CN104883238B - A kind of carrier time division multiplexing modulation/demodulation methods and system - Google Patents
A kind of carrier time division multiplexing modulation/demodulation methods and system Download PDFInfo
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Abstract
The present invention proposes a kind of carrier time division multiplexing modulation-demo-demodulation method and system (MC TDMA).Distribution and FFT transform are first interleaved before multi-carrier modulation is carried out to incoming symbol, time-domain symbol, which is transformed to frequency domain symbol signal, carries out MDFT processing.Transmitting terminal uses analysis filter group structure, signal to carry out IFFT conversion after carrying out pre-filtering.The position of prefilter reduces the PAPR values of system between NM point FFT and M points IFFT, using the symmetry of filter coefficient, and frequency domain symbol signal is assigned to different sub-band and carries out multi-carrier modulation.
Description
Technical field
The present invention relates to multi-carrier modulation demodulation techniques, more particularly to a kind of carrier time division multiplexing modulation/demodulation methods
And system (MC-TDMA).
Background technology
Mobile communication technology has gone through the development in four generations, and first generation wireless communication belongs to analogue communication, can only pass language
Sound signal, since second generation wireless network, mobile radio communication enters the digital network epoch, and voice-and-data can be passed at the same time
It is defeated.(LTE) mobile communication from the second generation to forth generation, with the development of modulation technique, data transfer rate is carried from 14.4Kbps
Height has arrived 1Gbps.Second generation wireless communication is logical using Gaussian Minimum Shift Keying (GMSK) modulation technique, third generation movement
Letter belongs to single-carrier modulated using quadrature phase shift keying (QPSK), both modulation techniques.
And in order to improve message transmission rate, the forth generation mobile radio communication using LTE standard as representative employs multicarrier
Modulation technique.In LTE standard, uplink uses single carrier frequency division multiple access technology (SC-FDMA), and downlink uses orthogonal frequency
Divide multiplexing multiple-user access technology (OFDMA).Multi-carrier modulation technology has anti-radio channel multi-path damping capacity, because more
In carrier modulation, high speed signal is divided into multiple low speed signals by IFFT, and low speed signal is then modulated to different sub-carrier
On, one signal with the long symbol cycle of synthesis is transmitted.
Future mobile communications development major impetus be Internet of Things (IoT) and Machine To Machine communication (M2M), IoT with
The characteristics of M2M communication is randomness, asynchronous, short data, low delay and low-power consumption and low cost.It is therefore desirable to study one kind
New modulation technique come meet future wireless system development the needs of, the present invention precisely in order to meeting these requirements and proposing.
The content of the invention
A kind of carrier time division is multiplexed modulator approach, it is characterised in that distribution is interleaved to incoming symbol；Using quick
Fourier transformation carries out FFT transform；Time-domain symbol is transformed to frequency domain symbol signal and carries out MDFT processing.
According to another embodiment of the invention, the MDFT processing in carrier time division multiplexing modulator approach is further wrapped
Include Substrip analysis filtering process, reverse Fourier transformation processing, and intertexture calculation process.Another implementation according to the present invention
Example, the Fast Fourier Transform (FFT) which is multiplexed in modulator approach further convert for a NM- point quick Fourier,
Here N, M are the positive integer more than or equal to 1.According to another embodiment of the invention, carrier time division multiplexing modulation methods
The sub-band analysis filtration processing included by MDFT processing in method is further used for carrying out preposition filter to NM point frequency domain symbols signal
Ripple, further according to ptototype filter construction of function coefficient matrix H, carries out NM point frequency domain symbol signals with coefficient matrix H right multiplied
To 2NM point frequency domain symbol signals.
According to another embodiment of the invention, the coefficient matrix H used in carrier time division multiplexing modulator approach,
It is further to move to right M/2 by a matrix circular for having 4Nx2N matrix element block to obtain.Another implementation according to the present invention
Example, the carrier time division are multiplexed the coefficient matrix H used in modulator approach, further comprise following submatrix hi, 0 He
hi,1：By RRC prototype function coefficient hs (n) (0<=n<=NM-1) be divided into N number of sub-block (including M points per sub-block), respectively by
The preceding M/2 points and rear M/2 points composition diagonal matrix hi of i-th sub-block, 0 and diagonal matrix hi, 1, i is between N-1 between 0 here
Integer.According to another embodiment of the invention, the coefficient matrix H used in carrier time division multiplexing modulator approach,
Wherein submatrix hi, 0 and submatrix hi, 1 arrangement mode it is as follows：
According to another embodiment of the invention, the MDFT processing in carrier time division multiplexing modulator approach includes inverse
It is further a reverse Fourier transformation of 2N M-point to Fourier transformation.
The present invention also proposes a kind of carrier time division multiplexing demodulation method, and this method includes：Prefix is gone in the docking collection of letters number, is passed through
The signal after prefix is removed in balanced device equilibrium, carries out IMDFT and handles synthesis band frequency-region signal entirely, the frequency-region signal of synthesis carries out quickly
Reverse Fourier transformation (IFFT) conversion obtains time-domain signal, then carries out that symbol is counter to sort to the signal of output, reflects through symbol
Penetrate processing and obtain the transmitting terminal incoming symbol signal rebuild.
