CN106789760A - A kind of jamproof single carrier channel is estimated and equalization methods and device - Google Patents

Abstract

The present invention provides a kind of jamproof single carrier channel and estimates and equalization methods and device.The device includes the first estimation module of the first Fourier transformation module being sequentially connected, LS frequency domain channels, interference position detection module and carries out the white noise suppression module that noise suppressed converts frequency domain again after being converted for time domain；The white noise suppression module includes the inverse Fourier transform module, time domain noise reduction processing module and the second Fourier transformation module that are sequentially connected；The AF panel module being connected with the white noise suppression module and interference position detection module output end.The technology of the present invention has carried out anti-interference optimization for complex jamming environment, system is using the characteristic and strong jamming detection algorithm for circulating CDMA channel estimation in frequency domain, frequency channel magnitude phase characteristic in track band, automatic detection interfering frequency scope, suppress the power spectrum component of interference, so as to effectively influence of the interior interference of cancellation band to system, wireless communication link reliability is improved.

Description

A kind of jamproof single carrier channel is estimated and equalization methods and device

Technical field

It is the channel estimation in frequency domain and balancing technique in a kind of spread spectrum radio communications system the present invention relates to a kind of communication technology, it is special It is not related to a kind of to suppress white noise and anti-single-frequency, the channel estimation and equalization method and device of arrowband interference.

Background technology

Since 21 century, space technology, unmanned air vehicle technique quickly grow, and association area communication environment is more severe, estimates in channel Meter and the important traffic technical elements such as balanced, still have more technological difficulties have it is to be solved with it is perfect.

It is relatively broad to the research of channel estimation and equalization technology both at home and abroad at present.The focus wherein studied is concentrated on based on pilot tone sequence The channel estimation technique of row.It can be divided into two classes：One class is channel estimation in frequency domain algorithm, such as least-squares estimation (Least Square, LS) algorithm, LS estimate do not need channel information, have the disadvantage poor anti jamming capability using it.Secondly also have minimum equal Square error (Minimum Mean Square Error, MMSE) and linear minimum mean-squared error (Linear Minimum Mean Square Error, LMMSE) algorithm for estimating, although the performance of channel estimation, the fortune but frequency domain channel covariance matrix is inverted can be improved Calculation amount is larger.In order to reduce computational complexity, subsequently have also been proposed singular value decomposition (Singular Value Decomposition, SVD) algorithm.Another kind of is the channel estimation method based on transform domain, is such as based on discrete Fourier transform (Discrete Fourier Transform, DFT) channel estimation method, single-carrier frequency division multiple access (Single Carrier Frequency-Division Multiple Access, SC-FDMA) channel estimation method etc..Existing balancing technique includes frequency domain equalization and time domain equalization. Typical single carrier frequency domain equalization (Single Carrier Frequency Domain Equalization, SC-FDE) can be with Reduction system is based on SC-FDE technologies to the sensitivity of frequency deviation, and single-carrier frequency-domain linear equalizer, iteration have been derived again DFF.

Although relevant channel estimation and equalization technology is also more ripe, it can not meet under sophisticated electronic environment very well Communicating requirement, if place working frequency range scope has, other systems are disturbed or electronic countermeasure is disturbed, and performance is poor, thus passes The channel estimation and equalization technology of system still has many key difficulties urgently to be resolved hurrily and perfect.

The content of the invention

The shortcoming of prior art, of the invention to be combined closely in the channel estimation and equalization communication technology and spread spectrum in view of the above, There is provided a kind of single carrier channel estimate with balancer and method, it is good anti-interference for realizing.

In order to achieve the above objects and other related objects, the present invention provides a kind of single carrier channel and estimates and balancer, the device Including for obtaining the first Fourier transformation mould by the single-carrier symbol frequency domain response output after digital front-end treatment and synchronization Block；Be connected with the first Fourier transformation module output end, the LS channels for carrying out channel estimation in frequency domain by LS criterions First estimation module；With the LS channels interference position detection module that just estimation module output end is connected and for time domain conversion simultaneously Do the white noise suppression module that frequency domain is transformed to after white noise noise restraint；The white noise suppression module includes and the LS channels The channel frequency domain response of acquisition is simultaneously transformed to the inverse Fourier transform module of time domain and Fu by the connection of first estimation module output end In leaf inverse transform module output end connection for carry out white Gaussian noise suppress treatment time domain noise reduction processing module and and time domain Noise reduction process module output end is connected to be transformed to the time domain of acquisition the second Fourier transformation module of channel frequency domain response；With The white noise suppression module and the AF panel module of interference position detection module output end connection.

