CN106302279A - FBMC system equalization method based on interference variance statistics - Google Patents

Abstract

The present invention discloses the FBMC system equalization method of a kind of interference variance statistics, first in the interference variance of transmitting terminal statistical system, prepare for follow-up equilibrium, because sending the randomness of signal, in the metastable communication scenes of communication system, the interference of FBMC system itself is relatively stable, the variance so disturbed also is fixing, demodulate according to traditional F BMC system (or MIMO FBMC system) at receiving terminal, then only need to be doing MMSE equilibrium when, system interference can be eliminated well plus the system interference variance counted at the variance of white Gaussian noise.

Description

FBMC system equalization method based on interference variance statistics

Technical field

The invention belongs to wireless communication technology field, be particularly used for filter bank multi-carrier system (FBMC), suitableeer Balancing technique in multiple antennas filter bank multi-carrier (MIMO-FBMC) system.

Background technology

In existing communication technology, filter bank multi-carrier (FBMC) system is with its higher availability of frequency spectrum, good Time-frequency focus characteristics, become one of major candidate of following mobile multimedia communication.It is discussed in detail and can be found in (Le Floch,M.Alard,and C.Berrou,“Coded Orthogonal Frequency Division Multiplex,” Proceedings of the IEEE,vol.83,pp.982–996,Jun.1995.)。

Traditional FBMC system signal handling process is:

First the mathematic(al) representation of transmission signal s (t) of definition FBMC system is:

$\begin{array}{c}s\left(t\right)=\underset{n}{\Σ}\underset{m=0}{\overset{M-1}{\Σ}}{a}_{m,n}g(t-{\mathrm{n\τ}}_0)j^{m+n}{e}^{j2{\mathrm{\πm\υ}}_{0}t}\\ g_{m,n}=g(t-{\mathrm{n\τ}}_0)j^{m+n}{e}^{j2{\mathrm{\πm\υ}}_{0}t}\end{array}---\left(1\right)$

Wherein a_m,nRepresent data on the m-th subcarrier of the n-th transmitting symbol, υ₀And τ₀Represent between FBMC system subcarrier Every with send signal interval, g (t) is expressed as mode filter function.

Compared to traditional orthogonal frequency division multiplexi, FBMC system only meets strict orthogonality condition in real number field, As follows:

Assuming that FBMC signal experienced by a multidiameter fading channel, channel pulse shock response is h (t), white Gaussian noise The mathematic(al) representation receiving signal for n (t), FBMC system is:

$y\left(t\right)=h\left(t\right)*s\left(t\right)+n\left(t\right)={\∫}_0^{\mathrm{\Δ}}h(t,\mathrm{\τ})s(t-\mathrm{\τ})d\mathrm{\τ}+n\left(t\right)---\left(3\right)$

When receiving terminal receives the transmission signal after multidiameter fading channel, after it is carried out matched filtering operation, receive Signal y (t) is expressed as:

$\begin{array}{c}y\left(t\right)=\mathrm{Re}(\underset{n}{\&Sigma;}\underset{n^{\&prime;}}{\&Sigma;}\underset{m=0}{\overset{M-1}{\&Sigma;}}\underset{m^{\&prime;}=0}{\overset{M-1}{\&Sigma;}}{a}_{m,n}<g_{m,n}|g_{m^{\&prime;},n^{\&prime;}}>H_m)+n^{\&prime;}\left(t\right)\\ =H_m{a}_{m,n}+\mathrm{Re}(\underset{m^{\&prime;}\&NotEqual;m,n^{\&prime;}\&NotEqual;n}{\&Sigma;}{a}_{m^{\&prime;},n^{\&prime;}}<g_{m,n}|g_{m^{\&prime;},n^{\&prime;}}>H_m)+n^{\&prime;}\left(t\right)\end{array}---\left(4\right)$

Wherein,AndRepresent all Intersymbol interference and subcarrier interference.

For the MIMO-FBMC system of multiple antennas, there is N_TRoot transmission antenna, N_RRoot reception antenna, then every transmission on frequency domain Data on antenna can be expressed as S_L×NtThrough H_Nt×NrMimo channel matrix.Then receive signal and can be expressed as V=H_{Nt× Nr}S_L×Nt+N.N is the white Gaussian noise of L × Nr.Only the frequency domain form of formula (1), (3) and (4) need to be substituted into V=H_Nt×NrS_L×Nt+N In formula, i.e. can get the expression formula of receiving terminal MIMO-FBMC, and distracter.

