CN103581096B - OFDM modulating and demodulating method and digital signal emitting and receiving system - Google Patents
OFDM modulating and demodulating method and digital signal emitting and receiving system Download PDFInfo
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Abstract
The invention discloses an OFDM modulating and demodulating method containing time domain training sequences and a digital signal emitting and receiving system. The principle of the OFDM modulating and demodulating method is that input data symbols are grouped with N input data symbols as one group to be converted in a time domain mode, the N is the number of subcarriers of the OFDM symbols, a cyclic prefix of each group input data symbols is established, the input data symbols are expanded into time domain data with the length of N+P, the P is the length of the cyclic prefix, the time domain training sequence with the length of P and a negation sequence for the time domain training sequence are generated for each group of time domain data, the time domain training sequences and the negation sequences of the time domain training sequences are overlapped on the groups of the time domain data to obtain bas band time domain symbols. By means of the technical scheme of the OFDM modulating and demodulating method, the complexity of reconstitution CP-OFDM symbols is reduced, noise caused by reconstitution is reduced, the channel estimating performance is improved, and a digital signal emitting and receiving system using the OFDM modulating and demodulating method can have better noise resistance.
Description
Technical field
The present invention relates to the modulation-demo-demodulation method and the system using the modulation-demo-demodulation method in communication system, more specifically
Say, be related to a kind of OFDM modulation-demo-demodulation methods comprising time-domain training sequence based on multicarrier, and using the modulation /demodulation
The digital signal transmission of method, reception system.
Background technology
CP-OFDM technologies are widely used in Modern Communication System.And different TDS-OFDM systems, such as DTMB
Multi-carrier mode, then time-domain training sequence is inserted between OFDM symbol, complete the same of receiving terminal using time-domain training sequence
The function such as step and channel estimation.TDS-OFDM technologies are effectively improved frequency resource utilization rate.However, due to not using circulation
Prefix, TDS-OFDM systems must reconstruct CP-OFDM symbols when the data of frequency domain are recovered.And during reconstruct, also must
Noises more in CP-OFDM can so be introduced.
The content of the invention
The purpose of the present invention aims to provide a kind of OFDM modulation-demo-demodulation methods comprising time-domain training sequence and data signal
Transmitting, reception system, have been effectively combined CP-OFDM and TDS-OFDM, improve existing digital signal transmission, reception system
Structure.
According to above-mentioned purpose, implement the OFDM modulation method comprising time-domain training sequence of the present invention, comprise the following steps：
Step one, time domain conversion is carried out by input data symbol with N number of as set of group, and wherein N is the subcarrier number of OFDM symbol；
Step 2, builds the Cyclic Prefix of every group of input data symbol, by the time domain number that input data sign extended to length is N+P
According to wherein P is the length of Cyclic Prefix；Step 3, time-domain training sequence of the length for P is generated to every group of time domain data, and
The time-domain training sequence negates sequence；Step 4, the sequence that negates of the time-domain training sequence and time-domain training sequence is folded
It is added on every group of time domain data, obtains base band time-domain symbol.
According to above-mentioned principal character, step 4 negates sequence wherein by the time-domain training sequence and time-domain training sequence
One of in the front P data of the time domain data that is added to, by the rear P data of another time domain data that is added to.
According to above-mentioned principal character, the base band time-domain symbol obtained through the superposition of step 4 is：；Wherein k represents kth group time domain data,It is the input of time domain
Data symbol,It is base band time-domain symbol,It is time-domain training sequence.
According to above-mentioned purpose, implement the OFDM demodulation method comprising time-domain training sequence of the present invention, including synchronization, channel
Estimate and balanced, synchronizing step converts base band data group, obtains time domain number of the baseband synchronization set of symbols through channel response
According to wherein the last P data of every group of baseband synchronization symbol are interference-free 2 times of time-domain training sequences；Channel estimation is walked
Suddenly channel estimation is done using interference-free time-domain training sequence, obtains channel impulse response；Equalization step will be rushed through channel
The time-domain training sequence for hitting response is deducted from base band data, obtains base band time-domain symbol.
