CN102238123B - Ranging code detecting method and device - Google Patents

Abstract

The invention discloses ranging code detecting method: carry out fast fourier transform FFT to the time-domain signal received, the ranging sub-carrier of the frequency-region signal obtained after the conversion obtains distance measuring signal, distance measuring signal is made up of at least two symbols in time domain; Phase compensation is carried out respectively to the sequence of other symbols except first outer symbol, weighting merges, obtain the sequence after merging; In the code table stored, select local code successively, utilize the sequence after the local code sequence and merging selected to carry out related operation, difference operation and FFT, and the sequence power generated after calculating FFT conversion, obtain the peak-to-average force ratio of this sequence; When peak-to-average force ratio is greater than the first threshold value, determine to carry ranging code in the time-domain signal received.The present invention discloses other ranging code detecting methods and ranging code checkout gear.Adopt the present invention can improve the verification and measurement ratio of ranging code.

Description

Ranging code detecting method and device

Technical field

The embodiment of the present invention relates to mobile broadband wireless field, especially relates to the ranging code detecting method in this field and device.

Background technology

IEEE (InstituteofElectricalandElectronicsEngineers, Institute of Electrical and Electronics Engineers) 802.16e is a kind of with the standard of the mobile wide-band wire-less accessing system based on OFDMA (OrthogonalFrequencyDivisionMultiplexingAccess, OFDM) technology.Range finding is that 802.16e agreement specifies a kind of process for adjusting mobile subscriber's carrier wave frequency deviation, timing offset and received power in OFDMA system.

Usually, base station can specify time/frequency source block to allow mobile subscriber find range, and this Resource Block is referred to as distance measurement zone (rangingregion).802.16e agreement defines 4 kinds of distance measuring methods, and one group of corresponding ranging code can be specified in base station for different distance measuring methods, and this ranging code is a kind of CDMA (CodeDivisionMultipleAccess, code division multiple access accesses) code.

When carrying out initial ranging, mobile subscriber selects a distance measurement zone that ranging code is being specified to send from the code table that base station is specified, and has been used for the system parameters Estimation and rectification of uplink distance measuring process.Base station detects the information such as the ranging code that mobile subscriber sends also calculates at that time partially, frequency deviation from the distance measuring signal received, and then feeds back to the mobile subscriber sending ranging code.Mobile subscriber is again according to the transmission parameter of these information adjustment oneself.

The ranging code detecting method of current employing mainly carries out according to the autocorrelation performance of ranging code, can be divided into time domain correlation and frequency domain correlation method.The former refers to that FFT (FastFourierTransform, fast fourier transform) is not to the time domain data received in base station, directly carries out relevant, peak detection operation to local code; After the latter refers to that base station converts the time domain data FFT received, the value extracted on ranging sub-channel carries out the operation such as related operation, IFFT (InverseFastFourierTransform, inverse fast Fourier transform) again with local code.

In actual practicality, there is the problems such as amount of calculation is very large, the interference that is subject to data user due to time domain correlation and be seldom used.The thought of frequency domain correlation method is succinct, realizes introducing that is simple, IFFT computing and makes again amount of calculation greatly be less than time domain correlation, be therefore usually used to the detection carrying out ranging code in reality.

Weigh range finding detection algorithm performance and generally have two indices: verification and measurement ratio and false alarm rate.False alarm rate refers to the probability detecting the ranging code that user does not send.Along with various advanced technology is as MIMO (Multiple-InputMultiple-Out-put, multiple-input and multiple-output), the utilization of beam forming technique beamforming etc., the performance index such as descending covering, throughput of base station are significantly enhanced, and the sensitivity (i.e. signal to noise ratio) of system worked well also reduces further.But the verification and measurement ratio of frequency domain correlation method under low signal-to-noise ratio is extremely low, makes systematic function be limited to up initial ranging code access and detect.The ranging detection method of current employing only considered the application scenarios of signal to noise ratio at more than 0dB mostly, and do not take in for the situation of signal to noise ratio far below 0dB, therefore under low signal-to-noise ratio, performance is undesirable.In addition, a lot of ranging detection method is all at AWGN (AdditivewhiteGaussiannoise, additive white Gaussian noise) derive under channel, and in actual application environment, channel mostly is multidiameter fading channel, do not mate with the environment of detection method, can cause declining further to the verification and measurement ratio of ranging code.

