CN1798280A - Digital multimedia receiver and its receiving method - Google Patents
Digital multimedia receiver and its receiving method Download PDFInfo
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- CN1798280A CN1798280A CNA2004101014313A CN200410101431A CN1798280A CN 1798280 A CN1798280 A CN 1798280A CN A2004101014313 A CNA2004101014313 A CN A2004101014313A CN 200410101431 A CN200410101431 A CN 200410101431A CN 1798280 A CN1798280 A CN 1798280A
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Abstract
The invention consists of: a tuner; an ADC; a demodulation unit comprising a single carrier demodulator used to the digital signal corresponding to the single carrier demodulation mode and a multi carrier demodulator used to demodulate the digital signal corresponding to the multi carrier demodulation mode; a selector used to select one signal from signals outputted from two demodulators; and a channel decoder used to decode the selected and demodulated signal. The invention can process both single carrier modulation signal and multi carrier modulation signal.
Description
Technical field
The present invention relates to a kind of digital multimedia receiver and digital multimedia signal method of reseptance, relate in particular to a kind of can processing single-carrier modulated signals and the reception and the method for reseptance thereof of the signal of multi-carrier modulation.
Background technology
In multimedia communication and broadcasting epoch, digitlization is all being carried out with the broadcasting of analogue type in countries in the world, especially in the developed country such as the U.S., and states such as Europe and Japan, digit broadcasting system has been developed and has dropped into utilization.Along with its fast development, in different countries, it was suggested the different standard that is used for digital broadcasting.
On December 24th, 1996, FCC (FCC) has proposed Advanced Television Systems Committee (ATSC) digital television standard as television broadcasting standard of future generation.All terrestrial broadcasting operators must abide by the ATSC standard about the standard of video/audio compression, packet data transmission structure and modulation and transmission system.Only about the standard of video format not by concrete regulation, but leave the industry decision for.
ATSC numeral TV standard utilizes single carrier VSB mode to transmit high-quality video, audio frequency and additional data on the bandwidth of 6MHz, and supports terrestrial broadcasting pattern and high data rate cablecast pattern simultaneously.The main aspect of this mode is to have the 8-VSB modulator approach of improved form of the existing analogue type VSB mode of conduct of digital signal modulation capability.
In Europe, for its high frequency efficiency and antijamming capability and with COFDM (Coded Orthogonal Frequency Division Multiplexing (COFDM)) system applies in DVB-T (digital video broadcast-terrestrial).
Other uses the data transmission scheme of different modulator approaches can be divided into multi-carrier scheme and single-carrier scheme.Thus, the conventional digital multi-media receiver can be divided into multi-carrier digital multi-media receiver and single carrier digital multimedia receiver.
Fig. 1 is the schematic block diagram of the conventional digital multi-media receiver of the expression signal that is used to handle multi-carrier modulation.
This traditional multi-carrier digital multi-media receiver comprises: tuner 110 is used for the multi-media signal of the tuning multi-carrier modulation that receives; ADC (analog to digital converter) 120, being used for the conversion of signals from tuner 110 outputs is digital signal; Lock unit 130 is used for that the signal from ADC 120 is carried out the timing recovery and carrier wave recovers; Fast Fourier transform (FFT) unit 140 is used for the signal from lock unit 130 outputs is carried out fast fourier transform; Balanced unit 150 is used for the signal of 140 outputs from the FFT unit is carried out equilibrium; QAM (quadrature amplitude modulation) symbol detection unit 160 is used for symbol detection is carried out in the output of equalizer; Preceding paragraph error correction (FEC) unit 170 is used for the signal from symbol detection unit 160 outputs is carried out the preceding paragraph error correction; With descrambler 180, be used for the signal of 170 outputs from the FEC unit is carried out descrambling to obtain mpeg stream.
Fig. 2 is the schematic block diagram that expression is used for the conventional digital multi-media receiver of processing single-carrier modulated signals.
This conventional single carrier digital multimedia receiver comprises: tuner 210 is used to receive the multi-media signal of single-carrier modulated; ADC 220, and being used for the conversion of signals from tuner 210 outputs is digital signal; (SYNC) unit 230 is used for carrying out and regularly recovers and the carrier wave recovery synchronously; Balanced unit 240 is used for the signal from lock unit 230 outputs is carried out equilibrium; (biasing) QAM symbol detection unit 250 is used for symbol detection is carried out in the output of balanced unit 240; FEC unit 260 is used for the signal of symbol detection unit 250 outputs is carried out the preceding paragraph error correction; With descrambler 270, be used for the signal of FEC unit 260 outputs is carried out descrambling to obtain mpeg stream.
So to the performance of single carrier transmitting system well still the performance of multicarrier transmission systems have permanent dispute well, but do not have concrete result.These two kinds of schemes all have merits and demerits separately.Therefore, the expectation broadcasting station allows to select to be fit to the transmission plan of its specific needs and broadcast environment from multiple transmission plan.In this case, need be able to receive the decode the receiver of the broadcast singal of single carrier and multi-carrier modulation, to watch Digital Television (DTV) program from the broadcasting station of using different transmission schemes.
