CN104022980B - A kind of ofdm system Signal to Interference plus Noise Ratio blind estimating method and system - Google Patents

Abstract

A kind of ofdm system Signal to Interference plus Noise Ratio blind estimating method and system, the ofdm signal for receiving accurately is divided into into sending signal, Gaussian Background noise and the impulse disturbances of multipath superposition, the mean power of single receiving multipath signals is calculated by obtaining the auto-correlation function of k-th signal every other sub-carrier number L, and the mean power sum of the OFDM digital signals for receiving is calculated according to the mean power of single receiving multipath signals, the statistic for finally calculating Signal to Interference plus Noise Ratio is estimated.Calculation procedure is few, estimates the time so as to save Signal to Interference plus Noise Ratio.And the value that can be estimated according to Signal to Interference plus Noise Ratio carries out the distribution and channel iterations decoding of channel resource, lifts the efficiency of transmission of ofdm system.

Description

A kind of ofdm system Signal to Interference plus Noise Ratio blind estimating method and system

Technical field

The present invention relates to a kind of ofdm system Signal to Interference plus Noise Ratio blind estimate technology.Relating in particular to a kind of impulse disturbances affects Under ofdm system Signal to Interference plus Noise Ratio blind estimating method and system.

Background technology

OFDM (Orthogonal Frequency Division Multiplexing are OFDM) is used as one Quadrature carrier modulation technology is planted, with the higher availability of frequency spectrum and good anti-multipath jamming ability, is widely used in the 4th Third-generation mobile communication (4G), power line communication (Power-Line-Communication, PLC) and various Digital Subscriber Line (Digital-Subscriber-Line, DSL) etc..Pattern of the OFDM modulation using framing transmission, an OFDM frame include L The sinusoidal subcarrier of MAQM or MPSK modulation.Digital information is mapped as multiple constellation point by OFDM first, carries out discrete fourier inverse Conversion (IDFT) obtains corresponding digital baseband signal, then the digital baseband for adding Cyclic Prefix (Cyclic Prefix, CP) Signal is continually fed into channel Jing after D/A (D/A) process.To the research process based on OFDM technology communication system In, Signal to Interference plus Noise Ratio (SINR, Signal to Interference plus Noise Ratio) estimates it is that one of which is important interior Hold, which, as the important indicator for weighing communication signal quality, is that such as Power Control, Dynamic Resource Allocation for Multimedia algorithm and iteration are translated The communication technologys such as code provide necessary channel condition information, so as to improve ofdm system transmission performance.Noise and interference are to affect SINR estimates the principal element of accuracy, in addition to the background noise based on Gauss model, also exists in actual applications not Few non-Gaussian signal and interference, for example between thunder and lightning, automobile engine, Electro-static Driven Comb and communication network internal unit Nature or the artificial factor such as interfere.These interference are general have burst, in short-term with strongly disturbing feature, by the persistent period The short and big irregular pulse of amplitude or noise spike are constituted, and are referred to as impulse disturbances.The non-Gaussian feature of impulse disturbances, usually Cause and assume that the performance of designed SINR methods of estimation is significantly degenerated based on Gauss.When this performance degradation reaches certain journey Degree and can not be ignored when, just corresponding process step must be redesigned according to the statistical property of interference, be estimated with improving SINR Meter performance.

Ofdm system SINR methods of estimation under the influence of impulse disturbances can be divided into data auxiliary and two class of unbound nucleus, The method of estimation of unbound nucleus is also commonly referred to as blind estimate.Data-aided method of estimation is realized simply, but needs timing to send out Agreement sequence is sent, the Shortcomings in efficiency of transmission, particularly in distributed collaborative communication, send training sequence and there is mechanism On obstacle.Blind estimating method overcomes data-aided deficiency, using maximal possibility estimation or cyclo-stationary analysis method The accurate estimation to SINR is obtained, main flow is occupied in actual applications.Chinese patent literature " CN10225586A " discloses one kind Based on the blind SNR estimating method of MIMO-OFDM signal cycle smooth performances, its smooth performance based on ofdm signal, suitably Choose the length of ofdm signal cyclic suffix so that the auto-correlation function of each sending signal possesses different zero points, by choosing Different cycle frequencys are selected, mimo channel is changed into multiple single-input single-output channels, then analysis receives the cycle of signal Auto-correlation functionRegularity of energy distribution, it is theoretical with reference to close approximation, finally realize the blind estimate of signal to noise ratio.The skill Art computation schemes step is complex so that the blind estimate step of signal to noise ratio is relatively complicated, time-consuming longer, and estimated accuracy also has Shortcoming.

The content of the invention

For this purpose, the technical problem to be solved is ofdm system Signal to Interference plus Noise Ratio blind estimate calculating in prior art Step is complex, and blind estimate is time-consuming longer, and estimated accuracy is not high, so as to propose a kind of ofdm system based on correlation analysiss Signal to Interference plus Noise Ratio blind estimating method and system.