According to above-mentioned principal character, the base band data that synchronizing step is received by after deducts the base band data for first receiving,
Eliminate the time-domain training sequence that Cyclic Prefix obtains 2 times.
According to above-mentioned principal character, the base band data received after this deducts the base band data for first receiving, the base for obtaining
It is with synchronizing symbol：
；Its
In, k represents the kth group base band data for receiving,For base band time-domain symbol,For baseband synchronization symbol,It is time domain
Input data symbol,For time-domain training sequence.Upper one is defined as to-n data of one group of data in the present invention
N-th of the inverse of group data, repeats no more later.
According to above-mentioned principal character, for every group of time-domain training sequence identical base band data, channel estimation steps are to even
Continue multigroup base band data to do averagely, the sequence for obtaining 2P length does channel estimation, when wherein the sequence of the 2P length includes one
Domain training sequence and time-domain training sequence negate sequence.
According to above-mentioned principal character, channel estimation steps are done averagely to continuous N group base band data, obtain：；
Wherein,；；Wherein,For the base band data after average,It is the input data symbol of time domain,It is one group of time-domain training sequence,It is channel impulse response.
According to above-mentioned principal character, the base band data different for every group of time-domain training sequence, channel estimation steps are utilized
Interference-free 2 times of the time-domain training sequence does channel estimation.
According to above-mentioned principal character, for one group of base band data, equalization step is decomposed into the base band data for receiving；Wherein,It is kth group base
Band data,It is to negate sequence through the training sequence or training sequence of channel impulse response,It is channel impulse response,It is that mean power isWhite Gaussian noise；By through the time-domain training sequence and time-domain training sequence of channel impulse response
The sequence that negates deduct from base band data, base band time-domain symbol is obtained after conversion.
According to above-mentioned purpose, implementing the digital signal emission system of the OFDM modulation method of the present invention includes randomization list
Unit, forward error correction coding unit, constellation mapping and interleave unit, system information signal generating unit, Multiplexing Unit, CP-OFDM build
Unit, time-domain training sequence superpositing unit, frame head form unit, Framing unit, baseband postprocessing unit and quadrature up-conversion list
Unit；Wherein, input data bitstream stream is scrambled through randomization unit with scrambler, is carried out into forward error correction coding unit afterwards
Forward error correction coding, subsequently into constellation mapping and interleave unit, forms symbol stream, and planetary of going forward side by side mapping is handed over afterwards
Knit, then be multiplexed with system information Jing Multiplexing Unit and to form input data symbol, into CP-OFDM construction units, then through time domain
Training sequence superpositing unit, is superimposed by the use of frame head as time-domain training sequence, forms frame, and afterwards frame forms unit with frame head
The frame head of generation is signal frame through Framing unit multiple connection, through baseband postprocessing cell translation be output signal, and through just
Hand in converter unit frequency conversion and be converted to radiofrequency signal.
According to above-mentioned purpose, implement the digital signal reception system of the OFDM demodulation method of the present invention include lock unit,
Balanced unit, channel estimating unit, demultiplexing unit, solution system information elements, constellation demapping are encoded with unit, solution is deinterleaved
Unit；Wherein, base band data group is done synchronization by lock unit, obtains baseband synchronization set of symbols；Channel estimating unit will not be by dry
The time-domain training sequence disturbed does channel estimation, obtains channel impulse response；Balanced unit is by through the time domain of channel impulse response
Training sequence is deducted from base band data, obtains base band time-domain symbol；Base band time-domain symbol is converted and divided by demultiplexing unit
Solution, obtains system information and data symbol；Solution system information elements extract data symbol according to system information；Constellation demapping with
Deinterleave unit to make data symbol demapping and deinterleave；Solution coding unit finally solves coding and obtains final data message.
