CN1781306A - Digital broadcast receiver - Google Patents
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- CN1781306A CN1781306A CN 200480011232 CN200480011232A CN1781306A CN 1781306 A CN1781306 A CN 1781306A CN 200480011232 CN200480011232 CN 200480011232 CN 200480011232 A CN200480011232 A CN 200480011232A CN 1781306 A CN1781306 A CN 1781306A
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Abstract
The present invention provides a digital broadcasting receiver. A tuner (101) has a dual AGC function, and frequency-converts an input signal into an IF signal. An orthogonal detector (102) calculates a complex signal from the IF signal. A demodulator (103) demodulates a digital signal from the complex signals. An error corrector (104) corrects the error of the digital signal. A signal level detector (105) calculates a level judgment signal from the IF signal. A demodulation level detector (107) detects a signal level of a demodulation signal on a desired band from an output signal of the demodulator. When a demodulation level judgment unit (108) generates a judgment signal representing an influence from interference waves in adjacent channel affecting on a signal on the desired band from the demodulation signal, a control signal generator (106) feeds back a gain control signal to the tuner in accordance with the judgment signal.
Description
Technical field
The present invention relates to the automatic gain controller is the digit broadcasting receiver at center, and it can control the influence that the signal in the adjacent channel causes the adjacent interference of digital broadcasting wave, and comprises the technology that is used to improve the digital broadcasting wave receiving feature.
Background technology
The digitlization of the communication technology has in recent years developed into broadcast world.Digital Television digital audio broadcasting service has been put to actual use.In Japan, the broadcast service by broadcasting satellite has become possibility, and business-like various experiments are also carried out to terrestrial broadcast, and has started new broadcast service.
Terrestrial digital broadcast wave and analog broadcasting ripple will be transmitted a period of time after its service beginning simultaneously.During numeral and analog broadcasting ripple coexistence time broadcasted therein, when the analog broadcasting ripple was present in the adjacent channel of digital broadcasting wave channel, digital broadcasting wave may be the disturbing wave to the analog broadcasting ripple.In order to prevent this problem, current digital broadcasting wave uses the signal level littler than analog broadcasting ripple to transmit.
In the above-mentioned situation of numeral and analog broadcasting ripple coexistence therein, JP-A 2000-312235 discloses the conventional art that is used to reduce analog-and digital-wave interference.
Fig. 1 shows with the configuration of automatic gain controller as the conventional digital radio receiver of its major part.Digit broadcasting receiver comprises tuner 101, quadrature detector (O.D.) 102, demodulator (DEM.) 103, error corrector (ERR.C.) 104, error-detecting/judging unit 114, signal (SG.) level detector 105 and control signal (C.SG.) generator 106.
Above-mentioned automatic gain controller is constructed as follows circuit: wherein, automatic gaining controling signal is produced based on the output signal of tuner 101 and the error correction result of error corrector 104, and is fed back tuner 101.Automatic gain controller according to conventional art is made of error-detecting/judging unit 114, signal level detecter 105 and control signal generator 106.
Fig. 2 shows the configuration of tuner 101.Tuner 101 has dual AGC function, will describe its signal processing below.
Band pass filter (hereinafter referred to as BPF) 201 limits the frequency band of input signals, and signal is outputed to RF-AGC amplifier 202.RF-AGC amplifier 202 is by controlling the gain from the output signal of BPF 201 from the gain control signal on the RF frequency band of control signal generator 106 (hereinafter referred to as the RF-AGC control signal) c1, in addition, the frequency band of the output of BPF 203 restriction RF-AGC amplifiers 202.Afterwards, first frequency transducer 204 converts the output frequency of BPF 203 to intermediate frequency based on channel selecting signal c3.The output band of SAW filter (SAW) 205 restriction first frequency transducers 204, (with signal) outputs to first intermediate frequency (IF) amplifier 206 then.The signal that the one IF amplifier 206 amplifies from SAW 205 subsequently, outputs to SAW filter 209 with signal.The output band of SAW filter 209 restrictions the one IF amplifier 206 outputs to signal IF-AGC amplifier 210 then.
IF-AGC amplifier 210 is based on the gain from the gain control signal on the IF frequency band of control signal generator 106 (hereinafter referred to as the IF-AGC control signal) c2 control SAW filter 209 output signals, and the signal after the gain controlling is outputed to second frequency transducer 211.Second frequency transducer 211 will controlled signal frequency convert the IF frequency in IF-AGC amplifier 210.The 2nd IF amplifier 212 is regulated the level of the signal that is converted into the IF frequency, and the signal after the level adjustment is outputed to the output signal of the quadrature detector 102 of Fig. 1 as tuner 101.
The quadrature detection that quadrature detector 102 is realized the digital signal after the digital modulation of for example OFDM (Orthodoxy Frequency Division Multiplex), and will output to demodulator 103 for the I and the Q signal of composite signal.Demodulator 103 demodulates digital signal from I and Q signal, and restituted signal is outputed to error corrector 104.
The correction processing that error corrector 104 is realized digital signal, and the digital signal after will proofreading and correct outputs to error rate detection/judging unit 114 and data processor (not shown).Error rate detection/judging unit 114 detects the error rate of digital signal after the error corrections, and according to error rate the optimal delay dot information is outputed to control signal generator 106.
Fig. 3 shows the configuration of signal level detecter 105.Signal level detecter 105 is made up of level computing block 105a, calculations of offset piece 105b and loop filter 105c.Level computing block 105a calculates from the level of the IF signal d1 of tuner 101 outputs, and result of calculation is outputed to calculations of offset piece 105b as power information pw.Calculations of offset piece 105b calculates from the difference between the power information pw of level computing block 105a output and the expectation level, and result of calculation is outputed to loop filter 105c as offset information.Loop filter 105c carries out integration with generation electrical level judging signal a1 to the offset information from calculations of offset piece 105b output, and electrical level judging signal a1 is outputed to the control signal generator 106 of Fig. 1.
Next, with the function of describing the operation of automatic gain controller and postponing point.Automatic gain controller is realized the gain controlling in two systems of RF and IF section in response to the field intensity of input broadcast wave, make that the signal level of signal can be constant after the demodulation.Postpone the transfer point of the value of a value that is RF-AGC control signal c1 and IF-AGC control signal c2 according to the demodulation state change.The function that postpones point will be described in detail later.
Generally speaking, the automatic gain control to the input signal signal level is to realize by the control of the automatic gain on control of the automatic gain on the RF frequency band (hereinafter referred to as RF-AGC) or IF frequency band (hereinafter referred to as IF-AGC).The two which postpones point value dp is used for determining making variable.
Fig. 4 is the figure that is used for the gain control features of description control signal generator 106.Abscissa is wherein represented the size of electrical level judging signal a1, and ordinate is represented AGC Amplifier Gain g.Fig. 4 (a) shows AGC Amplifier Gain control method when not having adjacent channel.Fig. 4 (b) shows AGC Amplifier Gain control method when having adjacent channel.
When the electrical level judging signal a1 that provides from signal level detecter 105 is very little, be retained as very big steady state value as RF-AGC control signal c1 control signal generator 106 output signals, that will be provided for RF-AGC amplifier 202.With regard to NF (noise pattern), gain is by more favourable as IF-AGC control signal c2 control control signal generator 106 another output signals, that will be provided for IF-AGC amplifier 210 as described.
But shown in Fig. 4 (b), when input signal comprised that any disturbing wave in the adjacent channel and RF-AGC control signal c1 are very big, signal may distortion in RF-AGC amplifier 202, thereby demonstrates non-linear amplification characteristic shown in Figure 5.When signal processing realizes, be included in noise component(s) on the n adjacent channel of expectation channel Bi by the waveform of restituted signal on the frequency axis, as shown in Figure 6 in nonlinear area.NF and distorted signals are in the relation of balance.Postponing some change signal delta dp (hereinafter referred to as step signal) is to increase or reduce the numerical value that postpones point value dp.No matter be to increase or reduce, be necessary that all NF and distorted signals are had the residing border of favourable relation as postponing point.
Shown in Fig. 4 (a), when not having disturbing wave in the adjacent channel, control signal generator 106 remains on predetermined value g1 with RF-AGC amplifier 202 for the gain less than the electrical level judging signal a1 of first threshold Wth1, and reduces RF-AGC amplifier 202 for the gain greater than the electrical level judging signal a1 of first threshold Wth1 when electrical level judging signal a1 becomes bigger.
Shown in Fig. 4 (b), when in adjacent channel, having interference signal, control information generator 106 remains on predetermined value g2 with RF-AGC amplifier 202 for the gain less than the electrical level judging signal a1 of the second threshold value Wth2, and reduces RF-AGC amplifier 202 for the gain greater than the electrical level judging signal a1 of the second threshold value Wth2 when electrical level judging signal a1 becomes bigger.The second threshold value Wth2 preferably is set to less than first threshold Wth1, thus the distortion of signal in the control RF-AGC amplifier 202.
Postpone therein in the fixing gain control features situation of point value, when postponing the judgement that there is not ripple in based on adjacent channel in point and be provided with, when on adjacent channel, having any disturbing wave, in RF-AGC amplifier 202, produce distortion with high signal level.When postponing the judgement that there is ripple in based on adjacent channel in point and be provided with, when having disturbing wave on the adjacent channel, receiving feature always causes very poor NF.Traditionally, the error rate of indication accepting state deterioration is monitored at the rear portion of DEM 103, and postpones point and be changed, thereby has realized having the seldom gain control features of error based on error rate information.
But in the digit broadcasting receiver that disposes according to Fig. 1, error rate is detected after error correction, and there are the following problems, promptly is attended by the very hysteresis of delay point change instruction of giving automatic gain controller under the situation of deinterleaving processing.
In addition, be necessary each grade realization is transmitted the correction processing of signal to classification, so be necessary each grade realization error rate is detected.But also be necessary to determine never select which error rate to be used for postponing some change instruction in the peer.
Therefore, make the present invention to address the above problem.Main purpose of the present invention is the digit broadcasting receiver that realization has following function: it detected the high interference ripple in the adjacent channel before realizing correction processing, suppress the deterioration of receiving feature and, and change automatically and postpone point to realize favourable accepting state no matter whether be that classification transmits.
Summary of the invention
Digit broadcasting receiver according to the present invention comprises: tuner, its amplification input signal is with the RF signal on the selection desired frequency band, and amplification RF signal becomes the IF signal so that the RF signal is carried out frequency inverted.Quadrature detector is based on the IF calculated signals I and the Q composite signal of tuner.Demodulator demodulates digital signal from the I of quadrature detector and Q composite signal.In this process, the signal level detecter in the automatic gain controller detects the signal level of received signal from tuner IF signal.The demodulation level detector detects the demodulation level of restituted signal on the expectation channel based on the demodulation output of demodulator.Next, demodulation electrical level judging unit produces demodulation electrical level judging signal according to the demodulation level signal of demodulation level detector, and this signal shows disturbing wave in adjacent channel to any influence of restituted signal on the expectation channel.The control signal generator produces gain control signal on the RF frequency band and the gain control signal on the IF frequency band according to demodulation electrical level judging signal, and these two gain control signals are fed back to tuner.