To solve above-mentioned technical problem, the technical scheme is that：

A kind of ofdm system Signal to Interference plus Noise Ratio blind estimating method, comprises the following steps：

Receive digital signal：The OFDM digital signals of OFDM transmitter transmitting are received by antenna, by the OFDM numbers Word signal is designated as y, y_kFor the k-th OFDM digital signal for receiving, its sending signal r being superimposed by multipath_k, Gaussian Background makes an uproar Sound n_kWith impulse disturbances v_kAddition is formed, i.e. y_k=r_k+n_k+v_k, wherein：x_kFor k-th sending signal, a_iFor The channel fading coefficient of i paths, then r_kFor the superposition of multipath signal, L_hFor the exponent number of channel impulse response；

Calculate the mean power of single receiving multipath signals：Auto-correlation function is defined, k-th signal every other sub-carrier is obtained The auto-correlation function of number L, be：

Wherein, L be ofdm signal sub-carrier number, k ∈ [0, L-1], E (y_ky^* _k+L) it is the conjugation letter for receiving signal and displacement L Number be multiplied after arithmetic average；Due to the reception signal of diverse location, background noise and impulse disturbances it is orthogonal,WithAs a result it is zero, i.e.,According to institute State L_hThe intersymbol interference that individual component is caused, obtains：L_cpFor the circulation of ofdm signal Prefix length, the auto-correlation function is obtained is：

In the formula, as k ∈ [L_h- 1, L_cpGained is calculated when -1]Represent the mean power of channel estimation； Because L in the case of normal pass_cp≥L_h, therefore there is k=L_cp- 1 causesSet up, obtain single Mean power S of receiving multipath signals_r=R_y(k, k+L), k=L_cp-1；

The mean power sum of the OFDM digital signals that calculating is received：Calculatek ∈ [0, L+L_cp- 1], that is, mean power sum S of the OFDM digital signals received described in obtaining_y：

S_y=R_y(k, k)=S_r+S_n+S_v, S here_rFor the mean power of single channel estimation, S_nMake an uproar for Gaussian Background The mean power and S of sound_vFor the mean power of impulse disturbances；

Calculate Signal to Interference plus Noise Ratio estimator：Using mean power S of the single receiving multipath signals_rReceive with described Mean power sum S of OFDM digital signals_yThe statistic for calculating Signal to Interference plus Noise Ratio is estimated, is designated as

Estimated result feeds back：According toResult of calculation, carries out channel resource allocation and channel iterations decoding.

It is described calculate single receiving multipath signals mean power the step of also include：Calculate the channel impulse response Exponent number L_hValue, make λ_k=R_y(k, k+L), k ∈ [0, L_cp- 1], the L is calculated using red pond information criterion_h：The L_kIt is designated asV (k, L)=k (2L-k) is defined, is led to Cross search AIC (k), k ∈ [0, L_cp- 1], the k value of minima position is obtained, then gained k value is the channel impulse and rings The exponent number L for answering_hOptimal estimating.

A kind of described ofdm system Signal to Interference plus Noise Ratio blind estimating method, it is further comprising the steps of：

Calculate the mean power of multiple receiving multipath signals：Known channel exponent number L_hOn the premise of, obtain many of different value of K Footpath receives mean power S of signal_r=R_y(k, k+L), k ∈ [L_h- 1, L_cp- 1], averagely, i.e., which is done sums

The mean power sum of the OFDM digital signals that calculating is received：Calculatek ∈[L_h- 1, L+L_cp- 1], that is, obtain mean power sum S of the OFDM digital signals for receiving for described k-th_y, S_y=R_y(k, K)=S_r+S_n+S_v, S_rFor the mean power of channel estimation, S_nFor the mean power and S of Gaussian Background noise_vFor pulse The mean power of interference；

The arithmetic average of the mean power sum of the OFDM digital signals that calculating is received：According to paid-in multiple OFDM The result of the mean power sum of digital signal, i.e. S_y=R_y(k, k), k ∈ [L_h- 1, L+L_cp- 1], averagely, i.e., which is done sums

Signal to Interference plus Noise Ratio optimal estimating：The statistic of the Signal to Interference plus Noise Ratio after calculation optimization is estimated to be designated as

A kind of ofdm system Signal to Interference plus Noise Ratio blind estimate system, including with lower module：

Digital signal reception module：The OFDM digital signals of OFDM transmitter transmitting are received by antenna, by the OFDM Digital signal is designated as y, y_kFor the k-th OFDM digital signal for receiving, its sending signal r being superimposed by multipath_k, Gaussian Background Noise n_kWith impulse disturbances v_kAddition is formed, i.e. y_k=r_k+n_k+v_k, wherein：x_kFor k-th sending signal, a_iFor The channel fading coefficient of the i-th paths, then r_kFor the superposition of multipath signal, L_hFor the exponent number of channel impulse response；