According to above-mentioned purpose, implement the input of digital signal emission system of the OFDM modulation method of the present invention to control all the way
Information processed and at least business datum all the way, the emission system includes scrambling unit, forward error correction coding unit, constellation mapping and symbol
Number interleave unit, frame head signal generating unit, CP-OFDM symbol construction units, time-domain training sequence superpositing unit, multi-frame synchronization channel
Signal generating unit, multi-frame Framing unit, baseband postprocessing unit and quadrature up-conversion unit；Wherein, use per business datum all the way
Independent coding and modulation, business datum and control information are scrambled respectively through scrambling unit, afterwards into forward error correction
Coding unit carries out forward error correction coding, subsequently into constellation mapping and interleave unit, forms symbol stream, and planetary of going forward side by side reflects
Penetrate, be interleaved afterwards, input data symbol is formed, into CP-OFDM construction units, then through time-domain training sequence superposition mould
Block is superimposed time-domain training sequence, is superimposed to form subframe as time-domain training sequence by the use of frame head, subframe and multi-frame synchronization channel Jing
Cross multi-frame Framing unit and be combined into multi-frame, through baseband postprocessing cell translation be output signal, and through quadrature up-conversion list
First frequency conversion is converted to radiofrequency signal.
According to above-mentioned purpose, implementing the digital signal reception system of the OFDM demodulation method of the present invention includes solution multi-frame list
Unit, lock unit, balanced unit, channel estimating unit, demultiplexing unit, control information constellation demapping and deinterleaving unit,
Control information solution coding unit, business datum constellation demapping and deinterleaving unit, business datum solution coding unit；Wherein, solve
The multi-frame for receiving is decomposed into multiple subframes by multi-frame unit；For each subframe, base band data group is done synchronization by lock unit, is obtained
To baseband synchronization set of symbols；Interference-free time-domain training sequence is done channel estimation by channel estimating unit, obtains Channel Impulse
Response；Balanced unit will be deducted through the time-domain training sequence of channel impulse response from base band data, obtain base band time domain symbol
Number；Base band time-domain symbol is converted and decomposed by demultiplexing unit, obtains control information and business datum；Control information constellation solution
Mapping enters planetary demapping to control information with deinterleaving with unit is deinterleaved；After control information solution coding unit solution coding
To per information such as modulation, the codings of business datum all the way；Business datum constellation demapping is with deinterleaving unit to per industry all the way
Business data are done demapping and are deinterleaved；Obtain per business datum all the way after business datum solution coding unit solution coding.
Technical scheme is employed, can reduce reconstructing the complexity of CP-OFDM symbols, reduce what reconstruct brought
Noise, improves the performance of channel estimation, so as to the digital signal transmission using OFDM modulation-demo-demodulation methods of the present invention, receive system
System can have more preferable noise resisting ability.
Description of the drawings
In the present invention, identical reference represents all the time identical feature, wherein：
Fig. 1 is the schematic diagram of OFDM modulation method of the present invention；
Fig. 2 is the schematic diagram of the overlying training sequence on CP-OFDM symbols；
Fig. 3 is the schematic diagram of the bright demodulation methods of this OFDM；
Fig. 4 is using the first digital signal emission system structure chart of OFDM modulation method of the present invention；
Fig. 5 is using the first digital signal reception system construction drawing of OFDM modulation method of the present invention；
Fig. 6 is using second digital signal emission system structure chart of OFDM modulation method of the present invention；
Fig. 7 is using second digital signal reception system construction drawing of OFDM modulation method of the present invention.
Specific embodiment
Technical scheme is further illustrated with reference to the accompanying drawings and examples.
Present invention firstly provides a kind of modulation demodulation system for combining CP-OFDM and TDS-OFDM, is mainly used in transmitting
, to the modulation of baseband signalling, and receiving terminal baseband signalling is to the demodulation of data symbol for the data symbol at end.
As shown in figure 1, the present invention is made up of in transmitting terminal following steps：
1. input data symbol is constructed into the CP-OFDM symbolic constructions for suiting the requirements by adding Cyclic Prefix.
2. time-domain training sequence is superimposed on above-mentioned CP-OFDM symbols.