As everyone knows, traditional digital multimedia receiver can not receive the signal of single-carrier modulated signals and multi-carrier modulation simultaneously, and there are a lot of inconvenience in this.
Summary of the invention
The objective of the invention is to address the above problem and/or shortcoming.Therefore, an aspect of of the present present invention is to provide a kind of receiver and method of reseptance thereof that is used for the signal of processing single-carrier modulated signals and multi-carrier modulation.
According to an aspect of the present invention, provide a kind of digital multimedia receiver that is used for the signal of processing single-carrier modulated signals and multi-carrier modulation, this receiver comprises: tuner, and the signal tuning that is used for receiving is to corresponding band; ADC (analog-digital converter), being used in the future, the tuning conversion of signals of self-tuner is a digital signal; Demodulating unit comprises being used for demodulation from the single carrier demodulation device of the single-carrier modulated signals of ADC be used for the multicarrier demodulator of demodulation from the signal of the multi-carrier modulation of ADC; Selector is used for selecting one of them according to the modulating mode indication from the signal of single carrier demodulation device and the output of multicarrier demodulator; And channel decoder, be used for the signal of selecting from the demodulation of demodulator output being decoded and exporting.
At the digital multimedia receiver that is used for the signal of processing single-carrier modulated signals and multi-carrier modulation according to the present invention, can use as RS (reed-solomon) block decoder and LDPC (low density parity check code) decoder as shared decoder.
According to a further aspect in the invention, provide a kind of digital multimedia signal method of reseptance that is used for the signal of processing single-carrier modulated signals and multi-carrier modulation, this method comprises: (a) with the multi-media signal that receives be tuned to corresponding band; (b) will in step (a), tuning conversion of signals be digital signal; (c) will be from the digital demodulation signal and the output of step (b); (d), from signal, select one of them from the signal of the single carrier demodulation of step (c) and multicarrier demodulation according to modulating mode indication; (e) signal decoding of the demodulation that will in step (d), select and output.
In step (e), carry out decoding with the LDPC pattern.
Description of drawings
By the following description of embodiment being carried out below in conjunction with accompanying drawing, above-mentioned and other purposes of the present invention and advantage will become apparent, wherein:
Fig. 1 is the schematic block diagram of the conventional digital multi-media receiver of the expression signal that is used to handle multi-carrier modulation;
Fig. 2 is the schematic block diagram that expression is used for the conventional digital multi-media receiver of processing single-carrier modulated signals;
Fig. 3 is the block diagram of expression according to the digital multimedia receiver of the signal that is used for processing single-carrier modulated signals and multi-carrier modulation of first embodiment of the invention;
Fig. 4 is the flow chart of the digital multimedia signal method of reseptance carried out in the digital multimedia receiver shown in Figure 3 of expression according to first embodiment of the invention;
Fig. 5 is the block diagram of expression according to the digital multimedia receiver of the signal that is used for processing single-carrier modulated signals and multi-carrier modulation of second embodiment of the invention;
Fig. 6 is the flow chart of the auto gain control method of execution during expression receives according to the digital multimedia shown in Fig. 5 of second embodiment of the invention;
Fig. 7 is the block diagram of expression according to the structure of the digital multimedia receiver of the signal that is used for processing single-carrier modulated signals and multi-carrier modulation of third embodiment of the invention;
Fig. 8 is the block diagram of demonstration according to the digital multimedia receiver of the signal that is used for processing single-carrier modulated signals and multi-carrier modulation of fourth embodiment of the invention;
Fig. 9 is the flow chart according to the digital multimedia method of reseptance of carrying out in digital multimedia receiver shown in Figure 8 of fourth embodiment of the invention;
Figure 10 is the block diagram of expression according to the structure of the digital multimedia receiver of the signal that is used for processing single-carrier modulated signals and multi-carrier modulation of fifth embodiment of the invention;
Figure 11 is the block diagram of demonstration according to the digital multimedia receiver of the signal that is used for processing single-carrier modulated signals and multi-carrier modulation of sixth embodiment of the invention;
Figure 12 is the flow chart according to the digital multimedia method of reseptance of carrying out in the digital multimedia receiver shown in Figure 11 of sixth embodiment of the invention;
Figure 13 is the block diagram of demonstration according to the digital multimedia receiver of the signal that is used for processing single-carrier modulated signals and multi-carrier modulation of seventh embodiment of the invention;
Figure 14 is the flow chart according to the digital multimedia method of reseptance of carrying out in digital multimedia receiver shown in Figure 13 of seventh embodiment of the invention; With
Figure 15 is the block diagram of expression according to the digital multimedia receiver of the signal that is used for processing single-carrier modulated signals or multi-carrier modulation of eighth embodiment of the invention.
Embodiment
Now, will describe embodiments of the invention in detail, its example is enumerated in the accompanying drawings, and wherein identical label is represented identical parts all the time.Embodiment is described with reference to the accompanying drawings to explain the present invention.