The mean power of single receiving multipath signals calculates module：Auto-correlation function is defined, k-th signal is obtained and is separated by son The auto-correlation function of carrier number L, be：

Wherein, L be ofdm signal sub-carrier number, k ∈ [0, L-1], E (y_ky^* _k+L) it is the conjugation letter for receiving signal and displacement L Number be multiplied after arithmetic average；Due to the reception signal of diverse location, background noise and impulse disturbances it is orthogonal,WithAs a result it is zero, i.e.,According to institute State L_hThe intersymbol interference that individual component is caused, obtains：L_cpFor the circulation of ofdm signal Prefix length, the auto-correlation function is obtained is：

In the formula, as k ∈ [L_h- 1, L_cpGained is calculated when -1]Represent the mean power of channel estimation；Cause For L in the case of normal pass_cp≥L_h, therefore there is k=L_cp- 1 causesSet up, obtain single connecing Receive mean power S of multipath signal_r=R_y(k, k+L), k=L_cp-1；

The mean power sum computing module of the OFDM digital signals for receiving：Calculate K ∈ [0, L+L_cp- 1], that is, mean power sum S of the OFDM digital signals received described in obtaining_y；

S_y=R_y(k, k)=S_r+S_n+S_v, S here_rFor the mean power of single channel estimation, S_nMake an uproar for Gaussian Background The mean power and S of sound_vFor the mean power of impulse disturbances；

Signal to Interference plus Noise Ratio estimator computing module：Using mean power S of the single receiving multipath signals_rWith the reception Mean power sum S of the OFDM digital signals for arriving_yThe statistic for calculating Signal to Interference plus Noise Ratio is estimated, is designated as

Estimated result feedback module：According toResult of calculation, carries out channel resource allocation and channel iterations decoding.

The mean power of the single receiving multipath signals calculates module to be included：The exponent number L of channel impulse response_hComputing module, Make λ_k=R_y(k, k+L), k ∈ [0, L_cp- 1], the L is calculated using red pond information criterion_h：Institute State L_kIt is designated asV (k, L)=k (2L-k) is defined, by searching for AIC (k), k ∈ [0, L_cp- 1], obtain The k value of minima position, then gained k value be the channel impulse response exponent number L_hOptimal estimating.

A kind of described ofdm system Signal to Interference plus Noise Ratio blind estimate system, is also included with lower module：

The mean power of multiple receiving multipath signals calculates module：Known channel exponent number L_hOn the premise of, obtain different value of K Channel estimation mean power S_r=R_y(k, k+L), k ∈ [L_h- 1, L_cp- 1], averagely, i.e., which is done sums

The mean power sum computing module of the OFDM digital signals for receiving：Calculatek ∈[L_h- 1, L+L_cp- 1], that is, obtain mean power sum S of the OFDM digital signals for receiving for described k-th_y, S_y=R_y(k, K)=S_r+S_n+S_v, S_rFor the mean power of channel estimation, S_nFor the mean power and S of Gaussian Background noise_vFor pulse The mean power of interference；

The arithmetic average computing module of the mean power sum of the OFDM digital signals for receiving：According to paid-in multiple The result of the mean power sum of OFDM digital signals, i.e. S_y=R_y(k, k), k ∈ [L_h- 1, L+L_cp- 1], which is done sums flat , i.e.,

Signal to Interference plus Noise Ratio optimal estimating module：The statistic of the Signal to Interference plus Noise Ratio after calculation optimization is estimated to be designated as

The above-mentioned technical proposal of the present invention has advantages below compared to existing technology：

The ofdm signal for receiving accurately is divided into multipath and is folded by a kind of ofdm system Signal to Interference plus Noise Ratio blind estimating method and system Plus sending signal, Gaussian Background noise and impulse disturbances, by the auto-correlation letter for obtaining k-th signal every other sub-carrier number L Number calculates the mean power of single receiving multipath signals, and calculates reception according to the mean power of single receiving multipath signals The mean power sum of the OFDM digital signals for arriving, the statistic for finally calculating Signal to Interference plus Noise Ratio are estimated.Calculation procedure is few, so as to Save Signal to Interference plus Noise Ratio and estimate the time, and estimated accuracy is high.In addition channel exponent number can also accurately be extracted.Finally may be used The distribution and channel iterations decoding of channel resource are carried out according to Signal to Interference plus Noise Ratio estimated value, the efficiency of transmission of ofdm system is lifted.

