One kind overlaps frequency-division complex modulation method, apparatus and system
Technical field
The present invention relates to the communications field, and in particular to one kind overlaps frequency-division complex modulation method, device and overlaps frequency division and answers
Use system.
Background technology
Frequency division multiplexing FDM (Frequency Division Multiplexing) is that one kind allows multiple to occupy narrower bandwidth
Signal share a technology for wider bandwidth.As shown in figure 1, the signal bandwidth being respectively utilized respectively B1, B2, B3,
B4 ..., certainly they can also occupy same band, △ B are Minimal Protective bandwidth, and real protection bandwidth can be with well-to-do.
△ B should be greater than peak frequency drift and the peak frequency of channel of the transition band width of used demultiplexer filter plus system
Diffusing capacity.This is most common frequency multiplexing technique, existing most of broadcast system, communication system and radar system etc.
All use this technology.The maximum feature of this technology is mutually isolated between the signal spectrum being utilized, will not
In the presence of interfering.
Therefore, traditional viewpoint is not overlapped in frequency domain between adjacent channel, to avoid being produced between adjacent channel
Interference, but the raising of spectrum efficiency of this limitation of the technology.The viewpoint of the frequency multiplexing technique of prior art is between each channel
Not only need not be mutually isolated, and can have very strong overlapped, as shown in Fig. 2 prior art is by the weight between channel
It is folded to be considered as a kind of new coding bound relation, and corresponding modulation and demodulation technology is proposed according to the restriction relation, therefore claim
For overlap frequency division multiplexing, this technology cause spectrum efficiency with overlap number of times K proportional increases, be K=3 in wherein Fig. 2
Situation.
In theory, when being carried out data transmission using overlap frequency multiplexing technique, overlapping number of times K can ad infinitum increase, because
This spectrum efficiency also can ad infinitum increase, but be had been found that with the increase for overlapping number of times K in the laboratory research stage, although frequency spectrum
Efficiency is increased, but transimission power consequently also increases, and the growth of transimission power is also limited to a certain extent in turn
The increase of number of times K is overlapped, so as to also limit the increase of spectrum efficiency.
The content of the invention
The application provides a kind of overlap frequency-division complex modulation method, apparatus and system.
According in a first aspect, provided in a kind of embodiment it is a kind of overlap frequency-division complex modulation method, comprise the following steps:
The smooth initial envelope waveform of waveform in one frequency domain is generated according to design parameter, wherein the initial envelope waveform
It is figure base window envelope waveform or its envelope waveform for developing window function;
The initial envelope waveform is shifted on frequency domain by predetermined spectrum intervals according to overlapping multiplexing number of times, is obtained
To each subcarrier envelope waveform;
The digital signal sequences of input are converted into sign symbol sequence;
Symbol in the sign symbol sequence is multiplied with each self-corresponding subcarrier envelope waveform, each subcarrier is obtained
Modulation envelope waveform;
The modulation envelope waveform of each subcarrier is overlapped on frequency domain, the multiple modulation Envelop waves on frequency domain are obtained
Shape;
Multiple modulation envelope waveform on the frequency domain is entered into line translation, the multiple modulation envelope waveform in time domain is obtained.
A kind of overlap frequency division multiplexing modulating device is provided according to second aspect, in a kind of embodiment, including:
Waveform generating module, for generating the smooth initial envelope waveform of waveform in a frequency domain, wherein the waveform is given birth to
Initial envelope waveform into module generation is figure base window envelope waveform or its envelope waveform for developing window function;
Shift module, for according to overlapping multiplexing number of times by the initial envelope waveform on the frequency domain by between predetermined frequency spectrum
Every being shifted, each subcarrier envelope waveform is obtained;
Modular converter, for the digital signal sequences of input to be converted into sign symbol sequence;
Multiplier module, for by the symbol in the sign symbol sequence and each self-corresponding subcarrier envelope waveform phase
Multiply, obtain the modulation envelope waveform of each subcarrier;
Laminating module, for the modulation envelope waveform of each subcarrier to be overlapped on frequency domain, obtains on frequency domain
Multiple modulation envelope waveform;
Conversion module, for the multiple modulation envelope waveform on the frequency domain to be entered into line translation, obtains the multiple modulation in time domain
Envelope waveform.