The present invention also provides one kind and carries out single carrier channel estimation and equalization methods using said apparatus, and the method at least includes following Step：Using the first Fourier transformation module by single-carrier symbol by after the frequency domain response for obtaining receiving symbol after Fourier transformation Output；Channel estimation in frequency domain is carried out by LS criterions, channel frequency domain response according to a preliminary estimate is obtained；Then time domain conversion is carried out Frequency domain is transformed to after doing white noise noise restraint；The step of carrying out interference position and detect simultaneously；Then AF panel is carried out, will be upper The result of step acquisition is stated as the MASK tables of AF panel module, quickly to do AF panel to strong jamming subchannel.

Because system of broadband wireless communication takes, frequency range is wider, and radio environment is often also more complicated, if had in working frequency range Specific electron can form fixed interference and system operation is impacted to local other communication systems of anti-interference or presence, cause System covering diminishes or even can not work.Compared to traditional dressing and Block-type pilot, present system is using orthogonal many code channel spread spectrums Scrambled after Walsh sequence pair pilot tones are multiplexed with data and by Gold sequence, realizing carrying out channel circumstance in real time Estimate simultaneously, to be effectively saved time domain piece resource, simplify frame structure.Although current existing noise suppressed SC-FDE is special The means that sharp technology is suppressed using noise in time domain, effectively inhibit influence of the noise to channel estimation characteristic, but in specific list Frequently, the Complex Channel environmental performance performance such as arrowband interference is poor.Apparatus of the present invention are optimized for such complex environment, are The intrinsic frequency division characteristic of system utilization fdma system, Auto-Sensing certain interference frequency range, and utilization circulates CDMA Channel estimation in frequency domain characteristic, frequency channel magnitude phase characteristic in track band effectively suppresses the power spectrum component of interference, eliminates The influence to system is disturbed to improve communication link reliability with interior.

Brief description of the drawings

Fig. 1 is shown as pilot interposition method schematic diagram of the present invention based on time-frequency two-dimensional plane；

Fig. 2 is shown as anti-interference channel estimation and equalization communication device module schematic diagram of the invention；

Fig. 3 is shown as the present invention and schematic diagram is analyzed and tracked to the power density of interference signal in frequency domain；

Fig. 4 is shown as performance curve of the system under white Gaussian noise and fading channel and the property after noise suppressed is processed Can curve；

Fig. 5 is shown as the performance curve of the anti-mono-tone interference of system；

Fig. 6 is shown as the performance curve of the anti-arrowband interference of system；

Fig. 7 is shown as performance curve of the system in sea clutter interference environment；

What Fig. 8 was shown as jamproof channel estimation and equalization of the invention implements flow chart.

Specific embodiment

Embodiments of the present invention are illustrated below by way of specific instantiation, those skilled in the art can be as disclosed by this specification Content understand other advantages of the invention and effect easily.The present invention can also add by way of a different and different embodiment To implement or apply, the various details in this specification can also be based on different viewpoints and application, without departing from essence of the invention Various modifications or alterations are carried out under god.

Refer to shown in accompanying drawing.It should be noted that the diagram provided in the present embodiment only illustrates of the invention in a schematic way Basic conception, component count, shape when only display is with relevant component in the present invention rather than according to actual implementation in schema then and Size is drawn, and it is actual when the implementing kenel of each component, quantity and ratio can be a kind of random change, and its assembly layout type State is likely to increasingly complex.

Spread spectrum technic has excellent anti-interference, anti-fading and anti-multipath performance, while having multiple access communication, confidentiality again Many advantages, such as, it is widely used and military communication, satellite communication and civil area.Direct sequence spread spectrum skill will send Information pseudo-random sequence expand on a frequency band very wide, and receiver is same with the pseudo noise code in and emitter The local code of step, the docking collection of letters number carries out relevant treatment.In spread spectrum system, the selection of spreading code is most important.It is related to The anti-multipath jamming of system, jamproof ability, be related to the secrecy of information data with it is hidden, be related to the performance of channel estimation.