In addition, digit broadcasting receiver according to the present invention comprises tuner, quadrature detector and demodulator, identical in its form and the above-mentioned digit broadcasting receiver.Status monitor in the automatic gain controller always detects demodulation state in the demodulation output of demodulator, and produces demodulation status signal.Retainer will keep a period of time from the demodulation status signal of status monitor output.Comparator is illustrated in the comparison signal of a period of time demodulation state transformation afterwards relatively from the demodulation status signal of status monitor output and the demodulation status signal that is kept by retainer with output.When the gain control signal on the RF of the tuner frequency band and the transfer point between the gain control signal on the IF frequency band were set to postpone point, converting unit was based on determining to postpone the variation of point from the comparison signal of comparator with from the demodulation status signal that status monitor obtains.Postpone the variation updating delay point value of some determining unit according to the delay point of determining by converting unit.Simultaneously, signal level detecter detects the signal level of received signal from tuner IF signal.The signal level that the control signal generator use to postpone the delay point value of some determining unit and signal level detecter produces gain control signal on the RF frequency band and the gain control signal on the IF frequency band, and the gain control signal that is produced is outputed to tuner.
According to above-mentioned the present invention, the high interference ripple in the adjacent channel can be detected before correction processing realizes, the deterioration of receiving feature is suppressed and whether with classification transmits irrelevantly, and postponed point and can be changed to reach favourable accepting state automatically.Therefore, having channel selection function in the tuner of dual AGC function can transmit therein in any environment of broadcasting simultaneously and further improved.In addition, when having a large amount of adjacent digital broadcast channel, the channel selection function in the tuner also can further be improved.
Description of drawings
Fig. 1 is the figure that illustrates the configuration of conventional digital radio receiver.
Fig. 2 is the block diagram that illustrates the internal configurations of tuner among each embodiment.
Fig. 3 is the block diagram that illustrates the internal configurations of signal level detecter.
Fig. 4 (a) and 4 (b) show the key diagram of the location mode that gains in the control signal generator.
Fig. 5 shows the figure of the I/O characteristic of RF-AGC amplifier.
Fig. 6 shows the figure of the frequency characteristic of FFT output.
Fig. 7 is the figure that illustrates according to the configuration of the digit broadcasting receiver of the embodiment of the invention 1.
Fig. 8 is the block diagram that illustrates the internal configurations of demodulation level detector.
Fig. 9 (A) and 9 (B) show NTSC signal in the adjacent channel to the key diagram of the influence of ofdm signal.
Figure 10 is the figure that illustrates according to the configuration of the digit broadcasting receiver of the embodiment of the invention 2.
Figure 11 is the figure that illustrates according to the configuration of the signal level decision block of embodiment 2.
Figure 12 is the figure that illustrates according to the configuration of the digit broadcasting receiver of the embodiment of the invention 3.
Figure 13 is the figure that illustrates according to the configuration of the tuner of the embodiment of the invention 3.
Figure 14 is the figure that illustrates according to the configuration of the digit broadcasting receiver of the embodiment of the invention 4.
Figure 15 is the block diagram that illustrates according to the internal configurations of the C/N detector of embodiment 4.
Figure 16 is the figure that illustrates according to the configuration of the digit broadcasting receiver of the embodiment of the invention 5.
Figure 17 is the figure that illustrates the internal configurations of the converting unit of using in the digit broadcasting receiver according to embodiment 5.
The performance diagram that Figure 18 shows demodulation state in the digit broadcasting receiver and postpones relation between the point.
Figure 19 is the figure that illustrates according to the configuration of the digit broadcasting receiver of the embodiment of the invention 6.
Figure 20 is the figure that illustrates the internal configurations of the converting unit of using in the digit broadcasting receiver according to embodiment 6.
The key diagram that Figure 21 shows in according to the digit broadcasting receiver of embodiment 6 demodulation status signal, postpones correlation between point and the step signal.
Figure 22 is the figure that illustrates according to the configuration of the digit broadcasting receiver of the embodiment of the invention 7.
Figure 23 shows in according to the digit broadcasting receiver of embodiment 7 demodulation status signal and postpones the state diagram that the time changes between the point.
Figure 24 is the figure that illustrates according to the configuration of the digit broadcasting receiver of the embodiment of the invention 8.
Figure 25 is the figure that illustrates according to the configuration of the digit broadcasting receiver of the embodiment of the invention 9.
Figure 26 is the figure that illustrates the internal configurations of the converting unit of using in the digit broadcasting receiver according to the embodiment of the invention 9.
Figure 27 shows the state diagram according to the operating condition of the converting unit of embodiment 9.
Figure 28 is the figure that illustrates according to the configuration of the digit broadcasting receiver of the embodiment of the invention 10.
Embodiment
(embodiment 1)
Below with reference to the digit broadcasting receiver of Fig. 7 description according to the embodiment of the invention 1.Fig. 7 is that to illustrate according to embodiment 1 be the figure of configuration of the digit broadcasting receiver at center with the automatic gain controller.
Digit broadcasting receiver shown in Fig. 7 comprises automatic gain controller 100A, tuner 101, quadrature detector 102, demodulator 103 and error corrector 104.Tuner 101 amplification input signals are with the RF signal on the selection desired frequency band, and amplification RF signal is to convert the RF signal frequency to the IF signal.Quadrature detector 102 calculates I and Q composite signal from the IF signal of tuner 101.Demodulator 103 is made of fft block 103a and equalizer (EQ) 103b, and demodulates digital signal from the I of quadrature detector 102 and Q composite signal.
Automatic gain controller 100A detects the signal level of received signal from the IF signal of tuner 101, and demodulator 103 detects demodulation state.Automatic gain controller 100A also judges from disturbing wave in the adjacent channel and acts on the level that influences on the restituted signal on the desired frequency band, thereby produce gain control signal on the RF frequency band and the gain control signal on the IF frequency band according to influence level and received signal level, and these two gain control signals are fed back to tuner 101 from disturbing wave in the adjacent channel.
Automatic gain controller 100A according to embodiment 1 comprises signal level detecter 105, control signal generator 106, demodulation level detector 107 and demodulation electrical level judging unit 108.
To describe the parts of automatic gain controller 100A now in detail.As shown in Figure 8, demodulation level detector 107 is made of demodulation frequency band extraction piece 107a, demodulation level computing block 107b and demodulation level storage piece 107c.Extract piece 107a and when the output signal of the fft block 103a that is provided Fig. 7, extract the signal of desired frequency band, and will extract and output to computing block 107b.Computing block 107b calculates from extracting the level of the signal that piece 107a provides, and will calculate and output to memory block 107c and demodulation electrical level judging unit 108.The demodulation level signal b1 that provides from computing block 107b is provided memory block 107c, and the output of being stored is outputed to judging unit 108.Demodulation electrical level judging unit 108 in response to from the providing of the demodulation level signal b2 that stores among the demodulation level signal b1 of computing block 107b and the memory block 107c, produces demodulation electrical level judging signal a2, and signal a2 is outputed to control signal generator 106.
Now with reference to Fig. 7 and the 8 delay point control of describing according to embodiment 1.When having disturbing wave in adjacent channel in certain reception environment, the IF signal d1 that is offered quadrature detector 102 from tuner 101 and the signal on the adjacent channel that is added on it have constituted the signal of expectation channel.Both the IF signal d1 that comprises the signal of expecting channel and this adjacent channel will be carried out that quadrature detection is handled and the FFT processing at this, and without any separating treatment.Signal level after the gain controlling is controlled as the constant signal level that presets that remains on.Therefore, when the disturbing wave in the adjacent channel exists, the value that shows by the signal level of expectation channel be reduced with adjacent channel in the suitable amount of disturbing wave.Therefore, from the influencing level and can judge of disturbing wave in the adjacent channel to the expectation channel by observing on the expectation channel after the demodulation transformation of signal level.
Demodulation level detector 107 extracts the expectation channel signal on the frequency axis from the FFT output signal d2 of fft block 103a, and with the level storage of extraction signal in demodulation level storage piece 107c, under this state, postpone point and be changed.When postponing the some change, the also corresponding change of RF-AGC control signal c1, but electrical level judging signal a1 still is identical value; Therefore, the I/O characteristic changing of RF-AGC amplifier 202.The change of I/O characteristic makes the scope of incoming level change, and the output of RF-AGC amplifier 202 is saturated under this scope; Therefore, the expectation channel signal level that calculates in computing block 107b also changes.The delay point changes before and the signal level (demodulation level signal) on the expectation channel afterwards is carried out comparison.More particularly, demodulation level signal b2 before the delay point change of memory block 107c output and the demodulation level signal b1 after the delay point change of computing block 107b output are carried out comparison demodulation electrical level judging unit 108.When postponing level signal b1 that point calculates after changing when postponing level signal b2 that point stored before changing, just expression is owing to postpone the change of point, and signal processing reduces in the saturated zone of the output of RF-AGC amplifier 202 therein.
On the contrary, when postponing level signal b1 that point calculates after changing when postponing the level signal b2 of point before changing, just expression is owing to postpone the change of point, and signal processing increases in the saturated zone of the output of RF-AGC amplifier 202 therein.Therefore, postponing point should be changed to the signal processing in the saturated zone of the output that makes RF-AGC amplifier 202 wherein and reduce.
When not carrying out signal processing in the saturated zone of the output of RF-AGC amplifier 202 therein, that is to say, when not having difference between demodulation level signal b1 and the demodulation level signal b2 that stored, just explanation does not have disturbing wave in adjacent channel, just needn't change the delay point in this case.
Updating delay point continuously.Be averaged the mean value that calculates by message level and can be used to the comparison signal level the demodulation level signal b1 under certain all period interval.
If the disturbing wave in the adjacent channel is the NTC analog signal, when the output of RF-AGC amplifier 202 was saturated, three grades of distortion components will appear on the characteristic frequency of expectation channel so.More specifically, shown in Fig. 9 (A), when the NTSC signal in the adjacent channel has than the higher frequency of expectation ofdm signal, three grades of distortion component 2f1-f2 and 2f1-f3 will appear, wherein the video carrier frequency of NTSC is f1, and colored carrier frequency is f2, and the audio frequency carrier frequency is f3.Under identical form, shown in Fig. 9 (B), when the NTSC signal in the adjacent channel has than the lower frequency of expectation ofdm signal, three grades of distortion component 2f2-f1 and 2f3-f1 will appear.