According to another embodiment of the invention, the IMDFT processing in the carrier time division multiplexing demodulation method is further
Calculation process, Fourier transformation processing, and the processing of subband integrated filter are knitted including reciprocal cross.
According to another embodiment of the invention, the fast reverse Fourier in the carrier time division multiplexing demodulation method becomes
Change, be further a NM- point fast reverse Fourier transformation.
According to another embodiment of the invention, the IMDFT processing in the carrier time division multiplexing demodulation method includes
Fourier transformation, is further a 2N M-point Fourier transformation.
According to another embodiment of the invention, included by the IMDFT processing in the carrier time division multiplexing demodulation method
Subband integrated filter processing, be further used for 2NM point frequency domain symbols signal carry out post-filtering, further according to coefficient matrix H
Transposition 2NM point frequency domain symbols signal is carried out right multiplied to arrive NM point frequency domain symbol signals.
The present invention also proposes a kind of carrier time division multiplexing MDFT systems, which includes transmitting terminal and receiving terminal, send
End includes：Map to obtain the symbol map unit of complex symbol signal for carrying out symbol to binary bit sequence；For right
Incoming symbol is interleaved the symbol sequencing unit of distribution, for time-domain symbol signal to be transformed to the quick of frequency domain symbol signal
Fourier transform unit；Make reverse Fourier transformation conversion after carrying out pre-filtering to frequency domain symbol signal as prefilter
MDFT units, MDFT units use analysis filter group structure；The receiving terminal includes：Prefix, equilibrium are gone in the docking collection of letters number
Processing acquisition mark signal removes prefix unit, balanced device；Knit computing for carrying out reciprocal cross, reciprocal cross is knitted computing obtain signal into
The IMDFT units of row MDFT inverse transformations obtain mark signal, are sent for the mark signal of acquisition to be carried out IFFT conversion
Hold the reverse Fast Fourier Transform (FFT) unit of reconstruction signal.
According to one embodiment of present invention, MDFT units include, sub-band analysis filtration part：For being accorded with to NM points frequency domain
Number signal carries out pre-filtering, and further according to ptototype filter construction of function coefficient matrix H, NM points frequency domain is accorded with coefficient matrix H
Number signal carries out right multiplied arriving 2NM point frequency domain symbol signals；IFFT conversion sections：For being carried out to 2NM point frequency domain symbols signal
2N M-point IFFT converts to obtain 2NM point time-domain signals；Intertexture arithmetic section：For being interleaved fortune to 2NM point time-domain signals
Calculation obtains NM points output complex symbol signal.
According to another embodiment of the invention, the reverse Fourier transformation in the MDFT units, it is implemented inverse
It is a reverse Fourier transformation of 2N M-point to Fourier transformation.
According to another embodiment of the invention, the reverse Fast Fourier Transform (FFT) unit, it is implemented reverse fast
Fast Fourier transformation is a reverse Fast Fourier Transform (FFT) of NM- points, here N, and M is the positive integer more than or equal to 1.
According to another embodiment of the invention, the IMDFT units, it is used for the symbol for NM points being removed channel disturbance
Signals revivification is 2NM point frequency domain symbol signals, post-filtering is carried out to 2NM point frequency domain symbols signal, further according to coefficient matrix H's
Transposition is multiplied to the 2NM point frequency domain symbols signal progress right side to arrive NM point frequency domain symbol signals.
MC-TDMA system structures proposed by the present invention realize that simply transmitting terminal passes through the distribution of incoming symbol intertexture and MDFT
Wave filter group realizes that receiving terminal uses MDFT synthesis filter group structures, and using FFT transform unit, intertexture computing eliminates adjacent
Intersubband disturbs, so as to allow the ability of the existing anti-unlimited channel multi-path decay of system also to have the ability of anti-carrier frequency drift, MC-TDMA
The advantages of collecting every other modulating system uses analysis filter group structure in a system, transmitting terminal.Receiving terminal is using synthesis
Filter bank structure, receiving terminal can disposably recover NM point transmitting terminal input signals, and delay is small, and can save prefix occupancy
Resource, using frequency domain zero setting balanced device, is realized simple.
Brief description of the drawings
Fig. 1 MC-TDMA multicarrier modulation system theory structure block diagrams；
Block diagram is realized in the multinomial decomposition of frequency domain MDFT wave filter groups in Fig. 2 MC-TDMA；
Fig. 3 PAPR analog result schematic diagrames；
Fig. 4 MC-TDMA system symbol bit error rate analog results；
The anti-carrier frequency drift analog result of Fig. 5 MC-TDMA systems.
Embodiment
As shown in the specification and claims, unless context clearly prompts exceptional situation, " one ", "one",
The word such as " one kind " and/or "the" not refers in particular to odd number, may also comprise plural number.It is, in general, that term " comprising " is only carried with "comprising"
Show including clearly identify the step of and element, and these steps and element do not form one it is exclusive enumerate, method or
Equipment may also include other step or element.