During design pilot tone, using thinkings of the CDMA when pilot tone is designed, i.e., pilot signal is multiplexed into data-signal.So Benefit be that will not in the frame structure take independent time interval resource, while frame structure can be simplified again.Simultaneously controllable pilot power The factor causes that its channel estimation under the conditions of specific spreading gain and equilibrium can be maintained at SNR ranges wider.Pilot tone is inserted Enter mode different from traditional Block-type pilot, Comb Pilot and plum blossom-shaped pilot tone, frequency pilot sign spreads over different frequent points and time Point is based on time-frequency two-dimensional plane interpolation, thus can more comprehensively estimate channel circumstance.Data division is divided into six encoding blocks, Each coding block structure contains 4 inverse discrete Fourier transforms (Inverse Discrete Fourier Transform, IDFT) Symbol, each IDFT symbol inserts one by the Walsh yards of frequency pilot sign of spread spectrum.Specific pilot tone insertion is as shown in Figure 1.

At a wireless receiver, the channel equalizer of use is realized in frequency domain.In addition, will also be in frequency domain to high intensity Frequency domain interference be tracked, analyze and suppress.Apparatus of the present invention are in time domain noise reduction treatment, interference position detection and interference suppression The key modules such as system have done numerous studies work, and the system architecture that channel is implemented is as shown in Figure 2.

A kind of jamproof single carrier channel estimates and balancer that the device is included for obtaining digital front-end output single carrier symbol Number frequency domain response output the first Fourier transformation module；Be connected with the first Fourier transformation module output end, for making The first estimation module of LS frequency domain channels of channel estimation in frequency domain is carried out with LS criterions；With the first estimation module output end of the LS channels The interference position detection module of connection and for time domain convert after carry out the white noise suppression module that noise suppressed converts frequency domain again； The white noise suppression module includes becoming with the LS channels channel frequency domain response that just estimation module output end is connected and will obtain Be changed to time domain inverse Fourier transform module and the inverse Fourier transform module output end connection for carrying out white Gaussian noise After suppressing the time domain noise reduction processing module for the treatment of and being connected to the Time Domain Processing that will be obtained with time domain noise reduction processing module output end Channel time domain response transform for frequency domain response the second Fourier transformation module；With the white noise suppression module and interference position Put the AF panel module of detection module output end connection.

First key function module of the invention is time domain noise reduction treatment, and the technique device can eliminate white Gaussian noise to channel The influence of estimation, reduces the mean square error of white Gaussian noise, to improve the performance of channel equalization.Specifically, by channel and going Except signal y (n) after Cyclic Prefix (Cyclic Prefix, CP) represents the discrete single-carrier symbol of the time-domain for receiving, It can be expressed as：

To send symbol, h (n) is channel dispersion time domain response to wherein x (n), and w (n) represents discrete and independent white Gaussian noise,Symbol represents convolution algorithm.AndA in formula_lIt is the gain of path l, l is the different path delays of time, L It is channel maximum path channel impulse response (Impulse Response of Channel, CIR).

Another key function module of apparatus of the present invention is interference position detection and corresponding AF panel, the technique device Potential interference signal can be detected and suppressed in frequency domain, be greatly enhanced the performance of channel equalizer.As shown in Figure 3.

In SC-FDMA systems, the present invention expands collection frequency division multiplexing (Discrete Fourier using DFT Transform Spread OFDM, DFT-S-OFDM) technology converted realizing single carrier, thus in LS frequency domain channels are estimated, Can be frequency domain subchannel that several mutually orthogonal subcarriers are moved by channel width equivalent partition.This figure is Interference Detection Algorithm is embodied, and by setting specified threshold, the channel frequency power spectrum estimated to LS is divided, and by disturbing position Detection algorithm is put, the strong jamming physical-layer sub-channel position of specialized narrowband or single-frequency is detected, disappeared so that subsequent module carries out interference Remove.

Apparatus of the present invention use frequency domain equalization, can avoid substantial amounts of matrix operation, and the realization for being effectively reduced channel equalization is complicated Degree.The tap coefficient of frequency domain equalizer is based on ZF (Zero Forcing, ZF) or least mean-square error (Minimum Mean Square Error, MMSE, MMSE) criterion calculate try to achieve.