Description of the drawings

In order that present disclosure is more likely to be clearly understood, the specific embodiment below according to the present invention is simultaneously combined Accompanying drawing, the present invention is further detailed explanation, wherein

Fig. 1 is a kind of flow chart of ofdm system Signal to Interference plus Noise Ratio blind estimating method of the invention；

Fig. 2 is a kind of ofdm system Signal to Interference plus Noise Ratio blind estimating method of the invention performance chart compared to existing technology；

Fig. 3 is a kind of ofdm system Signal to Interference plus Noise Ratio blind estimating method of the invention performance chart compared to existing technology；

Fig. 4 is a kind of ofdm system Signal to Interference plus Noise Ratio blind estimating method of the invention performance chart compared to existing technology；

Fig. 5 is a kind of ofdm system Signal to Interference plus Noise Ratio blind estimating method of the invention performance chart compared to existing technology；

Fig. 6 is a kind of structured flowchart of ofdm system Signal to Interference plus Noise Ratio blind estimate system of the invention.

Specific embodiment

Embodiment 1

It is shown in Figure 1, as one embodiment of the present of invention, a kind of ofdm system Signal to Interference plus Noise Ratio blind estimating method, bag Include following steps：

Receive digital signal：The OFDM digital signals of OFDM transmitter transmitting are received by antenna, by the OFDM numbers Word signal is designated as y, y_kFor the k-th OFDM digital signal for receiving, its sending signal r being superimposed by multipath_k, Gaussian Background makes an uproar Sound n_kWith impulse disturbances v_kAddition is formed, i.e. y_k=r_k+n_k+v_k, wherein：x_kFor k-th sending signal, a_iFor The channel fading coefficient of i paths, then r_kFor the superposition of multipath signal, L_hFor the exponent number of channel impulse response, background noise n_kClothes It is zero from average, variance isNormal distribution, impulse disturbances v_kIt is zero to obey average, and variance isNon-gaussian distribution；

Calculate the mean power of single receiving multipath signals：Auto-correlation function is defined, k-th signal every other sub-carrier is obtained The auto-correlation function of number L, be：

Wherein, L be ofdm signal sub-carrier number, k ∈ [0, L-1], E (y_ky^* _k+L) it is the conjugation letter for receiving signal and displacement L Number be multiplied after arithmetic average；Due to the reception signal of diverse location, background noise and impulse disturbances it is orthogonal,WithAs a result it is zero, i.e.,According to institute State L_hThe intersymbol interference that individual component is caused, obtains：L_cpFor the circulation of ofdm signal Prefix length, the auto-correlation function is obtained is：

In the formula, as k ∈ [L_h- 1, L_cpGained is calculated when -1]Represent the mean power of channel estimation；Cause For L in the case of normal pass_cp≥L_h, therefore there is k=L_cp- 1 causesSet up, obtain single connecing Receive mean power S of multipath signal_r=R_y(k, k+L), k=L_cp-1；

The mean power sum of the OFDM digital signals that calculating is received：Calculatek ∈ [0, L+L_cp- 1], that is, mean power sum S of the OFDM digital signals received described in obtaining_y；

S_y=R_y(k, k)=S_r+S_n+S_v, S here_rFor the mean power of single channel estimation, S_nMake an uproar for Gaussian Background The mean power and S of sound_vFor the mean power of impulse disturbances；

Calculate Signal to Interference plus Noise Ratio estimator：Using mean power S of the single receiving multipath signals_rWith the OFDM numbers for receiving Mean power sum S of word signal_yThe statistic for calculating Signal to Interference plus Noise Ratio is estimated, is designated as

Estimated result feeds back：According toResult of calculation, carries out channel resource allocation and channel iterations decoding.Carry out When classic algorithm MAP and Log-MAP algorithms of Turbo iterative decodings are realized, need to obtain the Signal to Interference plus Noise Ratio for receiving signal (SINR) information.Above-mentioned algorithm is needed as soft input, soft output (Soft-Input Soft-Output, SISO) decoding algorithm Prior information to be received in input, while exporting posterior information.Calculate forward-facing state probability and after to state probability when all It is relevant with branch metric, and the calculating of branch metric depends on Signal to Interference plus Noise Ratio parameter.If Signal to Interference plus Noise Ratio mismatch, that is, decode institute Signal to Interference plus Noise Ratio is not corresponded with the Signal to Interference plus Noise Ratio in actual channel, can cause the reduction of decoding performance.In addition in resource allocation Algorithm be all in the case of Signal to Interference plus Noise Ratio is known in the channel just, according to the biography of the seriousness optimized distribution information of noise jamming It is defeated, the lifting of transmission performance is obtained with this.

It is described calculate single receiving multipath signals mean power the step of also include：Calculate the channel impulse response Exponent number L_hValue, make λ_k=R_y(k, k+L), k ∈ [0, L_cp- 1], the L is calculated using red pond information criterion_h：The L_kIt is designated asV (k, L)=k (2L-k) is defined, By searching for AIC (k), k ∈ [0, L_cp- 1], the k value of minima position is obtained, then gained k value is the channel impulse The exponent number L of response_hOptimal estimating.

