CN1111337C - Ground transmission system for digital high-definition television - Google Patents
Ground transmission system for digital high-definition television Download PDFInfo
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- CN1111337C CN1111337C CN 99109828 CN99109828A CN1111337C CN 1111337 C CN1111337 C CN 1111337C CN 99109828 CN99109828 CN 99109828 CN 99109828 A CN99109828 A CN 99109828A CN 1111337 C CN1111337 C CN 1111337C
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Abstract
The present invention relates to a transmitting terminal used in a digital high-definition television near-field transmission system. The digital high-definition television near-field transmission system adopts 8MHz bandwidth of 8VSB modulation; the system adopts two error correction codes of RS encoder (3) and a TCM encoder (5), and also adds an interlacing circuit (4) to sufficiently exert the error correction capability of an RS code. A receiver adopts a PAL suppression circuit (25) which suppresses a comb filter with PAL-D interference so as to ensure the simulcast of HDTV and conventional PAL-D. In the system, a phase tracking circuit (27) is used to eliminate residual phase errors in a signal. The system can adopt a preequalization circuit to reduce nonlinear distortion and in-band fluctuation in a signal transmitted by a transmitter.
Description
The present invention relates to the high definition TV field, relate in particular to a kind of 8MHz bandwidth ground transmission system for digital high-definition television of the 8VSB of employing modulation.
Digital high-definition television (HDTV) is the radio data system of a new generation, be the product of digital image processing techniques and very lagre scale integrated circuit (VLSIC) (VLSIC) technical development to certain phase, representing the level of national science and technology development, it is a big hot research field of International Technology circle in recent years.The picture quality of the brilliance that it provides can satisfy the visual characteristic of human eye better.Comprise many countries of China, carried out the research to high definition TV hardware implementation method one after another, some countries successfully develop functional prototype of high definition TV.Formulation for the high definition TV ground transmission standard has at present entered agenda.
Purpose of the present invention will provide a kind of ground transmission system for digital high-definition television exactly, and it has adopted the 8MHz bandwidth of 8VSB modulation.
According to one aspect of the present invention, the transmitting terminal that uses in a kind of ground transmission system for digital high-definition television is provided, said ground transmission system for digital high-definition television adopts the 8MHz bandwidth of 8VSB modulation, and it is characterized in that: said transmitting terminal comprises: frame forms circuit, scrambler, RS encoder, interleave circuit, TCM encoder, section is synchronous and field synchronization circuit, MUX, pre-equalization circuit, pilot tone are inserted circuit, VSB modulation circuit, IF amplifier; Form circuit, scrambler, RS encoder, interleave circuit, TCM encoder through frame in proper order from source encoder and the next mpeg signal of multiplexer; Shu Chu signal segment sync signal and field sync signal synchronous with section and that the field synchronization circuit produces carried out multiplexing at the MUX place thus; This multiplexing signal inserts circuit, VSB modulation circuit, IF amplifier through pre-equalization circuit, pilot tone more successively, forms intermediate-freuqncy signal thus and is sent to transmitter.
According to another aspect of the present invention, the receiving terminal that uses in a kind of ground transmission system for digital high-definition television is provided, said ground transmission system for digital high-definition television adopts the 8MHz bandwidth of 8VSB modulation, and it is characterized in that: said receiving terminal comprises: tuner, IF amplifier, VSB demodulation/analog-to-digital conversion/synchronization timing circuit, voltage controlled oscillator, PAL suppress circuit, equalizer, phase tracking circuit, TCM decoder, deinterleave circuit, RS decoder, remove scrambler, mpeg format restore circuit; Behind tuner, IF amplifier, deliver to VSB demodulation/analog-to-digital conversion/synchronization timing circuit from the high-definition TV signal that reception antenna receives, this VSB demodulation/analog-to-digital conversion/synchronization timing circuit is finished VSB demodulation, analog-to-digital conversion and synchronization timing, and export AGC signal tuning device, IF amplifier, and the AFC signal is delivered to tuner; Suppress circuit, equalizer, phase tracking circuit, TCM decoder, deinterleave circuit, RS decoder, remove scrambler, mpeg format restore circuit by PAL successively again from the signal of VSB demodulation/analog-to-digital conversion/synchronization timing circuit output, the signal of final output is delivered to demultiplexing and source decoder.