Specific embodiment

Apparatus of the present invention are applied to carrier wave communication system, are realized by DFT-S-OFDM single carrier modulation techniques, and DFT counts It is that 1024, IDFT points are 2048.Its sending signal waveform has relatively low PARR (peak-to-average force ratio), can avoid because peak is equal The distortion of RF power amplification device and the low problem of conversion efficiency are brought than too high, such that it is able to be system in the case of identical power consumption, Broader scope can be covered.The present invention jamproof channel estimation and equalization implements flow as shown in Figure 8, real Applying step includes：

Step S1, generates local pilot tone.Local pilot tone is 1024 by length by complex symbol p=(1+i)/2 and is all 1 'sAfter sequence spread spectrum, and pass throughSequence scrambling is obtained, wherein for scramblingSequence length is 1024, The general generator polynomial generation using in LTE protocol.Because system uses frequency domain LS channel estimations, therefore, it is also desirable to incite somebody to action this Ground pilot tone transforms to frequency domain, and channel frequency domain response is calculated for use in quick.Generally, can the frequency domain response of local pilot tone to Amount is computed in advance, and deposits in locally, and its frequency domain response can be expressed as：

Step S2, LS channel estimation in frequency domain.Digital receiver front end output data is by the single load after synchronization unit and removal CP Ripple symbolWherein N is a sampling point number for discrete single-carrier symbol.A single-carrier symbol in the present invention Have 2048 sampling points, i.e. N=2048, the frequency domain response by obtaining receiving symbol after Fourier transform Frequency domain response by obtaining receiving symbol after subcarrier in frequency domain demapping

Present system uses channel estimation in frequency domain, is transformed into frequency domain representation, then accordingly output can be with for k-th frequency domain of subcarrier It is expressed as：

Y (k)=X (k) H (k)+W (k), 0≤k≤N-1

To send discrete symbols frequency domain response, W (k) is zero-mean channel white Gaussian noise frequency domain response to wherein X (k), and H (k) is Channel frequency domain response, it can be expressed as

Channel estimation in frequency domain is carried out by LS criterions, obtaining channel frequency domain response according to a preliminary estimate is：

To receive discrete single-carrier symbol frequency domain response, P (k) is local pilot tone frequency domain response to wherein Y (k), as can be seen from the above equation, Estimate still there is very big noise jamming at the beginning of LS frequency domain channels, it is necessary to when using method once, frequency domain response above is transformed to Domain, is specifically embodied as：

WhereinForBecause most of CIR power is concentrated in L tap of first few, therefore, subtract Noise power less or outside zeroization channel tap can improve the systematic function of channel estimation.

Step S31, carries out noise noise suppression and transforms to frequency domain again after time domain conversion.Estimate channel response at the beginning of the frequency domain that step S2 is obtainedBy obtaining time domain channel response after 1024 points of DFT transformAccording to white noise inhibitory theory proposed by the present invention, lead to Crossing following formula carries out white Gaussian noise suppression treatment, it is assumed that maximum channel impulse response length is L, then press down by noise Time domain channel response h after system₂N () is：

Wherein h1 (n) is the time domain channel response after estimation at the beginning of LS channels, and the size of L values is by under selecting system channel circumstance in formula Maximum multipath time delay and signal bandwidth together decide on.

In present system, channel maximum delay 0.5us and signal bandwidth are transformed to 15.36Mhz for 7.68Mhz by single carrier, Then sent by twice up-sampling, thus obtained by formula：

Wherein t_xIt is the single sampling point symbol duration, k of eating dishes without rice or wine_dUp-sampling transformation parameter, by after white noise noise restraint, being System is significantly improved, as shown in figure 4, giving performance curve and warp of the system under white Gaussian noise and fading channel The performance curve crossed after noise suppressed treatment.

Step S32, interference position detection.The present invention uses U (n) as strong jamming detection statistic, and its expression formula is：

In formula | H₁(k) | estimate frequency domain response at the beginning of LS frequency domain channels.It is analyzed by U (k) detection statistics, setting detection door Thr is limited to, to being tracked and judging with strongly disturbing subchannel, decision rule is：

SC_Index (k) is identified for subchannel interference position, if current sub-channel statistic is more than thresholding, otherwise mark 0, mark 1. The present invention chooses Thr=5dB according to experimental data test optimization.As shown in figure 3, give the present invention believing interference in frequency domain Number power density be analyzed and track schematic diagram.