A kind of overlap Frequency Division Multiplexing system, including transmitter and receiver are provided according to the third aspect, in a kind of embodiment;
The emitter includes:
Above-mentioned overlap frequency division multiplexing modulating device, the multiple modulation Envelop waves of output signal sequence are carried for modulating generation
Shape;
Emitter, for the multiple modulation envelope waveform to be transmitted into receiver;
The receiver includes:
Reception device, for receiving the multiple modulation envelope waveform;
Frequency division multiplexing demodulating equipment is overlapped, for being demodulated to the multiple modulation envelope waveform for receiving, decoding is eventually passed through
Obtain final input bit sequence.
According to the overlap frequency-division complex modulation method, apparatus and system of above-described embodiment, because generation is figure Ji Chuanbao
Network waveform or its initial envelope waveform for developing the window function waveform in frequency domain are smoothed, and correspondingly, it is concentrated in time domain self-energy
And the duration is shorter, thus by its modulation formed polyphony adjust envelope waveform time domain energy concentrate and the duration compared with
It is short, therefore its availability of frequency spectrum is high, signal transmission rate is also high, and only needs to relatively low transimission power, has when being demodulated
The relatively low bit error rate.
Brief description of the drawings
Fig. 1 is the shared waveform diagram for wider bandwidth of each signal in conventional frequency division multiplexing technology;
Fig. 2 is the coding bound relation schematic diagram formed after overlapping between each channel in existing overlap frequency division technique;
Fig. 3 is the structural representation of overlap Frequency Division Multiplexing system in a kind of embodiment of the application;
Fig. 4 is the structural representation of overlap frequency division multiplexing modulating device in a kind of embodiment of the application;
Fig. 5 is the structural representation of reception device in a kind of embodiment of the application;
Fig. 6 is the structural representation of overlap frequency division multiplexing demodulating equipment in a kind of embodiment of the application;
Fig. 7 is the schematic flow sheet of overlap frequency-division complex modulation method in a kind of embodiment of the application;
Fig. 8 is that output signal sequence determines the schematic flow sheet of method in a kind of embodiment of the application;
Fig. 9 is the principle of stacking schematic diagram of K roads waveform multiplexing in a kind of embodiment of the application;
Figure 10 is three kinds of frequency domain figures of figure base window envelope waveform in a kind of embodiment of the application;
Figure 11 be a kind of embodiment of the application in using scheme base window envelope waveform as initial envelope waveform modulation obtain it is each
Three kinds of frequency domain figures of subcarrier envelope waveform and multiple modulation envelope waveform;
Figure 12 be a kind of embodiment of the application in using scheme base window envelope waveform as initial envelope waveform modulation obtain answer
Three kinds of time-domain diagrams of modulation envelope waveform;
Figure 13 is the principle of stacking schematic diagram of 3 road waveform multiplexings in a kind of embodiment of the application;
Figure 14 is the frequency domain figure of rectangular window envelope waveform in a kind of embodiment of the application;
Figure 15 be a kind of embodiment of the application in using rectangular window envelope waveform as initial envelope waveform modulation obtain answer
The time-domain diagram of modulation envelope waveform;
Figure 16 be a kind of embodiment of the application in using rectangular window envelope waveform as initial envelope waveform modulation obtain answer
The time-domain diagram of modulation envelope waveform;
Figure 17 is Input output Relationship figure in a kind of embodiment of the application;
Figure 18 is a kind of embodiment interior joint state transition diagram of the application;
Figure 19 is to lead envelope waveform scheming base window single order in a kind of embodiment of the application to be modulated as initial envelope waveform
Three kinds of frequency domain figures of the multiple modulation envelope waveform for arriving.
Specific embodiment
The present invention is described in further detail below by specific embodiment combination accompanying drawing.
In to overlapping frequency multiplexing technique research, inventor has found that the growth of transimission power is main with the signal that is re-used
The frequency spectrum of (modulating window function) is relevant, and the shape to multiplexed signals frequency spectrum not as contemplated by theory, bandwidth are not appointed
What is required.Although there are many window functions in the prior art, can freely use in theory various window functions to transmit positive and negative symbol
Number sequence is modulated, but due to rectangular window compared to other window functions producing, design and application it is upper be easier, cost more
It is low, therefore rectangular window preferentially is used when signal modulation is carried out at present, and the spectrum waveform of square wave is more precipitous in both sides, so that
Its energy in time-domain is not concentrated, and the duration is long, therefore multiplexing waveform systematic function is very poor, causes required transmission work(
Rate and the bit error rate are all very high.
Based on above-mentioned discovery, in embodiments of the present invention, square is better than using a kind of when application overlaps frequency multiplexing technique
The window function of shape ripple is modulated to the sign symbol sequence transmitted.