According to another aspect of the present invention, a kind of ground transmission system for digital high-definition television is provided, it comprises said transmitting terminal in above-mentioned two aspects and receiving terminal, it is characterized in that:
Adopt to postpone to carry out PAL-D interference inhibition, and the comb filter transfer function is 1-D for the comb filter of N=16
16
Symbol rate is 14.285714MHz, and rolloff-factor is 12%, is easy to realize; The HDTV signal bandwidth is 8MHz, makes full use of the channel of 8MHz;
HDTV pilot tone P is placed on the position of PAL-D pix carrier 0.892857MHz, and IF-FRE is 38.892857MHz;
Field structure is that per 208 data segments insert a field synchronization segments;
Segment structure is that 4 sign fields of per 828 data symbols insertion are synchronous;
Clean data transfer rate 25.700615Mbps;
Adopt the error correction coding scheme of RS (207,187,10) and TCM (3,2,2);
Pilot power is 0.3dB.
According to another aspect of the present invention, a kind of ground transmission system for digital high-definition television is provided, it comprises preceding two described transmitting terminals in aspect and receiving terminal, it is characterized in that:
Adopt to postpone to carry out PAL-D interference inhibition, and the comb filter transfer function is 1+D for the comb filter of N=12
12
Symbol rate is 13.300856MHz, and rolloff-factor is 19.66%, is easy to realize; The HDTV signal bandwidth is 7.958MHz, has utilized the channel of 8MHz preferably;
HDTV pilot tone P is placed on the position of PAL-D pix carrier 0.554202MHz, and IF-FRE is 38.554202MHz;
Field structure is that per 312 data segments insert a field synchronization segments;
Segment structure is that 4 sign fields of per 828 data symbols insertion are synchronous;
Clean data transfer rate 23.967038Mbps;
Adopt the error correction coding scheme of RS (207,187,10) and TCM (3,2,2);
Pilot power is 0.3dB.
Describe the present invention below in conjunction with accompanying drawing.
Fig. 1 is the block diagram according to the transmitting terminal of a kind of ground transmission system for digital high-definition television of the present invention.
Fig. 2 is the block diagram according to the receiving terminal of a kind of ground transmission system for digital high-definition television of the present invention.
Fig. 3 is the signal format according to a kind of ground transmission system for digital high-definition television of the present invention.
Fig. 4 shows the spectrum structure of PAL-D signal.
Fig. 5 (A) and Fig. 5 (B) have shown two kinds of structures of comb filter.
Fig. 6 (A) and Fig. 6 (B) have shown and Fig. 5 (A) and the corresponding equivalent transmission characteristic of Fig. 5 (B).
Fig. 7 shows the relative position of HDTV and PAL-D signal.
Fig. 8 has shown HDTV roll-off characteristic, PAL signal spectrum, comb filter characteristic.
Fig. 9 has shown the relative position of HDTV and PAL-D signal.
Figure 10 has shown HDTV roll-off characteristic, PAL signal spectrum, comb filter characteristic.
Figure 11 (A) has shown the N road TCM coding circuit that adopts in the transmitting terminal.
Figure 11 (B) has shown the decoding circuit of the N road TCM that adopts in the receiver.
Below in conjunction with Fig. 1 and Fig. 2 ground transmission system for digital high-definition television of the present invention is described.It has adopted the 8MHz bandwidth of 8VSB modulation, and Fig. 1 has shown the block diagram of transmitting terminal, and Fig. 2 has shown the block diagram of receiving terminal.Dotted line is represented optional among the figure.
As shown in Figure 1, the transmitter of ground transmission system for digital high-definition television of the present invention comprises that frame forms circuit 1, scrambler 2, RS encoder 3, interleave circuit 4, TCM encoder 5, section is synchronous and field synchronization circuit 6, MUX7, pre-equalization circuit 8, pilot tone are inserted circuit 9, VSB modulation circuit 10, IF amplifier 11 etc.
Form circuit 1, scrambler 2, RS encoder 3, interleave circuit 4, TCM encoder 5 through frame in proper order from source encoder and the next mpeg signal of multiplexer.Shu Chu signal segment sync signal and field sync signal synchronous with section and that field synchronization circuit 6 produces carried out multiplexing at the MUX7 place thus.This multiplexing signal inserts circuit 9, VSB modulation circuit 10, IF amplifier 11 through pre-equalization circuit 8, pilot tone more successively, forms intermediate-freuqncy signal and is sent to the transmitter (not shown).