Build CP-OFDM symbols
Input data symbol can be that message bit stream is obtained through various forward error corrections with constellation point.Forward direction
Error correcting code can be LDPC code, RS codes, BCH code, convolutional code etc., and constellation point can be various QAM, PSK or APSK, this
It is bright that this is not limited.By input data symbol with N number of as set of group, such as kth group is.N is
The subcarrier number of OFDM symbol.Every group of signal is carried out such as down conversion
Obtain time domain.To be expanded to per group by building Cyclic Prefix, wherein P is the length of protection interval.
Superposition time-domain training sequence
Time-domain training sequence of the length for P is generated to every group of time domain data, and the time domain instruction
That practices sequence negates sequence.Time-domain training sequence can be PN, the time-domain representation of frequency domain PN or CAZAC sequences etc., and the present invention is right
This is not limited.Training sequence can be identical with per group, it is also possible to which each group is different, and the present invention is not also limited this.During by this P
Domain training sequence be added to respectively on every group of time domain data with being negated for it, is obtained, such as Fig. 2 institutes
Show.The mode being wherein superimposed is：
Obtain one group of group data order output base band time-domain symbol has just been obtained into.To one group of data in the present invention
- n data are defined as n-th of the inverse of one group of data, repeat no more later.
As shown in figure 3, the receiving terminal of the present invention is made up of following steps：
1. synchronous
2. channel estimation
3. balanced
It is synchronous
Receiving terminal receives the kth group data of base band, and define, then
.Wherein,It is channel punching
Hit response,It is that mean power isWhite Gaussian noise.
Base band data first to receiving makees such as down conversion
.Wherein
, definition
HereFor baseband synchronization symbol（Group）.
It is noted that per groupLast P data be interference-free, andIt is
Mean power isWhite Gaussian noise.ThereforeIt isHave passed through byThe channel of definition and average
Power isAdditive white Gaussian noise obtained from data.Accordingly, receiving terminal can be adopted and allowedWith it is localRelated method and corresponding series of algorithms is synchronized to receiving data.The present invention to these into
Ripe synchronized algorithm is not limited.It is convenient herein for explaining, first by the data for receiving with corresponding to transmitting packet
Method be grouped, actually, it is readily seen that fromObtainConversion and do not need grouping information, can directly dock
The data flow for receiving enters line translation.
Channel estimation
Channel estimation methods one
Equally obtain using the conversion mentioned in synchronization, then basisIncluded in it is interference-freeCarry out channel estimation.The present invention is not also limited these ripe channel estimation methods.
Channel estimation methods two
If the time-domain training sequence of every group of data of transmitting is identical, it is, continuous N group can be received
Base band data is carried out averagely, is obtained：
Wherein
。
Increase M can effectively makeMiddle time domain trains sequence
The suffered interference reduction of row.AndContain continuous 2P
Individual time-domain training sequence, the wherein sequence of the 2P length include negating for a time-domain training sequence and time-domain training sequence
Sequence：.Channel estimation can be made using this 2P continuous time-domain training sequence
The multipalh length that can be resisted increases to 2P, the well beyond restriction of circulating prefix-length P.Even and if multipalh length less than etc.
In the case of P, 2P continuous time-domain training sequence can also greatly increase the precision of channel estimation.
It is balanced
If channel estimation has obtained accurate channel impulse response, and.Then receiving terminal is received
Kth group base band data last N number of data
.Wherein
.Due to
With, it is known that receiving terminal can be obtained, and by its fromIn deduct, obtain
.It is N number of to per groupCarry out
As down conversion is obtained
Wherein
.Understand,Can pass throughObtain, andMean power also can pass throughIt is calculated.
Thus estimate using various ripe OFDM equalization algorithms.The present invention is not limited these ripe equalization algorithms
It is fixed.