The signal that is extracted piece 107a extraction by the demodulation frequency band is limited to because characteristic frequency thereon appears in three grades of distortion components of NTSC signal, and this is carried out level calculating this set specific frequency signal in demodulation level computing block 107b, thereby reduces circuit scale.The signal that extracts in extracting piece 107a can have near center certain frequency range characteristic frequency, thereby neatly in response to any frequency hysteresis, described characteristic frequency is the frequency at three grades of distortion places occurring owing to the NTSC signal.Signal in the adjacent channel is that the situation of NTSC signal will be described to example; But said method also can be applied to any signal except that the NTSC signal.
In above-mentioned example, automatic gain controller 100A is based on the signal level on the expectation channel that calculates in demodulation level detector 107, and the output of RF-AGC amplifier 202 is therein carried out signal processing in the saturated zone.But, configuration can be to notify the signal of carrying out signal processing in the saturated zone of the output of RF-AGC amplifier 202 therein to be output to control signal generator 106, the change that postpones point is then started, thereby in response to this signal, the signal processing in the saturated zone of the output of RF-AGC amplifier 202 therein reduces.
In addition, in above-mentioned example, the IF signal d1 that will be transfused to electrical level judging signal a1 to control signal generator 106 and be according to tuner 101 calculates.But electrical level judging signal a1 can calculate according to the baseband signal from front quadrature detector 102.
(embodiment 2)
Next, with reference to the digit broadcasting receiver of Figure 10 description according to the embodiment of the invention 2.Figure 10 is that to illustrate be the figure of configuration of the digit broadcasting receiver at center with the automatic gain controller according to embodiment 2.
Digit broadcasting receiver according to embodiment 2 also comprises, in digit broadcasting receiver shown in Figure 7, and time shaft filter 109 between quadrature detector 102 and demodulator 103 and the automatic gain controller 100B different with automatic gain controller 100A.
When since the imaging component that causes of sampling from the output signal of wherein removing by when quadrature detector 102 offers signal level detecter 105, signal level detecter 105 produces electrical level judging signal a1, and signal a1 is outputed to control signal generator 106.Detect the level that the signal e2 that provides from time shaft filter 109 is provided level calculator 110, and result of calculation is outputed to judging unit 111 as detection level signal a3.Judging unit 111 receives from the detection level signal a3 that detects level calculator 110.Judging unit 111, before the imaging component that causes in sampling is removed from the level computing block 105a of signal level detecter 105, receive when detecting level signal a3 and receiving power information pw, signal level is judged that signal a4 outputs to control signal generator 106 from detecting level calculator 110.
Now with reference to Figure 10 and the 11 delay point control of describing according to embodiment 2.When having disturbing wave in adjacent channel in certain reception environment, the signal on the expectation channel that the signal outside the expectation channel provides is output to tuner 101.In said process, 109 in time shaft filter extracts the signal e2 on the expectation channel.Signal level judging unit 111 is relatively as the detection level signal a3 of extraction signal e2 level and the power information pw that calculates in level computing block 105a.When detecting level signal a3 less than power information pw with regard to signal level, just there is disturbing wave in explanation in adjacent channel.Therefore control signal generator 106 changes the delay point.
When electrical level judging signal a1 was identical value, the RF-AGC control signal c1 that is fed back to RF-AGC amplifier 202 from control signal generator 106 was owing to the delay point that changes changes.This has correspondingly increased or has reduced the signal processing of carrying out in the saturated zone of the output of RF-AGC amplifier 202 therein.Postponing point should be changed by this way, makes that the signal processing in the above-mentioned zone is reduced.
When not having signal processing to be performed in the saturated zone of the output of RF-AGC amplifier 202 therein, that is to say, when detecting when not having difference between level signal a3 and the power information pw, just think that the disturbing wave in the adjacent channel does not exist.In this case, control signal generator 106 does not change the delay point.
By the comparison of signal level in the signal level judging unit 111, updating delay point continuously.Detect level signal a3 and power information pw can be under certain all period interval the value of being averaged, thereby mean value is used to the comparison signal level.
In the present embodiment, at level computing block 105a with detect the signal level that calculates in the level calculator 110 and be compared, whether there is signal processing to be performed thereby detect in the saturated zone of the output of RF-AGC amplifier 202 therein.Perhaps, directly notify the signal of the signal processing of carrying out in the saturated zone of the output of RF-AGC amplifier 202 therein to be output to control signal generator 106 from tuner 110, thereby in response to this signal in the following manner start delay point change, make that the signal processing in the saturated zone of the output of RF-AGC amplifier 202 wherein is reduced.
(embodiment 3)
Next, with reference to the digit broadcasting receiver of Figure 12 description according to the embodiment of the invention 3.Figure 12 is that to illustrate according to embodiment 3 be the figure of configuration of the digit broadcasting receiver at center with the automatic gain controller.
According to the digit broadcasting receiver of present embodiment except with embodiment 1 identic quadrature detector 102, demodulator 103 and error corrector 104, also comprise tuner 101C and automatic gain controller 100C, each all has and the configuration different according to those configurations of embodiment 1 and 2.Automatic gain controller 100C comprises signal level detecter 105 and control signal detector 106.In the present embodiment, tuner 101C detects the existence of disturbing wave in the adjacent channel, and adjacent judgement signal h1 is outputed to control signal generator 106, thus the control lag point.
Now with reference to Figure 12 and the 13 delay point control of describing according to embodiment 3.As shown in figure 13, tuner 101C is the tuner that also provides Fig. 2 of first electrical level detection block 215, second electrical level detection block 216 and adjacent judgement (A.J.) piece 217.Input first intermediate frequency (IF) signal d3 detects its signal level, and the first intermediate frequency signal level a5 is outputed to adjacent decision block 217 in first electrical level detection block 215.Input the 2nd IF signal d4 detects its signal level, and the 2nd IF signal level a6 is outputed to adjacent decision block 217 in second electrical level detection block 216.Adjacent decision block 217 is judged the interference level that is caused by the disturbing wave in the adjacent channel according to an IF signal level a5 and the 2nd IF signal level a6, and adjacent judgement signal h1 is outputed to control signal generator 106.
When having disturbing wave in adjacent channel, the input signal of the SAW filter 209 of tuner 101 comprises the signal outside the expectation channel therein, and still, any component outside the expectation channel all is removed from the output signal of SAW filter 209.The signal level of the input and output signal of SAW filter 209 is compared, and makes that the existence of disturbing wave is detected in the adjacent channel, postpones point and is also correspondingly changed.
When postponing point when under electrical level judging signal a1 is in the situation of identical value, being changed, be fed back the RF-AGC control signal c1 change of RF-AGC amplifier 202.In this case, the signal processing in the saturated zone of the output of RF-AGC amplifier 202 therein increases or reduces.Therefore, postponing point should be changed the signal processing that makes in this zone and be reduced.
When not having signal processing to be performed in the saturated zone of the output of RF-AGC amplifier 202 therein, just, when not having difference between an IF signal level a5 and the 2nd IF signal level a6, just thinking does not have disturbing wave in adjacent channel, therefore postpones point and is not changed.
Be necessary by the continuous updating delay point of the signal level in the more adjacent decision block 217.Perhaps, the signal level of an IF signal d3 and the 2nd IF signal d4 is averaged with specific periodic intervals, and this mean value can be used for the comparison signal level.
In addition, in the present embodiment, the electrical level judging signal a1 that is imported into control signal generator 106 is calculated by the IF signal d1 according to tuner 101.But electrical level judging signal a1 can calculate according to the baseband signal from quadrature detector 102.
(embodiment 4)
Now with reference to the digit broadcasting receiver of Figure 14 description according to the embodiment of the invention 4.Figure 14 is that to illustrate be the figure of configuration of the digit broadcasting receiver at center with the automatic gain controller according to the embodiment of the invention 4.
Except tuner 101, quadrature detector 102, demodulator 103 and the error corrector 104 identical, also comprise the automatic gain controller 100D that has with according to the different configuration of the configuration of embodiment 1 to 3 according to the digit broadcasting receiver of present embodiment with embodiment 1.Automatic gain controller 100D comprises signal level detecter 105, control signal generator 106, C/N detector 112 and C/N judging unit 113.
C/N detector 112 is made of C/N computing block 112a and C/N memory block 112a, as shown in figure 15.C/N computing block 112a calculates carrier power and noise electrical power based on the restituted signal j that provides from demodulator 103, calculates carrier wave/noise (C/N) information then, and C/N information i1 is outputed to C/N memory block 112b and C/N judging unit 113.The C/N information i1 that provides from C/N computing block 112a is provided C/N memory block 112b, and the canned data i1 of institute is outputed to C/N judging unit 113.C/N judging unit 113 uses from the C/N information i1 of C/N computing block 112a input and produces C/N from the C/N information i2 that C/N memory block 112b imports judges signal h2, and signal h2 is outputed to control signal generator 106.
Now with reference to Figure 14 and the 15 delay point control of describing according to embodiment 4.When having disturbing wave in the adjacent channel under certain reception environment, the IF signal d1 that offers quadrature detector 102 from tuner 101 has constituted the signal on the desired signal that comprises signal on the adjacent channel.Desired signal and the IF signal d1 together of the signal combination on this adjacent channel are carried out quadrature detection processing and demodulation process, and without any separating treatment.
C/N detector 112 is based on calculated signals carrier power and noise electrical power from demodulator 103, and comprises the C/N memory block 112b of the C/N information i1 that stores the signal that calculates, and this is to postpone under the reformed state of point.Reformed delay point can change the RF-AGC control signal c1 of the RF-AGC amplifier 202 that feeds back to tuner 101.In view of the above, the output of RF-AGC amplifier 202 does not have saturated and be changed residing incoming level scope change and the yet corresponding change of C/N information i1 that calculates in C/N computing block 112a.The C/N information i1 that calculates according to the change that postpones point and be provided for C/N judging unit 113 postponing the C/N information i2 that point calculates and be stored among the C/N memory block 112b before changing, and C/N judging unit 113 relatively provides the information of coming.
When postponing C/N information i1 that point calculates after being changed when postponing the C/N information i2 of point before changing, be illustrated in that the delay point signal processing in response to change is reduced in the saturated zone (nonlinear area) of the output of RF-AGC amplifier 202 wherein.On the contrary, when postponing C/N information i2 that point calculates before being changed when postponing the C/N information i1 of point after changing, be illustrated in that the delay point signal processing in response to change is increased in the saturated zone of the output of RF-AGC amplifier 202 wherein.Postponing point should be changed in the following manner, makes that signal processing is reduced in the saturated always zone of the output of RF-AGC amplifier 202 therein.