Because the HDTV terrestrial broadcasting will adapt to huge numbers of families' condition of acceptance, must consider abominable condition of acceptance, will be under the condition of considering the receiver cost, reduce the threshold level signal to noise ratio of receiver as far as possible, so this system has adopted two kinds of error correction coder, RS encoder 3 (code length 207 bytes, information bit 187 bytes, check digit 20 bytes, error correcting capability 10 bytes), TCM encoder 5 (trellis coded modulation, 4 states, code check 2/3), in order to give full play to the error correcting capability of RS sign indicating number, also added interleave circuit 4, to tackle the interference of burst.This error correction coding/decoding scheme in theory 10
-6Thresholding signal to noise ratio during the error rate is 14.9dB.
Because the terrestrial broadcasting channel certainly exists the multipath transmission, so adopted equalizer 8 in system.
In this system the section of being provided with synchronously and the field synchronization circuit so that make receiver can be under abominable condition of acceptance operate as normal, can correctly separate and be in harmonious proportion recovered clock, synchronously, in system, be provided with corresponding pilot tone and section, field structure.
Native system has also adopted the scrambler circuit, guarantees the randomization of transmission data, makes system works in optimum state.
Referring to Fig. 2, the receiver of ground transmission system for digital high-definition television of the present invention comprises that tuner 21, IF amplifier 22, VSB demodulation/analog-to-digital conversion/synchronization timing circuit 23, voltage controlled oscillator 24, PAL suppress circuit 25, equalizer 26, phase tracking circuit 27, TCM decoder 28, deinterleave circuit 29, RS decoder 30, remove scrambler 31, mpeg format restore circuit 32 etc.
Behind tuner 21, IF amplifier 22, deliver to VSB demodulation/analog-to-digital conversion/synchronization timing circuit 23 from the high-definition TV signal that reception antenna receives, finish VSB demodulation, analog-to-digital conversion and synchronization timing at this, and output AGC signal tuning device 21, IF amplifier 22, and the AFC signal is only delivered to tuner 21.Suppress circuit 25, equalizer 26, phase tracking circuit 27, TCM decoder 28, deinterleave circuit 29, RS decoder 30, remove scrambler 31, mpeg format restore circuit 32 etc. by PAL successively again from the signal of VSB demodulation/analog-to-digital conversion/synchronization timing circuit 23 outputs, the signal of final output is delivered to demultiplexing and source decoder.
Adopted PAL to suppress circuit 25 in receiver, it is to suppress the comb filter that PAL-D disturbs, and broadcasts to guarantee HDTV and the same of conventional PAL-D.
In system, adopted phase tracking circuit 27, with phase error residual in the erasure signal.
Can adopt pre-equalization circuit in the system, to reduce non-linear distortion and the passband fluctuation of transmitter in transmitting.
Fig. 3 is the signal format of system transmissions.The segment structure of the signal format of transmission and the packet format of MPEG-II signal are corresponding, and each MPEG-II bag signal comprises the packet header of a byte and the data of 187 bytes, and 187 byte datas wherein become 207 bytes after encoding through RS in the transmission system; After TCM and the insertion of section field synchronization, the MPEG-II packet header of a byte is replaced synchronously by the section of 4 symbols, and the data of 207 bytes then become the transmission data of 828 symbols.And insert a field synchronization segments again every the plurality of data section, analyze after a while at this paper the blanking time of field synchronization.
Frequency configuration to ground transmission system for digital high-definition television of the present invention describes below.
Digital high-definition television (HDTV) ground transmission system generally adopts the transmission means with existing simulated television (as the PAL-D standard) channel compatibility, because it is limited at a regional available terrestrial broadcasting channel resource, so digital high-definition television terrestrial broadcasting is at present mainly selected to forbid channel (as the adjacent channel of same service area or the same channel of adjacent service area) and transmitted, in the quite a long time, will realize together with broadcasting with the common simulation TV.
Select for use forbidding channel and existing simulated television with under the broadcast mode at HDTV, will inevitably have mutual interference mutually between HDTV signal and the anolog TV signals.Because the transmitting power of HDTV signal is more much smaller than the transmitting power of PAL-D signal under the identical condition of coverage, and the digital HDTV signal spectrum is similar to the white Gaussian Profile in arrowband usually, therefore the HDTV signal only is equivalent to a little Gaussian noise with respect to the PAL-D signal.But the PAL-D signal but is a very important interference source with respect to the HDTV signal, must carry out suitable processing to it.