Fig. 3 is the block diagram according to the digital multimedia receiver of the signal that is used for processing single-carrier modulated signals and multi-carrier modulation of first embodiment of the invention.
With reference to Fig. 3, this digital multimedia receiver comprises: tuner 310, be used for the multi-media signal that will receive be tuned to corresponding band, wherein, multi-media signal is the signal of single-carrier modulated signals or multi-carrier modulation; ADC (analog-digital converter) 320, being used in the future, the tuning conversion of signals of self-tuner 310 is a digital signal; Demodulating unit 330, comprise the demodulator 331 and the demodulator 332 that is used for the signal demodulation and the output of multi-carrier modulation that are used for single-carrier modulated signals demodulation and output, wherein, when digital signal was imported into demodulating unit 330, one or two in two demodulators will be from digital demodulation signal and the output of ADC320; Selector 340 is used for being selected effective signal what export from demodulating unit 330 by the signal of demodulation according to the modulating mode indication; With shared channel decoder 350, be used for select from the signal decoding of the demodulation of demodulating unit 330 outputs and the signal that output obtains.
In demodulating unit 330, one or two operation in demodulator 331 and the demodulator 332 is also handled the digital signal of importing.If input signal is a single-carrier modulated signals, then demodulator 331 moves the also signal of output single carrier demodulation correctly.If digital signal is the signal of multi-carrier modulation, then the signal of multicarrier demodulation is also correctly exported in demodulator 332 operations.
The shared channel decoder 350 that is used to single carrier transmission pattern and multi-carrier transmission pattern is connected in demodulating unit 330 by selector 340, and RS block decoder and LDPC decoder can be used as shared channel decoder 350.
Now, with reference to Fig. 3 and Fig. 4 operation according to the digital multimedia receiver of first embodiment of the invention is described.
Fig. 4 is the flow chart of the digital multimedia signal method of reseptance of execution in receiving according to the digital multimedia shown in Fig. 3 of first embodiment of the invention.
At step S410, tuner 310 arrives corresponding band with the signal tuning that receives.Then, at step S420, ADC 320 is the tuning signal digitalized and output digital signal of self-tuner 310 in the future.
At step S430, demodulating unit 330 will and be exported the signal of demodulation from the digital demodulation signal of ADC 320.Here, one or two in the demodulator can processing digital signal in the demodulating unit 330.Specifically, if the signal of input is a single-carrier modulated signals, then demodulator 331 is also exported the digital signal demodulation correctly of input under single carrier mode.If the signal of input is the signal of multi-carrier modulation, then demodulator 332 is also exported the digital signal demodulation correctly of input under multi-carrier mode.
At step S440, selector 340 is always selected effective signal according to the modulating mode indication in the signal of demodulation unit 330.If selector 340 learns that according to the pattern modulation intelligence digital signal that is input to demodulating unit 330 is a single-carrier modulated signals, then selector 340 is selected from the signal of the demodulation of demodulator 331 outputs.If select 340 to learn that according to modulating mode indication the digital signal that is input to demodulating unit 330 is the signal of multi-carrier modulation, then selector 340 is selected from the signal of the demodulation of demodulator 332 outputs.
At step S450, shared channel decoder 350 will be from the signal decoding and the output of the demodulation of selector 340.
The digital multimedia receiver with said structure and the method for reseptance of the application of the invention can be by the modulating modes of the multi-media signal determining to receive, and the signal of single-carrier modulated signals and multi-carrier modulation all can be processed.Thereby the hardware of this receiver is realized being simplified, and the receptivity of receiver is enhanced.
Fig. 5 is the block diagram of expression according to the digital multimedia receiver of the signal that is used for processing single-carrier modulated signals and multi-carrier modulation of second embodiment of the invention.
As shown in Figure 5, this digital multimedia receiver comprises: tuner 510, ADC 520, be used for indicating the AGC (automatic gain controller) 530 of the gain of controlling the tuning signal that is input to ADC 520 and being used for the demodulating unit 540 that indication is carried out demodulation to digital signal according to modulating mode according to modulating mode.
The structural similarity of the structure of digital multimedia receiver shown in Figure 5 and receiver shown in Figure 3.In order to simplify, selector and decoder are not shown among Fig. 5.In addition, the tuner 310 among tuner 510 and ADC 520 and Fig. 3 is identical with the function of ADC 320, and therefore, the abridged is to their detailed description.
The signal of single-carrier modulated signals and multi-carrier modulation has different PAPR (peak-to-average power ratio) characteristic, and the signal of multi-carrier modulation is compared with single-carrier modulated signals has relative big PAPR.The AGC algorithm that is used for these two kinds of modulating modes is also inequality.In above-mentioned receiver, only used an AGC, therefore, at the digital multimedia receiver of the signal that is used for processing single-carrier modulated signals and multi-carrier modulation, AGC 530 should indicate according to the modulating mode of the modulating mode of indicating multi-media signal and adopt corresponding algorithm.