When not having signal processing to be performed in the saturated zone of the output of RF-AGC amplifier 202 therein, just, when not having difference between C/N information i1 and the C/N information i2 that stored, just thinking does not have disturbing wave in adjacent channel, therefore postpones point and is not changed.
Updating delay point continuously.The signal level of demodulation level signal b1 is the volume value of being averaged under certain all period interval, thereby mean value can be used to the comparison signal level.
Be compared in current C/N information i1 and the C/N information i2 description in front of being stored.About interchangeable measure, the C/N information i2 that demonstrates the remarkable deterioration of receiving feature can be stored in the memory in advance, thereby current C/N information i1 can compare with the C/N information i2 that reads from memory, makes to postpone the some Be Controlled.
In addition, in the present embodiment, the electrical level judging signal a1 that is imported into control signal generator 106 is calculated by the IF signal d1 according to tuner 101.Electrical level judging signal a1 can calculate according to the baseband signal from front quadrature detector 102.
(embodiment 5)
Now with reference to the digit broadcasting receiver of Figure 16 to 18 description according to the embodiment of the invention 5.Figure 16 is the figure that illustrates according to the configuration of the major part of the digit broadcasting receiver of the embodiment of the invention 5.Digit broadcasting receiver comprises tuner 101, quadrature detector 102, demodulator 103 and the error corrector 104 as embodiment 1, and comprises the automatic gain controller 100E that has with according to the different configurations of automatic gain controller of embodiment 1 to 4.
103 pairs of demodulators carry out analog-to-digital conversion from composite signal quadrature detector 102 outputs, that be made up of I and Q signal, and composite signal carried out the demodulation process comprise Synchronous Processing, then restituted signal j is outputed to error corrector 104 and status monitor 120.Status monitor 120 produces the demodulation status signal s of the restituted signal j demodulation state that expression provides from demodulator 103, and signal s is outputed to the first input end and the converting unit 123 of retainer 121, comparator 122.Retainer 121 will keep a period of time from the demodulation status signal s that status monitor 120 provides, and signal s will be provided to second input of comparator 122.
Converting unit 123 comprises state decision block 123a and selection piece 123b, as shown in figure 17.State decision block 123a judges demodulation state or poor by the demodulation status signal s that provides from the status monitor 120 of Figure 16 is provided, and judged result is outputed to selection piece 123b.Select piece 123b to determine to postpone the variation step width Delta dp of point, and will change step and output to as step signal and postpone a determining unit 124 based on the judged result that provides from state decision block 123a with from the comparison signal k that comparator 122 provides.Delay point determining unit 124 is upgraded based on the change that postpones point and definite point value that postpones.And comprise counter.
Postponing some determining unit 124 increases or reduces according to the step signal that provides from converting unit 123 and postpone point value, and will postpone point value and output to control signal generator 106 as postponing a value signal dp.The signal level of the IF signal that provides from tuner 101 is provided for signal level detecter 105, and signal level is outputed to control generation unit 106 as the incoming level signal.
With reference to Figure 17 and the 18 delay point control methods of describing according to present embodiment.As example, demodulation status signal s, for example error rate and become the noisiness of bigger value when the influence of disturbing wave increases in from adjacent channel is set up.The control method of using demodulation status signal s will be described below.The first threshold of demodulation status signal s is s1, and with the better (s≤s1) and from the very little situation of the influence of disturbing wave in the adjacent channel as a reference of demodulation state wherein.This situation is corresponding to the area B among Figure 18, and wherein, state decision block 123a judges demodulation state with fine based on the demodulation status signal s that provides from status monitor 120.Select piece 123b to select to have the step width 1 of very little change scope, and will be worth as step signal and output to delay point determining unit 124 shown in Figure 16 based on the comparison signal that provides from comparator 122.Under this form, for example, the delay point value dp1 of Figure 18 can be finally and optimum value dp2 converge to a bit.
Simultaneously, in from adjacent channel the very big and demodulation state of the influence of disturbing wave (s＞s1), in the time of shown in the regional A of Figure 18, the excursion of step width 1 can not cause any significant difference of demodulation state by remarkable deterioration.Then, state decision block 123a judges demodulation state just in deterioration based on the demodulation status signal s that provides from status monitor 120, and the step signal of selecting piece 123b will have the positive step width 2 of the excursion bigger than step width 1 outputs to some determining unit 124 and irrelevant with the comparison signal that provides from comparator 122 is provided.Step signal with step width 2 of bigger excursion is used, and makes accepting state be transformed into the zone of s≤s1 from the zone of s＞s1, and these zones are shown in Figure 18.Like this, postpone point change before and just producing significant difference between afterwards the demodulation state, and effectively moved based on delay point control from the comparison signal of comparator 122.Therein in the situation of the very poor s＞s1 of demodulation state because demodulation status signal s need be changed enabling wherein to realize the state of comparison, so needn't find make postpone point can be by the optimal delay point of unidirectional control just to be increased.
When postponing point when becoming much larger than above-mentioned state, receiving feature just may be because NF and deterioration, shown in the zone C of Figure 18.In this case, can not cause receiving feature because NF and certain value of deterioration, except aforesaid operations, also in postponing some determining unit 124, set in advance threshold value and make and postpone point to be no more than certain value be threshold value for demodulation status signal is arranged to.When improving receiving feature, it will be favourable that demodulation status signal s tightly is controlled at threshold value.Control signal generator 106 is based on the gain of the signal level control RF signal that postpones point value and received signal and the gain of IF signal.
(embodiment 6)
Now with reference to the digit broadcasting receiver of accompanying drawing description according to the embodiment of the invention 6.Figure 19 is the figure that illustrates according to the configuration of the major part of the digit broadcasting receiver of embodiment 6.Digit broadcasting receiver also comprises the automatic gain controller 100F that has with according to the different configurations of automatic gain controller of embodiment 1 to 4 except comprising tuner 101, quadrature detector 102, demodulator 103 and the error corrector 104 as embodiment 1.
Converting unit 125 comprises state decision block 125a and selection piece 125b, as shown in figure 20.State decision block 125a is by the demodulation status signal that provides from status monitor 120 as shown in figure 19 being provided and being judged demodulation state or poor from the delay point value dp that postpones 124 outputs of some determining unit, and judged result outputed to selects piece 125b.
Now with reference to the delay point control method of Figure 19 to 21 description according to present embodiment.As example, wherein to exist as a reference from the situation of some influences of disturbing wave in the adjacent channel.In the control that postpones to realize when point value is positioned at as Figure 18 zone A with bottom shown in the B with identical according to the control method of embodiment 5.In postponing the zone of point greater than dp2, have negative step width 3 than step width 1 bigger excursion and be provided among the selection piece 125b in the converting unit 125, as shown in figure 20, to prevent receiving feature because the NF deterioration.
When postponing point value dp and demodulation status signal s when all very big, its excursion reduces than step width 1 long step signal, and postpones point value dp and be output to and postpone a some determining unit 124.With regard to improving receiving feature because for the receiving feature when NF and deterioration, it is favourable using the negative step signal with great changes scope, because it is very big to postpone point value dp.When using the selection piece 125b of for example three kinds of selections of step width 1, step width 2 and step width 3, can realize simultaneously that high interference suppresses and low-noise characteristic.Figure 21 shows according to demodulation status signal s and postpones the step signal of point value dp.
(embodiment 7)
Now with reference to the digit broadcasting receiver of accompanying drawing description according to the embodiment of the invention 7.Figure 22 is the figure that illustrates according to the configuration of the major part of the digit broadcasting receiver of this embodiment.
Digit broadcasting receiver comprise with according to the identical tuner 101 of the configuration of embodiment 1, quadrature detector 102, demodulator 103 and error corrector 104, and comprise the automatic gain controller 100G that has with according to the different configurations of automatic gain controller of embodiment 1 to 6.
Optimal delay point retainer (hereinafter referred to as optimum DP retainer) 126 keeps from the signal of the delay point value dp that postpones 124 outputs of some determining unit, and further keeps from the demodulation status signal s of status monitor 120 outputs.Optimum DP retainer when the clock signal that is provided to from time schedule controller 127, is selected optimal delay point value dp and optimal delay point value dp is outputed to control signal generator 106.Any other part is all identical with the configuration shown in Figure 16, therefore omits the description to these same sections here.
The function of optimum DP retainer 126 and time schedule controller 127 is described referring now to Figure 23.The renewal of demodulation status signal s is identical at interval with the renewal of the step signal of exporting from converting unit 123 at interval, and also identical at interval with the renewal of the delay point value that is offered optimum DP retainer 126 by delay point determining unit 124.Demodulation status signal and every aforementioned update cycle of signal of postponing point value with change according to the identical mode of the digit broadcasting receiver of embodiment 5.But, when the environment that is used when digit broadcasting receiver changes in time, for example in moving situation about receiving, postpone point value dp and can not be fixed on steady state value.
For postponing a time span of upgrading interval n times (n is an integer) is period T, and phase T obtains the optimal delay point weekly.Automatic gain controller is operated then and makes resulting delay point as postponing the point that point begins to change at next cycle.More specifically, as shown in figure 23, the time from t=0 to T in the district minimum value of demodulation status signal s be Nmin1.Delay point value dpm1 when optimum DP retainer 126 obtains getting minimum value Nmin1, and storage and keep this value dpm1.Then, the delay point control of describing as embodiment 5 is implemented, and makes value dmp1 as postponing to put at the next cycle T piece starting point dpm1 that to be t=T begin to change in the 2T.
At t=2T when the 3T, when the obtained delay point value during as dpm2 of the minimum value Nmin2 of demodulation status signal s is stored in the same manner and kept.Dpm2 is set to postpone the point that point begins to change during to 4T at t=3T.Aforesaid operations is repeated, make demodulation status signal s change to gradually with reception environment in minimum (optimum) value assemble, and postpone point and change also in response to this and assemble.
(embodiment 8)
Digit broadcasting receiver according to the embodiment of the invention 8 is described below with reference to accompanying drawings.Figure 24 is the figure that illustrates according to the configuration of the major part of the digit broadcasting receiver of embodiment 8.
Digit broadcasting receiver comprise with according to the identical tuner 101 of the configuration of embodiment 1, quadrature detector 102, demodulator 103 and error corrector 104, and comprise the automatic gain controller 100H that has with according to the different configurations of automatic gain controller of embodiment 1 to 6.
Automatic gain controller 100H is made up of signal level detecter 105, control signal generator 106, status monitor 120, retainer 121, comparator 122, converting unit 125, a delay point determining unit 124, optimal delay point retainer 126 and time schedule controller 127.
Optimal delay point retainer (hereinafter referred to as optimum DP retainer) 126 keeps from postponing the signal of the delay point value dp that some determining unit 124 provides, and further keeps from the demodulation status signal s of status monitor 120 outputs.Optimum DP retainer 126 when providing clock signal by time schedule controller 127, will postpone some dp and output to control signal generator 106.