Summary of the invention

The embodiment of the present invention provides a kind of ranging code detecting method, extremely low in order to solve the verification and measurement ratio of ranging code detecting method under low signal-to-noise ratio proposed in prior art, makes systematic function be limited to the problem of up initial ranging code access detection, comprising:

Carry out fast fourier transform FFT to the time-domain signal through single antenna reception, the ranging sub-carrier of the frequency-region signal obtained after the conversion obtains distance measuring signal, described distance measuring signal is made up of at least two symbols in time domain;

Carry out phase compensation respectively to the sequence of other symbols except first outer symbol, offset is that the equivalent phase of cyclic prefix CP length postpones;

Merging is weighted to the sequence that sequence and other each symbols of first symbol obtain after phase compensation, obtain the sequence after merging, the weights of wherein weighting are positioned between (0,1), each weights sum equals 1, and is directly proportional to the data message amount that each symbol carries;

In the code table stored, select local code successively, the sequence after utilizing the sequence of the local code selected and merging carries out related operation;

Difference operation and FFT are carried out to the sequence obtained after related operation, and calculates the power of each value in the sequence generated after difference operation and conversion;

According to the power of value each in the sequence generated after difference operation and conversion, determine peak-to-average force ratio, described peak-to-average force ratio is the ratio of the peak power that is respectively worth of the sequence generated after difference operation and conversion and average power;

When peak-to-average force ratio is greater than the first threshold value, determine to carry ranging code in the time-domain signal received, described first threshold value is not less than the threshold value corresponding to the default ranging code verification and measurement ratio upper limit.

The embodiment of the present invention also provides a kind of ranging code detecting method, extremely low in order to solve the verification and measurement ratio of ranging code detecting method under low signal-to-noise ratio proposed in prior art, makes systematic function be limited to the problem of up initial ranging code access detection, comprising:

During the multiple time-domain signal received via multiple antennas, all proceed as follows to obtain the sequence generated through difference operation to each time-domain signal respectively: carry out fast fourier transform FFT to time-domain signal, the ranging sub-carrier of the frequency-region signal obtained after the conversion obtains distance measuring signal, and described distance measuring signal is made up of at least two symbols in time domain; Carry out phase compensation respectively to the sequence of other symbols except first outer symbol, offset is that the equivalent phase of cyclic prefix CP length postpones; Merging is weighted to the sequence that sequence and other each symbols of first symbol obtain after phase compensation, obtain the sequence after merging, the weights of wherein weighting are positioned between (0,1), each weights sum equals 1, and is directly proportional to the data message amount that each symbol carries; In the code table stored, select local code successively, the sequence after utilizing the sequence of the local code selected and merging carries out related operation, and carries out difference operation to the sequence obtained after related operation;

The sequence of the multiple sequences through difference operation generation obtained respectively is worth corresponding addition, obtains the sequence after being added, and carry out FFT;

Calculate the power of sequence obtained after FFT conversion, determine peak-to-average force ratio, described peak-to-average force ratio is the ratio of the peak power that is respectively worth of the sequence generated after difference operation and conversion and average power;

When peak-to-average force ratio is greater than the first threshold value, determine to carry ranging code in the time-domain signal received, described first threshold value is not less than the threshold value corresponding to the default ranging code verification and measurement ratio upper limit.

The embodiment of the present invention also provides a kind of ranging code checkout gear, extremely low in order to solve the verification and measurement ratio of ranging code detecting method under low signal-to-noise ratio proposed in prior art, makes systematic function be limited to the problem of up initial ranging code access detection, comprising:

Compensating module, for carrying out fast fourier transform FFT to the time-domain signal through single antenna reception, the ranging sub-carrier of the frequency-region signal obtained after the conversion obtains distance measuring signal, described distance measuring signal is made up of at least two symbols in time domain; Carry out phase compensation respectively to the sequence of other symbols except first outer symbol, offset is that the equivalent phase of cyclic prefix CP length postpones;

Weighting block, is weighted merging for the sequence obtained after phase compensation sequence and other each symbols of first symbol, obtains the sequence after merging, wherein the weights of weighting are positioned at (0,1) between, each weights sum equals 1, and is directly proportional to the data message amount that each symbol carries;

Computing module, for selecting local code successively in the code table stored, the sequence after utilizing the sequence of the local code selected and merging carries out related operation; Difference operation and FFT are carried out to the sequence obtained after related operation, and calculates the power of each value in the sequence generated after difference operation and conversion; Calculate the power of sequence obtained after FFT conversion, determine peak-to-average force ratio, described peak-to-average force ratio is the ratio of the peak power that is respectively worth of the sequence generated after difference operation and conversion and average power;

First determination module, for when peak-to-average force ratio is greater than the first threshold value, determine to carry ranging code in the time-domain signal received, described first threshold value is not less than the threshold value corresponding to the default ranging code verification and measurement ratio upper limit.