The characteristics of signals that AGC 530 measures from the digital signal of ADC 520 as average power or average amplitude (magnitude), and according to being input to the gain of the tuning signal of ADC 520 subsequently from tuner 510 with the adjustment of the corresponding AGC algorithm of modulating mode, thereby, from the amplitude of the signal of tuner 510 output within the suitable opereating specification of ADC 520.For example, because the difference of PAPR, the target power that is used for the AGC of multi-carrier mode is set to the low value of target power than the AGC of single carrier mode.Like this, ADC 520 and true(-)running corresponding with the modulating mode of multi-media signal.
AGC 530 is RF (radio frequency) AGC or IF (intermediate frequency) AGC.
Fig. 6 is the flow chart of the auto gain control method carried out in the digital multimedia receiver of representing according to a second embodiment of the present invention shown in Figure 5.
At step S610, the tuner 510 tuning multi-media signals that receive.
At step S620, ADC 520 will be a digital signal from the tuning conversion of signals of tuner 510 outputs.
At step S630, the characteristics of signals that AGC 530 measures from the digital signal of ADC 520 as average power and average amplitude.
At step S640, AGC 530 indicates according to the result who measures and modulating mode and controls the gain that is input to the signal of ADC 520 from tuner 510.
By use have said structure according to digital multimedia receiver of the present invention and auto gain control method, can come the signal of processing single-carrier modulated signals and multi-carrier modulation by the modulating mode of the multi-media signal determining to receive.In addition, according to the modulating mode of the multi-media signal that receives can receiver control the gain of tuner.Thereby the realization of the hardware of receiver is simplified, and the receptivity of receiver is enhanced.
Fig. 7 is the block diagram of expression according to the structure of the digital multimedia receiver of the signal that is used for processing single-carrier modulated signals and multi-carrier modulation of third embodiment of the invention.
Digital multimedia receiver shown in Figure 7 comprises tuner 710, ADC 720, lock unit 730, demodulating unit 740 and channel decoder 750.
Timing recovery block 730T comprises sampling unit 731, first loop filter 732 and Timing Error Detector (TED) 733 again.At this, TED733 detects the output signal of sampling unit 731 again and calculates timing error to indicate based on modulating mode, and its output signal is fed to first loop filter 732.The output signal of 732 couples of TED 733 of first loop filter is carried out filtering, is fed to sampling unit 731 through the signal of first loop filter, 732 filtering again.Sampling unit 731 uses through the timing error of first loop filter, 732 filtering and estimates to compensate timing slip from the digital signal of ADC 720 again.And sampling unit 731 can comprise withdrawal device and the interpolation device that is respectively applied for extraction and interpolation again.Because different for the timing error detection algorithm of single-carrier modulated pattern and multi-carrier modulation pattern, so realize in TED 733 for the algorithm of described two kinds of patterns, TED 733 is based on the corresponding algorithm of modulating mode indication selection.In such cases, timing error information is by modulating mode indication decision.
Demodulating unit 740 will be from the synchronous signal demodulation of lock unit 730 based on modulating mode indication.
From above description as can be seen, digital multimedia receiver according to the present invention is indicated based on modulating mode and is carried out synchronously.
According to the receiver structure of Fig. 7, regularly recover to recover to take place once the back carrier wave takes place.Yet in fact, timing recovery block 730T can place different positions, takes place before demodulation as long as regularly recover.That is to say that the position of timing recovery block 730T and carrier recovery block 730C can exchange.
The modulating mode indication can receive from the mode detector (not shown).
By using the structure of digital multimedia receiver shown in Figure 7, can be based on single-carrier modulated pattern and multi-carrier modulation pattern compensation timing slip and frequency shift (FS).Therefore, receiver can correctly be operated single-carrier modulated pattern and multi-carrier modulation pattern.
Receiving filter is used in the digital multimedia receiver usually, to reduce inter symbol interference and additional noise.The system that is used for single-carrier modulated pattern and multi-carrier modulation pattern should have different bandwidth owing to different spectral characteristics.In order only to use a shared receiving filter with processing single-carrier modulated pattern and multi-carrier modulation pattern in digital multimedia receiver, the characteristic of receiving filter should be changed by using different pre-determined factor collection.For this reason, the filter coefficient set that is used for the shared receiving filter of single-carrier modulated pattern and multi-carrier modulation pattern should be updated according to modulating mode.
Fig. 8 is the block diagram of demonstration according to the digital multimedia receiver of the signal that is used for processing single-carrier modulated signals and multi-carrier modulation of fourth embodiment of the invention.
With reference to Fig. 8, this digital multimedia receiver comprises tuner 810, ADC 820, filter coefficient unit 830, receiving filter 840, demodulating unit 850 and channel decoder 860.
The multi-media signal that tuner 810 tuning (down conversion) receives through antenna.
Receiving filter 840 according to by filter coefficient storage 831 that provide with single-carrier modulated pattern or the corresponding filter coefficient set of multi-carrier modulation pattern, will be from the digital signal filter of ADC 820.Receiving filter 840 can be square root raised cosine (SRRC) filter.Being used as the SRRC filter that is complementary with transmitting terminal SRRC filter maximizes signal to noise ratio by matched signal.