A kind of described ofdm system Signal to Interference plus Noise Ratio blind estimating method, it is further comprising the steps of：

Calculate the mean power of multiple receiving multipath signals：Known channel exponent number L_hOn the premise of, obtain many of different value of K Footpath receives mean power S of signal_r=R_y(k, k+L), k ∈ [L_h- 1, L_cp- 1], averagely, i.e., which is done sums

The mean power sum of the OFDM digital signals that calculating is received：Calculatek∈ [L_h- 1, L+L_cp- 1], that is, obtain mean power sum S of the OFDM digital signals for receiving for described k-th_y, S_y=R_y(k, k) =S_r+S_n+S_v, S_rFor the mean power of channel estimation, S_nFor the mean power and S of Gaussian Background noise_vIt is dry for pulse The mean power disturbed；

The arithmetic average of the mean power sum of the OFDM digital signals that calculating is received：According to paid-in multiple OFDM The result of the mean power sum of digital signal, i.e. S_y=R_y(k, k), k ∈ [L_h- 1, L+L_cp- 1], averagely, i.e., which is done sums

Signal to Interference plus Noise Ratio optimal estimating：The mean power sum of the OFDM digital signals received using above-mentioned calculating and calculating The statistics of the Signal to Interference plus Noise Ratio after the result calculation optimization of the arithmetic average of the mean power sum of the OFDM digital signals for receiving Amount estimation is designated as For arithmetic average, its statistical property for obtaining compares single computing energy It is enough more accurate.

The method that contrast prior art estimates Signal to Interference plus Noise Ratio using cyclo-stationary, the application have carried out property in Fig. 2-Fig. 5 Can compare that (Cyclostationarity Analysis curves represent the circulation that Chinese patent literature " CN10225586A " is proposed Stationarity method, Correlation Coefficient Analysis curves represent this method).It can be observed from fig. 2 that at which His parameter is identical, and only in the case of background noise difference, this method is obtained in that the estimated accuracy of nearly 15dB is lifted.Fig. 3 shows Show that impulse disturbances power is different, in the case of other specification identical, this method performance boost is simultaneously when impulse disturbances power is less It is not notable, but now impulse disturbances are not serious for the impact of communication system, so negligible.And in impulse disturbances work( When rate is larger, this method has the improvement of 15dB in performance.Fig. 4 shows that impulse disturbances probability of happening is different, and other specification is identical In the case of, this method is obtained in that the performance improvement of 15-20dB in estimated accuracy.Finally, Fig. 5 shows that other specification is identical, But the asynchronous performance comparison of data volume of each computing.Can be clearly seen that from curvilinear path even this method is only used Calculating Signal to Interference plus Noise Ratio, the estimated accuracy which obtains is also than 1000 OFDM using cyclo-stationary method for 100 OFDM frames Frame estimated result comes high, illustrates this method not only in estimated accuracy, also has advantage, it is easier to engineering in terms of operand Using.

Embodiment 2

As shown in fig. 6, a kind of ofdm system Signal to Interference plus Noise Ratio blind estimate system, including with lower module：

Digital signal reception module：The OFDM digital signals of OFDM transmitter transmitting are received by antenna, by the OFDM Digital signal is designated as y, y_kFor the k-th OFDM digital signal for receiving, its sending signal r being superimposed by multipath_k, Gaussian Background Noise n_kWith impulse disturbances v_kAddition is formed, i.e. y_k=r_k+n_k+v_k, wherein：x_kFor k-th sending signal, a_iFor The channel fading coefficient of the i-th paths, then r_kFor the superposition of multipath signal, L_hFor the exponent number of channel impulse response, background noise n_k It is zero to obey average, and variance isNormal distribution, impulse disturbances v_kIt is zero to obey average, and variance isNon-gaussian distribution；

The mean power of single receiving multipath signals calculates module：Auto-correlation function is defined, k-th signal is obtained and is separated by son The auto-correlation function of carrier number L, be：

Wherein, L be ofdm signal sub-carrier number, k ∈ [0, L-1], E (y_ky^* _k+L) it is the conjugation letter for receiving signal and displacement L Number be multiplied after arithmetic average；Due to the reception signal of diverse location, background noise and impulse disturbances it is orthogonal,WithAs a result it is zero, i.e.,According to The L_hThe intersymbol interference that individual component is caused, obtains：L_cpFollowing for ofdm signal Ring prefix length, the auto-correlation function is obtained is：

In the formula, as k ∈ [L_h- 1, L_cpGained is calculated when -1]Represent the mean power of channel estimation；Cause For L in the case of normal pass_cp≥L_h, therefore there is k=L_cp- 1 causesSet up, obtain single connecing Receive mean power S of multipath signal_r=R_y(k, k+L), k=L_cp-1；

The mean power sum computing module of the OFDM digital signals for receiving：Calculatek ∈ [0, L+L_cp- 1], that is, mean power sum S of the OFDM digital signals received described in obtaining_y；