The basic skills that tackles the co-channel interference of PAL-D is that the HDTV signal is carried out comb filtering, the fundamental component of the PAL-D signal that wherein comprises with filtering.But the filtering characteristic of comb filter is in fact mainly decided by channel parameter, and it comprises band efficiency, symbol rate and spectrum position (pilot carrier frequency) etc., and also can influence the setting of other parameter of HDTV ground transmission system thus.The present invention by reasonably arranging HDTV ground transmission system (VSB) parameter and design corresponding comb filter, make and to be suppressed effectively, thereby help the operate as normal of high definition TV ground transmission system with broadcasting the influence of PAL-D signal under the condition to the HDTV signal.
At present, only there is a few countries to propose to meet this country in the world with broadcasting the channel parameter configuration that system requires.Wherein channel parameter based on the COFDM standard of frequency spectrum fluting has been designed in Europe, and co-channel interference has designed channel parameter based on the VSB standard of digital comb filtering and United States advanced television systems committee (ATSC) is at NTSC.The China's current simulated television adopts the PAL-D system, the co-channel interference of anti-NTSC and the channel parameter of the co-channel interference of anti-PAL-D dispose exist very big different.Main cause is that the frequency spectrum of NTSC and PAL-D TV signal structurally itself just exists very big difference.
Fig. 4 shows the spectrum structure of PAL-D signal, and in the bandwidth of whole 8MHz, signal energy mainly concentrates near pix carrier V, color sub-carrier C and the sound carrier A.Wherein, sound accompaniment unmodulated carrier ERP be defined as pix carrier ERP 1/10th; And the content and the COLOR COMPOSITION THROUGH DISTRIBUTION of the relative size of carrier chrominance signal energy and picture intelligence energy and television image are relevant, and the former is approximately than low tens to twenties dB of the latter usually.
The spectrum structure of PAL-D signal has confidential relation with line frequency, and satisfies the integral multiple relation between frequency interval between C (color sub-carrier), A (sound carrier) and the V (pix carrier) and the half-line frequency, specifically is expressed as follows:
V＝0
A＝6.5MHz＝416f
H
F in the following formula
H/ 4 is relevant with the mechanism of PAL-D signal interlacing paraphase; f
H/ 625 (being 25Hz) are field frequency just, and this slight biasing can be so that the integral multiple component of the contained field frequency of luminance signal reaches minimum with the influence between the integral multiple component of the contained field frequency of colourity signal.
The method that the anti-PAL-D that adopts in the high definition TV (HDTV) that adopts VSB to modulate disturbs has mainly been utilized the comb filtering characteristic of digital comb filter.
The realization of comb filter can be adopted dual mode, i.e. 1-D
NOr 1+D
N, shown in Fig. 5 (A) and Fig. 5 (B), among the figure up and down two branch roads can be that addition also can be to subtract each other.T is a symbol period among the figure, and N is the exponent number of comb filter, i.e. the exponent number of shift register.The equivalent transmission characteristic corresponding with Fig. 5 (A) is shown in Fig. 6 (A), and fs is a symbol rate here, and its frequency characteristic is pectination, 0, fs/N, 2fs/N ... the kfs/N position exists zero point, and k is an integer.Because the position of 0 reference frequency of comb filter is the position of the pilot tone P of HDTV signal just, so the HDTV pilot tone was on zero point.The equivalent transmission characteristic corresponding with Fig. 5 (B) is shown in Fig. 6 (B), and dead-center position is fs/ (2N), 3fs/ (2N), (2k-1) fs/ (2N), and the HDTV pilot tone is on the peak dot.
In conjunction with Fig. 4 and Fig. 6 as can be known, should will be arranged between V, C, the A on the dead-center position of comb filter transmission characteristic as far as possible, could play good inhibitory effect to the fundamental component of PAL-D signal energy like this.Most of energy of PAL-D signal mainly concentrates near the pix carrier, and the energy of carrier chrominance signal is less, the shared smaller bandwidth of audio signal and be in the edge of channel, and its gross energy is about 1/10th of pix carrier.For audio signal, make its transmission zero on the one hand near comb filter as far as possible, make it to obtain inhibition to a certain degree, it is in the edge that the HDTV signal spectrum roll-offs on the other hand, can carry out further effectively filtering by being matched to mode filter to it at receiving terminal.Like this, should guarantee at first that the V of PAL-D signal was on the zero point of comb filter transmission characteristic, make simultaneously could obtain the co-channel interference of best PAL-D and suppress in C component and the A position at close zero point as far as possible.