Multi-carrier modulation technology is widely used in using LTE standard as the forth generation mobile radio communication of representative, especially
It is that downlink employs orthogonal frequency division multiplexing multiuser access (OFDMA) technology.Multi-carrier modulation technology has natural resist
Radio channel multi-path damping capacity, because in multi-carrier modulation, high speed signal is divided into multiple low speed signals by IFFT, so
Low speed signal is modulated in different sub-carrier afterwards, one signal with the long symbol cycle of synthesis is transmitted.Due to symbol
The extension in cycle, the ability of signal resistance multipath fading have obtained large increase, and therefore, multi-carrier modulation technology is high-speed radio
Communicate indispensable part.
OFDMA and SC-FDMA is more sensitive to carrier frequency drift.In addition, the PAPR values of OFDMA are bigger than normal.SC- in contrast
The PAPR values of FDMA are small.The LTE standard used in present forth generation mobile radio communication uses SC- i.e. in uplink communication
FDMA.Due to the multi-carrier nature of SC-FDMA modulated signals to be kept, LTE standard is using the SC- for concentrating intercalation model
FDMA(SC-LFDMA).Although the PAPR values of SC-LFDMA are lower than OFDMA, but still have with the theoretical minimum value of PAPR very big
Difference, that is to say, that its PAPR also has improved possibility.OFDMA and SC-FDMA needs the sub-carrier frequencies for sending and receiving end
Stringent synchronization is kept, this is to receiving and the crystal oscillator precision of transmitting terminal proposes very high requirement.
The reason for existing multicarrier modulation system PAPR values are big is due to the use of reverse Fourier transformation (IFFT conversion).
Since the basic function of IFFT conversion is complex-exponential function, and complex-exponential function is superimposed amplitude value by the multiplication of random mark and becomes
Greatly, especially when the phase of the complex exponential after multiplication is consistent, range value is maximum, and PAPR values at this moment are also maximum.Reduce OFDMA systems
The method of PAPR values is many in system, but these methods can only solve the problems, such as that PAPR values are high, can not be fully solved OFDMA system
The influence that subcarrier drift brings system performance.
The alternative for improving the anti-carrier frequency drift ability of multicarrier modulation system is to be replaced with wave filter group in OFDMA system
IFFT, can be compared with because wave filter group prototype function frequency characteristic is better than the frequency characteristic of the rectangular window function in IFFT
The good interference (ICI) eliminated between subcarrier.In addition, good prototype function frequency characteristic can also improve the power spectrum of system
Density, reduces the power leakage between subband, improves the validity of signal transmission.However, filter bank multi-carrier is modulated
(FBMC) the characteristics of system, first, PAPR values are larger, second, delay length, because good frequency characteristic requires very long prototype filter
Ripple device function coefficients.These features constrain the application of FBMC multicarrier modulation systems in practice.
Analysis shows, reducing PAPR values has two kinds of basic skills, first, the power peak of modulation symbol is reduced, second, shortening
The length of IFFT conversion.The frequency resolution of modulating system can also be reduced at the same time by shortening the length of IFFT conversion, improve system
Anti- carrier frequency drift ability.Since theory minimum PAPR values are the PAPR of former incoming symbol signal, so, if modulation output symbol
Former incoming symbol can be approached as far as possible, then PAPR values are lower.In single-carrier modulated, incoming symbol carries out FFT first
Carrier wave maps, and then carries out IFFT modulation again.The pattern mapped according to carrier wave, the modulation symbol after FFT/IFFT is converted are
The weighted sum (concentrating mapping) of incoming symbol, or the repetition of incoming symbol (interweave mapping).PAPR values directly affect movement
The service time of battery of terminal (mobile phone), therefore, PAPR values are more low better for uplink communication.
All at present modulator approaches and system (including the system used in a standard) cannot all solve OFDMA at the same time
Middle high PAPR and the problem of high carrier frequency drift susceptibility.Present invention incorporates the advantages of SC-FDMA and FBMC modulation techniques, one
Successfully solves the problems, such as above-mentioned two puzzlement wireless communication physical layer in a modulating system for many years.MC- proposed by the present invention
TDMA multicarrier modulation systems can be not only used for high-speed communication and can be used for IoT and M2M communication.
The specific embodiment of the present invention is a kind of carrier time division multiplexing modulation-demo-demodulation method, to incoming symbol into
Distribution and FFT transform first are interleaved to incoming symbol before row multi-carrier modulation, time-domain symbol is transformed to frequency domain symbol letter
Number, MDFT processing then is carried out to frequency domain symbol signal.It should be noted that description herein is only a specific embodiment
Main process, be not considered as unique embodiment, each step therein it is not necessary to, whole flow process and its tool
Body step is also not limited in figure and described above.For example, it can still do phase before being interleaved distribution for incoming symbol
Some answered give processing step, and FFT transform and the order of MDFT processing can do appropriate adjustment.Clearly for ability
, all may be without departing substantially from the principle of the invention, the situation of structure after present invention and principle is understood for the professional in domain
Under, the various modifications and variations in form and details are carried out to this system, but these modifications and variations are still in the power of the present invention
Within the scope of profit is claimed.