Demodulating unit 850 indicates the digital signal of demodulation by receiving filter 840 filtering according to modulating mode.Demodulating unit 850 comprises first switch 851, OQAM demodulator 852, FFT unit 853, qam demodulator 854 and second switch 855.
In addition, first switch 851 can be omitted.In this case, one of OQAM demodulator 852 and qam demodulator 854 or both work.At length, be input to OQAM demodulator 852 and FFT unit 853 simultaneously by the signal of receiving filter 840 filtering, one of OQAM demodulator 852 and FFT unit 853 or both are allowed to work.
In addition, in the present embodiment, demodulator 852 also can be a qam demodulator.
Describe the operating process of the digital multimedia receiver shown in Fig. 8 in detail now with reference to Fig. 9.Fig. 9 is the flow chart according to the digital multimedia method of reseptance of carrying out in digital multimedia receiver shown in Figure 8 of fourth embodiment of the invention.
With reference to Fig. 9, in step S910, the signal that receives is by tuning (down conversion).In step S920, the signal of tuning (down conversion) is converted into digital signal.
In step S930, this digital signal is filtered according to the modulating mode indication.More particularly, provide filter coefficient set according to modulating mode indication, and based on this filter coefficient set with digital signal filter.
In step S940, filtered digital signal is indicated by demodulation according to modulating mode.At length, if the modulating mode indication is the indication of single-carrier modulated pattern, so filtered signal is separated by OQAM and is transferred by demodulation, if the modulating mode indication is the indication of multi-carrier modulation pattern, so filtered signal is separated by FFT and QAM and transferred by demodulation.
At last, in step S950, the signal after the demodulation is decoded.
In addition, in step S940, if the modulating mode indication is the indication of single-carrier modulated pattern, so filtered signal also can be separated by QAM and transfer by demodulation.
Because shared filter is used for the signal of single-carrier modulated signals and multi-carrier modulation, so the realization of digital multimedia receiver is simplified, and the handling property of digital multimedia receiver is enhanced.
Figure 10 is the block diagram of expression according to the structure of the digital multimedia receiver of the signal that is used for processing single-carrier modulated signals and multi-carrier modulation of fifth embodiment of the invention.
Digital multimedia receiver shown in Figure 10 comprises tuner 1010, ADC 1020, lock unit 1030, demodulating unit 1040, selector 1050 and channel decoder 1060.
The multi-media signal of 1010 pairs of receptions of tuner be tuned to corresponding wave band.ADC 1020 will be a digital signal through tuning analog signal conversion by sampling and quantification.
Lock unit 1030 carries out the digital signal of ADC 1020 conversions with the modulating mode indication synchronously.
Demodulating unit 1040 will be from the synchronous signal demodulation of lock unit 1030.Demodulating unit 1040 comprises first demodulation block 1041 and second demodulation block 1042.But the single-carrier modulated signals of first demodulation block 1041 and second demodulation block, 1042 difference demodulate reception and the signal of multi-carrier modulation.Based on modulating mode indication, being activated of described two demodulation block with the corresponding demodulation block of modulating mode.
First demodulation block 1041 comprise be used for balanced from the synchronous single-carrier modulated signals of lock unit 1030 first balanced unit 1043 and be used for the OQAM unit 1044 of demodulation from the signal of first balanced unit, 1043 equilibriums.First balanced unit 1043 also comprises the first equalization filter 1043a and coefficient update device 1043b.
The first equalization filter 1043a uses the equalizing coefficient that is provided by coefficient update device 1043b to carrying out equilibrium from lock unit 1030 synchronous signals.Coefficient update device 1043b uses from lock unit 1030 synchronous signal, the output of equalizer and the estimation that reference signal is carried out the calculating of equalizing coefficient.
In the single-carrier modulated pattern, the first equalization filter 1043a uses the equalizing coefficient that is provided by coefficient update device 1043b to carrying out equilibrium from lock unit 1030 synchronous signals.The output of the first equalization filter 1043a is imported into OQAM unit 1044 and therein by demodulation.Be imported into selector 1050 for you to choose from the signal of OQAM unit 1044 demodulation.Coefficient update device 1043b detects from lock unit 1030 synchronous signal, equalizers and exports and reference signal, and upgrades equalizing coefficient, and equalizing coefficient information is offered equalization filter 1043a.
At this, prearranged signal is used as reference signal as the PN sequence.If first balanced unit 1043 is in direct judgment model (decision-directed mode), OQAM demodulation output is used as reference signal so.
Equalizing coefficient is according to employed equalization algorithm and difference.Therefore the realization of coefficient update device 1043b is by the kind decision of employed equalization filter.At the existing algorithm that is used for the equilibrium of single-carrier modulated signals, for example in linear equalization, frequency domain equalization and the decision feedback equalization (decision-feedbackequalization), use the DFE algorithm better.When processing single-carrier modulated signals, the use of DFE filter provides the more performance of the demodulating equipment of proposition.
OQAM unit 1044 can replace with QAM pattern demodulator.