Fig. 3 is refer to, overlapping Frequency Division Multiplexing system includes emitter 1 and receiver 2.
Emitter 1 includes overlapping frequency division multiplexing modulating device 10 and emitter 20, wherein, overlap frequency division multiplexing modulation dress
Put 10 for modulate generation carry the multiple modulation envelope waveform of output signal sequence, emitter 20 is for by above-mentioned multiple modulation bag
Network waveform is transmitted into receiver 2.
Fig. 4 is refer to, overlapping frequency division multiplexing modulating device 10 includes waveform generating module 11, shift module 12, modulus of conversion
Block 13, multiplier module 14, laminating module 15 and conversion module 16.
Waveform generating module 11 is used to generate the smooth initial envelope waveform of waveform in a frequency domain according to design parameter.
In one embodiment, the design parameter at least bandwidth width including initial envelope waveform.
Shift module 12 is used to that initial envelope waveform to be pressed into predetermined spectrum intervals on frequency domain according to overlapping multiplexing number of times
Shifted, obtained each subcarrier envelope waveform.In one embodiment, spectrum intervals is that subcarrier spectrum is spaced △ B, its neutron
Carrier spectrum interval △ B=B/K, B are the bandwidth of initial envelope waveform, and K is overlap multiplexing number.In one embodiment, it is described
Inverses of the subcarrier spectrum interval △ B more than or equal to systematic sampling.
Modular converter 13 is used to for the digital signal sequences of input to be converted into sign symbol sequence.In one embodiment, turn
The digital signal sequences of input are converted into sign symbol sequence and are specially by mold changing block 13:In the digital signal sequences that will be input into
0 is converted to+A, and 1 in digital signal sequences is converted to-A, to form sign symbol sequence and export.For example, A=1, in a tool
In body embodiment, modular converter 13 use BPSK modulation systems, will be input into { 0,1 } bit sequence by modulation conversion into+
1, -1 } symbol sebolic addressing.
Multiplier module 14 is used for the symbol in above-mentioned sign symbol sequence and each self-corresponding subcarrier envelope waveform phase
Multiply, obtain the modulation envelope waveform of each subcarrier.
Laminating module 15 is used to be overlapped the modulation envelope waveform of above-mentioned each subcarrier on frequency domain, obtains on frequency domain
Multiple modulation envelope waveform.
Conversion module 16 is used to that the multiple modulation envelope waveform on above-mentioned frequency domain to be transformed to the multiple modulation envelope in time domain
Waveform.In one embodiment, conversion module 16 can use fourier inverse transformation, by the multiple modulation Envelop waves on above-mentioned frequency domain
Deformation changes the multiple modulation envelope waveform in time domain into.
The multiple modulation envelope waveform of above-mentioned modulation generation carries output corresponding with the sign symbol sequence being converted to
Signal sequence, this output signal sequence is made up of the output signal of each spectrum intervals, and the output signal of each spectrum intervals is each frequency
Result after the operation values superposition of the modulation envelope waveform in spectrum interval, when modulation envelope waveform is by plus sign and subcarrier envelope
Waveform is multiplied when obtaining, and its operation values is+1, is multiplied with subcarrier envelope waveform by minus symbol when obtaining, and its operation values is -1.
Referring back to Fig. 3, receiver 2 includes reception device 30 and overlaps frequency division multiplexing demodulating equipment 40, wherein, receive dress
30 are put for the above-mentioned multiple modulation envelope waveform that receiving and transmitting unit 20 sends, overlapping frequency division multiplexing demodulating equipment 40 is used to dock
The multiple modulation envelope waveform of receipts is demodulated decoding.
Fig. 5 is refer to, reception device 30 includes sign synchronization module 31 and digital signal processing module 32.
Sign synchronization module 31 is used to form sign synchronization in time-domain to the multiple modulation envelope waveform for receiving.
Digital signal processing module 32 is used to be sampled the interval reception signal of each symbol time, quantifies, and is allowed to
It is changed into receiving symbol sebolic addressing.
Fig. 6 is refer to, overlapping frequency division multiplexing demodulating equipment 40 includes that spectrum block 41, frequency segmentation module 42, convolution are compiled
Code module 43 and data detection module 44.
Spectrum block 41 is used to enter line translation to form receipt signal frequency spectrum by the reception symbol sebolic addressing in above-mentioned time-domain.