The modulation-demo-demodulation method comprising time-domain training sequence of the present invention has the advantages that：
1. for TDS-OFDM systems, such as DTMB must be by a frame signal due to multipath in order to reconstruct CP-OFDM
" hangover " for causing is added to the head of signal.The noise of " hangover " part is necessarily also added to what is reconstructed by the additive process
In CP-OFDM symbols.And the problem is non-existent in CP-OFDM systems, such as DVB-T and DVB-T2.The present invention can keep away
Exempt to be superimposed unnecessary noise.
The training sequence that the channel estimation of TDS-OFDM systems can be used is no longer than the protection interval of the system.And
What the system in the present invention can be superimposed the time-domain training sequence being superimposed in a tail with the Cyclic Prefix of next frame
Time-domain training sequence regards a longer training sequence as, and its length is the twice of protection interval.In conjunction with such as multi-frame mean
Etc. method, the multipalh length that channel estimation can be resisted can be greatly increased, and improve precision.
The present invention have also been devised various transmittings that can utilize the above-mentioned modulator approach comprising time-domain training sequence, reception system
System, its structure refers to Fig. 4-7.
The first digital signal emission system structure as shown in Figure 4, it includes randomization unit, forward error correction coding list
Unit, constellation mapping and interleave unit, system information signal generating unit, Multiplexing Unit, CP-OFDM construction units, frame head formed unit,
Time-domain training sequence superpositing unit, Framing unit, baseband postprocessing unit and quadrature up-conversion unit.
Input data bitstream stream is scrambled through randomization unit with scrambler, is carried out into forward error correction coding unit afterwards
Forward error correction coding, subsequently into constellation mapping and interleave unit, forms symbol stream, and planetary of going forward side by side mapping is handed over afterwards
Knit, then be multiplexed with system information Jing Multiplexing Unit and to form input data symbol, into CP-OFDM construction units, using the present invention
CP-OFDM build the data symbol structure with CP, i.e. time domain data.In some systems（Such as DTMB）In, frame head is one
The specific PN sequences of group, and the time-domain training sequence of the present invention does not limit its type, can be the time-domain representation of PN, frequency domain PN
Or CAZAC sequences etc., therefore be added to frame head as time-domain training sequence on CP-OFDM time domain datas, can be simultaneously reached
The purpose of addition frame head and time-domain training sequence.Afterwards, using the baseband signalling for obtaining as the frame structure of the first system frame
Body, the frame head that afterwards frame is generated with frame head formation unit is signal frame through Framing unit multiple connection, through baseband postprocessing list
Unit is converted to output signal（In 8MHz bandwidth）, and be converted to radiofrequency signal through quadrature up-conversion unit frequency conversion（UHF and VHF
In band limits）.
The structure of the digital signal reception system of the above-mentioned digital signal emission system of correspondence is as shown in Figure 5.Receiving terminal bag
Include lock unit, balanced unit, channel estimating unit, demultiplexing unit, solution system information elements, constellation demapping and deinterleave
Unit, solution coding unit.
Lock unit converts base band data group, obtains time domain data of the baseband synchronization set of symbols through channel response.
Interference-free time-domain training sequence is done channel estimation by channel estimating unit, obtains channel impulse response.Balanced unit is by Jing
The time-domain training sequence for crossing channel impulse response is deducted from base band data, obtains base band time-domain symbol, is transmitted single to demultiplexing
Unit.Base band time-domain symbol is converted and decomposed by demultiplexing unit, obtains system information and data symbol, solves system information elements
Data symbol is extracted according to system information and is sent to constellation demapping and deinterleaving unit, afterwards demapping is done to data symbol
Encode with deinterleaving, solving, obtain final data message.
Second digital signal emission system structure as shown in Figure 6, it includes scrambling unit, forward error correction coding list
Unit, constellation mapping and symbol interleaving unit, CP-OFDM symbol construction units, time-domain training sequence superpositing unit, multi-frame synchronization letter
Road signal generating unit, multi-frame Framing unit, baseband postprocessing unit and quadrature up-conversion unit.