S_y=R_y(k, k)=S_r+S_n+S_v, S here_rFor the mean power of single channel estimation, S_nMake an uproar for Gaussian Background The mean power and S of sound_vFor the mean power of impulse disturbances；

Signal to Interference plus Noise Ratio estimator computing module：Using mean power S of the single receiving multipath signals_rWith the reception Mean power sum S of the OFDM digital signals for arriving_yThe statistic for calculating Signal to Interference plus Noise Ratio is estimated, is designated as

Estimated result feedback module：According toResult of calculation, carries out channel resource allocation and channel iterations decoding.According toResult of calculation, carries out channel resource allocation and channel iterations decoding.In classic algorithm MAP for carrying out Turbo iterative decodings When realizing with Log-MAP algorithms, need to obtain Signal to Interference plus Noise Ratio (SINR) information for receiving signal.Above-mentioned algorithm as soft input, Soft output (Soft-Input Soft-Output, SISO) decoding algorithm, needs to receive prior information in input, while output Posterior information.Calculate forward-facing state probability and after to state probability when all relevant with branch metric, and the calculating of branch metric Signal to Interference plus Noise Ratio parameter is depended on again.If Signal to Interference plus Noise Ratio mismatch, that is, decode Signal to Interference plus Noise Ratio used and do with the letter in actual channel Make an uproar than not corresponding, the reduction of decoding performance can be caused.All it is in addition in the channel known to Signal to Interference plus Noise Ratio in resource allocation algorithm In the case of just, according to the transmission of the seriousness optimized distribution information of noise jamming, the lifting of transmission performance is obtained with this.

The mean power of the single receiving multipath signals calculates module to be included：The exponent number L of channel impulse response_hCalculate mould Block, makes λ_k=R_y(k, k+L), k ∈ [0, L_cp- 1], the L is calculated using red pond information criterion_h： The L_kIt is designated asV (k, L)=k (2L-k) is defined, by searching for AIC (k), k ∈ [0, L_cp- 1], obtain The k value of minima position, then gained k value be the channel impulse response exponent number L_hOptimal estimating.

A kind of described ofdm system Signal to Interference plus Noise Ratio blind estimate system, is also included with lower module：

The mean power of multiple receiving multipath signals calculates module：Known channel exponent number L_hOn the premise of, obtain different value of K Channel estimation mean power S_r=R_y(k, k+L), k ∈ [L_h- 1, L_cp- 1], averagely, i.e., which is done sums

The mean power sum computing module of the OFDM digital signals for receiving：Calculate k∈[L_h- 1, L+L_cp- 1], that is, obtain mean power sum S of the OFDM digital signals for receiving for described k-th_y, S_y=R_y(k, K)=S_r+S_n+S_v, S_rFor the mean power of channel estimation, S_nFor the mean power and S of Gaussian Background noise_vFor pulse The mean power of interference；

The arithmetic average computing module of the mean power sum of the OFDM digital signals for receiving：According to paid-in multiple The result of the mean power sum of OFDM digital signals, i.e. S_y=R_y(k, k), k ∈ [L_h- 1, L+L_cp- 1], which is done sums flat , i.e.,

Signal to Interference plus Noise Ratio optimal estimating module：The mean power sum of the OFDM digital signals received using above-mentioned calculating and Signal to Interference plus Noise Ratio after the result calculation optimization of the arithmetic average of the mean power sum of the OFDM digital signals that calculating is received Statistic is estimated to be designated as SINR,

Obviously, above-described embodiment is only intended to clearly illustrate example, and the not restriction to embodiment.It is right For those of ordinary skill in the art, can also make on the basis of the above description other multi-forms change or Change.There is no need to be exhaustive to all of embodiment.And thus it is extended obvious change or Among changing still in the protection domain of the invention.

Claims (6)

1. a kind of ofdm system Signal to Interference plus Noise Ratio blind estimating method, it is characterised in that comprise the following steps：

Receive digital signal：The OFDM digital signals of OFDM transmitter transmitting are received by antenna, OFDM numerals are believed Number it is designated as y, y_kFor the k-th OFDM digital signal for receiving, its sending signal r being superimposed by multipath_k, Gaussian Background noise n_k With impulse disturbances v_kAddition is formed, i.e. y_k=r_k+n_k+v_k, wherein：x_kFor k-th sending signal, a_iFor i-th The channel fading coefficient in path, then r_kFor the superposition of multipath signal, L_hFor the exponent number of channel impulse response；

Calculate the mean power of single receiving multipath signals：Auto-correlation function is defined, k-th signal every other sub-carrier number L is obtained Auto-correlation function, be：