In one embodiment, spectrum block 41 uses Fourier transform, the reception symbol sebolic addressing in above-mentioned time-domain is transformed into and is connect
Receive signal spectrum.
Frequency segmentation module 42 is used in frequency domain be segmented receipt signal frequency spectrum with subcarrier spectrum interval △ B
Receive signal subsection frequency spectrum.
Convolutional encoder module 43 is used to carry out convolution volume to the reception signal subsection frequency spectrum that each subcarrier spectrum is spaced in △ B
Code, obtains between the sign symbol sequence that the digital signal sequences in receipt signal frequency spectrum and emitter 1 through being input into are converted into
One-to-one relationship.
Data detection module 44 is used for according to above-mentioned one-to-one relationship, detects above-mentioned sign symbol sequence.
Fig. 7 is refer to, frequency-division complex modulation method is overlapped disclosed herein as well is one kind, it is comprised the following steps:
Step S11, the initial envelope waveform smoothed according to waveform in design parameter one frequency domain of generation.In an embodiment
In, the design parameter at least bandwidth width including initial envelope waveform.
Step S12, the initial envelope waveform is entered on frequency domain by predetermined spectrum intervals according to overlapping multiplexing number of times
Row displacement, obtains each subcarrier envelope waveform.In one embodiment, spectrum intervals is that subcarrier spectrum is spaced △ B, and its neutron is carried
Ripple spectrum intervals △ B=B/K, B are the bandwidth of initial envelope waveform, and K is overlap multiplexing number.In one embodiment, the son
Inverses of the carrier spectrum interval △ B more than or equal to systematic sampling.
Step S13, the digital signal sequences of input are converted into sign symbol sequence.In one embodiment, step S13 will
The digital signal sequences of input are converted into sign symbol sequence and are specially:In the digital signal sequences of input 0,1 is converted to
± A, A value are non-zero Arbitrary Digit, to form sign symbol sequence.For example, in one embodiment, step S13 uses BPSK
Modulation system, will be input into { 0,1 } bit sequence by modulation conversion into {+1, -1 } symbol sebolic addressing.
Step S14, the symbol in above-mentioned sign symbol sequence is multiplied with each self-corresponding subcarrier envelope waveform, obtained
The modulation envelope waveform of each subcarrier.
Step S15, the modulation envelope waveform of above-mentioned each subcarrier is overlapped on frequency domain, obtains the polyphony on frequency domain
Envelope waveform processed.
Step S16, the multiple modulation envelope waveform transformed to the multiple modulation envelope waveform on above-mentioned frequency domain in time domain.One
In specific embodiment, step S16 can use fourier inverse transformation, and the multiple modulation envelope waveform on above-mentioned frequency domain is transformed into time domain
On multiple modulation envelope waveform.
The multiple modulation envelope waveform of above-mentioned modulation generation carries output corresponding with the sign symbol sequence being converted to
Signal sequence, as shown in figure 8, this output signal sequence can be determined by following steps:
Step S17, when modulation envelope waveform be multiplied with subcarrier envelope waveform by plus sign obtain when, make the modulation envelope
The operation values of waveform are+1, when modulation envelope waveform is multiplied by minus symbol with subcarrier envelope waveform to be obtained, make the modulation bag
The operation values of network waveform are -1;
Step S18, for each spectrum intervals, the operation values of the modulation envelope waveform being located in the spectrum intervals are folded
Plus, the output signal of the spectrum intervals is drawn, so as to form output signal sequence.
The above is illustrated with the example of a reality again below.
The sign symbol sequence that the digital signal sequences of input might as well be made to be converted into is X={ X0, X1..., XN-1, can see
Arrive, the length of sign symbol sequence is N, and N is positive integer.
To the sign symbol sequence X={ X0, X1..., XN-1Overlap frequency division multiplexing modulated process it is as follows:
Smooth initial envelope waveform H (f) of waveform in a frequency domain is generated according to design parameter in step s 11.
The initial envelope waveform is pressed by predetermined spectrum intervals on frequency domain according to overlapping multiplexing number of times in step s 12
Shifted, obtained each subcarrier envelope waveform.In one embodiment, specifically, by the frequency displacement 0 respectively of initial envelope waveform H (f)
To N-1 subcarrier spectrum interval △ B, N number of subcarrier envelope waveform is obtained, wherein i-th subcarrier envelope waveform is H (f-
I* Δ B), 0≤i≤N-1;△ B=B/K, B are the bandwidth of initial envelope waveform H (f) at subcarrier spectrum interval, and K is overlapping multiplexing
Number of times.