The input of second system architecture includes all the way/multi-channel service data flow and all the way control information stream.Per industry all the way
, using independent coding and modulation, its coding and modulating mode can flexible configurations according to actual needs for business data flow.Business datum
Scrambled through scrambling unit, carried out forward error correction coding into forward error correction coding unit afterwards, reflected subsequently into constellation
Penetrate and interleave unit, form symbol stream, planetary of going forward side by side mapping is interleaved afterwards, forms input data symbol.This outer control
Information similarly carries out above-mentioned process.Business datum, control information after treatment converts again and adds frame head by IDFT
The Data Data symbol of modulator approach of the present invention is formed, into CP-OFDM construction units, is built using the CP-OFDM of the present invention
Data symbol structure with CP, i.e. time domain data, in this constructive superposition time-domain training sequence, in some systems, frame head
It is one group of specific PN/PN-MC sequence, and the time-domain training sequence of the present invention does not limit its type, can be PN, frequency domain PN
Time-domain representation or CAZAC sequences etc., therefore be added to frame head as time-domain training sequence on CP-OFDM time domain datas, together
When can reach addition frame head and time-domain training sequence purpose.Afterwards, using the baseband signalling for obtaining as the third system
The subframe of frame structure, afterwards subframe and multi-frame synchronization channel be combined into multi-frame through multi-frame Framing unit, through baseband postprocessing
Cell translation is output signal, and is converted to radiofrequency signal through quadrature up-conversion unit frequency conversion.
The digital signal reception system architecture of the above-mentioned digital signal emission system of correspondence is as shown in Figure 7.Receiving terminal includes solution
Multi-frame unit, lock unit, balanced unit, channel estimating unit, demultiplexing unit, control information constellation demapping and deinterleaving
Unit, control information solution coding unit, business datum constellation demapping and deinterleaving unit, business datum solution coding unit.
Demultiplex frame unit and the multi-frame for receiving is decomposed into into multiple subframes, for each subframe, lock unit is by base band data
Group does synchronization, obtains baseband synchronization set of symbols.Interference-free time-domain training sequence is done channel estimation by channel estimating unit, is obtained
To channel impulse response.Balanced unit will be deducted through the time-domain training sequence of channel impulse response from base band data, be obtained
Base band time-domain symbol, transmits to demultiplexing unit.Base band time-domain symbol is converted and decomposed by demultiplexing unit, obtains control letter
Breath and business datum.First enter planetary demapping to control information and deinterleave, solution is encoded, obtain per business datum all the way
The information such as modulation, coding, further according to these information to doing demapping and deinterleaving, solution coding per business datum all the way, obtain every
Business datum all the way.
It will be understood to one skilled in the art that, the specification of the above is only the one kind in numerous embodiments of the invention
Or several embodiments, and not use limitation of the invention.Any impartial change for embodiment described above, modification with
And the technical scheme such as equivalent substitute, as long as meeting the spirit of the present invention, all will fall in claims of the present invention
In the range of protecting.
Claims (7)
1. a kind of OFDM demodulation method comprising time-domain training sequence, including synchronization, channel estimation and equilibrium, is characterized in that：
Synchronizing step converts base band data group, obtains time domain data of the baseband synchronization set of symbols through channel response, wherein
The last P data of every group of baseband synchronization symbol are interference-free 2 times of time-domain training sequences；
Channel estimation steps do channel estimation using interference-free time-domain training sequence, obtain channel impulse response；
Equalization step will be deducted through the time-domain training sequence of channel impulse response from base band data, obtain base band time domain symbol
Number,
Wherein, base band time-domain symbol is：
Wherein k represents kth group time domain data, sK, mIt is the input data symbol of time domain, xK, mIt is base band time-domain symbol, pK, mWhen being
Domain training sequence,
The base band data that synchronizing step is received by after deducts the base band data for first receiving, and eliminates Cyclic Prefix and obtains 2 times
Time-domain training sequence, the baseband synchronization symbol for obtaining is：
Wherein, k represents the kth group base band data for receiving, xK, mFor base band time-domain symbol, x 'K, mFor baseband synchronization symbol, sK, m
It is the input data symbol of time domain, pK, mFor time-domain training sequence, wherein, N for OFDM symbol subcarrier number, before P is for circulation
The length sewed.