Have in MDFT process parts, and traditional FBMC (OFDM/OQAM) modulation schemes with classical MDFT processing structures
Distinguished, using synthesis filter group structure, and in the present invention, transmitting terminal uses transmitting terminal in traditional FMBC
Analysis filter group structure, what is carried out after signal progress pre-filtering is IFFT conversion rather than traditional FFT transform.Preposition filter
Between NM point FFT and M points IFFT, it serves a dual purpose in MC-TDMA for the position of ripple device, first, utilizing filter coefficient
Symmetry reduces the PAPR values of system, second, frequency domain symbol signal, which is assigned to different sub-band, carries out multi-carrier modulation.Retouching herein
The main process of an only specific embodiment is stated, is not considered as unique embodiment, each step therein is not
It is necessary, whole flow process and its specific steps are also not limited in figure and described above.
The further specific embodiment of the present invention then proposes a kind of carrier time division multiplex system, which includes
Transmitting terminal and receiving terminal, transmitting terminal include：Map to obtain complex symbol signal for carrying out symbol to binary bit sequence
Symbol map unit；For being interleaved the symbol sequencing unit of distribution to incoming symbol, for time-domain symbol signal to be converted
For Fast Fourier Transform (FFT transform) unit of frequency domain symbol signal；Frequency domain symbol signal is carried out as prefilter
Make the MDFT units of IFFT conversion after pre-filtering, MDFT units use analysis filter group structure；Receiving terminal includes：To receiving
Signal goes prefix, equilibrium treatment to obtain mark signal and removes prefix unit, balanced device；Computing is knitted for carrying out reciprocal cross, to reciprocal cross
Knit computing and obtain the IMDFT units that signal carries out MDFT inverse transformations, it is anti-for the mark signal of acquisition to be carried out fast Flourier
Convert the IFFT units that (IFFT conversion) obtains transmitting terminal reconstruction signal.Description herein is only the master of a specific embodiment
Want process, be not considered as unique embodiment, unit therein it is not necessary to, whole flow process and its specific step
It is rapid to be also not limited in figure and described above.For example, the communication quality quality depending on wireless channel, balanced device here
Frequency domain zero setting balanced device can be used to use non-zero setting type balanced device, blind equalizer can be used to use non-blind
Balanced device, can use self-adaptation type balanced device to use non-self-adapting type balanced device.Obviously, it is similar, for ability
, all may be without departing substantially from the principle of the invention, the situation of structure after present invention and principle is understood for the professional in domain
Under, the various modifications and variations in form and details are carried out to this system, but these modifications and variations are still in the power of the present invention
Within the scope of profit is claimed.
Further, the position of transmitting terminal prefilter is between NM point FFT and M points IFFT, the filter coefficient
With symmetry, frequency domain symbol signal is assigned to different sub-band and carries out multi-carrier modulation.
It is N for access customer number, the sub-carrier number of each user is the system of M, and total sub-carrier number is L=NM, symbol
Number map unit carries out symbol mapping, obtains M time domain incoming symbol signal, symbol sequencing unit is to M time domain incoming symbol
Signal is assigned on NM time point using intertexture allocation model, and FFT transform unit carries out FFT fortune to NM point time-domain symbols signal
Calculation obtains NM point frequency domain symbol signals.
Further, MDFT units include, sub-band analysis filtration part：For to NM points transmitting terminal incoming symbol signal into
Row FFT transform obtains NM point frequency domain symbol signals, according to ptototype filter construction of function coefficient matrix H, with coefficient matrix H to NM
The point frequency domain symbol signal progress right side is multiplied to arrive 2NM point frequency domain symbol signals；IFFT conversion sections：For to 2NM point frequency domain symbols
Signal carries out 2N M-point IFFT and converts to obtain 2NM point time-domain signals；Intertexture arithmetic section：For to 2NM point time-domain signals into
Row intertexture computing obtains NM points output complex symbol signal.2NM point time domain complex signals are divided into upper and lower two by intertexture arithmetic section
Road, on all the way signal be not delayed, under all the way signal have a delay, to upper and lower two paths of signals carry out 2 times sampling after, respectively
Alternating takes real and imaginary parts, synthesizes complex symbol signal, 2NM point complex signals is become NM point complex signals.Coefficient matrix H by
The coefficient of MDFT analysis filter groups shifts to obtain by M/2 dot cycles, more than MDFT analysis filter system numbers are risen by square root
String RRC functions are formed, and the dimension of H-matrix is 2NMxNM.The construction coefficient matrix H is specifically included, and has MxNM square by one
The matrix circular of battle array element blocks moves to right M/2 and obtains the matrix H that size is 2NMxNM, the M/2 on the M/2 points shift-in left side that the right removes
Point, shifts from first MxNM matrixes BOB(beginning of block) until the 2N-1 matrix block end.