Because HDTV signal effective bandwidth is fs/2, therefore total N/2 comb refers to the cycle in effective bandwidth.
The principle of choosing N mainly comprises three aspects: the first, and the comb filter that is determined by parameter N must be able to provide PAL-D interference rejection capability preferably; The second, can not make the complexity of rear end Viterbi decoder increase too many; The 3rd, utilize channel width as far as possible, make transmission code rate higher.
In sum, for the situation of Fig. 4 (a), can select N=16, this moment, the parameter of Channel Transmission was:
| Channel width | 8MHz (0.0714285MHz is to 7.9285715MHz) |
| Effective bandwidth | 7.1428571MHz |
| Remaining bandwidth | 0.8571429MHz |
| Pilot frequency locations | Than the low 0.892857MHz of PAL image carrier |
| Symbol rate | 14.285714M symbol/second |
| The base band rolloff-factor | 12% symmetry |
| PAL signal leakage | 19.38% (100/0/100/0 colour bar) 8.23% (actual PAL TV) |
Be described as follows:
1.HDTV channel take into-0.0714285MHz to 7.9285715MHz (with respect to the PAL TV signal), the actual 8MHz that takies.The frequency spectrum that symmetry is roll-offed is finished jointly by transmitting-receiving two-end and to be roll-offed.
2. adopt G (D)=1-D
16Comb filter, symbol rate can reach 14.285714MHz, and the position, valley point of comb filter is 4.464MHz and 6.25MHz, and is far away from the position of sound accompaniment, but because HDTV roll-off characteristic and the acting in conjunction of comb filter characteristic, the sound accompaniment of PAL signal is leaked quite little.
The downward adjacent channel of frequency spectrum of HDTV signal was expanded 71.4285kHz (frequency spectrum of the ATSC adjacent channel that makes progress was expanded about 45.8kHz this moment; The sound accompaniment bandwidth of PAL TV is ± 75kHz, and the space of 175kHz is arranged from the channel edge, thus the HDTV signal take smaller 71.4285kHz bandwidth to the PAL signal less than influence, the PAL TV signal also is influence not to the HDTV signal certainly; Because it is the HDTV signal has roll-off filter, very little still more at the power at channel edge, and near the interference signal the channel edge also is received the roll-off filter elimination of end), roll-offing of HDTV signal is 12%, can realize.
The relative position of HDTV and PAL-D signal is (P is the pilot tone of HDTV) as shown in Figure 7.
HDTV roll-off characteristic, PAL signal spectrum (100/0/100/0 colour bar, sound accompaniment power are image carrier power 1/10th), comb filter characteristic are seen Fig. 8.
The peak power of the peakedness ratio image carrier of carrier chrominance signal will be hanged down 25dB at least in the actual PAL television spectrum, so Fig. 8 is a schematic diagram.
The IF-FRE f of HDTV signal
IFor
f
I＝38MHz+0.892857MHz＝38.892857MHz (2)
For the situation of Fig. 4 (b), can select N=12, this moment, the parameter of Channel Transmission was:
| Channel width | (7.958MHz 42.023kHz is to 8MHz) |
| Effective bandwidth | 6.650428MHz |
| Remaining bandwidth | 1.307548MHz |
| Pilot frequency locations | Than the low 0.554202MHz of PAL image carrier |
| Symbol rate | 13.300856M symbol/second |
| The base band rolloff-factor | 19.66% symmetry |
| PAL signal leakage | 13.08% (100/0/100/0 colour bar) 6.86% (actual PAL TV) |
Be described as follows:
1.HDTV channel take into 42.023kHz to 8MHz (with respect to the PAL TV signal), the actual 7.958MHz that takies.The frequency spectrum that symmetry is roll-offed is finished jointly by transmitting-receiving two-end and to be roll-offed.
2. adopt G-(D)=1+D
12Comb filter, symbol rate is 13.300856MHz, and the position, valley point of comb filter is 4.43362MHz and 6.650428MHz, and is far away from the position of sound accompaniment, but because HDTV roll-off characteristic and the acting in conjunction of comb filter characteristic, the sound accompaniment of PAL signal is leaked quite little.
This moment, the television channel of whole 8MHz only had 42kHz not to be utilized in HDTV signal spectrum left side, and the availability of frequency spectrum is very high.Rolloff-factor is 19.66%, is highly susceptible to spectrum shaping.