On the other hand, second demodulation block 1042 comprises the FFT unit that is used for the signal of synchronous multi-carrier modulation is transformed into from time domain frequency domain, be used for second balanced unit 1046 of the balanced signal of changing and be used for the QAM unit 1047 of demodulation from the signal of second balanced unit, 1046 equilibriums.Second balanced unit 1046 further comprises the second equalization filter 1046a and channel estimator 1046b.
In the multi-carrier modulation pattern, channel estimator 1046b uses reference signal to estimate, in such cases, the PN sequence of extracting from the synchronous signal of lock unit 1030 is used as reference signal, and channel estimating information is offered the second equalization filter 1046a.FFT unit 1045FFT conversion is from the synchronous signal of lock unit 1030.The second equalization filter 1046a uses the signal from the balanced FFT conversion of channel estimating information of channel estimator 1046b.QAM unit 1047, is selected for indicating according to modulating mode with the input as selector 1050 of the signal that produces demodulation with the signal of the QAM pattern demodulation second equalization filter 1046a equilibrium.
In fact, other prearranged signal can be used as reference signal as pilot sub-carrier.Pilot sub-carrier is detected from the output of FFT unit 1045.
Selector 1050 is selected to indicate corresponding output signal with the input as channel decoder 1060 with modulating mode from the output of OQAM unit 1044 and QAM unit 1047.
Channel decoder 1060 is with the signal decoding of demodulation and export this signal.At this, the LDPC decoder can be used as channel decoder.
Thus, demodulating unit shown in Figure 10 has the ability of equalizing signal, but the signal of the single-carrier modulated signals of demodulate reception and multi-carrier modulation.
Use the demodulating unit shown in Figure 10 can be based on single-carrier modulated pattern and multi-carrier modulation pattern compensation channel distortion.Thereby, can improve the performance of the digital multimedia receiver that is used for these two kinds of patterns, and reduce channel errors.
Can processing single-carrier modulated signals and the cost of the digital multimedia receiver of the signal of multi-carrier modulation in order to reduce, can use a shared ADC.But, since the character of single-carrier modulated pattern and multi-carrier modulation pattern uniqueness, the symbol-rate difference of these two kinds of modulating modes.Therefore, in the processing path of digital multimedia receiver, the output of shared ADC should be extracted to being suitable for the different symbol-rate of single-carrier modulated pattern and multi-carrier modulation pattern.
For example, the sample rate of supposing ADC is r1, and the symbol-rate of single-carrier modulated pattern and multi-carrier modulation pattern is respectively r2 and r3.The extraction yield N of single-carrier modulated pattern: 1 equals r1: r2, the extraction yield M of multi-carrier modulation pattern: 1 equals r1: r3.Because r3 is less than r2, M is greater than N.
Figure 11 is the block diagram of demonstration according to the digital multimedia receiver of the signal that is used for processing single-carrier modulated signals and multi-carrier modulation of sixth embodiment of the invention.
With reference to Figure 11, this digital multimedia receiver comprises tuner 1110, ADC 1120, extracting unit 1130, demodulating unit 1140 and channel decoder 1150.
The multi-media signal that tuner 1110 tuning (down conversion) receives through antenna.
ADC 1120 will be a digital signal by tuner 1110 tuning conversion of signals by sampling, quantification and coding.
Extracting unit 1130 is according to the digital signal of modulating mode indication extraction from ADC 1120.Extracting unit 1130 comprises first switch 1131, first withdrawal device 1132 and second withdrawal device 1133.
First switch 1131 is according to one in modulating mode indication selection first withdrawal device 1132 and second withdrawal device 1133.More particularly, if the modulating mode indication is the indication of single-carrier modulated pattern, first switch 1131 is selected the digital signal that first withdrawal device, 1132, the first withdrawal devices 1132 receive through first switch 1131 so.First withdrawal device 1132 is with N: 1 extracts the digital signal from ADC1120.If the modulating mode indication is the indication of multi-carrier modulation pattern, first switch 1131 is selected the digital signal that second withdrawal device, 1133, the second withdrawal devices 1133 receive through first switch 1131 so.Second withdrawal device 1133 is with M: 1 extracts the digital signal from ADC 1120.Here, come predetermined respectively N and M corresponding to single-carrier modulated pattern and multi-carrier modulation pattern.
The signal that demodulating unit 1140 demodulation are extracted by extracting unit 1130.Demodulating unit 1140 comprises OQAM demodulator 1141, FFT unit 1142, qam demodulator 1143 and second switch 1144.
OQAM demodulator 1141 will be by the signal demodulation of first withdrawal device, 1132 extractions.The 1142 pairs of signals that extracted by second withdrawal device 1133 in FFT unit are carried out the FFT conversion, and qam demodulator 1143 will be by the signal demodulation of FFT unit 1142FFT conversion.
Second switch 1144 is indicated one that selects in OQAM demodulator 1141 and the qam demodulator 1143 according to modulating mode.The function of the second switch 855 among the function of second switch 1144 and Fig. 8 is identical, has therefore omitted the detailed description to it.
Channel decoder 1150 decodings are by the signal of demodulating unit 1140 demodulation.Channel decoder 1150 can be the LDPC decoder.