Further, receiving terminal balanced device carries out FFT transform acquisition frequency-region signal after prefix is gone to mark signal, by frequency domain
The system function of signal divided by channel, converts to obtain the signal for removing channel disturbance through IFFT.Receiving terminal IMDFT units：For
The mark signal for NM points being removed channel disturbance is reduced to 2NM point symbol signals, and 2N M-point is carried out to 2NM point symbols signal
FFT transform obtains 2NM point frequency-region signals, and the transposed matrix H of the right multiplying factor matrix H of 2NM point frequency-region signals is then obtained NM points
Signal
MC-TDMA system structures proposed by the present invention realize that simply transmitting terminal passes through the distribution of incoming symbol intertexture and MDFT
Wave filter group realizes that receiving terminal uses IMDFT synthesis filter group structures, using FFT transform unit.Intertexture computing eliminates adjacent
Intersubband disturbs, and after intertexture computing, 2NM point symbol signals become NM point symbol signals.Sub-carrier number is M, N number of overloading
Ripple modulation symbol is transmitted in N number of period respectively, by adjusting N and M system can be allowed to obtain optimal time frequency resolution, so that
The ability of the existing anti-radio channel multi-path decay of system is allowed also to have the ability of anti-carrier frequency drift, the every other modulation of MC-TDMA collection
The advantages of system, uses analysis filter group structure in a system, transmitting terminal.Receiving terminal uses synthesis filter group structure, connects
Receiving end can disposably recover NM point transmitting terminal input signals, and delay is small, and can save the resource of prefix occupancy, be put using frequency domain
Zero balanced device, is realized simple.
It is described in further detail below in conjunction with the implementation of attached drawing and instantiation to the present invention.It should be evident that below
Attached drawing in description is only some embodiments of the present invention, for those of ordinary skill in the art, is not paying wound
On the premise of the property made is worked, other similar scenes can also be applied the present invention to according to these attached drawings.Unless from language environment
In it is apparent or separately explain, in figure identical label represent it is identical structurally and operationally.
It is as shown in Figure 1 MC-TDMA multicarrier modulation system theory structure block diagrams, MC-TDMA multicarrier modulation system bags
Include：Transmitting terminal and receiving terminal, transmitting terminal include, symbol map unit, symbol sequencing unit, NM- point FFT transform unit, subband
Analysis filtering, 2N M-point IFFT conversion, intertexture arithmetic element；Receiving terminal includes, and arithmetic element, 2N M-point FFT are knitted in reciprocal cross
Converter unit, sub-band synthesis filter, NM- point IFFT converter units, the anti-sequencing unit of symbol, the anti-map unit of symbol.
Input binary bit sequence s (n) through symbol map unit carry out symbol mapping, symbol mapping can use QPSK or
QAM methods, obtain needing the complex symbol signal being modulated after symbol maps.Complex symbol signal sorts by symbol
Unit handles symbol sequence, and symbol sequence uses intertexture sequencing model, that is to say, that a mark signal is inserted into every N points,
For single user (uplink), the value between two non-zero symbol signals is zero, is come for multi-user's (downlink transfer)
Say, the value between two non-zero symbol signals is the signal of other users, and NM point symbol signals are obtained after sequencing unit processing.Obtain
The sequence mark signal obtained is handled through NM- point FFT transform units, and then sub-band analysis filtration unit analyzes signal
After filtering, it is sent into 2N M-point IFFT converter unit and is converted, obtain modulated signal, the signal obtained is interleaved
Computing, channel is sent into after prefixing and is sent to receiving terminal.Prefix is gone in the receiving terminal docking collection of letters number, after equalised device is to removing prefix
Signal carry out equilibrium treatment, be re-fed into reciprocal cross knit arithmetic element processing after, M-point FFT transform unit carries out 2N M-point to it
FFT transform obtains frequency domain sub-band signal, and band frequency-region signal entirely is synthesized after subband integrated filter, and the frequency-region signal of synthesis is sent into
NM- point IFFT converter units obtain time-domain signal, carry out that symbol is counter sorts to the signal of IFFT converter units output, most afterwards through symbol
Number reflection penetrate cell processing obtain rebuild transmitting terminal incoming symbol signal.
Specifically, to multiple access modulating system, it is assumed that total sub-carrier number is L=NM, what each user assigned to
Sub-carrier number is M.Sub-carrier signal obtains M mark signal after the mapping of symbol map unit, and M mark signal is by handing over
Arithmetic element is knitted to be assigned on L time point using interleaved symbol allocation model.L point FFT transform is carried out to complex symbol signal,
Time-domain symbol signal is transformed to frequency domain and obtains frequency-region signal.
As shown in Fig. 2, MDFT wave filters group is the part before FFT unit, it is made of three parts, Part I is preposition filter
Ripple unit, Part II are IFFT converter units, and Part III is signal interleaving arithmetic element.
MDFT wave filter groups include：Sub-band analysis filtration part, IFFT conversion sections, signal interleaving arithmetic section, subband
After analyzing filtering part and the completion pre-filtering of IFFT conversion sections and IFFT conversion, signal interleaving arithmetic section is to 2NM glyphs
Number signal is interleaved computing, obtains the output of NM points complex symbol and is transmitted.