The relative position of HDTV and PAL-D signal as shown in Figure 9.
HDTV roll-off characteristic, PAL signal spectrum (100/0/100/0 colour bar, sound accompaniment power are image carrier power 1/10th), comb filter characteristic are seen Figure 10.
The peak power of the peakedness ratio image carrier of carrier chrominance signal will be hanged down 25dB at least in the actual PAL television spectrum, so Figure 10 is a schematic diagram.
The IF-FRE f of HDTV signal
IFor
f
I＝38MHz+0.554202MHz＝38.554202MHz (3)
The following describes the setting of other system parameters
1、TCM
Owing to used comb filter in the HDTV receiver, TCM decoding complexity has increased greatly.In order to reduce the decoding complexity of TCM, in receiver, used the decoding circuit of N road (N is the exponent number of comb filter) TCM, also adopt N road TCM circuit at transmitting terminal simultaneously, as Figure 11 (A) and Figure 11 (B).Transmitting terminal N road TCM coding circuit alternation among Figure 11 (A).Receiving terminal N road TCM decoding circuit alternation among Figure 11 (B).
After having used N road TCM coding and decoding circuit, the complexity of TCM decoding has descended greatly.If do not use comb filter (not having co-channel PAL-D signal disturbs), decoding circuit is 4 states, (has co-channel PAL-D signal to disturb) under the situation of using comb filter, and decoding circuit is 8 states.
Use N road TCM coding and decoding circuit to be equivalent to add an interior interleave circuit, this has certain benefit to the antijamming capability that improves system.
Specific implementation can be with reference to other patent of our unit.
2, section field structure
The signal that system transmissions has been mentioned in the front is for the section field structure, and each field signal comprises a field synchronization segments and plurality of data section.
For adopting 1-D
16The system of comb filter, in to interweave be 16 grades; On the other hand, during the section field synchronization, TCM coding and decoding circuit are idle (a section field sync signal do not participate in coding), but in the correctly synchronous influence that TCM is deciphered of the section of removal of receiving terminal, the section work of TCM decoder later synchronously is not sequenced, but skips 4 decoders.Specific implementation can be with reference to other patent of our unit.
On the other hand, the MPEG-II data of coming from multiplexer are the pack arrangements of 188 bytes, the clock of HDTV transmission system will produce with PLL (phase-locked loop) from this data format, if the frequency dividing ratio of PLL is bigger, the shake of the transmission system clock that produces is just big, so must choose corresponding field structure, make the frequency dividing ratio of PLL that a suitable numerical value be arranged.
According to above situation, adopt the 8MHz bandwidth high definition TV ground transmission system of 8VSB modulation adopting 1-D
16Comb filter the time field structure be that per 208 data segments insert a field synchronization segments.
Equally, adopt the 8MHz bandwidth high definition TV ground transmission system of 8VSB modulation adopting 1+D
12Comb filter the time field structure be that per 312 data segments insert a field synchronization segments.
Provided the design that has the 8MHz bandwidth high definition TV ground transmission system that adopts the 8VSB modulation under the co-channel disturbed condition of PAL-D by top description the present invention.Scheme has comprised determining of the determining of the selecting for use of system spectrum setting, comb filter, symbol rate, section field structure, or the like.Its major parameter is as follows:
Scheme one:
1, adopt delay to carry out PAL-D and disturb inhibition for the comb filter of N=16, and pectination
Filter transfer function is 1-D
16
2, symbol rate is 14.285714MHz, and rolloff-factor is 12%, is easy to realize; The HDTV letter
Number bandwidth is 8MHz, makes full use of the channel of 8MHz.
3, HDTV pilot tone P is placed on the position of PAL-D pix carrier 0.892857MHz,
IF-FRE is 38.892857MHz.
4, field structure is that per 208 data segments insert a field synchronization segments.
5, segment structure is that 4 sign fields of per 828 data symbols insertion are synchronous.
6, clean data transfer rate 25.700615Mbps.
7, adopt the error correction coding scheme of RS (207,187,10) and TCM (3,2,2).
8, pilot power is 0.3dB.
Scheme two:
1, adopt delay to carry out PAL-D and disturb inhibition for the comb filter of N=12, and pectination
Filter transfer function is 1+D
12
2, symbol rate is 13.300856MHz, and rolloff-factor is 19.66%, is easy to realize; HDTV
Signal bandwidth is 7.958MHz, has utilized the channel of 8MHz preferably.