2. the OFDM demodulation method comprising time-domain training sequence as claimed in claim 1, is characterized in that, for every group of time domain instruction
Practice sequence identical base band data, channel estimation steps are done averagely to continuous multigroup base band data, and the sequence for obtaining 2P length is done
What channel estimation, the wherein sequence of the 2P length included a time-domain training sequence and time-domain training sequence negates sequence.
3. the OFDM demodulation method comprising time-domain training sequence as claimed in claim 2, is characterized in that, channel estimation steps pair
Continuous N group base band data does averagely, obtains：
Wherein,；
Wherein,For the base band data after average, sK, mIt is the input data symbol of time domain, p0, p1..., pP-1It is one group of time domain
Training sequence, hlIt is channel impulse response, L is the number of channel impulse response.
4. the OFDM demodulation method comprising time-domain training sequence as claimed in claim 1, is characterized in that, for every group of time domain instruction
Practice the different base band data of sequence, channel estimation steps do channel estimation using interference-free 2 times of the time-domain training sequence.
5. the OFDM demodulation method comprising time-domain training sequence as claimed in claim 1, is characterized in that, for one group of base band number
According to equalization step is decomposed into the base band data for receiving
Wherein, yK, mIt is kth group base band data,It is to negate sequence through the training sequence or training sequence of channel impulse response
Zero is arranged or takes, hlIt is channel impulse response, nk,m+PIt is that mean power is N0White Gaussian noise；Will be through channel impulse response
Time-domain training sequence and the sequence that negates of time-domain training sequence deduct from base band data, base band time domain symbol is obtained after conversion
Number.
6. the digital signal reception system of a kind of OFDM demodulation method comprising time-domain training sequence of a kind of application claim 1
System, is characterized in that, the reception system includes lock unit, balanced unit, channel estimating unit, demultiplexing unit, solution system letter
Interest statement unit, constellation demapping and deinterleaving unit, solution coding unit；Wherein, base band data group is done synchronization by lock unit, is obtained
Baseband synchronization set of symbols；Interference-free time-domain training sequence is done channel estimation by channel estimating unit, obtains Channel Impulse sound
Should；Balanced unit will be deducted through the time-domain training sequence of channel impulse response from base band data, obtain base band time-domain symbol；
Base band time-domain symbol is converted and decomposed by demultiplexing unit, obtains system information and data symbol；Solution system information elements root
Data symbol is extracted according to system information；Constellation demapping does demapping to data symbol with deinterleaving with unit is deinterleaved；Solution is compiled
Code unit finally solves coding and obtains final data message.
7. the digital signal reception system of a kind of OFDM demodulation method comprising time-domain training sequence of a kind of application claim 1
System, is characterized in that, the reception system includes demultiplexing frame unit, lock unit, balanced unit, channel estimating unit, demultiplexing list
Unit, control information constellation demapping and deinterleaving unit, control information solution coding unit, business datum constellation demapping and solution are handed over
Knit unit, business datum solution coding unit；Wherein, demultiplex frame unit and the multi-frame for receiving is decomposed into into multiple subframes；For each
Base band data group is done synchronization by subframe, lock unit, obtains baseband synchronization set of symbols；When channel estimating unit will be interference-free
Domain training sequence does channel estimation, obtains channel impulse response；Balanced unit will train sequence through the time domain of channel impulse response
Row are deducted from base band data, obtain base band time-domain symbol；Base band time-domain symbol is converted and decomposed by demultiplexing unit, is obtained
Control information and business datum；Control information constellation demapping enters planetary demapping to control information with solution with unit is deinterleaved
Interweave；Modulation, the coding information per business datum all the way is obtained after control information solution coding unit solution coding；Business datum star
Seat demapping is done demapping and is deinterleaved with unit is deinterleaved to every business datum all the way；Business datum solution coding unit solution is encoded
After obtain per business datum all the way.
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