The symbol in above-mentioned sign symbol sequence is multiplied with each self-corresponding subcarrier envelope waveform in step S14,
Obtain the modulation envelope waveform of each subcarrier.In one embodiment, specifically, by N number of symbol of above-mentioned sign symbol sequence with
The corresponding subcarrier envelope waveform of each symbol is multiplied, and N number of modulation envelope waveform by subcarrier-modulated is obtained, wherein i-th
Modulation envelope waveform is Xi* H (f-i* Δ B), 0≤i≤N-1.
The modulation envelope waveform of above-mentioned each subcarrier is overlapped on frequency domain in step S15, is obtained on frequency domain
Multiple modulation envelope waveform
Multiple modulation envelope waveform S (f) on above-mentioned frequency domain is entered into line translation in step s 16, the polyphony in time domain is obtained
Envelope waveform S (t) processed.
Multiple modulation envelope waveform S (f) and S (t) of above-mentioned modulation generation are carried and sign symbol sequence X={ X0,
X1..., XN-1Corresponding output signal sequence S={ S0, S1..., SN-1}.Output signal sequence S={ S0, S1..., SN-1Can be by
Step S17 and step S18 in Fig. 8 is determined.In one embodiment, specifically, Fig. 9 is refer to, is the waveform multiplexing of K roads
Principle of stacking schematic diagram, it is in quadrangle form.The item of each of which row represents a symbol X to be sentiWith it is corresponding
The modulation envelope waveform X that subcarrier envelope waveform H (f-i* Δ B) is formed after being multipliedi* the K sampled point of H (f-i* Δ B), same
The item of one row represents that these samples, in same spectrum intervals, can be overlapped, and draws the output letter of the spectrum intervals
Number, so as to form output signal sequence.In the present embodiment, coefficient A0To AK-1It is 1 all to make it.
Embodiment one
In the present embodiment, initial envelope waveform is figure base (Tukey) window envelope waveform, figure base (Tukey) window envelope waveform
Waveform is smoothed in frequency domain.
It is illustrated with a specific example below.
Might as well with overlapping multiplexing number of times K=3, the sign symbol sequence X that the digital signal sequences of input are converted into=- 1 ,+
1 ,+1, -1 ,+1 ,+1 ,+1, -1 } as a example by, wherein X1=-1, X2=+1, X3=+1, X4=-1, X5=+1, X6=+1, X7=+1, X8
=+1, it can be seen that the length N=8 of sign symbol sequence X.
In step s 11, figure base (Tukey) window envelope waveform H (f) is generated according to design parameter, in an embodiment
In, bandwidth B=63 of figure base (Tukey) window envelope waveform H (f), such as Figure 10 (a), shown in (b) and (c), respectively figure base
(Tukey) frequency domain figure of window envelope waveform H (f) when R=0.1,0.5 and 0.9, wherein R is ratio of the conical region to steady state value
Example, span is 0 to 1, and as R=0, figure base (Tukey) window envelope waveform is just equivalent to rectangular window envelope waveform, works as R=1
When, figure base (Tukey) window envelope waveform is just equivalent to Hanning window envelope waveform.As can see from Figure 10, with the increase of R,
Conical region is more and more, and figure base (Tukey) window envelope waveform is increasingly smoothed.In one embodiment, figure base (Tukey)
Window envelope waveform H (f) can be represented with following date expression:
As 0≤f≤R/2,
As R/2≤f≤1- (R/2), H (f)=1;
When 1- (during R/2)≤f≤1,
Wherein R values are 0 to 1.
In step s 12, figure base (Tukey) window envelope waveform H (f) is pressed pre- on frequency domain according to overlapping multiplexing number of times K
Fixed spectrum intervals is shifted, and obtains each subcarrier envelope waveform.Specifically, by figure base (Tukey) window envelope waveform H (f)
0 to 7 subcarrier spectrum interval △ B of frequency displacement, obtain 8 sub- carrier envelope waveforms, wherein i-th subcarrier envelope waveform respectively
It is H (f-i* Δ B), 0≤i≤7;Subcarrier spectrum is spaced △ B=B/K=63/3=21.