Step S4, AF panel.Using step S32 obtain result SC_Index (k) as AF panel module MASK tables, Quickly to do AF panel to strong jamming subchannel, and domain channel response Hc (k) suppressed after interference is expressed as：

By the way that after AF panel treatment, system is significantly improved, and as shown in Figure 5, Figure 6, sets forth the anti-list of system Frequency interference and the performance curve of anti-arrowband interference.

Step S5, correlation criterion does frequency domain equalization.Apparatus of the present invention carry out frequency domain equalization using ZF or MMSE criterions.Step The domain channel response that rapid S4 is obtainedAs frequency domain equalization tap coefficient.

Alternatively, the frequency domain channel equalization algorithm based on ZF criterions can be expressed as：

Wherein Y_oK () is frequency domain response of the discrete data symbol by output after equilibrium, Y_i(k) for discrete data symbol input frequently Domain response,It is H_cThe complex conjugate of (k).

Alternatively, the frequency domain channel equalization algorithm based on MMSE criterions can be expressed as：

Wherein SNR_estIt is the estimation signal to noise ratio for currently receiving symbol.

Two, real-time conditions parameters and simulating, verifying

In order to verify the noise suppressed and jamproof performance of invention, using instrument Matlab is in white Gaussian noise, decline and disturbs Under channel circumstance, simulation analysis have been carried out.Simulation parameter sets as shown in the table：

1. system relevant configured parameter is as shown in the table

2. fading channel model, employs following typical rural model (cost207RAx6) channel model, its parameter such as following table institute Show:

The path delay of time/us	0	0.1	0.2	0.3	0.4	0.5
							Path loss/dB	0	-4	-8	-12	-16	-20

3. interference model：

Mono-tone interference refers to the interference signal using single sine wave or multiple sine waves.In the signal bandwidth of 7.68MHz, To each circulation single-carrier symbol, the interference for producing a frequency random, on the symbol, the power of interference presets superposition.

Wherein：I is interference signal, and P is interfering signal power, and f is the frequency values of the interference for randomly generating, and k is data point sequence number, f_s=15.36MHz is system sampling frequency, and BW=7.68MHz is signal bandwidth

Arrowband interference has multi-frequency composition relative to single tone jamming, there is certain bandwidth, is a kind of interference of artificial addition channel. The bandwidth of narrow-band interference signal is far smaller than signal bandwidth, so interference signal is all concentrated very much in time domain and frequency domain energy, power profit It is high with rate.During invention device Performance Evaluation, it is contemplated that interference signal a width of 200KHz of band, corresponding to a width of The number of the subcarrier of 7.5KHz is 26.To each circulation single-carrier symbol, in all of 1024 channel distortion experienced bandwidth It is interior, an interference is produced, its frequency is continuous 26 positions for randomly generating, by interference superposition on the symbol, the work(of interference Rate presets.

Sea clutter is a kind of sea addition interference, different according to oceanic condition, and the sea clutter distributed model of selection is different.The present invention The main logarithm normal distribution, Wei Buer two kinds of models of distribution of have chosen of emulation carries out performance evaluation.

Improved or under sea condition high in the taste of radar, the afterbody of clutter is more long, and backscattering characteristic deviate from rayleigh distributed, The distribution of amplitudes of logarithm normal distribution is more conform with, its probability density function is：

Wherein μ and σ is respectively the average value and standard deviation of variable logarithm.Its desired value and variance is for respectivelyThen its mean power is P=Var+E²=exp (2 σ²+2μ).Emulation μ=0 is taken in experiment, is then hadAnd its mean power P presets.

In the case of being closely serious clutter, it is the most suitable to be distributed using Wei Buer.This distribution it is asymmetric less than logarithm The asymmetry of normal distribution, so to the more uniform situation of sea clutter amplitude scintillation, it is more particularly suitable from Wei Buer distributions, Its probability density function is：

Wherein λ is scale parameter, represents the median of distribution, and k is form parameter, shows the degree of skewness of distribution, according to difference Sea condition, changes between 1.4 to 2.If k=2, just turn into rayleigh distributed, if k=1 is exactly exponential probability density function.People After it have studied more data, it is believed that for the radar of fine resolution, sea clutter distribution afterbody elongate situation Wei cloth Your distribution fits more more particularly suitable than with logarithm normal distribution.In emulation, we take k=1.5, and average according to default sea clutter Power, the anti-value for releasing λ.