3, HIDTV pilot tone P is placed on the position of PAL-D pix carrier 0.554202MHz,
IF-FRE is 38.554202MHz.
4, field structure is that per 312 data segments insert a field synchronization segments.
5, segment structure is that 4 sign fields of per 828 data symbols insertion are synchronous.
6, clean data transfer rate 23.967038Mbps.
7, adopt the error correction coding scheme of RS (207,187,10) and TCM (3,2,2).
8, pilot power is 0.3dB.
Claims (8)
1, the transmitting terminal that uses in a kind of ground transmission system for digital high-definition television, said ground transmission system for digital high-definition television adopts the 8MHz bandwidth of 8VSB modulation, and it is characterized in that: said transmitting terminal comprises: frame forms circuit (1), scrambler (2), RS encoder (3), interleave circuit (4), TCM (trellis-coded modulation) encoder (5), section is synchronous and field synchronization circuit (6), MUX (multiplexer) (7), pilot tone are inserted circuit (9), VSB modulation circuit (10), IF (intermediate frequency) amplifier (11); Form circuit (1), scrambler (2), RS encoder (3), interleave circuit (4), TCM (trellis-coded modulation) encoder (5) through frame in proper order from source encoder and the next mpeg signal of multiplexer; Shu Chu signal segment sync signal and field sync signal synchronous with section and that field synchronization circuit (6) produces located to carry out multiplexing at MUX (multiplexer) (7) thus; This multiplexing signal inserts circuit (9), VSB modulation circuit (10), IF (intermediate frequency) amplifier (11) through pilot tone more successively, forms intermediate-freuqncy signal thus and is sent to transmitter.
2, the transmitting terminal that uses in a kind of ground transmission system for digital high-definition television according to claim 1 is characterized in that: be provided with pre-equalization circuit (8) between said MUX (7) and pilot tone insertion circuit (9).
3, the transmitting terminal that uses in a kind of ground transmission system for digital high-definition television according to claim 1 is characterized in that: said RS encoder (3) adopts: code length 207 bytes, information bit 187 bytes, check digit 20 bytes, error correcting capability 10 bytes; Said TCM encoder (5) adopts: trellis coded modulation, 4 states, code check 2/3.
4, the receiving terminal that uses in a kind of ground transmission system for digital high-definition television, said ground transmission system for digital high-definition television adopts the 8MHz bandwidth of 8VSB modulation, and it is characterized in that: said receiving terminal comprises: tuner (21), IF amplifier (22), VSB demodulation/analog-to-digital conversion/synchronization timing circuit (23), voltage controlled oscillator (24), PAL suppresses circuit (25), equalizer (26), phase tracking circuit (27), TCM decoder (28), deinterleave circuit (29), RS decoder (30), remove scrambler (31), mpeg format restore circuit (32); Behind tuner (21), IF amplifier (22), deliver to VSB demodulation/analog-to-digital conversion/synchronization timing circuit (23) from the high-definition TV signal that reception antenna receives, this VSB demodulation/analog-to-digital conversion/synchronization timing circuit (23) is finished VSB demodulation, analog-to-digital conversion and synchronization timing, and output AGC signal; Suppress circuit (25), equalizer (26), phase tracking circuit (27), TCM decoder (28), deinterleave circuit (29), RS decoder (30), remove scrambler (31), mpeg format restore circuit (32) by PAL successively again from the signal of VSB demodulation/analog-to-digital conversion/synchronization timing circuit 23 outputs, the signal of final output is delivered to demultiplexing and source decoder.
5, the receiving terminal that uses in a kind of ground transmission system for digital high-definition television according to claim 4, it is characterized in that: said VSB demodulation/analog-to-digital conversion/synchronization timing circuit (23) outputs to tuner (21) and IF amplifier (22) simultaneously with the AGC signal, and the AFC signal is delivered to tuner (21).
6, the receiving terminal that uses in a kind of ground transmission system for digital high-definition television according to claim 4 is characterized in that: it is to suppress the comb filter that PAL-D disturbs that PAL suppresses circuit (25).