In step S14,8 symbols in sign symbol sequence X are multiplied with each self-corresponding subcarrier envelope waveform,
The modulation envelope waveform of each subcarrier is obtained, wherein i-th subcarrier envelope waveform is Xi* H (f-i* Δ B), 0≤i≤7, respectively
The frequency domain figure of subcarrier envelope waveform such as Figure 11, wherein Figure 11 (a), (b) and (c) are represented work as figure base (Tukey) window envelope respectively
In waveform H (f) when parameter R=0.1,0.5 and 0.9, the subcarrier envelope envelope waveform that modulation is obtained, wherein in the various figures, ripple
Shape 1,2 represents the frequency domain figure of each subcarrier envelope waveform after being multiplied with 3.
In step S15, the modulation envelope waveform of above-mentioned each subcarrier is overlapped on frequency domain, obtained on frequency domain
Multiple modulation envelope waveformAs shown in figure 11, Figure 11 (a), (b) and (c) are represented work as respectively
In figure base (Tukey) window envelope waveform H (f) during parameter R=0.1,0.5 and 0.9, the multiple modulation envelope waveform that modulation is obtained, its
In in each figure, waveform 4 is the frequency domain figure of multiple modulation envelope waveform S (f).
In step s 16, multiple modulation envelope waveform S (f) on above-mentioned frequency domain is entered into line translation, obtains the polyphony in time domain
Envelope waveform S (t) processed, S (t)=ifft (S (f)), ifft are Fourier inversion function.Multiple modulation envelope waveform in time domain
As shown in figure 12, Figure 12 (a), (b) and (c) are represented as parameter R=in figure base (Tukey) window envelope waveform H (f) S (t) respectively
0.1st, 0.5 and 0.9 when, the time-domain diagram of multiple modulation envelope waveform that modulation is obtained, it can be seen that its energy in time-domain is concentrated
And the duration is short, wherein the abscissa of Figure 12 represents sampled point, and ordinate represents power, and unit is dB.Finally by this time domain
On multiple modulation envelope waveform S (t) send.
This multiple modulation spectrum signal S (f) and S (t) carry with sign symbol sequence X=- 1 ,+1 ,+1, -1 ,+1 ,+
1 ,+1, -1 } corresponding output signal sequence S={ S0, S1..., S7}.Output signal sequence is by step S17 and step S18
Calculated what is come.In one embodiment, the principle of stacking schematic diagram that K roads waveform is multiplexed in reference picture 9, by multiplexing number K,
Coefficient A0To A2And symbol X1To X7Value all substitute into wherein, the 3 multiplex superposed figures of road waveform of Figure 13 are can obtain, so as to calculate
Go out with sign symbol sequence X={ -1 ,+1 ,+1, -1 ,+1 ,+1 ,+1, -1 } corresponding output signal sequence S=-1,0 ,+1 ,+1,
+ 1 ,+1 ,+3 ,+1 }.
As can see from Figure 10, figure base (Tukey) window envelope waveform H (f) is in R=0.1, its in frequency domain by 0,
Waveform is smoother, and with the increase of R, spectrum waveform is increasingly smoothed.This causes what is formed after being superimposed by its frequency-domain linear to answer
Waveform of modulation envelope waveform S (f) on frequency domain is also very smooth, meanwhile, with the increase of R, multiple modulation envelope waveform S (f) exists
Waveform on frequency domain is also increasingly smoothed, it will be clear that this point, the smooth multiple modulation of waveform on frequency domain from Figure 11
Envelope waveform S (f) is converted into multiple modulation envelope waveform S (t) in time domain, and multiple modulation envelope waveform S (t) can quantity set in time domain
In and the duration it is short, meanwhile, with the increase of R, multiple modulation envelope waveform S (t) energy in time domain concentrate all the more and continue
Time is all the more short, it will be clear that this point from Figure 12.Therefore, the multiple modulation Envelop waves being transmitted after being modulated
Shape, its waveform on frequency domain is smoothed, and energy is concentrated and the duration is short in time domain so that the overlap frequency division multiplexing of the application is adjusted
Method processed, apparatus and system have excellent good performance, are specifically described below.
If Figure 14 is the frequency domain figure of rectangular window envelope waveform, it can be seen that its broader bandwidth, by 1 beginning on frequency domain,
Frequency spectrum is unsmooth, very precipitous, and this causes to be existed as the multiple modulation envelope waveform that initial envelope waveform is modulated and is formed by it
It is also unsmooth on frequency domain, it will be clear that this point from Figure 15, so that the multiple modulation envelope waveform is in time domain
The power dissipation and duration is more long, it will be clear that this point from Figure 16.
