801 .

此时,在将第1低通滤波器802的通过增益调节成1的情况下,代码提取器805对信号的增益不产生任何影响,因此将增益调节单元809设置在增效器806的下一端的图8的实施例与图7的实施例是等效的。At this time, when the pass gain of the first low-pass filter 802 is adjusted to 1, the code extractor 805 does not have any influence on the gain of the signal, so the gain adjustment unit 809 is arranged at the next end of the multiplier 806 The embodiment of FIG. 8 is equivalent to the embodiment of FIG. 7 .

在图8中,增益调节单元809可以解释为对增效器(误差检测器)806的增益进行调节。In FIG. 8 , the gain adjustment unit 809 can be interpreted as adjusting the gain of the multiplier (error detector) 806 .

在频率相位锁定环路系统中,在导频信号变弱的情况下,图5所示的相位锁定环路的S-曲线的增益相对减小。在图8的本发明的第2实施例中,对从增效器806中提取的误差的增益进行扩大,因此在导频信号变弱的情况下对整个环路的增益进行调节。In a frequency-phase-locked loop system, when the pilot signal becomes weaker, the gain of the S-curve of the phase-locked loop shown in FIG. 5 decreases relatively. In the second embodiment of the present invention shown in FIG. 8, the gain of the error extracted from the multiplier 806 is amplified, so that the gain of the entire loop is adjusted when the pilot signal becomes weak.

通过以上予以说明的内容,该领域的工作人员可以了解到,能够在不脱离本发明的技术思想的范围之内进行多种变更和修正。From the above description, those skilled in the art can understand that various changes and corrections can be made without departing from the technical idea of the present invention.

因而,本发明的技术范围不限于实施例中所记录的内容,而应由权利要求范围来确定。Therefore, the technical scope of the present invention is not limited to what is recorded in the embodiments, but should be determined by the scope of claims.

Claims (8)