7, a kind of ground transmission system for digital high-definition television, it comprises claim 1 and 4 said transmitting terminal and receiving terminals, it is characterized in that:
Adopt to postpone to carry out PAL-D interference inhibition, and the comb filter transfer function is 1-D for the comb filter of N=16
16
Symbol rate is 14.285714MHz, and rolloff-factor is 12%, is easy to realize; The HDTV signal bandwidth is 8MHz, makes full use of the channel of 8MHz;
HDTV pilot tone P is placed on the position of PAL-D pix carrier 0.892857MHz, and IF-FRE is 38.892857MHz;
Field structure is that per 208 data segments insert a field synchronization segments;
Segment structure is that 4 sign fields of per 828 data symbols insertion are synchronous;
Clean data transfer rate 25.700615Mbps;
Adopt the error correction coding scheme of RS (207,187,10) and TCM (3,2,2);
Pilot power is 0.3dB.
8, a kind of ground transmission system for digital high-definition television, it comprises claim 1 and 4 said transmitting terminal and receiving terminals, it is characterized in that:
Adopt to postpone to carry out PAL-D interference inhibition, and the comb filter transfer function is 1+D for the comb filter of N=12
12
Symbol rate is 13.300856MHz, and rolloff-factor is 19.66%, is easy to realize; The HDTV signal bandwidth is 7.958MHz, has utilized the channel of 8MHz preferably;
HDTV pilot tone P is placed on the position of PAL-D pix carrier 0.554202MHz, and IF-FRE is 38.554202MHz;
Field structure is that per 312 data segments insert a field synchronization segments;
Segment structure is that 4 sign fields of per 828 data symbols insertion are synchronous;
Clean data transfer rate 23.967038Mbps;
Adopt the error correction coding scheme of RS (207,187,10) and TCM (3,2,2);
Pilot power is 0.3dB.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 99109828 CN1111337C (en) | 1999-07-16 | 1999-07-16 | Ground transmission system for digital high-definition television |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 99109828 CN1111337C (en) | 1999-07-16 | 1999-07-16 | Ground transmission system for digital high-definition television |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1245383A CN1245383A (en) | 2000-02-23 |
| CN1111337C true CN1111337C (en) | 2003-06-11 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 99109828 Expired - Fee Related CN1111337C (en) | 1999-07-16 | 1999-07-16 | Ground transmission system for digital high-definition television |
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| Country | Link |
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| CN (1) | CN1111337C (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101406015B (en) * | 2006-04-04 | 2012-01-04 | 三星电子株式会社 | Method for resetting grid code modulation encoder to known state |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7675994B2 (en) * | 2001-04-02 | 2010-03-09 | Koninklijke Philips Electronics N.V. | Packet identification mechanism at the transmitter and receiver for an enhanced ATSC 8-VSB system |
| KR100736500B1 (en) * | 2001-04-25 | 2007-07-06 | 엘지전자 주식회사 | Communication system of VSB digital TV |
| KR100510679B1 (en) * | 2003-03-21 | 2005-08-31 | 엘지전자 주식회사 | Digital VSB transmitting system and enhanced data multiplexing method in a VSB transmitting system |
| KR100906339B1 (en) * | 2002-06-14 | 2009-07-06 | 삼성전자주식회사 | Single Carrier Transmitter capable of inserting field-synch. of variable symbols into a field |
| KR100920723B1 (en) * | 2002-10-08 | 2009-10-07 | 삼성전자주식회사 | Single carrier transmission system capable of acclimating dynamic environment and a method therefore |
| WO2004062283A1 (en) * | 2003-01-06 | 2004-07-22 | Electronics And Telecommunications Research Institute | Digital television transmitter and receiver for transmitting and receiving dual stream using 4 level vestigial side band robust data |
| CN1319376C (en) * | 2003-11-13 | 2007-05-30 | 上海交通大学<Del/> | Signal transmission method in digital signal transmission system |
| CN100356792C (en) * | 2004-03-29 | 2007-12-19 | 上海交通大学 | Mixed transmission method in digital television ground troadcasting transmission system |
| CN101534382B (en) * | 2009-04-21 | 2011-04-20 | 珠海无线蜂网科技有限公司 | Method, system and device for RF synchronous transmitting broadcast television signal |
| CN105429729B (en) * | 2015-11-03 | 2018-11-09 | 西安烽火电子科技有限责任公司 | A kind of ultrashort continuous phase Trellis-coded modulation coherent demodulation method |
-
1999
- 1999-07-16 CN CN 99109828 patent/CN1111337C/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101406015B (en) * | 2006-04-04 | 2012-01-04 | 三星电子株式会社 | Method for resetting grid code modulation encoder to known state |
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|---|---|
| CN1245383A (en) | 2000-02-23 |
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