Therefore, it can be seen that comparing as obtained from rectangular window envelope waveform is modulated as initial envelope waveform
Multiple modulation envelope waveform, the multiple modulation envelope as obtained from figure base (Tukey) window envelope waveform is modulated as initial envelope waveform
Waveform, its frequency domain occupied bandwidth is the same, but energy concentrates the duration short in time domain, so that the availability of frequency spectrum of the application
It is improved, meanwhile, energy concentrates the duration short in time domain, causes that the transmission rate of the application is improved again, separately
Outward, as figure base (Tukey) window envelope waveform as initial envelope waveform modulate obtained from multiple modulation envelope waveform in frequency domain very
It is smooth so that waveform of the application on to frequency domain carries out the high precision of waveform cutting, reduces the bit error rate.
The above-mentioned modulation as initial envelope waveform by figure base (Tukey) window envelope waveform that is sent by emitter 1 and obtain
Multiple modulation envelope waveform S (t) in time domain, can be received and be demodulated by receiver 2.Specifically, polyphony first to receiving
Envelope waveform processed forms sign synchronization in time-domain;Then, the interval reception signal of each symbol time is sampled, measured
Change, be allowed to be changed into receiving symbol sebolic addressing;Then, the reception symbol sebolic addressing in above-mentioned time-domain is entered into line translation to form reception letter
Number frequency spectrum;Then, receipt signal frequency spectrum with subcarrier spectrum interval △ B be segmented in frequency domain and obtain receiving signal subsection frequently
Spectrum.By after above-mentioned treatment, the reception symbol sebolic addressing that spectrum waveform cutting is obtained for S=-1,0 ,+1 ,+1 ,+1 ,+1 ,+3 ,+
1 }, be multiple modulation spectrum signal S (f) and S (t) carry with sign symbol sequence X=- 1 ,+1 ,+1, -1 ,+1 ,+1 ,+1, -
1 } corresponding output signal sequence S={ -1,0 ,+1 ,+1 ,+1 ,+1 ,+3 ,+1 }.It is exactly finally according to certain decoding algorithm pair
Spectrum waveform after cutting enters row decoding.In one embodiment, specifically Input output Relationship figure in Figure 17 and
Node state transfer figure in Figure 18, carry out between symbol before and after compare, node transfer path is obtained, so as to enter row decoding.
Specifically, turning back to reference picture 17, to represent input+1, downward branch represents input -1 to upward branch (path), carefully
Observation can find that the tree graph reforms into repetition after the 3rd, because the tree that every node from labeled as a gives off
Branch has same output, and the conclusion is equally applicable to node b, c, d.They are nothing more than being following several possibility, such as Figure 18
It is shown, (through input+1) node a and (through input -1) node b as can be seen from the figure can only be transferred to from node a, while b is only
Can arrive (input+1) c and (input -1) d, c can only arrive (input+1) a and (input -1) b, d can only arrive (be input into+1) c and (be input into -
1)d.The reason for producing this phenomenon is very simple, because only that adjacent K symbol can just be formed mutual " interference ".So working as frequency
When K, domain data are input to channel, the 1st data come earliest have moved out a frequency interval of rightmost.Therefore
The output of channel further depends on the input of preceding K-1 frequency data except the input depending on existing frequency data.The present embodiment
In, node state transfer path is to blacken thick line in Figure 17, and node transfer path is that -1 (it is the first of S to receive symbol sebolic addressing
Individual symbol is -1) ->b->c->a->b->c->a->a->B, according to this transfer relationship be obtain the symbol sebolic addressing of input for -1 ,+
1 ,+1, -1 ,+1 ,+1 ,+1, -1 }, it can be seen that the symbol sebolic addressing drawn after decoding as sign symbol sequence X.
Embodiment two
Compared to embodiment one, in the present embodiment, initial envelope waveform is that smooth figure base (Tukey) window of waveform is drilled in frequency domain
Become the envelope waveform of window function, such as figure base (Tukey) window pulse shaping consecutive mutiply function, all-order derivative, all-order derivative sum etc.
A series of envelope waveform of functional forms on figure base (Tukey) window pulse shaping.
Below so that initial envelope waveform leads envelope waveform for figure base (Tukey) window single order as an example, it is described in detail.
Still with overlapping multiplexing number of times K=3 in embodiment one, sign symbol sequence X=- 1 ,+1 ,+1, -1 ,+1 ,+1 ,+1, -
1 } as a example by.