In the digit broadcasting receiver according to this embodiment, a delay point determining unit 124 will postpone point value dp and output to converting unit 125.Digit broadcasting receiver can output to by the step signal that will select in selection piece 125 shown in Figure 20 and postpone some determining unit 124 and suppresses the distorted signals that caused by the disturbing wave in the adjacent channel, and can prevent receiving feature because the NF of increase and deterioration.
(embodiment 9)
Digit broadcasting receiver according to the embodiment of the invention 9 is described below with reference to accompanying drawings.Figure 25 is the figure that illustrates according to the configuration of the major part of the digit broadcasting receiver of embodiment 9.
Digit broadcasting receiver comprise with according to the identical tuner 101 of the configuration of embodiment 1, quadrature detector 102, demodulator 103 and error corrector 104, and comprise the automatic gain controller 100I that has with according to the different configurations of automatic gain controller of embodiment 1 to 6.
Automatic gain controller 100I is made up of signal level detecter 105, control signal generator 106, status monitor 120, retainer 121, comparator 122, delay point (DP) determining unit 124, synchronous regime watch-dog 128 and converting unit 129.
Synchronous regime watch-dog 128 is monitored synchronous regime according to the Synchronous Processing of carrying out in demodulator 103, and will control beginning label F and output to converting unit 129, makes that postponing point control begins when being scheduled to synchronous regime being entered by restituted signal.Synchronous regime watch-dog 128 will be controlled beginning label F and output to converting unit 129, make postpone point control and just begin after a period of time being entered by restituted signal after the predetermined synchronous regime.
Converting unit 129 comprises control counter 129a, state decision block 129b and selection piece 129c, as shown in figure 26.Control counter 129a is reset by the control beginning label F that provides from synchronous regime controller 128, carries out counting afterwards, and control number N is increased when the step signal from converting unit 129 outputs is updated at every turn.Control counter 129a will control number N then and output to state decision block 129b.The demodulation status signal s that provides from status monitor shown in Figure 19 120 is provided state decision block 129b, from postponing the delay point value dp that some determining unit 124 provides shown in Figure 19 and count N from the control that control counter 129a provides and judge demodulation state or poor, and judged result outputed to select piece 129c.
Now with reference to the delay point control method of Figure 27 description according to this embodiment.
At first, when control number N was 0, just and then after the control beginning and demodulation status signal s when very little, step width 1 was used as step signal and outputs to and postpone a some determining unit 124.Afterwards, when control number N be 1 or when bigger, step width 1 is outputed to specially as step signal postpones a some determining unit 124.This is because when not having disturbing wave in adjacent channel, not necessarily needs to increase to postpone that point prevents because the deterioration that NF caused.
When control number N is 0 and demodulation status signal s when very big, its excursion is selected and be output to as step signal and postpone a some determining unit 124 based on the judgement that may have disturbing wave in adjacent channel greater than the step width 2 of step width 1 excursion.The excursion of step width 2 is greater than the excursion of step width 1, and the step direction is only for just.
When control number N is 1, to postpone point value dp very big and comparison signal demonstrates identical or during worse demodulation state, selected for the step width 3 of negative step, and based on the change that postpones point value dp improvement in performance not have the judgement excursion that helps be used as step signal to output to and postpone a determining unit 124 greater than the step width 3 of the excursion of step width 1.
When control number N is 1, postpones the very big and comparison signal of point value dp when demonstrating better demodulation state, be used as step signal based on the judgement step width 1 that has disturbing wave to exist in the adjacent channel and output to and postpone a some determining unit 124.
When control number N is 2 or when bigger, step width 1 is outputed to specially as step signal postpones a some determining unit 124.
In the described mode that relatively postpones very little and the demodulation state separately when very big of point value, whether exist disturbing wave to be judged rapidly in the adjacent channel, thereby quickened the convergence of optimal delay point value.
(embodiment 10)
Digit broadcasting receiver according to the embodiment of the invention 10 is described below with reference to accompanying drawings.Figure 28 is the figure that illustrates according to the configuration of the major part of the digit broadcasting receiver of embodiment 10.
Digit broadcasting receiver comprise with according to the identical tuner 101 of the configuration of embodiment 1, quadrature detector 102, demodulator 103 and error corrector 104, and comprise the automatic gain controller 100J that has with according to the different configurations of automatic gain controller of embodiment 1 to 6.
Automatic gain controller 100J is made up of signal level detecter 105, control signal generator 106, status monitor 120, retainer 121, comparator 122, a delay point determining unit 124, optimum DP retainer 126, time schedule controller 127, synchronous regime watch-dog 128 and converting unit 129.
Optimal delay point retainer 126 keeps from postponing the signal of the delay point value dp that some determining unit 124 provides, and keeps from the demodulation status signal s of status monitor 120 outputs.Optimum DP retainer 126 also at clock signal by when time schedule controller 127 provides, will postpone point value dp and output to control signal generator 106.Any other parts are all identical with the configuration shown in Figure 25, therefore omit the description to same section here.
Optimum DP retainer 126 and time schedule controller 127 with work according to the identical mode of the digit broadcasting receiver of embodiment 7.To output to converting unit 129 from the signal of the delay point value dp that postpones 124 outputs of some determining unit according to the digit broadcasting receiver of present embodiment.Digit broadcasting receiver can output to by the step signal that will select in the selection piece 129c of Figure 26 and postpone some determining unit 124 and suppress the distorted signals that caused by the disturbing wave in the adjacent channel.And, can also prevent receiving feature because the increase of NF and deterioration.
In the embodiment that describes so far, digit broadcasting receiver is described to attach most importance to automatic gain controller, but the invention is not restricted to this.The present invention can also be applied to use the automatic gain controller of the wireless transmission receiver of OFDM transfer approach.
Except that static the reception, can also move in the digit broadcasting receiver of reception, shorten at interval and can just can obtain more stable receiving feature with identical during static state receives by moving the renewal that postpones point in the reception.
In addition, in digit broadcasting receiver,, and can depend on use and reception environment and change from the value of the clock signal of time schedule controller 127 output fixed value not necessarily according to embodiment 7,8 and 10.
In addition, in digit broadcasting receiver, postpone point control and use and the different bigger step width of step width that changes with very little speed forward or negative sense according to embodiment 5 to 10.But digit broadcasting receiver is not limited to the setting that large stepped width has an excursion very much, but can provide a plurality of step width with different excursions to make that step signal can be based on condition is selected more specifically.In this manner, can quicken convergence with the optimal delay point value.
In addition, in the digit broadcasting receiver according to embodiment 5 to 10, the step width that is used to postpone point control can not use fixed value always, but can depend on elapsed time length and control number after the control beginning and change.Can depend on elapsed time length and control number after the control beginning and the step width that reduces to be used to postpone point control gradually according to the digit broadcasting receiver of embodiment 5 to 10.In this manner, the deterioration that prevented performance owing to postpone the rapid change of point value.
In addition, in the delay point control of in digit broadcasting receiver, carrying out according to embodiment 5 to 10, in order to control the deterioration of NF, postpone point value and be set in advance and be very little value, and step signal is converted will postpone point value according to reception environment and is increased to bigger value.On the contrary, postpone point value and can be set in advance and be very big value, thereby and step signal can be converted will postpone point value and be reduced to littler value and search for the optimal delay point value.
In addition, in digit broadcasting receiver according to embodiment 5 to 10, about postponing point control, to be described as that demodulation status signal becomes bigger when the further deterioration of accepting state, but for example the demodulation status signal of CNR (carrier-to-noise ratio) may be arranged to when the further deterioration of accepting state and becomes littler.
In addition, in the digit broadcasting receiver according to embodiment 5 to 10, about postponing point control, with the automatic gain control of describing based on signal level before the demodulation, still the automatic gain control according to signal level after the demodulation also is available.
In addition, in the digit broadcasting receiver according to embodiment 5 to 10, the delay point control in the automatic gain control is always unessential.Postponing point control may finish behind certain hour to reduce power consumption.And in the automatic gain controller according to the digit broadcasting receiver of embodiment 1 to 6, postponing point control can temporarily be stopped certain hour, and restarts behind certain hour.
In addition, in digit broadcasting receiver, postpone point control and can temporarily be stopped certain hour, and restart during by deterioration in demodulation state according to embodiment 5 to 10.This has successfully helped flexible response and power-saving to the reception environment that changes.
Industrial applicibility
Comprise the automatic gain controller that has low-noise characteristic and be used to suppress the characteristic of adjacent-channel interference therein according to digit broadcasting receiver of the present invention, it has superiority as the receiver in digital TV broadcasting and the digital radio broadcasting.Can also improve the control of received signal level according to digit broadcasting receiver of the present invention, transmit in the environment of broadcasting simultaneously especially therein with dual AGC function harmonizing device.Not only can suitably be used for broadcast environment simultaneously according to digit broadcasting receiver of the present invention, but also can be used for wherein a large amount of digital broadcast channel environment adjacent one another are.
Claims
(according to the modification of the 19th of treaty)
1. digit broadcasting receiver comprises:
Tuner, its amplification input signal is with the RF signal on the selection desired frequency band, and amplification RF signal is to convert the RF signal frequency to the IF signal;
Quadrature detector, it is according to the IF calculated signals I and the Q composite signal of described tuner;
Demodulator, it demodulates digital signal from the I of described quadrature detector and Q composite signal; And
Automatic gain controller, it detects the signal level of received signal from described tuner IF signal, detect the demodulation state in the described demodulator, judge that disturbing wave is to the level of the influence of restituted signal on the desired frequency band in the adjacent channel, produce gain control signal on the RF frequency band and the gain control signal on the IF frequency band according to the signal level that influences level and described received signal, and these two gain control signals are fed back to described tuner.
2. according to the digit broadcasting receiver of claim 1, wherein
Described automatic gain controller comprises:
Signal level detecter, it detects the signal level of received signal from the IF signal of described tuner;
The demodulation level detector, it detects the demodulation level signal of restituted signal on the desired frequency band from the demodulation output of described demodulator;
Demodulation electrical level judging unit, its demodulation level signal according to the demodulation level detector produces demodulation electrical level judging signal, and the disturbing wave in this demodulation electrical level judging signal indication adjacent channel is to the influence of restituted signal on the expectation channel; And
The control signal generator, its signal level according to the demodulation electrical level judging signal of described demodulation electrical level judging unit and described signal level detecter produces gain control signal on the RF frequency band and the gain control signal on the IF frequency band, so that these two gain control signals are fed back to described tuner, and
Described tuner comprises:
The RF-AGC amplifier, it is based on the level of the control of the gain control signal on RF frequency band RF signal; And
The IF-AGC amplifier, it is based on the level of the control of the gain control signal on IF frequency band IF signal.