The average and variance of the distribution are respectively：Γ is gamma letter Number.Its mean power is：As k=1.5, Its mean power P presets.

Time domain white noise rejection of the present invention shows system referring to Fig. 4, in figure under AWGN and fading channel, by time domain White noise Processing for removing and the performance curve without white noise Processing for removing, and it is 10 that system has in the bit error rate^-3During level, Under AWGN and fading channel environment, by after time domain white noise suppression treatment, probably there is 11dB gains.

Interference Detection of the present invention and rejection show rejection ability of the system to strong mono-tone interference referring to Fig. 5,6,7, Fig. 5, It is 10 that system has in the bit error rate^-3During level, by the way that after I-cancellati on (interference is eliminated) treatment, systematic function has 8.6dB Gain.Fig. 6 shows the rejection ability that system is disturbed strong arrowband, and it is 10 that system has in the bit error rate^-3During level, pass through After I-cancellati on (interference is eliminated) treatment, systematic function has the gain of 8.9dB.Fig. 7 shows that system is dry in sea clutter The performance curve of environment is disturbed, by curve it will be seen that not having the lifting in performance by I-cancellati on.This Because the probability distribution of sea clutter is relatively random, its probability density distribution is closer to white Gaussian noise, but system still may be used By time domain white noise noise reduction process, to influence to weaken on it.

So, the present invention effectively overcomes a variety of technical disadvantages of prior art, and with industrial utilization very high.

The above-described embodiments merely illustrate the principles and effects of the present invention, not for the limitation present invention.It is any to be familiar with this skill The personage of art all can carry out modifications and changes under without prejudice to spirit and scope of the invention to above-described embodiment.Therefore, such as Those of ordinary skill in the art completed under without departing from disclosed spirit and technological thought all etc. Effect modifications and changes, should be covered by claim of the invention.

Claims (13)

1. a kind of jamproof single carrier channel is estimated and balancer, it is characterised in that the device includes

For the first Fourier transformation module that the frequency domain response for obtaining digital front-end output single carrier symbol is exported；

Be connected with the first Fourier transformation module output end, the LS for carrying out channel estimation in frequency domain using LS criterions The first estimation module of channel；

Converted with the LS channels interference position detection module that just estimation module output end is connected and for time domain laggard Row noise suppressed converts the white noise suppression module of frequency domain again；The white noise suppression module includes estimating with the beginning of the LS channels The channel frequency domain response of acquisition is simultaneously transformed to the inverse Fourier transform module of time domain and Fu by the connection of meter module output end In leaf inverse transform module output end connection for carry out white Gaussian noise suppress treatment time domain noise reduction processing module and with It is frequency domain response that time domain noise reduction processing module output end is connected to the channel time domain response transform after the Time Domain Processing that will be obtained The second Fourier transformation module；

The AF panel module being connected with the white noise suppression module and interference position detection module output end.

2. jamproof single carrier channel according to claim 1 is estimated and balancer, it is characterised in that the device enters one Step includes the frequency domain channel equalization module being connected with the AF panel module output end.

3. jamproof single carrier channel according to claim 1 is estimated and balancer, it is characterised in that first Fu In leaf transformation module input be provided with the local pilot tone module of the generation that local pilot tone is transformed into frequency domain.

4. the device described in a kind of use claim 1 carries out single carrier channel estimation and equalization methods, it is characterised in that：The method At least comprise the following steps：

Using the first Fourier transformation module by single-carrier symbol by obtaining receiving the frequency domain response of symbol after Fourier transformation After export；

Channel estimation in frequency domain is carried out by LS criterions, channel frequency domain response according to a preliminary estimate is obtained；

Then carry out time domain conversion carry out white noise noise restraint after transform to frequency domain；

The step of carrying out interference position and detect simultaneously；Then AF panel is carried out, the result that above-mentioned steps are obtained is used as dry The MASK tables of suppression module are disturbed, quickly to do AF panel to strong jamming subchannel.