$\begin{array}{c}{R}_y(k,k+L)=E\left(y_k{y^{*}}_{k+L}\right)\\ =E\[(r_k+n_k+v_k)(r_{k+L}^{*}+n_{k+L}^{*}+v_{k+L}^{*})\]\\ =E\[r_k{r}_{k+L}^{*}\]+E\[r_k{n}_{k+L}^{*}+r_k{v}_{k+L}^{*}\]+E\[(n_k+v_k)(r_{k+L}^{*}+n_{k+L}^{*}+v_{k+L}^{*})\]\end{array},$

Wherein, L be ofdm signal sub-carrier number, k ∈ [0, L-1], E (y_ky^* _k+L) it is the conjugated signal phase for receiving signal and displacement L Arithmetic average after taking advantage of；Due to the reception signal of diverse location, background noise and impulse disturbances it is orthogonal, WithAs a result it is zero, i.e.,According to the L_hIndividual component The intersymbol interference for causing, obtains：L_cpFor the circulating prefix-length of ofdm signal, The auto-correlation function is obtained is：

$R_y(k,k+L)=E\[r_k{r}_{k+L}^{*}\]=\left\{\begin{array}{cc}\underset{i=0}{\overset{k}{\Σ}}|a_i{|}^2{\mathrm{\σ}}_x^2,& k=0,\mathrm{...},L_h-2\\ \underset{i=0}{\overset{L_h-1}{\Σ}}|a_i{|}^2{\mathrm{\σ}}_x^2,& k=L_h-1,L_h,...,L_{cp}-1\end{array}\right.;$

In the formula, as k ∈ [L_h- 1, L_cpGained is calculated when -1]Represent the mean power of channel estimation；Because just L under normal passage situation_cp≥L_h, therefore there is k=L_cp- 1 causesSet up, obtain single reception many Mean power S of footpath signal_r=R_y(k, k+L), k=L_cp-1；

The mean power sum of the OFDM digital signals that calculating is received：Calculatek ∈ [0, L+L_cp- 1], that is, mean power sum S of the OFDM digital signals received described in obtaining_y：

S_y=R_y(k, k)=S_r+S_n+S_v, S here_rFor the mean power of single channel estimation, S_nFor Gaussian Background noise Mean power and S_vFor the mean power of impulse disturbances；

Calculate Signal to Interference plus Noise Ratio estimator：Using mean power S of the single receiving multipath signals_rIt is digital with the OFDM for receiving Mean power sum S of signal_yThe statistic for calculating Signal to Interference plus Noise Ratio is estimated, is designated as

Estimated result feeds back：According toResult of calculation, carries out channel resource allocation and channel iterations decoding.

2. a kind of ofdm system Signal to Interference plus Noise Ratio blind estimating method according to claim 1, it is characterised in that the calculating list The step of mean power of individual receiving multipath signals, also includes：Calculate the exponent number L of the channel impulse response_hValue, make λ_k=R_y (k, k+L), k ∈ [0, L_cp- 1], the L is calculated using red pond information criterion_h： The L_kIt is designated asV (k, L)=k (2L-k) is defined, by searching for AIC (k), k ∈ [0, L_cp- 1], obtain The k value of minima position is taken, then gained k value is the exponent number L of the channel impulse response_hOptimal estimating.

3. a kind of ofdm system Signal to Interference plus Noise Ratio blind estimating method according to claim 1 and 2, it is characterised in that also include Following steps：

Calculate the mean power of multiple receiving multipath signals：Known channel exponent number L_hOn the premise of, obtain the multipath reception of different value of K Mean power S of signal_r=R_y(k, k+L), k ∈ [L_h- 1, L_cp- 1], averagely, i.e., which is done sums

The mean power sum of the OFDM digital signals that calculating is received：Calculatek ∈[L_h- 1, L+L_cp- 1], that is, obtain mean power sum S of the OFDM digital signals for receiving for described k-th_y, S_y=R_y(k, K)=S_r+S_n+S_v, S_rFor the mean power of channel estimation, S_nFor the mean power and S of Gaussian Background noise_vFor pulse The mean power of interference；

The arithmetic average of the mean power sum of the OFDM digital signals that calculating is received：It is digital according to paid-in multiple OFDM The result of the mean power sum of signal, i.e. S_y=R_y(k, k), k ∈ [L_h- 1, L+L_cp- 1], averagely, i.e., which is done sums

Signal to Interference plus Noise Ratio optimal estimating：The statistic of the Signal to Interference plus Noise Ratio after calculation optimization is estimated to be designated as

4. a kind of ofdm system Signal to Interference plus Noise Ratio blind estimate system, it is characterised in that include with lower module：

Digital signal reception module：The OFDM digital signals of OFDM transmitter transmitting are received by antenna, the OFDM is digital Signal is designated as y, y_kFor the k-th OFDM digital signal for receiving, its sending signal r being superimposed by multipath_k, Gaussian Background noise n_kWith impulse disturbances v_kAddition is formed, i.e. y_k=r_k+n_k+v_k, wherein：x_kFor k-th sending signal, a_iFor i-th The channel fading coefficient of paths, then r_kFor the superposition of multipath signal, L_hFor the exponent number of channel impulse response；