Pre-filter is by analysis filter group group that an extraction yield is M/2 (port number for taking wave filter group is M)
Into to input signal x (n) progress Substrip analysis processing, M subband signal of acquisition.Choose the filter that prototype function coefficient is h (n)
Ripple device group, z in Fig. 2-1Represent a delay.Each frame NM point incoming symbol signal x (n) enter prefilter along delay line,
Then M/2 sampling is carried out, obtains the output of NM roads, the output of NM roads obtains the output of M roads after superposition.Wherein, N is by modulating system
Number of users determines that M is determined by sub-carrier number.The output of M roads obtains M roads modulated signal after inverse fourier transform (IFFT).Adjust
Signal processed needs to be interleaved computing before transmitting, so as to remove the interference of intersubband.Intertexture computing includes transmitting terminal intertexture fortune
Calculate and computing two parts are knitted in receiving terminal reciprocal cross, the intertexture arithmetic section of transmitting terminal is by withdrawal device of the decimation value for 2, real
With imaginary-part operation unit form, signal enter intertexture arithmetic section after be divided into up and down two-way, be not delayed all the way above, below one
Lu Youyi delays.For upper and lower two paths of signals after 2 times of sampling are carried out, alternating takes real and imaginary parts, the real and imaginary parts value of extraction
One new complex symbol signal value of synthesis is transmitted.The real and imaginary parts computing of adjacent two passage, which needs to interweave, to be carried out, such as
What is carried out all the way on the previous passage of fruit is real part computing, then the upper of current channel needs to carry out imaginary-part operation all the way.In Fig. 2, z-1
Represent one delay, ↓ M/2 represent M/2 sampling, ↑ M/2 represent M/2 interpolation, h (n) represent RRC ptototype filter functions, Re { } and
IM { } is real imaginary-part operation, x (n) andTransmitting terminal input signal and receiving terminal reconstruction signal are represented respectively.
Due to 2 times of sampling and intertexture computing, the input of 2NM points becomes the output of NM points, so as to ensure the defeated of MC-TDMA systems
It is consistent with output to enter symbolic number.After above-mentioned processing, cyclic prefix is added to the complex symbol signal of synthesis, subsequently into nothing
Line channel is sent.
MDFT wave filter groups are optimal can in the following way, and pre-filtering part is according to ptototype filter construction of function coefficient
Matrix H, carries out NM point frequency domain symbol signals with coefficient matrix H right multiplied to arrive 2NM point frequency domain symbol signals, IFFT conversion sections
2N M-point IFFT conversion is carried out to 2NM point frequency domain symbols signal, obtains 2NM point time-domain signals, intertexture arithmetic section is to 2NM points
Time-domain signal is interleaved computing, obtains NM point complex symbol signal outputs.
Specifically, it is as follows according to the method for ptototype filter construction of function coefficient matrix H, if ptototype filter is RRC
(square root raised cosine function) function, then ptototype filter function coefficients h (n) can be expressed as：
Wherein, M is equal to sub-carrier number, and r represents the roll-off factor of RRC functions, determines the stopband attenuation of RRC function filters
The factor, the scope of RRC function variables n are determined by the length NM of prefilter.The construction of coefficient matrix H is not limited to
State method and design parameter setting.
Construct coefficient matrix H, it is assumed that access customer number N, the sub-carrier number that each user assigns to are M, and H-matrix is by one
A matrix circular for having 4Nx2N matrix element block moves to right M/2 and obtains, wherein, matrix element block hi,0,hi,1(0<=i<=N-
1) it is two diagonal matrixs, if RRC prototype function coefficient hs (n) (0<=n<=NM-1) being divided into N number of sub-block, (every sub-block includes M
Point), hi,0,hi,1It is made of respectively the preceding M/2 points and rear M/2 points of the i-th sub-block.The size of H is 2NMxNM.In the mistake of cyclic shift
Cheng Zhong, the M/2 points on the M/2 points shift-in left side that the right removes.Displacement is from first MxNM matrixes BOB(beginning of block) to the 2N-1 matrix
Block end.
We illustrate matrix H, and h to a specific example belowi,0And hi,1Construction.If number of users N=2, sub- load
Wave number M=8, roll-off factor r=0.5, prototype function coefficient h (n) is obtained according to RRC formula:
Matrix element block h0,0,h0,1,h1,0,h1,1Respectively：
Matrix H is finally obtained to be equal to
NM point frequency domain signal Xs (k) are carried out with coefficient matrix H it is right it is multiplied arrive 2NM point symbol signals, then, to 2NM glyphs
Number signal carries out 2N M-point IFFT (inverse fast fourier transform) computing, obtains 2NM point time-domain signals.
Receiving terminal carries out the operation opposite with transmitting terminal.Receiving terminal docks received signal and carries out prefix process first,
Then equalised device carries out balancing operational and removes channel disturbance, after arithmetic element processing is knitted in feeding reciprocal cross, M-point FFT transform unit
2N M-point FFT transform is carried out to it and obtains frequency domain sub-band signal, full band signal is synthesized through subband integrated filter, is sent into NM- points
IFFT converter units obtain time-domain signal, carry out that symbol is counter sorts to the signal of converter unit output, through the anti-map unit of symbol
Processing obtains transmitting terminal and rebuilds mark signal.
The present invention can use frequency domain zero setting balanced device.Signal after frequency domain zero setting balanced device will go prefix carries out FFT transform
To frequency domain, then divided by channel system function H (k) (Fourier transformation of channel impulse response h (n)), finally carry out IFFT
(inverse fast fourier transform) conversion obtains removing the signal of channel disturbance.