In addition, similar with Fig. 8, first switch 1131 can omit.
In addition, in the present embodiment, demodulator 1141 also can be a qam demodulator.
Describe the operating process of the digital multimedia receiver shown in Figure 11 in detail now with reference to Figure 12.Figure 12 is the flow chart according to the digital multimedia method of reseptance of carrying out in the digital multimedia receiver shown in Figure 11 of sixth embodiment of the invention.
With reference to Figure 12, in step S1210, the signal that receives is by tuning (down conversion).In step S1220, the signal of tuning (down conversion) is converted into digital signal.
In step S1230, indication is extracted digital signal according to modulating mode.At length, if modulating mode indication is the indication of single-carrier modulated pattern, digital signal is by with N so: 1 extracts, if the modulating mode indication is the indication of multi-carrier modulation pattern, digital signal is by with M so: 1 extracts.Here, come predetermined respectively N and M corresponding to single-carrier modulated pattern and multi-carrier modulation pattern.
In step S1240, the signal after the extraction is by demodulation.More particularly, if the modulating mode indication is the indication of single-carrier modulated pattern, N so: the signal after 1 extraction passes through the OQAM demodulation by demodulation.If modulating mode indication is the indication of multi-carrier modulation pattern, M so: 1 signal after extracting by FFT conversion and QAM demodulation by demodulation.
At last, in step S1250, the signal after the demodulation is decoded.
In addition, in step S1240, if the modulating mode indication is the indication of single-carrier modulated pattern, N so: the signal after 1 extraction also can be by the QAM demodulation by demodulation.
Because withdrawal device is changed the symbol-rate of the signal of sample rate and single-carrier modulated signals and multi-carrier modulation respectively pro rata, so only use a shared ADC at digital multimedia receiver.Therefore, the hardware of digital multimedia receiver is realized being simplified, and the signal of single-carrier modulated signals and multi-carrier modulation can correctly be handled.
Can improve the efficient of error correction coding by using data interleaver.Data interleaver has been disperseed burst error.Because according to different modulating modes, the data frame structure difference can be different so limit the parameter of data interleaver function, to be used for single-carrier modulated pattern and multi-carrier modulation pattern.Therefore, in digital multimedia receiver, the parameter that is used for deinterleaver should change according to different modulating modes.In addition, the LDPC sign indicating number is because its super error correction ability can be used for single-carrier modulated pattern and multi-carrier modulation pattern.
Figure 13 is the block diagram of demonstration according to the digital multimedia receiver of the signal that is used for processing single-carrier modulated signals and multi-carrier modulation of seventh embodiment of the invention.
With reference to Figure 13, this digital multimedia receiver comprises tuner 1310, ADC 1320, demodulating unit 1330, deinterleaver 1340 and LDPC decoder 1350.
The multi-media signal that tuner 1310 tuning (down conversion) receives through antenna.
Therefore, have only a deinterleaver to be used for the signal of processing single-carrier modulated signals and multi-carrier modulation.Therefore, the parameter of deinterleaver 1340 should be indicated according to modulating mode and is determined.
The signal decoding that LDPC decoder 1350 will be deinterleaved by deinterleaver 1340.LDPC decoder 1350 also can be replaced by the decoder of other type.
In addition, similar with the situation of Fig. 9, first switch 1331 can omit.
In addition, in the present embodiment, demodulator 1332 also can be a qam demodulator.
Figure 14 is the flow chart according to the digital multimedia method of reseptance of carrying out in digital multimedia receiver shown in Figure 13 of seventh embodiment of the invention.
With reference to Figure 14, in step S1410, the signal that receives is by down conversion.In step S1420, the signal of down conversion is converted into digital signal.
In step S1430, this digital signal is indicated by demodulation according to modulating mode.At length, if the modulating mode indication is the indication of single-carrier modulated pattern, this digital signal is separated by OQAM and is transferred by demodulation so, if the modulating mode indication is the indication of multi-carrier modulation pattern, this digital signal is separated by FFT conversion and QAM and transferred by demodulation so.
In step S1440, deinterleave according to the signal of modulating mode indication with demodulation.In this case, indication comes definite and applies the parameter that deinterleaves according to modulating mode.
At last, in step S1450, the signal after the demodulation is decoded by LDPC.
In addition, in step S1430, if the modulating mode indication is the indication of single-carrier modulated pattern, this digital signal also can be separated by QAM and be transferred by demodulation so.
Owing to have only a deinterleaver to be used for the signal of single-carrier modulated signals and multi-carrier modulation, so the realization of digital multimedia receiver is simplified.In addition, because used the LDPC decoder with super error correction ability in digital multimedia receiver, the handling property of digital multimedia receiver is enhanced.
Figure 15 is the block diagram of expression according to the digital multimedia receiver of the signal that is used for processing single-carrier modulated signals or multi-carrier modulation of eighth embodiment of the invention.