Summary of the invention

The present invention solves above-mentioned technical problem, it is proposed that a kind of FBMC system equalization side based on interference variance statistics Method, only need to measure in more stable communication environment and count MIMO-FBMC (or FBMC) system system in such circumstances originally The variance of body interference, in an equalizer, the process as the variance of interference is done with the variance of white Gaussian noise just can eliminate number Interference according to symbol.

The technical solution used in the present invention is: FBMC system equalization method based on interference variance statistics, including:

S1, transmitting terminal data process；Specifically include following step by step:

S10, the interference variance of statistical system；

S11, to originally transmitted data, carry out quadrature amplitude modulation；

S12, step S11 modulate after data block header add pilot frequency sequence；

S13, the data obtaining step S12 are orthogonalized phase mapping；

S14, the data obtaining step S13 carry out IFFT conversion；

S15, step S14 is obtained data it is filtered processing, and launch；

S2, receiving terminal data process, specifically include following step by step:

S21, the data received are carried out matched filtering process；

S22, the data obtaining step S21 carry out FFT, obtain originally transmitted data；

S23, the data obtaining step S22, extract channel information according to pilot frequency sequence, then according to the channel letter extracted Breath, does equilibrium treatment to channel, noise and system interference simultaneously；

S24, the data obtaining step S23 carry out recovering orthogonalization phase mapping and process；

S25, the data obtaining step S24 carry out QAM demodulation.

Further, the equilibrium treatment described in step S23 is follow-on equilibrium treatment, particularly as follows: by the variance of noise With step S0 is added up the system interference Variance Addition obtained.

Further, described follow-on equilibrium treatment is completed by following formula:

Wherein, H represents channel frequency value, and X represents the signal after transmitting terminal processes, and I represents system interference item, and N represents Noise signal, E | X |²Represent signal power, E | I |²Represent system interference power, E | N |²Represent noise power, θ_{Improve MMSE}Represent The output of modified model equilibrium treatment.

Beneficial effects of the present invention: the FBMC system equalization method based on interference variance statistics of the present invention, is first sending out The interference variance of sending end statistical system, prepares for follow-up equilibrium, because sending the randomness of signal, relative in communication system In stable communication scenes, the interference of FBMC system itself is relatively stable, then the variance of interference is also fixing, at receiving terminal Demodulate according to traditional F BMC system (or MIMO-FBMC system), then only need to be doing MMSE equilibrium when, at white Gaussian noise Variance at can eliminate system interference well plus the system interference variance that counted.

Accompanying drawing explanation

The schematic diagram of the most typical FBMC system that Fig. 1 provides for the present invention.

The schematic diagram of the most typical MIMO-FBMC system that Fig. 2 provides for the present invention.

The schematic diagram of the FBMC system of the interference statistics variance equalization methods that Fig. 3 provides for the present invention.

The schematic diagram of the MIMO-FBMC system of the interference statistics variance equalization methods that Fig. 4 provides for the present invention.

Detailed description of the invention

For ease of skilled artisan understands that the technology contents of the present invention, below in conjunction with the accompanying drawings present invention is entered one Step explaination.

Being illustrated in figure 1 the schematic diagram of the most typical FBMC system, Fig. 2 is the most typical MIMO-FBMC system Schematic diagram, the present invention, by increasing system interference statistical module, measures in more stable communication environment and counts MIMO- The variance of FBMC (or FBMC) system system in such circumstances interference itself, and in follow-on equalizer, interference Variance do with the variance of white Gaussian noise as process, it is achieved offset interference purpose, the interference statistics variance of the application is equal The FBMC system structure of weighing apparatus method is as it is shown on figure 3, include: transmitting terminal and receiving terminal；

The transmitting terminal of described every antenna includes: system interference statistical module, QAM modulation module, pilot frequency sequence add mould Block, orthogonalization phase mapping module, IFFT change module, filtration module and transmitter unit；Described system interference statistical module For adding up system interference, described QAM modulation module is for carrying out quadrature amplitude modulation to originally transmitted data, described Pilot frequency sequence adds module for the data block header after QAM modulation module is modulated is added pilot frequency sequence, described orthogonalization Phase mapping module is orthogonalized phase mapping for the data that pilot tone is added module output, and described IFFT change module is used Carrying out IFFT conversion in the data exporting orthogonalization phase mapping module, described filtration module is for defeated to IFFT change module The data gone out are filtered processing, and described transmitter unit is for launching the output data of filtration module；