MC-TDMA is a kind of multicarrier modulation system based on wave filter group, uses modified DFT (MDFT) wave filter
Group.MC-TDMA is on the basis of traditional filter bank multi-carrier modulating system (FBMC), by introducing single-carrier modulated system
The advantages of system and obtain.MC-TDMA systems have the two-fold advantage of multicarrier and single-carrier system, and existing low-down power peak is equal
Value is than (PAPR) and has very strong anti-radio channel multi-path to decay and the asynchronous energy of carrier wave.The close theoretical minimum of PAPR values, than
The PAPR values of single carrier frequency division multiplexing (SC-FDMA) system used in LTE standard are also low.Emulation shows, MC-TDMA systems
Anti- carrier wave ability to be asynchronous be more than 10 times of OFDM.MC-TDMA multicarrier modulation systems can be not only used for uplink communication
(uplink) it can also be used for downlink communication (downlink).The power consumption that MC-TDMA systems can reduce terminal device can also reduce
The power consumption of base station equipment, while the required precision to terminal device clock frequency can be reduced.MC-TDMA systems have design spirit
It is living, realize the characteristics of easy, high-speed communication can be used for and can be used for Internet of Things Network Communication.
Fig. 3,4,5 give the analog result figure compared MC-TDMA multicarrier modulation systems performance proposed by the present invention.
Fig. 3 provides the analog result of PAPR, and s represents symbol displacement in figure, and solid line represents OFDMA system, and dotted line represents SC-FDMA systems
System, dotted line represent MC-TDMA systems.Can be clearly seen from Fig. 3, the PAPR values of MC-TDMA systems are minimum, than OFDMA and
SC-FDMA has fairly obvious improvement.What Fig. 4 was provided is the comparison figure of symbol error rate, from figure it can also be seen that, MC-TDMA
The bit error rate it is minimum.The performance that Fig. 5 gives the anti-subcarrier drift of system compares, it can be seen from the figure that in 10% carrier wave
In the case of drift, MC-TDMA still has good performance, and at this moment OFDMA and SC-FDMA systems cannot work.
It should be apparent that the present invention proposes that performance of the MC-TDMA systems than OFDMA and SC-FDMA is all good from analog result.MC-
TDMA, which both can be used for uplink communication, can be used for downlink communication, both can be used for high-speed communication can be used for it is asynchronous
Low-speed communication.
Illustrative embodiments listed by the present invention are as described above, but the only to facilitate case for understanding the present invention and using
Example, is not limited to the present invention.In the case of without departing substantially from inventive concept and essence, those skilled in the art
Various corresponding modifications and variations, patent protection model of the invention can be made in the formal or details of implementation according to the present invention
Enclose, the scope that claims of being still subject to are defined.
Claims (9)
1. a kind of carrier time division is multiplexed modulator approach, it is characterised in that when time domain incoming symbol signal is assigned to a series of
Between be interleaved distribution on point and obtain a series of time domain incoming symbol signals；It is defeated to a series of time domains using Fast Fourier Transform (FFT)
Enter mark signal progress FFT transform and obtain a series of frequency domain symbol signals；MDFT processing is carried out to frequency domain symbol signal；
The MDFT processing includes：Pre-filtering is carried out to NM point frequency domain symbols signal, further according to ptototype filter construction of function
Coefficient matrix H, NM point frequency domain symbol signals are carried out with coefficient matrix H it is right it is multiplied arrive 2NM point frequency domain symbol signals, to 2NM points
Frequency domain symbol signal carries out 2N M-point IFFT conversion, obtains 2NM point time domain complex signals；To 2NM point time domain complex signals into
Row intertexture computing, obtains NM points output complex symbol signal；Wherein N is access customer number, and M is the sub-carrier number of each user；
The coefficient matrix H is shifted to obtain by the coefficient of MDFT analysis filter groups by M/2 dot cycles, MDFT analysis filter systems
Number is made of square root raised cosine RRC functions, and the dimension of coefficient matrix H is 2NM x NM.
2. modulator approach according to claim 1, it is characterised in that：The Fast Fourier Transform (FFT) includes：It is implemented
Fourier transformation converted for NM- point quick Fourier, N, M are the positive integer more than or equal to 1 here.
3. modulator approach according to claim 1, it is characterised in that：The coefficient matrix H, including following submatrix
hi,0And hi,1：By the way that RRC prototype function coefficient hs (n) are divided into N number of sub-block, wherein 0<=n<=NM-1, M is included per sub-block
Point, forms diagonal matrix h by the preceding M/2 points and rear M/2 points of the i-th sub-block respectivelyi,0With diagonal matrix hi,1, i is between 0 here
To the integer between N-1.