3. according to the digit broadcasting receiver of claim 2, wherein
The demodulation level detector comprises:
The demodulation frequency band extracts piece, and it is from being extracted the signal on the desired frequency band in the frequency signal of fourier transform described demodulator;
Demodulation level computing block, it calculates the level that extracts the signal on the desired frequency band that obtains in the piece at described demodulation frequency band; And
Demodulation level storage piece, its transfer point between the gain control signal on the gain control signal on the RF frequency band and the IF frequency band in described tuner keep when being set to postpone postponing point change before signal level on the desired frequency band, and
Signal level after signal level before described demodulation level detector will postpone a little to change on the desired frequency band changes with the delay point on the desired frequency band compares, and judges that disturbing wave is to the level of the influence of desired frequency band in the adjacent channel.
4. according to the digit broadcasting receiver of claim 3, wherein
Described demodulation frequency band extracts piece and only extracts three grades of frequency bands that distortion occurs that cause owing to the outer signal of desired frequency band thereon.
5. according to the digit broadcasting receiver of claim 3, wherein
Described demodulation frequency band extracts piece and only extracts three grades of frequency bands that distortion occurs that caused by the NTSC signal thereon.
6. according to the digit broadcasting receiver of claim 1, wherein
The time shaft filter that extracts the signal on the desired frequency band from the I of demodulator and Q signal is provided between quadrature detector and the demodulator,
Described automatic gain controller comprises:
Signal level detecter, it detects the signal level of received signal from the IF signal of described tuner;
Detect the level calculator, it is according to the level of the signal on the output signal calculation expectation frequency band of described time shaft filter;
The signal level judging unit, it judges signal according to the signal level on the desired frequency band that is obtained by described detection level calculator and by the disturbing wave that the signal level that described signal level detecter obtains produces in the expression adjacent channel to the signal level of the influence of signal on the desired frequency band; And
The control signal generator, its signal level according to described signal level judging unit judges that the signal level of signal and described signal level detecter feeds back to described tuner with the gain control signal on gain control signal on the RF frequency band and the IF frequency band, and
Described tuner comprises:
The RF-AGC amplifier, it is based on the level of the control of the gain control signal on RF frequency band RF signal; And
The IF-AGC amplifier, it is based on the level of the control of the gain control signal on IF frequency band IF signal.
7. according to the digit broadcasting receiver of claim 1, wherein
Described tuner comprises based on the RF-AGC amplifier of the level of the control of the gain control signal on RF frequency band RF signal and the IF-AGC amplifier of controlling the level of IF signal based on the gain control signal on the IF frequency band, amplification input signal is to select the RF signal on the desired frequency band, amplification RF signal is to be converted to the IF signal with the RF signal frequency, and produce in the expression adjacent channel disturbing wave to the adjacent judgement signal of the influence of signal on the desired frequency band, and
Described automatic gain controller comprises the control signal generator, and it feeds back to described tuner according to the adjacent judgement signal of described tuner and the signal level of described signal level detecter with the gain control signal on gain control signal on the RF frequency band and the IF frequency band.
8. according to the digit broadcasting receiver of claim 7, wherein
Described tuner also comprises except RF-AGC amplifier and IF-AGC amplifier:
First electrical level detection block, it calculates by frequency inverted is the signal level of first intermediate frequency signal of intermediate frequency;
The frequency band limits filter, it limits the frequency band of first intermediate frequency signal, and converts first intermediate frequency signal to second intermediate frequency signal;
Second electrical level detection block, it calculates the signal level of second intermediate frequency signal; And
Adjacent decision block, it is the signal level of first and second intermediate frequency signal relatively, judges that adjacent interference ripple in the adjacent channel is to the influence of desired frequency band.
9. according to the digit broadcasting receiver of claim 1, wherein
Described automatic gain controller comprises:
The C/N detector, its restituted signal according to described demodulator calculates C/N;
C/N judging unit, its C/N information according to described C/N detector produce represents that disturbing wave is to the C/N judgement signal of the influence of signal on the desired frequency band in the adjacent channel;
Signal level detecter, it detects the signal level of received signal from the IF signal of described tuner; And
The control signal generator, it judges that according to the signal level of described signal level detecter and the C/N of described C/N judging unit signal feeds back to described tuner with the gain control signal on gain control signal on the RF frequency band and the IF frequency band, and
Described tuner comprises:
The RF-AGC amplifier, it is based on the level of the control of the gain control signal on RF frequency band RF signal; And
The IF-AGC amplifier, it is based on the level of the control of the gain control signal on IF frequency band IF signal.
10. according to the digit broadcasting receiver of claim 9, wherein
Described C/N detector comprises:
The C/N calculation element, its restituted signal according to described demodulator calculates C/N information; And
The C/N storage device, it stores the C/N information of described C/N calculation element, and
Described C/N judgment means relatively postpones the C/N information before the change and postpones the C/N information of point after changing, and judges that the disturbing wave in the adjacent channel was to the influence of desired frequency band when in the described tuner transfer point between the gain control signal on the gain control signal on the RF frequency band and IF frequency band was set to postpone.
11. according to the digit broadcasting receiver of claim 10, wherein
The C/N information that the comparison of described C/N detector calculates in the C/N calculation element and be stored in fixation of C/N information in the memory in advance.
12. according to the digit broadcasting receiver of claim 1, wherein
Described automatic gain controller comprises:
Status monitor, it detects demodulation state from the demodulation output of described demodulator, to produce demodulation status signal;
Retainer, it will keep a period of time from the demodulation status signal of described status monitor output;
Comparator, it is illustrated in the comparison signal of this section effluxion demodulation state variation afterwards relatively from the demodulation status signal of described status monitor output and the demodulation status signal that is kept by described retainer with output;
Converting unit, it is when the transfer point between the gain control signal on the gain control signal on the RF frequency band and the IF frequency band is set to postpone point in described tuner, determine to postpone the variation of point based on the comparison signal of described comparator with by the demodulation status signal that status monitor obtains, select step width with the step width of when demodulation state is good, selecting to have little excursion and when the demodulation state difference with big excursion;
Postpone the some determining unit, it is according to the value of the variation updating delay point of the delay point of being determined by described converting unit;
Signal level detecter, it detects the signal level of received signal from described tuner IF signal; And
Control signal generator, its signal level according to the delay point value of described delay point determining unit and described signal level detecter produce gain control signal on the RF frequency band and the gain control signal on the IF frequency band.
13. according to the digit broadcasting receiver of claim 12, wherein
Described converting unit comprises:
The accepting state decision block, it judges accepting state according to demodulation status signal; And
Select piece, it determines to postpone the variation of point according to the comparative result of described comparator and the judged result of described accepting state decision block.
14. according to the digit broadcasting receiver of claim 12, wherein
Described converting unit comprises:
The accepting state decision block, it is according to demodulation status signal and postpone point value judgement accepting state; And
Select piece, it determines to postpone the variation of point according to the comparative result of described comparator and the judged result of described accepting state decision block.
15. according to the digit broadcasting receiver of claim 13, wherein
Select piece from a plurality of different delay points change, to select and definite specific delay point variation.
16. according to the digit broadcasting receiver of claim 15, wherein
A plurality of delay points variations of selecting in selecting piece comprise at least one value that is changed significantly different with other.
17. according to the digit broadcasting receiver of claim 1, wherein
Described automatic gain controller comprises:
Status monitor, it detects demodulation state from the demodulation output of described demodulator, to produce demodulation status signal;
Retainer, it will keep a period of time from the demodulation status signal of described status monitor output;
Comparator, it relatively from the demodulation status signal of described status monitor output and the demodulation status signal that is kept by described retainer, represents the comparison signal that the time of demodulation state changes with output;
Converting unit, it is when the transfer point between the gain control signal on the gain control signal on the RF frequency band and the IF frequency band is set to postpone point in described tuner, determines to postpone the variation of point based on the demodulation status signal that the comparison signal and the status monitor of described comparator obtains;
Postpone the some determining unit, it is according to the value of the variation updating delay point of the delay point of being determined by described converting unit;
Time schedule controller, it produces timing control signal, and the generation cycle of described timing control signal is the several times in cycle when the delay point value in the described delay point determining unit is upgraded;
Optimal delay point retainer, its timing control signal according to the demodulation status signal of the delay point value of described delay point determining unit, described status monitor and described time schedule controller detects the optimal delay point in described a period of time, and output optimal delay point value is to defer to the change of accepting state;
Signal level detecter, it detects the signal level of received signal from described tuner IF signal; And
The control signal generator, it is according to gain control signal on signal level generation RF frequency band of the received signal of optimal delay point value that is kept by described optimal delay point retainer and described signal level detecter and the gain control signal on the IF frequency band.
18. according to the digit broadcasting receiver of claim 17, wherein
Described optimal delay point retainer storage also keeps interior optimal demodulation state of described time schedule controller control time section and the optimal delay point value of this moment.
19. according to the digit broadcasting receiver of claim 17, wherein
Described optimal delay point retainer upgrades by the value of described time schedule controller at the optimal delay point of each control time section storage and maintenance.
20. according to the digit broadcasting receiver of claim 17, wherein
Described converting unit comprises:
The accepting state decision block, it judges accepting state according to demodulation status signal; And
Select piece, it determines to postpone the variation of point according to the comparative result of described comparator and the judged result of described accepting state decision block.
21. according to the digit broadcasting receiver of claim 17, wherein
Described converting unit comprises:
The accepting state decision block, it is according to demodulation status signal and postpone point value judgement accepting state; And
Select piece, it determines to postpone the variation of point according to the comparative result of described comparator and the judged result of described accepting state decision block.
22. according to the digit broadcasting receiver of claim 20, wherein
Described selection piece is selected from a plurality of different delay points change and is determined that specific delay point changes.
23. according to the digit broadcasting receiver of claim 22, wherein
A plurality of delay points variations of selecting in described selection piece comprise at least one value that is changed significantly different with other.
24. according to the digit broadcasting receiver of claim 1, wherein
Described automatic gain controller comprises:
Status monitor, it detects demodulation state from the demodulation output of described demodulator, to produce demodulation status signal;
Retainer, it will keep a period of time from the demodulation status signal of described status monitor output;
Comparator, it relatively from the demodulation status signal of described status monitor output and the demodulation status signal that is kept by described retainer, represents the comparison signal that the time of demodulation state changes with output;
The synchronous regime watch-dog, it detects synchronous regime to produce the control beginning label from the output of demodulator;
Converting unit, it is when the transfer point between the gain control signal on the gain control signal on the RF frequency band and the IF frequency band is set to postpone point in described tuner, and the control beginning label that obtains in demodulation status signal that obtains based on the comparison signal of described comparator, described status monitor and the described synchronous regime watch-dog determines to postpone the variation of point;
Postpone the some determining unit, it is according to the value of the variation updating delay point of the definite delay point of described converting unit;
Signal level detecter, it detects the signal level of received signal from described tuner IF signal; And
Control signal generator, its signal level according to the delay point value of described delay point determining unit and described signal level detecter produce gain control signal on the RF frequency band and the gain control signal on the IF frequency band.