The mean power of single receiving multipath signals calculates module：Auto-correlation function is defined, k-th signal every other sub-carrier is obtained The auto-correlation function of number L, be：

$\begin{array}{c}{R}_y(k,k+L)=E\left(y_k{y^{*}}_{k+L}\right)\\ =E\[(r_k+n_k+v_k)(r_{k+L}^{*}+n_{k+L}^{*}+v_{k+L}^{*})\]\\ =E\[r_k{r}_{k+L}^{*}\]+E\[r_k{n}_{k+L}^{*}+r_k{v}_{k+L}^{*}\]+E\[(n_k+v_k)(r_{k+L}^{*}+n_{k+L}^{*}+v_{k+L}^{*})\]\end{array},$

Wherein, L be ofdm signal sub-carrier number, k ∈ [0, L-1], E (y_ky^* _k+L) it is the conjugated signal phase for receiving signal and displacement L Arithmetic average after taking advantage of；Due to the reception signal of diverse location, background noise and impulse disturbances it is orthogonal,WithAs a result it is zero, i.e.,Root According to the L_hThe intersymbol interference that individual component is caused, obtains：L_cpFor ofdm signal Circulating prefix-length, the auto-correlation function is obtained is：

$R_y(k,k+L)=E\[r_k{r}_{k+L}^{*}\]=\left\{\begin{array}{cc}\underset{i=0}{\overset{k}{\Σ}}|a_i{|}^2{\mathrm{\σ}}_x^2,& k=0,\mathrm{...},L_h-2\\ \underset{i=0}{\overset{L_h-1}{\Σ}}|a_i{|}^2{\mathrm{\σ}}_x^2,& k=L_h-1,L_h,...,L_{cp}-1\end{array}\right.;$

In the formula, as k ∈ [L_h- 1, L_cpGained is calculated when -1]Represent the mean power of channel estimation；Because just L under normal passage situation_cp≥L_h, therefore there is k=L_cp- 1 causesSet up, obtain single reception many Mean power S of footpath signal_r=R_y(k, k+L), k=L_cp-1；

The mean power sum computing module of the OFDM digital signals for receiving：Calculatek ∈ [0, L+L_cp- 1], that is, mean power sum S of the OFDM digital signals received described in obtaining_y：

S_y=R_y(k, k)=S_r+S_n+S_v, S here_rFor the mean power of single channel estimation, S_nFor Gaussian Background noise Mean power and S_vFor the mean power of impulse disturbances；

Signal to Interference plus Noise Ratio estimator computing module：Using mean power S of the single receiving multipath signals_rWith the OFDM numbers for receiving Mean power sum S of word signal_yThe statistic for calculating Signal to Interference plus Noise Ratio is estimated, is designated as

Estimated result feedback module：According toResult of calculation, carries out channel resource allocation and channel iterations decoding.

5. a kind of ofdm system Signal to Interference plus Noise Ratio blind estimate system according to claim 4, it is characterised in that described single to connect The mean power calculating module for receiving multipath signal includes：The exponent number L of channel impulse response_hComputing module, makes λ_k=R_y(k, k+L), K ∈ [0, L_cp- 1], the L is calculated using red pond information criterion_h：The L_k It is designated asV (k, L)=k (2L-k) is defined, by searching for AIC (k), k ∈ [0, L_cp- 1], obtain minimum It is worth the k value of position, then gained k value is the exponent number L of the channel impulse response_hOptimal estimating.

6. a kind of ofdm system Signal to Interference plus Noise Ratio blind estimate system according to claim 4, it is characterised in that also including following Module：

The mean power of multiple receiving multipath signals calculates module：Known channel exponent number L_hOn the premise of, obtain many of different value of K Footpath receives mean power S of signal_r=R_y(k, k+L), k ∈ [L_h- 1, L_cp- 1], averagely, i.e., which is done sums

The mean power sum computing module of the OFDM digital signals for receiving：Calculate k∈[L_h- 1, L+L_cp- 1], that is, obtain mean power sum S of the OFDM digital signals for receiving for described k-th_y, S_y=R_y(k, K)=S_r+S_n+S_v, S_rFor the mean power of channel estimation, S_nFor the mean power and S of Gaussian Background noise_vFor pulse The mean power of interference；

The arithmetic average computing module of the mean power sum of the OFDM digital signals for receiving：According to paid-in multiple OFDM The result of the mean power sum of digital signal, i.e. S_y=R_y(k, k), k ∈ [L_h- 1, L+L_cp- 1], averagely, i.e., which is done sums

Signal to Interference plus Noise Ratio optimal estimating module：The statistic of the Signal to Interference plus Noise Ratio after calculation optimization is estimated to be designated as