4. modulator approach according to claim 3, it is characterised in that：The submatrix h that the coefficient matrix H is includedi,0With
Submatrix hi,1Arrangement mode it is as follows：
A kind of 5. carrier time division multiplexing demodulation method, it is characterised in that：Before the docking collection of letters number goes prefix, equalised device equilibrium to go
Signal after sewing, carries out IMDFT processing synthesis band frequency-region signal entirely, and the frequency-region signal of synthesis carries out fast reverse Fourier IFFT
Conversion obtains time-domain signal, then carries out that symbol is counter to sort to the time-domain signal of output, and penetrating processing through symbol reflection obtains what is rebuild
Transmitting terminal incoming symbol signal；
The IMDFT processing includes：Calculation process, Fourier transformation processing, and the processing of subband integrated filter are knitted in reciprocal cross, described
Fourier transformation, its Fourier transformation implemented is a 2N M-point Fourier transformation, the subband integrated filter processing tool
Body is, post-filtering is carried out to 2NM point frequency domain symbols signal, further according to coefficient matrix H transposition to 2NM point frequency domain symbol signals
The progress right side is multiplied to arrive NM point frequency domain symbol signals；N is access customer number, and M is the sub-carrier number of each user；The coefficient matrix
H is shifted to obtain by the coefficient of MDFT analysis filter groups by M/2 dot cycles, and MDFT analysis filter system numbers are by square root liter
Cosine RRC functions are formed, and the dimension of coefficient matrix H is 2NM x NM.
6. demodulation method according to claim 5, it is characterised in that：The fast reverse Fourier transformation, what it was implemented
Reverse Fourier transformation is a NM- point fast reverse Fourier transformation.
7. a kind of carrier time division is multiplexed MDFT systems, which includes transmitting terminal and receiving terminal, it is characterised in that transmitting terminal bag
Include：Map to obtain the symbol map unit of complex symbol signal for carrying out symbol to binary bit sequence；For to input
Symbol is interleaved the symbol sequencing unit of distribution, for time-domain symbol signal to be transformed in quick Fu of frequency domain symbol signal
Leaf transformation unit；It is mono- to the MDFT for making reverse Fourier transformation after the progress pre-filtering of frequency domain symbol signal as prefilter
Member, MDFT units use analysis filter group structure；The receiving terminal includes：The docking collection of letters number goes prefix, equilibrium treatment to obtain
Mark signal removes prefix unit, balanced device；Computing is knitted for carrying out reciprocal cross, it is inverse that computing acquisition signal progress MDFT is knitted to reciprocal cross
The IMDFT units of conversion obtain mark signal, and transmitting terminal reconstruction letter is obtained for the mark signal of acquisition to be carried out IFFT conversion
Number reverse Fast Fourier Transform (FFT) unit；
MDFT units include, sub-band analysis filtration part：For carrying out pre-filtering to NM point frequency domain symbols signal, further according to original
Mode filter construction of function coefficient matrix H, carries out NM point frequency domain symbol signals with coefficient matrix H right multiplied to arrive 2NM point frequency domains
Mark signal；IFFT conversion sections：When converting to obtain 2NM points for carrying out 2N M-point IFFT to 2NM point frequency domain symbols signal
Domain signal；Intertexture arithmetic section：NM points output complex symbol signal is obtained for being interleaved computing to 2NM point time-domain signals；N
For access customer number, M is the sub-carrier number of each user；
The IMDFT units, it is used to NM points remove the mark signal of channel disturbance and is reduced to 2NM point frequency domain symbol signals,
Post-filtering is carried out to 2NM point frequency domain symbols signal, 2NM point frequency domain symbols signal is carried out further according to the transposition of coefficient matrix H
The right side is multiplied to arrive NM point frequency domain symbol signals.
8. carrier time division according to claim 7 is multiplexed MDFT systems, it is characterised in that inverse in the MDFT units
To Fourier transformation, its reverse Fourier transformation implemented is a reverse Fourier transformation of 2N M-point.
9. carrier time division according to claim 7 is multiplexed MDFT systems, it is characterised in that the reverse fast Fourier
Converter unit, its reverse Fast Fourier Transform (FFT) implemented are a reverse Fast Fourier Transform (FFT) of NM- points, and N, M are here
Positive integer more than or equal to 1.
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| CN107026809B (en) * | 2016-01-29 | 2020-10-30 | 中兴通讯股份有限公司 | Data processing method and device |
| CN106713203B (en) * | 2016-03-31 | 2019-06-07 | 展讯通信（上海）有限公司 | FBMC sends signal creating method and device |
| CN106130946A (en) * | 2016-06-08 | 2016-11-16 | 重庆邮电大学 | A kind of biorthogonal frequency-division multiplex multi-carrier modulation/demodulation methods and system |
| CN107733830B (en) | 2016-08-12 | 2021-12-10 | 中兴通讯股份有限公司 | Method, device and system for generating multi-carrier signal |
| US10567205B2 (en) * | 2017-01-26 | 2020-02-18 | Qualcomm Incorporated | Frequency and time domain multiplexing for low peak-to-average power ratio (PAPR) waveform design with multiple streams |
| CN108111458A (en) * | 2017-12-29 | 2018-06-01 | 中山大学花都产业科技研究院 | A kind of inverse Fourier transform algorithm applied to NB-IoT |
| CN110247703A (en) * | 2019-04-25 | 2019-09-17 | 清华大学 | Equalization methods before a kind of segmentation frequency domain in high speed visible light communication system |
| CN114826856B (en) * | 2022-03-17 | 2023-07-18 | 国网智能电网研究院有限公司 | Wireless communication method and device based on carrier modulation and communication terminal |
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