25. according to the digit broadcasting receiver of claim 24, wherein
Described converting unit comprises:
Control counter, it is reset in response to the control beginning label that obtains in described synchronous regime controller, and carries out counting when the delay point variation of exporting from described converting unit is updated at every turn, thereby adds up to the control number;
The state decision block, it judges accepting state according to demodulation status signal, delay point value and control number; And
Select piece, it determines to postpone the variation of point according to the comparative result of described comparator and the judged result of described state decision block.
26. according to the digit broadcasting receiver of claim 25, wherein
Described selection piece is selected from a plurality of different delay points change and is determined that specific delay point changes.
27. according to the digit broadcasting receiver of claim 26, wherein
A plurality of delay points variations of selecting in described selection piece comprise at least one value that is changed significantly different with other.
28. according to the digit broadcasting receiver of claim 1, wherein
Described automatic gain controller comprises:
Status monitor, its demodulation output from described demodulator detects demodulation state, to produce demodulation status signal;
Retainer, it will keep a period of time from the demodulation status signal of described status monitor output;
Comparator, it relatively from the demodulation status signal of status monitor output and the demodulation status signal of described retainer maintenance, represents the comparison signal that the time of demodulation state changes with output;
Synchronous regime watch-dog, its output according to described demodulator detect synchronous regime to produce the control beginning label;
Converting unit, it is when the transfer point between the gain control signal on the gain control signal on the RF frequency band and the IF frequency band is set to postpone point in described tuner, and the control beginning label that obtains in demodulation status signal that obtains based on the comparison signal of described comparator, described status monitor and the described synchronous regime watch-dog determines to postpone the variation of point;
Postpone the some determining unit, it is according to the value of the variation updating delay point of the delay point of being exported by described converting unit;
Time schedule controller, its generation are used for the timing control signal that each fixed cycle is checked the optimal delay point value;
Optimal delay point retainer, its timing control signal according to the demodulation status signal of the delay point value of described delay point determining unit, described status monitor and described time schedule controller detects the optimal delay point in the certain hour section, and output optimal delay point value;
Signal level detecter, it detects the signal level of received signal from described tuner IF signal; And
Control signal generator, the optimal delay point value that it keeps according to described optimal delay point retainer and the signal level of described signal level detecter produce gain control signal on the RF frequency band and the gain control signal on the IF frequency band.
29. according to the digit broadcasting receiver of claim 28, wherein
Described optimal delay point retainer storage also keeps interior optimal demodulation state of described time schedule controller control time section and the optimal delay point value of this moment.
30. according to the digit broadcasting receiver of claim 28, wherein
Described optimal delay point retainer upgrades the control time section storage of each described time schedule controller and the value of the optimal delay point that keeps.
31. according to the digit broadcasting receiver of claim 28, wherein
Described converting unit comprises:
Control counter, it is reset in response to the control beginning label that obtains in described synchronous regime watch-dog, and carries out counting when the delay point variation of exporting from described converting unit is updated at every turn, thereby adds up to the control number;
The accepting state decision block, it judges accepting state according to demodulation status signal, delay point value and control number; And
Select piece, it determines to postpone the variation of point according to the comparative result of described comparator and the judged result of described accepting state decision block.
32. according to the digit broadcasting receiver of claim 31, wherein
Described selection piece is selected from a plurality of different delay points change and is determined that specific delay point changes.
33. according to the digit broadcasting receiver of claim 32, wherein
A plurality of delay points variations of selecting in described selection piece comprise at least one value that is changed significantly different with other.
Claims (33)
1. digit broadcasting receiver comprises:
Tuner, its amplification input signal is with the RF signal on the selection desired frequency band, and amplification RF signal is to convert the RF signal frequency to the IF signal;
Quadrature detector, it is according to the IF calculated signals I and the Q composite signal of described tuner;
Demodulator, it demodulates digital signal from the I of described quadrature detector and Q composite signal; And
Automatic gain controller, it detects the signal level of received signal from described tuner IF signal, detect the demodulation state in the described demodulator, judge that disturbing wave is to the level of the influence of restituted signal on the desired frequency band in the adjacent channel, produce gain control signal on the RF frequency band and the gain control signal on the IF frequency band according to the signal level that influences level and described received signal, and these two gain control signals are fed back to described tuner.
2. according to the digit broadcasting receiver of claim 1, wherein
Described automatic gain controller comprises:
Signal level detecter, it detects the signal level of received signal from the IF signal of described tuner;
The demodulation level detector, it detects the demodulation level signal of restituted signal on the desired frequency band from the demodulation output of described demodulator;
Demodulation electrical level judging unit, its demodulation level signal according to the demodulation level detector produces demodulation electrical level judging signal, and the disturbing wave in this demodulation electrical level judging signal indication adjacent channel is to the influence of restituted signal on the expectation channel; And
The control signal generator, its signal level according to the demodulation electrical level judging signal of described demodulation electrical level judging unit and described signal level detecter produces gain control signal on the RF frequency band and the gain control signal on the IF frequency band, so that these two gain control signals are fed back to described tuner, and
Described tuner comprises:
The RF-AGC amplifier, it is based on the level of the control of the gain control signal on RF frequency band RF signal; And
The IF-AGC amplifier, it is based on the level of the control of the gain control signal on IF frequency band IF signal.
3. according to the digit broadcasting receiver of claim 2, wherein
The demodulation level detector comprises:
The demodulation frequency band extracts piece, and it is from being extracted the signal on the desired frequency band in the frequency signal of fourier transform described demodulator;
Demodulation level computing block, it calculates the level that extracts the signal on the desired frequency band that obtains in the piece at described demodulation frequency band; And
Demodulation level storage piece, its transfer point between the gain control signal on the gain control signal on the RF frequency band and the IF frequency band in described tuner keep when being set to postpone postponing point change before signal level on the desired frequency band, and
Signal level after signal level before described demodulation level detector will postpone a little to change on the desired frequency band changes with the delay point on the desired frequency band compares, and judges that disturbing wave is to the level of the influence of desired frequency band in the adjacent channel.
4. according to the digit broadcasting receiver of claim 3, wherein
Described demodulation frequency band extracts piece and only extracts three grades of frequency bands that distortion occurs that cause owing to the outer signal of desired frequency band thereon.
5. according to the digit broadcasting receiver of claim 3, wherein
Described demodulation frequency band extracts piece and only extracts three grades of frequency bands that distortion occurs that caused by the NTSC signal thereon.
6. according to the digit broadcasting receiver of claim 1, wherein
The time shaft filter that extracts the signal on the desired frequency band from the I of demodulator and Q signal is provided between quadrature detector and the demodulator,
Described automatic gain controller comprises:
Signal level detecter, it detects the signal level of received signal from the IF signal of described tuner;
Detect the level calculator, it is according to the level of the signal on the output signal calculation expectation frequency band of described time shaft filter;
The signal level judging unit, it judges signal according to the signal level on the desired frequency band that is obtained by described detection level calculator and by the disturbing wave that the signal level that described signal level detecter obtains produces in the expression adjacent channel to the signal level of the influence of signal on the desired frequency band; And
The control signal generator, its signal level according to described signal level judging unit judges that the signal level of signal and described signal level detecter feeds back to described tuner with the gain control signal on gain control signal on the RF frequency band and the IF frequency band, and
Described tuner comprises:
The RF-AGC amplifier, it is based on the level of the control of the gain control signal on RF frequency band RF signal; And
The IF-AGC amplifier, it is based on the level of the control of the gain control signal on IF frequency band IF signal.
7. according to the digit broadcasting receiver of claim 1, wherein
Described tuner comprises based on the RF-AGC amplifier of the level of the control of the gain control signal on RF frequency band RF signal and the IF-AGC amplifier of controlling the level of IF signal based on the gain control signal on the IF frequency band, amplification input signal is to select the RF signal on the desired frequency band, amplification RF signal is to be converted to the IF signal with the RF signal frequency, and produce in the expression adjacent channel disturbing wave to the adjacent judgement signal of the influence of signal on the desired frequency band, and
Described automatic gain controller comprises the control signal generator, and it feeds back to described tuner according to the adjacent judgement signal of described tuner and the signal level of described signal level detecter with the gain control signal on gain control signal on the RF frequency band and the IF frequency band.
8. according to the digit broadcasting receiver of claim 7, wherein
Described tuner also comprises except RF-AGC amplifier and IF-AGC amplifier:
First electrical level detection block, it calculates by frequency inverted is the signal level of first intermediate frequency signal of intermediate frequency;
The frequency band limits filter, it limits the frequency band of first intermediate frequency signal, and converts first intermediate frequency signal to second intermediate frequency signal;
Second electrical level detection block, it calculates the signal level of second intermediate frequency signal; And
Adjacent decision block, it is the signal level of first and second intermediate frequency signal relatively, judges that adjacent interference ripple in the adjacent channel is to the influence of desired frequency band.
9. according to the digit broadcasting receiver of claim 1, wherein
Described automatic gain controller comprises:
The C/N detector, its restituted signal according to described demodulator calculates C/N;
C/N judging unit, its C/N information according to described C/N detector produce represents that disturbing wave is to the C/N judgement signal of the influence of signal on the desired frequency band in the adjacent channel;
Signal level detecter, it detects the signal level of received signal from the IF signal of described tuner; And
The control signal generator, it judges that according to the signal level of described signal level detecter and the C/N of described C/N judging unit signal feeds back to described tuner with the gain control signal on gain control signal on the RF frequency band and the IF frequency band, and
Described tuner comprises:
The RF-AGC amplifier, it is based on the level of the control of the gain control signal on RF frequency band RF signal; And
The IF-AGC amplifier, it is based on the level of the control of the gain control signal on IF frequency band IF signal.
10. according to the digit broadcasting receiver of claim 9, wherein
Described C/N detector comprises:
The C/N calculation element, its restituted signal according to described demodulator calculates C/N information; And
The C/N storage device, it stores the C/N information of described C/N calculation element, and
Described C/N judgment means relatively postpones the C/N information before the change and postpones the C/N information of point after changing, and judges that the disturbing wave in the adjacent channel was to the influence of desired frequency band when in the described tuner transfer point between the gain control signal on the gain control signal on the RF frequency band and IF frequency band was set to postpone.