5. single carrier channel according to claim 4 is estimated and equalization methods, it is characterised in that：Also include the step of frequency domain equalization Suddenly.

6. single carrier channel according to claim 5 is estimated and equalization methods, it is characterised in that：The step of frequency domain equalization Carried out using ZF or MMSE criterions.

7. single carrier channel according to claim 6 is estimated and equalization methods, it is characterised in that：Frequency domain letter based on ZF criterions Trace equalization algorithmic notation is：

$Y_o\left(k\right)=\frac{Y_i\left(k\right)}{H_c\left(k\right)}=Y_i\left(k\right)\·H_c^{*}\left(k\right),0\≤k\≤N-1$

Wherein Y_oK () is frequency domain response of the discrete data symbol by output after equilibrium, Y_iK () is the input of discrete data symbol Frequency domain response,It is H_cThe complex conjugate of (k).

8. single carrier channel according to claim 6 is estimated and equalization methods, it is characterised in that：Frequency based on MMSE criterions Domain Channel Equalization Algorithm is expressed as：

$Y_o\left(k\right)=\frac{Y_i\left(k\right)\·H_c^{*}\left(k\right)}{|H_c\left(k\right){|}^2+\frac{1}{{\mathrm{SNR}}_{est}}},0\≤k\≤N-1$

Wherein SNR_estIt is the estimation signal to noise ratio for currently receiving symbol.

9. single carrier channel according to claim 4 is estimated and equalization methods, it is characterised in that：By single-carrier symbol by Fu In obtain after leaf transformation receiving also including the step of generating local pilot tone, and handle before exporting after the frequency domain response of symbol The frequency domain response vector of local pilot tone is computed in advance, and deposits in local.

10. single carrier channel according to claim 4 is estimated and equalization methods, it is characterised in that：Generate local pilot tone Step refers to that local pilot tone is 1024 by length by complex symbol p=(1+i)/2 and is all 1After sequence spread spectrum, And pass throughSequence scrambling is obtained, wherein for scramblingSequence length is 1024, using the life in LTE protocol Into Polynomial generation.

11. single carrier channels according to claim 4 are estimated and equalization methods, it is characterised in that：White noise suppression is done in time domain conversion Make an uproar after treatment refers to estimate channel response at the beginning of frequency domain by acquisition the step of transform to frequency domainBy 1024 points of DFT transform After obtain time domain channel responseWhite Gaussian noise suppression treatment is carried out by following formula, it is assumed that maximum Channel Impulse Response length is L, then by the time domain channel response h after noise suppressed₂N () is：

$h_2\left(n\right)=\left\{\begin{array}{cc}h1\left(n\right),& 0\≤n\≤L-1\\ 0,& n\≥L\end{array}\right.$

Wherein h1 (n) is the time domain channel response after estimation at the beginning of LS channels, and the size of L values is by selecting system channel circumstance in formula Lower maximum multipath time delay and signal bandwidth are together decided on.

12. single carrier channels according to claim 4 are estimated and equalization methods, it is characterised in that：Interference position detecting step bag Include and use U (n) as strong jamming detection statistic, its expression formula is：

$U\left(k\right)=\frac{\left|H_1\left(k\right)\right|}{\frac{1}{N}\underset{n=0}{\overset{N-1}{\Σ}}\left|H_1\left(n\right)\right|},0\≤k\≤N-1$

In formula | H₁(k) | estimate frequency domain response at the beginning of LS channels；It is analyzed by U (k) detection statistics, setting inspection Survey thresholding is Thr, and to being tracked and judging with strongly disturbing subchannel, decision rule is：

$SC\_Index\left(k\right)=\left\{\begin{array}{cc}0,& U\left(k\right)>Thr\\ 1,& U\left(k\right)\≤Thr\end{array}\right.,0\≤k\≤N-1$

SC_Index (k) is identified for subchannel interference position, if current sub-channel statistic is more than thresholding, mark 0 is no Then mark 1.

13. single carrier channels according to claim 4 are estimated and equalization methods, it is characterised in that：Frequency after AF panel step Domain channel response Hc (k) is expressed as：

$H_c\left(k\right)=\left\{\begin{array}{cc}{H}_2\left(k\right),& SC\_Index\left(k\right)=1\\ 0,& SC\_Index\left(k\right)=0\end{array}\right.,0\≤k\≤N-1.$