The receiving terminal of described every antenna includes: receive unit, matched filtering module, FFT module, the equilibrium of improvement Module, remove orthogonalization phase mapping module and QAM demodulation module；Described reception unit is for receiving the number from transmitting terminal According to；Described matched filtering module is for carrying out matched filtering process to the data received；Described FFT module for Join filtered data and carry out FFT process, obtain originally transmitted data；The balance module of described improvement is for simultaneously to letter Road, noise and system interference do equilibrium treatment；Described go orthogonalization phase mapping module for the number that balance module is exported Process according to carrying out recovery orthogonalization phase mapping；Described QAM demodulation module is for going orthogonalization phase mapping module to export Data carry out QAM demodulation.

The FBMC system equalization method based on interference variance statistics of the present invention, including:

S1, transmitting terminal data process；Specifically include following step by step:

S10, the interference variance of statistical system；Only need to measure in more stable communication environment and count MIMO-FBMC The variance of (or FBMC) system system in such circumstances interference itself；The interference of this system in the case of simulation analysis, big portion It is all Gaussian distributed or nearly Gauss distribution.

S11, to originally transmitted data, carry out quadrature amplitude modulation；

S12, step S11 modulate after data block header add pilot frequency sequence；

S13, the data obtaining step S12 are orthogonalized phase mapping；

S14, the data obtaining step S13 carry out IFFT conversion；

S15, step S14 is obtained data it is filtered processing, and launch；

S2, receiving terminal data process, specifically include following step by step:

S21, the data received are carried out matched filtering process；

S22, the data obtaining step S21 carry out FFT, obtain originally transmitted data；

S23, the data obtaining step S22, extract channel information according to pilot frequency sequence, then according to the channel letter extracted Breath, does equilibrium treatment to channel, noise and system interference simultaneously；In an equalizer, variance and the white Gaussian noise of interference Variance do same process, Gaussian distributed or the interference of similar Gauss distribution can be eliminated.

Equalization operation is done, if being because first doing equalization operation, due in reality after receiving terminal first carries out plus-minus operation In the communication system on border, channel is estimated is devious, the most first does equilibrium and can increase interference.And first carry out plus-minus behaviour Making, because in this communication environment, the coefficient of the channel between originally transmitted data and assistance data is it is believed that approximate phase With, the most just eliminate the interference that channel estimation bias is brought.

S24, the data obtaining step S23 carry out recovering orthogonalization phase mapping and process；

S25, the data obtaining step S24 carry out QAM demodulation.

Above-mentioned interpolation pilot frequency sequence, orthogonalization phase mapping, IFFT conversion, Filtering Processing, matched filtering process, FFT become Change, QAM modulation demodulates the conventional treatment technology being communication technical field, does not do too much explanation at this.

Eliminate the principle of system interference: ambiguity function is a kind of very important when carrying out signal-specificity analysis frequently Function.

First ambiguity in definition function A_g(τ, υ) is:

$A_g(\mathrm{\&tau;},\mathrm{\&upsi;})={\&Integral;}_{?}{e}^{-j2}\mathrm{\&pi;}\mathrm{\&upsi;}tg(t+\frac{\mathrm{\&tau;}}{2})g*(t-\frac{\mathrm{\&tau;}}{2})dt\left(5\right)$

Wherein, υ and τ represents FBMC system subcarrier discontinuous variable and sends signal interval variable, and g (t) is expressed as Mode filter function, g^*T () represents the conjugation of g (t).

If (m, n) the transmission signal at place is a to FBMC system transmitting terminal time-frequency lattice site_m,n, then corresponding to receiving terminal time-frequency Reception signal on lattice point (m ', n ') position can be expressed as:

${\hat{a}}_{m^{\&prime;},n^{\&prime;}}=a_{m,n}+\underset{m\&NotEqual;m^{\&prime;},n\&NotEqual;n^{\&prime;}}{\&Sigma;}{a}_{m^{\&prime;},n^{\&prime;}}<g_{m,n}|g_{m^{\&prime;},n^{\&prime;}}>---\left(6\right)$

Above formula can be expressed as with ambiguity function:

υ₀And τ₀Represent FBMC system subcarrier spacing value and send signal interval value, definition time-frequency coordinate be (m, n) Lattice point neighborhood be Ω_+m,+n=(p, q), | p |≤+ m, | q |≤+ n}, and have (p, q) ≠ (0,0).Due to wave filter time Frequently focus characteristics, wave filter interference mostlys come near receiving this circle data symbol of symbol, that is (+m ,+n)=(1, 1).In like manner, in MIMO-FBMC system, receiving the reception value after signal is disturbed by wave filter can be expressed as:

${\hat{a}}_{m,n}=\underset{j=1}{\overset{Nr}{\&Sigma;}}\underset{p,q}{\&Sigma;}{a}_{m+p,n+q}^j{j}^{p+q+p(q+2n)}{A}_g^{*}({\mathrm{q\&tau;}}_0,{\mathrm{p\&upsi;}}_0)---\left(8\right)$

I is made to be equal in interference value part i.e. formula (6)Part, it is assumed that FBMC demodulation after defeated Going out signal is:

V=HX+I+N (9)

Wherein, H is channel frequency value, and X is for sending signal, and I is system interference item, and N is AWGN signal.Connecing after another equilibrium The collection of letters number is Y=V θ, then the error power between output signal Y and input signal X is:

E|Y-X|²=E | (HX+I+N)-X |²=E | (H θ-1) X+I θ+N θ |² (10)

Owing to signal is uncorrelated with noise, signal and noise are the most uncorrelated with channel.Institute's above formula can be rewritten as:

E|Y-X|²=E | (H θ-1) X |²+E|Iθ|²+E|Nθ|²

=E | (H θ-1) |²E|X|²+|θ|²(E|I|²+E|N|²) (11)

=E | X |²(|H|²|θ|²-Hθ-H^*θ^*+1)+|θ|²(E|I|²+E|N|²)

According to MMSE criterion, θ is asked by formula (11) partial derivative, and makes it be equal to zero, then can obtain:

E|X|²(|H|²θ^*-H)+θ^*(E|I|²+E|N|²)=0 (12)

Such that it is able to obtain follow-on equalizer:

Wherein, E | X |²Expression signal power, and E | I |²、E|N|²Represent jamming power and noise power respectively.In like manner, may be used It is equally applicable to MIMO-FBMC system with the MMSE equalizer that release improves.

Those of ordinary skill in the art it will be appreciated that embodiment described here be to aid in reader understanding this Bright principle, it should be understood that protection scope of the present invention is not limited to such special statement and embodiment.For ability For the technical staff in territory, the present invention can have various modifications and variations.All within the spirit and principles in the present invention, made Any modification, equivalent substitution and improvement etc., within should be included in scope of the presently claimed invention.

Claims (3)

1. FBMC system equalization method based on interference variance statistics, it is characterised in that including:

S1, transmitting terminal data process；Specifically include following step by step:

S10, the interference variance of statistical system；

S11, to originally transmitted data, carry out quadrature amplitude modulation；

S12, step S11 modulate after data block header add pilot frequency sequence；

S13, the data obtaining step S12 are orthogonalized phase mapping；

S14, the data obtaining step S13 carry out IFFT conversion；

S15, step S14 is obtained data it is filtered processing, and launch；

S2, receiving terminal data process, specifically include following step by step:

S21, the data received are carried out matched filtering process；

S22, the data obtaining step S21 carry out FFT, obtain originally transmitted data；

S23, the data obtaining step S22, extract channel information according to pilot frequency sequence, then according to the channel information extracted, Channel, noise and system interference are done equilibrium treatment simultaneously；

S24, the data obtaining step S23 carry out recovering orthogonalization phase mapping and process；

S25, the data obtaining step S24 carry out QAM demodulation.

FBMC system equalization method based on interference variance statistics the most according to claim 1, it is characterised in that step Equilibrium treatment described in S23 is follow-on equilibrium treatment, particularly as follows: by what statistics in the variance of noise and step S0 obtained be System interference variance is added.

The most according to claim 2 based on interference variance statistics FBMC system equalization method, it is characterised in that described in change The equilibrium treatment expression formula entering type is:

Wherein, H represents channel frequency value, and X represents transmission signal, and I represents system interference item, and N represents noise signal, E | X |²Represent Signal power, E | I |²Represent system interference power, E | N |²Represent noise power, θ_{Improve MMSE}Represent the defeated of modified model equilibrium treatment Go out.