1、一种残留边带接收机,就将所接收的通带模拟信号解调成基带数字信号的数字电视的接收机而言,其特征在于,包括:1. A vestigial sideband receiver, as far as the received passband analog signal is demodulated into the digital television receiver of the baseband digital signal, it is characterized in that it includes: 在通过天线选择所要频道的频率并向中频转换之后,仅使上述中频的一定带宽通过并进行数字化的数字处理单元;After the frequency of the desired channel is selected by the antenna and converted to the intermediate frequency, only a certain bandwidth of the above intermediate frequency is passed and digitized; 将在经过数字化的通带信号中去除还原载波时不需要的信号的低通滤波器的输出信号的功率值与所设置的标准值或临界值进行比较,根据比较结果,将经过数字化的通带信号中的导频成分调节为想要的大小并还原基带的载波的载波还原单元;Compare the power value of the output signal of the low-pass filter that removes the unnecessary signal when restoring the carrier in the digitized passband signal with the set standard value or critical value, and according to the comparison result, the digitized passband The carrier restoration unit that adjusts the pilot component in the signal to the desired size and restores the baseband carrier; 在基带信号中去除导频信号并提取同步信号的同步解调单元;A synchronous demodulation unit that removes the pilot signal from the baseband signal and extracts the synchronous signal; 利用同步信号去除基带信号的线形噪音及残留相位噪音的噪音去除单元;A noise removal unit that removes linear noise and residual phase noise of the baseband signal by using the synchronous signal; 对经过噪音去除的基带信号进行解码的解码单元。A decoding unit for decoding the noise-removed baseband signal. 2、如权利要求1所述的残留边带接收机,其特征在于:2. The vestigial sideband receiver as claimed in claim 1, characterized in that: 同步解调单元包括:去除导频信号的DC去除器和在去除了导频信号的信号中提取同步信号的同步化单元;The synchronous demodulation unit includes: a DC remover for removing the pilot signal and a synchronization unit for extracting a synchronous signal from the signal from which the pilot signal has been removed; 噪音去除单元包括:在去除了导频信号的信号中去除线形噪音的频道均衡器和在去除了线形噪音的信号中去除残留相位噪音的相位追踪器;The noise removal unit includes: a channel equalizer for removing line noise from the pilot signal removed signal and a phase tracker for removing residual phase noise in the line noise removed signal; 解码单元包括:对去除了噪音的基带信号进行解码的FEC单元。The decoding unit includes: an FEC unit for decoding the noise-removed baseband signal. 3、一种载波还原器,其特征在于,包括:3. A carrier restorer, characterized in that it comprises: 将来自频率相位锁定环路的振荡频率与经数字转换的通带信号相乘,对基带信号的载波进行还原并输出的合成增效器;Multiply the oscillation frequency from the frequency phase-locked loop with the digitally converted passband signal, restore and output the carrier of the baseband signal; 利用基带信号的导频信号使基带信号的频率和相位锁定,使振荡频率生成的频率相位锁定环路;Using the pilot signal of the baseband signal to lock the frequency and phase of the baseband signal, and make the frequency phase lock loop generated by the oscillation frequency; 将输入频率相位锁定环路的基带信号的功率值与所设置的标准值或临界值进行比较,将从合成增效器中输出的基带信号中所包括的导频信号调节成想要的大小并向频率相位锁定环路输出的增益控制装置。Comparing the power value of the baseband signal input into the frequency phase locked loop with the set standard value or critical value, adjusting the pilot signal included in the baseband signal output from the synthesizer to the desired size and Gain control for the output of the frequency phase locked loop. 4、如权利要求3所述的载波还原器,其特征在于,增益控制装置包括:4. The carrier restorer according to claim 3, wherein the gain control device comprises: 在从输入频率相位锁定环路的基带信号中去除了载波还原所不必要的数字成分的信号后,计算合成增效器的基带信号功率的功率计算单元;将经计算的功率值与所设置的标准值或临界值进行比较并输出的比较单元;After the signal of the digital component unnecessary for carrier restoration is removed from the baseband signal of the input frequency phase locked loop, the power calculation unit that calculates the baseband signal power of the synthesizing booster; compares the calculated power value with the set A comparison unit that compares and outputs a standard value or a critical value; 设置在合成增效器和频率相位锁定环路之间,根据依据比较单元的输出结果对从合成增效器中输出的基带信号的增益进行控制来对导频信号的大小进行调节并输出经还原的载波的增效调节单元。Set between the synthesis multiplier and the frequency phase locked loop, according to the output result of the comparison unit to control the gain of the baseband signal output from the synthesis multiplier to adjust the size of the pilot signal and output the restored The synergistic adjustment unit of the carrier. 5、如权利要求4所述的载波还原器,其特征在于:5. The carrier restorer according to claim 4, characterized in that: 在上述合成增效器中,如果经数字转换的通带信号具有90度相位差的通带的I、Q信号被输入,则将其与振荡频率相乘并合成基带的I、Q信号;增效调节单元则由对基带的I、Q的信号的各自的增效进行控制的第1、第2增效调节单元构成。In the above synthesizing multiplier, if the digitally converted passband signal has a passband I, Q signal with a phase difference of 90 degrees is input, it is multiplied by the oscillation frequency and the I, Q signal of the baseband is synthesized; The effect adjustment unit is composed of first and second effect adjustment units that control the respective gains of the baseband I and Q signals. 6、如权利要求4所述的载波还原器,其特征在于,频率相位锁定环路包括:6. The carrier restorer according to claim 4, wherein the frequency phase locked loop comprises: 由在通过增益调节单元的基带的I信号中去除不必要的数据成分之后锁定频率的第1低通滤波器、延迟器、代码提取器、增效器、环路滤波器及频率振荡器构成的频率锁定环路;Consists of the first low-pass filter, delayer, code extractor, multiplier, loop filter, and frequency oscillator that locks the frequency after removing unnecessary data components from the baseband I signal passing through the gain adjustment unit frequency locked loop; 由在上述基带的Q信号中去除不必要的数据成分之后锁定相位的第2低通滤波器、增效器、环路滤波器、及频率振荡器构成的相位锁定环路。A phase-locked loop composed of a second low-pass filter, multiplier, loop filter, and frequency oscillator that locks the phase after removing unnecessary data components from the baseband Q signal. 7、如权利要求6所述的载波还原器,其特征在于:上述功率计算单元对通过第1低通滤波器的基带I信号的功率进行计算。7. The carrier restorer according to claim 6, wherein the power calculation unit calculates the power of the baseband I signal passing through the first low-pass filter. 8、如权利要求3所述的载波还原器,其特征在于,上述增益控制装置包括:8. The carrier restorer according to claim 3, wherein the above-mentioned gain control device comprises: 在从输入频率相位锁定环路的基带信号中去除了载波还原所不必要的数据成分的信号后,对合成增效器的基带信号的功率进行计算的功率计算单元;A power calculation unit for calculating the power of the baseband signal of the synthesizing booster after removing the signal of the unnecessary data component from the baseband signal of the input frequency phase locked loop; 将所计算的功率值与所设置的标准值或临界值进行比较并输出的比较单元;A comparison unit that compares the calculated power value with the set standard value or critical value and outputs it; 设置在频率相位锁定环路的频率及相位误差检测单元与环路滤波器之间,根据比较单元中的输出结果对从频率及相位误差检测单元中输出基带信号的增益进行控制来调节导频信号的大小并输出至环路滤波器的增益调节单元。Set between the frequency and phase error detection unit and the loop filter of the frequency phase locked loop, and adjust the pilot signal by controlling the gain of the baseband signal output from the frequency and phase error detection unit according to the output result in the comparison unit and output to the gain adjustment unit of the loop filter.
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