In step s 11, figure base (Tukey) window single order is generated according to design parameter and leads envelope waveform H (f), one
In embodiment, figure base (Tukey) window single order leads bandwidth B=63 of envelope waveform H (f), and such as Figure 19 (a), (b) divide with shown in (c)
It is not frequency domain figure that the single order by figure base (Tukey) window envelope waveform when R=0.1,0.5 and 0.9 is led.Can from figure
Arrive, the waveform that figure base (Tukey) window single order leads envelope waveform H (f) is smoothed, meanwhile, with the increase of R, waveform is also increasingly put down
It is sliding.
In step s 12, figure base (Tukey) window single order is led in frequency domain by envelope waveform H (f) according to overlapping multiplexing number of times K
On shifted by predetermined spectrum intervals, obtain each subcarrier envelope waveform.Specifically, figure base (Tukey) window single order is led
0 to 7 subcarrier spectrums of frequency displacement are spaced △ B to envelope waveform H (f) respectively, obtain 8 sub- carrier envelope waveforms, wherein i-th son
Carrier envelope waveform is H (f-i* Δ B), 0≤i≤7;Subcarrier spectrum is spaced △ B=B/K=63/3=21.
In step S14,8 symbols in sign symbol sequence X are multiplied with each self-corresponding subcarrier envelope waveform,
The modulation envelope waveform of each subcarrier is obtained, wherein i-th subcarrier envelope waveform is Xi* H (f-i* Δ B), 0≤i≤7.
In step S15, the modulation envelope waveform of above-mentioned each subcarrier is overlapped on frequency domain, obtained on frequency domain
Multiple modulation envelope waveform
In step s 16, multiple modulation envelope waveform S (f) on above-mentioned frequency domain is entered into line translation, obtains the polyphony in time domain
Envelope waveform S (t) processed, S (t)=ifft (S (f)).Finally multiple modulation envelope waveform S (t) in this time domain is sent.It
Rear reception multiple modulation envelope waveform S (t) and decoding process is demodulated to it, it is similar with the process in embodiment one,
This is repeated no more.
It can be observed from fig. 19 that figure base (Tukey) window single order leads envelope waveform H (f) smoothed in frequency-domain spectrum, with R's
Increase, spectrum waveform is increasingly smoothed.This causes multiple modulation envelope waveform S (f) formed after being superimposed by its frequency-domain linear in frequency
Waveform on domain is also very smooth, meanwhile, with the increase of R, waveform of multiple modulation envelope waveform S (f) on frequency domain is also increasingly
Smooth, smooth multiple modulation envelope waveform S (f) of waveform is converted into multiple modulation envelope waveform S (t) in time domain, polyphony on frequency domain
Envelope waveform S (t) processed in time domain concentrate and the duration is short by energy, meanwhile, with the increase of R, multiple modulation envelope waveform S
T () energy is concentrated all the more and the duration is all the more short in time domain.Therefore, the multiple modulation Envelop waves being transmitted after being modulated
Shape, its waveform on frequency domain is smoothed, and energy is concentrated and the duration is short in time domain so that the overlap frequency division multiplexing of the application is adjusted
Method processed, apparatus and system have excellent good performance.Compared to from rectangular window envelope waveform as initial envelope waveform system,
The application leads envelope waveform as initial envelope waveform from smooth figure base (Tukey) the window single order of waveform on frequency domain, based on
The reasons why embodiment one is similar so that the application availability of frequency spectrum is high, and signal transmission rate is also high, and only need to relatively low biography
Defeated power, has the relatively low bit error rate when being demodulated.
Each embodiment of the application, (window function, that is, initial envelope are modulated for now with overlap frequency division multiplexing waveform
Waveform) it is analyzed, it has been successfully found a kind of suitable for overlapping frequency-division complex modulation method, device and the frequency-domain waveform of system
Function, waveform is smoothed on this frequency-domain waveform function requirements frequency domain, so that it is transformed into after time domain, and energy is concentrated and the duration is short,
Using this frequency-domain waveform function as initial envelope waveform after, the multiple modulation envelope waveform that obtains of modulation is flat in the same waveform of frequency domain
Sliding, energy is concentrated and the duration is short in time domain, so that the overlap frequency-division complex modulation method of the application, device and being
System in the timing of overlapping multiplexing number of times K mono-, its relative to rectangular window function as initial envelope waveform system, the availability of frequency spectrum and
Transmission speed be refer to greatly improve, and transimission power and the bit error rate are greatly reduced.
Use above specific case is illustrated to the present invention, is only intended to help and understands the present invention, is not used to limit
The system present invention.For those skilled in the art, according to thought of the invention, can also make some simple
Deduce, deform or replace.