With reference to Figure 15, digital multimedia receiver comprises: tuner 1510, be used for the multi-media signal that will receive be tuned to corresponding band; ADC 1520, and being used for the tuning conversion of signals from tuner 1510 outputs is digital signal; Demodulator 1530 is used for the digital signal of demodulation from ADC1520; Code element is removed mapper 1540, is used for going mapping from the signal of the demodulation of demodulator 1530 output; With LDPC decoder 1550, be used for and remove the signal decoding of mapper 1540 and the signal that output obtains from code element.
In the digital multimedia transmission system of the bit stream that requires the video/audio of transmission of high-definition under error-free situation, use powerful error correcting code extremely important to reduce bit error rate.The LDPC sign indicating number has stronger error correcting capability as a kind of error correcting code, and therefore, the LDPC sign indicating number can combine with the digital multimedia transmission system corresponding to single-carrier modulated pattern or multi-carrier modulation pattern.
Use under the situation of LDPC encoder with the raising error correcting capability at the digital multimedia transmitter, in receiver, should correspondingly use the LDPC decoder.In this case, can improved receptivity.
When the multi-media signal that receives was single-carrier modulated signals, it was that the OQAM code element goes mapper or QAM code element to remove mapper that code element is removed mapper 1540.
When the multi-media signal that receives was the signal of multi-carrier modulation, it was that the QAM code element is removed mapper that code element is removed mapper 1540.
By using above-mentioned receiver, can improved error correcting capability.
As mentioned above, according to an aspect of the present invention, digital multimedia receiver can processing single-carrier modulated signals and the signal of multi-carrier modulation, and has the structure of simplification and high receptivity.
According to a further aspect in the invention, by using the LDPC decoder, the decoding performance that digital multimedia receives significantly improves.
Though represent with reference to specific embodiment and described the present invention, it should be appreciated by those skilled in the art, under the situation that does not break away from the spirit and scope of the present invention that are defined by the following claims, can carry out the modification of various forms and details to it.
Claims (4)
1, a kind of digital multimedia receiver that is used for the signal of processing single-carrier modulated signals and multi-carrier modulation comprises:
Tuner, be used for the multi-media signal that will receive be tuned to corresponding band;
ADC, being used in the future, the tuning conversion of signals of self-tuner is a digital signal;
Demodulating unit comprises being used for carrying out the single carrier demodulation device of demodulation with the single carrier mode digital signal corresponding and be used for the multicarrier demodulator that carries out demodulation with multi-carrier modulation pattern digital signal corresponding from ADC from ADC;
Selector is used for selecting one according to the modulating mode indication from the signal of single carrier demodulation device and the output of multicarrier demodulator; With
The shared channel decoder, being used for will be from the signal decoding and the output of the demodulation of selector output.
2, the digital multimedia receiver that is used for the signal of processing single-carrier modulated signals and multi-carrier modulation as claimed in claim 1, wherein, the shared channel decoder is the LDPC decoder.
3, a kind of digital multimedia signal method of reseptance that is used for the signal of processing single-carrier modulated signals and multi-carrier modulation comprises the steps:
(a) with the multi-media signal that receives be tuned to corresponding band;
(b) will in step (a), tuning conversion of signals be digital signal;
(c) will be from the digital demodulation signal of step (b), and the signal of the signal of output single carrier demodulation and multicarrier demodulation;
(d) from signal, select one according to modulating mode indication from the signal of the single carrier demodulation of step (c) and multicarrier demodulation; With
(e) signal decoding that will demodulation in step (d) and output.
4, the digital multimedia signal method of reseptance that is used for the signal of processing single-carrier modulated signals and multi-carrier modulation as claimed in claim 3 wherein, in step (e), is carried out decoding with the LDPC pattern.
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| CNA2004101014313A CN1798280A (en) | 2004-12-20 | 2004-12-20 | Digital multimedia receiver and its receiving method |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101106446B (en) * | 2006-07-10 | 2010-08-25 | 三星电机株式会社 | Dual-system transmitting and receiving device |
| US8385473B2 (en) | 2007-03-16 | 2013-02-26 | Thomson Licensing | Apparatus and method for classifying modulations in multipath environments |
| CN104519287A (en) * | 2013-09-26 | 2015-04-15 | 晨星半导体股份有限公司 | Television signal receiving device and method for judging whether channel comprises television program signal or not |
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2004
- 2004-12-20 CN CNA2004101014313A patent/CN1798280A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101106446B (en) * | 2006-07-10 | 2010-08-25 | 三星电机株式会社 | Dual-system transmitting and receiving device |
| US8385473B2 (en) | 2007-03-16 | 2013-02-26 | Thomson Licensing | Apparatus and method for classifying modulations in multipath environments |
| CN101627600B (en) * | 2007-03-16 | 2013-07-10 | 汤姆逊许可公司 | Apparatus and method for classifying modulations in multipath environments |
| CN104519287A (en) * | 2013-09-26 | 2015-04-15 | 晨星半导体股份有限公司 | Television signal receiving device and method for judging whether channel comprises television program signal or not |
| CN104519287B (en) * | 2013-09-26 | 2018-01-02 | 晨星半导体股份有限公司 | TV signal receiver and judge channel whether the method for including TV programme signal |
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