11. according to the digit broadcasting receiver of claim 10, wherein
The C/N information that the comparison of described C/N detector calculates in the C/N calculation element and be stored in fixation of C/N information in the memory in advance.
12. according to the digit broadcasting receiver of claim 1, wherein
Described automatic gain controller comprises:
Status monitor, it detects demodulation state from the demodulation output of described demodulator, to produce demodulation status signal;
Retainer, it will keep a period of time from the demodulation status signal of described status monitor output;
Comparator, it is illustrated in the comparison signal of this section effluxion demodulation state variation afterwards relatively from the demodulation status signal of described status monitor output and the demodulation status signal that is kept by described retainer with output;
Converting unit, it determines to postpone the variation of point based on the comparison signal of described comparator with by the demodulation status signal that status monitor obtains when the transfer point between the gain control signal on the gain control signal on the RF frequency band and the IF frequency band is set to postpone point in described tuner;
Postpone the some determining unit, it is according to the value of the variation updating delay point of the delay point of being determined by described converting unit;
Signal level detecter, it detects the signal level of received signal from described tuner IF signal; And
Control signal generator, its signal level according to the delay point value of described delay point determining unit and described signal level detecter produce gain control signal on the RF frequency band and the gain control signal on the IF frequency band.
13. according to the digit broadcasting receiver of claim 12, wherein
Described converting unit comprises:
The accepting state decision block, it judges accepting state according to demodulation status signal; And
Select piece, it determines to postpone the variation of point according to the comparative result of described comparator and the judged result of described accepting state decision block.
14. according to the digit broadcasting receiver of claim 12, wherein
Described converting unit comprises:
The accepting state decision block, it is according to demodulation status signal and postpone point value judgement accepting state; And
Select piece, it determines to postpone the variation of point according to the comparative result of described comparator and the judged result of described accepting state decision block.
15. according to the digit broadcasting receiver of claim 13, wherein
Select piece from a plurality of different delay points change, to select and definite specific delay point variation.
16. according to the digit broadcasting receiver of claim 15, wherein
A plurality of delay points variations of selecting in selecting piece comprise at least one value that is changed significantly different with other.
17. according to the digit broadcasting receiver of claim 1, wherein
Described automatic gain controller comprises:
Status monitor, it detects demodulation state from the demodulation output of described demodulator, to produce demodulation status signal;
Retainer, it will keep a period of time from the demodulation status signal of described status monitor output;
Comparator, it relatively from the demodulation status signal of described status monitor output and the demodulation status signal that is kept by described retainer, represents the comparison signal that the time of demodulation state changes with output;
Converting unit, it is when the transfer point between the gain control signal on the gain control signal on the RF frequency band and the IF frequency band is set to postpone point in described tuner, determines to postpone the variation of point based on the demodulation status signal that the comparison signal and the status monitor of described comparator obtains;
Postpone the some determining unit, it is according to the value of the variation updating delay point of the delay point of being determined by described converting unit;
Time schedule controller, its generation are used for the timing control signal that each fixed cycle is checked the optimal delay point value;
Optimal delay point retainer, its timing control signal according to the demodulation status signal of the delay point value of described delay point determining unit, described status monitor and described time schedule controller detects the optimal delay point in the certain hour section, and output optimal delay point value;
Signal level detecter, it detects the signal level of received signal from described tuner IF signal; And
The control signal generator, it is according to gain control signal on signal level generation RF frequency band of the received signal of optimal delay point value that is kept by described optimal delay point retainer and described signal level detecter and the gain control signal on the IF frequency band.
18. according to the digit broadcasting receiver of claim 17, wherein
Described optimal delay point retainer storage also keeps interior optimal demodulation state of described time schedule controller control time section and the optimal delay point value of this moment.
19. according to the digit broadcasting receiver of claim 17, wherein
Described optimal delay point retainer upgrades by the value of described time schedule controller at the optimal delay point of each control time section storage and maintenance.
20. according to the digit broadcasting receiver of claim 17, wherein
Described converting unit comprises:
The state decision block, it judges accepting state according to demodulation status signal; And
Select piece, it determines to postpone the variation of point according to the comparative result of described comparator and the judged result of described state decision block.
21. according to the digit broadcasting receiver of claim 17, wherein
Described converting unit comprises:
The state decision block, it is according to demodulation status signal and postpone point value judgement accepting state; And
Select piece, it determines to postpone the variation of point according to the comparative result of described comparator and the judged result of described state decision block.
22. according to the digit broadcasting receiver of claim 20, wherein
Described selection piece is selected from a plurality of different delay points change and is determined that specific delay point changes.
23. according to the digit broadcasting receiver of claim 22, wherein
A plurality of delay points variations of selecting in described selection piece comprise at least one value that is changed significantly different with other.
24. according to the digit broadcasting receiver of claim 1, wherein
Described automatic gain controller comprises:
Status monitor, it detects demodulation state from the demodulation output of described demodulator, to produce demodulation status signal;
Retainer, it will keep a period of time from the demodulation status signal of described status monitor output;
Comparator, it relatively from the demodulation status signal of described status monitor output and the demodulation status signal that is kept by described retainer, represents the comparison signal that the time of demodulation state changes with output;
The synchronous regime watch-dog, it detects synchronous regime to produce the control beginning label from the output of demodulator;
Converting unit, it is when the transfer point between the gain control signal on the gain control signal on the RF frequency band and the IF frequency band is set to postpone point in described tuner, and the control beginning label that obtains in demodulation status signal that obtains based on the comparison signal of described comparator, described status monitor and the described synchronous regime watch-dog determines to postpone the variation of point;
Postpone the some determining unit, it is according to the value of the variation updating delay point of the definite delay point of described converting unit;
Signal level detecter, it detects the signal level of received signal from described tuner IF signal; And
Control signal generator, its signal level according to the delay point value of described delay point determining unit and described signal level detecter produce gain control signal on the RF frequency band and the gain control signal on the IF frequency band.
25. according to the digit broadcasting receiver of claim 24, wherein
Described converting unit comprises:
Control counter, it is reset in response to the control beginning label that obtains in described synchronous regime controller, and carries out counting when the delay point variation of exporting from described converting unit is updated at every turn, thereby adds up to the control number;
The state decision block, it judges accepting state according to demodulation status signal, delay point value and control number; And
Select piece, it determines to postpone the variation of point according to the comparative result of described comparator and the judged result of described state decision block.
26. according to the digit broadcasting receiver of claim 25, wherein
Described selection piece is selected from a plurality of different delay points change and is determined that specific delay point changes.
27. according to the digit broadcasting receiver of claim 26, wherein
A plurality of delay points variations of selecting in described selection piece comprise at least one value that is changed significantly different with other.
28. according to the digit broadcasting receiver of claim 1, wherein
Described automatic gain controller comprises:
Status monitor, its demodulation output from described demodulator detects demodulation state, to produce demodulation status signal;
Retainer, it will keep a period of time from the demodulation status signal of described status monitor output;
Comparator, it relatively from the demodulation status signal of status monitor output and the demodulation status signal of described retainer maintenance, represents the comparison signal that the time of demodulation state changes with output;
Synchronous regime watch-dog, its output according to described demodulator detect synchronous regime to produce the control beginning label;
Converting unit, it is when the transfer point between the gain control signal on the gain control signal on the RF frequency band and the IF frequency band is set to postpone point in described tuner, and the control beginning label that obtains in demodulation status signal that obtains based on the comparison signal of described comparator, described status monitor and the described synchronous regime watch-dog determines to postpone the variation of point;
Postpone the some determining unit, it is according to the value of the variation updating delay point of the delay point of being exported by described converting unit;
Time schedule controller, its generation are used for the timing control signal that each fixed cycle is checked the optimal delay point value;
Optimal delay point retainer, its timing control signal according to the demodulation status signal of the delay point value of described delay point determining unit, described status monitor and described time schedule controller detects the optimal delay point in the certain hour section, and output optimal delay point value;
Signal level detecter, it detects the signal level of received signal from described tuner IF signal; And
Control signal generator, the optimal delay point value that it keeps according to described optimal delay point retainer and the signal level of described signal level detecter produce gain control signal on the RF frequency band and the gain control signal on the IF frequency band.
29. according to the digit broadcasting receiver of claim 28, wherein
Described optimal delay point retainer storage also keeps interior optimal demodulation state of described time schedule controller control time section and the optimal delay point value of this moment.
30. according to the digit broadcasting receiver of claim 28, wherein
Described optimal delay point retainer upgrades the control time section storage of each described time schedule controller and the value of the optimal delay point that keeps.
31. according to the digit broadcasting receiver of claim 28, wherein
Described converting unit comprises:
Control counter, it is reset in response to the control beginning label that obtains in described synchronous regime watch-dog, and carries out counting when the delay point variation of exporting from described converting unit is updated at every turn, thereby adds up to the control number;
The accepting state decision block, it judges accepting state according to demodulation status signal, delay point value and control number; And
Select piece, it determines to postpone the variation of point according to the comparative result of described comparator and the judged result of described accepting state decision block.
32. according to the digit broadcasting receiver of claim 31, wherein
Described selection piece is selected from a plurality of different delay points change and is determined that specific delay point changes.
33. according to the digit broadcasting receiver of claim 32, wherein
A plurality of delay points variations of selecting in described selection piece comprise at least one value that is changed significantly different with other.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2003170288 | 2003-06-16 | ||
| JP170288/2003 | 2003-06-16 | ||
| JP416299/2003 | 2003-12-15 | ||
| JP131133/2004 | 2004-04-27 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1781306A true CN1781306A (en) | 2006-05-31 |
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ID=36770706
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200480011232 Pending CN1781306A (en) | 2003-06-16 | 2004-06-15 | Digital broadcast receiver |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1781306A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2011091602A1 (en) * | 2010-01-29 | 2011-08-04 | 联发科技股份有限公司 | Television signal processing device and television signal processing method |
| CN102939746A (en) * | 2010-06-02 | 2013-02-20 | 三菱电机株式会社 | Digital broadcast receiver |
-
2004
- 2004-06-15 CN CN 200480011232 patent/CN1781306A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2011091602A1 (en) * | 2010-01-29 | 2011-08-04 | 联发科技股份有限公司 | Television signal processing device and television signal processing method |
| CN102726039A (en) * | 2010-01-29 | 2012-10-10 | 联发科技股份有限公司 | Television signal processing device and television signal processing method |
| CN102726039B (en) * | 2010-01-29 | 2014-08-20 | 联发科技股份有限公司 | Television signal processing device and television signal processing method |
| CN102939746A (en) * | 2010-06-02 | 2013-02-20 | 三菱电机株式会社 | Digital broadcast receiver |
| CN102939746B (en) * | 2010-06-02 | 2016-06-01 | 三菱电机株式会社 | Digital broadcasting transmitter |
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