The embodiment of the present invention provides a kind of ranging code checkout gear, extremely low in order to solve the verification and measurement ratio of ranging code method under low signal-to-noise ratio proposed in prior art, makes systematic function be limited to the problem of up initial ranging code access detection, comprising:

Obtain module, for receive via multiple antennas multiple time-domain signal time, all proceed as follows to obtain the sequence generated through difference operation to each time-domain signal respectively: carry out fast fourier transform FFT to time-domain signal, the ranging sub-carrier of the frequency-region signal obtained after the conversion obtains distance measuring signal, and described distance measuring signal is made up of at least two symbols in time domain; Carry out phase compensation respectively to the sequence of other symbols except first outer symbol, offset is that the equivalent phase of cyclic prefix CP length postpones; Merging is weighted to the sequence that sequence and other each symbols of first symbol obtain after phase compensation, obtain the sequence after merging, the weights of wherein weighting are positioned between (0,1), each weights sum equals 1, and is directly proportional to the data message amount that each symbol carries; In the code table stored, select local code successively, the sequence after utilizing the sequence of the local code selected and merging carries out related operation, and carries out difference operation to the sequence obtained after related operation;

Summation module, for the sequence of the multiple sequences through difference operation generation obtained respectively is worth corresponding addition, obtains the sequence after being added, and carries out FFT; Calculate the power of sequence obtained after FFT conversion, determine peak-to-average force ratio, described peak-to-average force ratio is the ratio of the peak power that is respectively worth of the sequence generated after difference operation and conversion and average power;

3rd determination module, for when peak-to-average force ratio is greater than the first threshold value, determine to carry ranging code in the time-domain signal received, described first threshold value is not less than the threshold value corresponding to the default ranging code verification and measurement ratio upper limit.

According to the method that the embodiment of the present invention provides, the two or more symbol comprised by distance measuring signal carries out addition merging on frequency domain can improve signal to noise ratio, and then can solve mention in background technology cause ranging code verification and measurement ratio low because of low signal-to-noise ratio, thus make system be limited to the problem of up initial ranging code access detection, improve the performance of system.

Accompanying drawing explanation

The flow chart of the first ranging code detecting method that Fig. 1 provides for the embodiment of the present invention;

Fig. 2 for the embodiment of the present invention provide relevant after frequency domain sequence in the flow chart of the first defining method of power corresponding to each frequency domain value;

The flow chart of the second ranging code detecting method that Fig. 3 provides for the embodiment of the present invention;

Fig. 4 for the embodiment of the present invention provide relevant after frequency domain sequence in the flow chart of the second defining method of power corresponding to each frequency domain value;

The particular flow sheet of the ranging code detecting method that Fig. 5 provides for the embodiment of the present invention;

The first structural representation of the first ranging code checkout gear that Fig. 6 provides for the embodiment of the present invention;

The structural representation of the computing module that Fig. 7 provides for the embodiment of the present invention;

The second structural representation of the first ranging code checkout gear that Fig. 8 provides for the embodiment of the present invention;

The first structural representation of the second ranging code checkout gear that Fig. 9 provides for the embodiment of the present invention;

The structural representation of the acquisition module that Figure 10 provides for the embodiment of the present invention;

The structural representation of the summation module that Figure 11 provides for the embodiment of the present invention;

The second structural representation of the second ranging code checkout gear that Figure 12 provides for the embodiment of the present invention.

Embodiment

To mention for solving prior art, the verification and measurement ratio of frequency domain correlation method under low signal-to-noise ratio is extremely low, systematic function is made to be limited to the problem of up initial ranging code access detection, embodiments provide two kinds of ranging code detecting methods, be applicable to the application scenarios utilizing single-antenna received signal, another kind is applicable to the application scenarios utilizing multiple antennas Received signal strength.

For solving the problems of the technologies described above, the first ranging code detecting method that the embodiment of the present invention provides, be applicable to the application scenarios utilizing single-antenna received signal, concrete handling process as shown in Figure 1, comprising:

Step 101, acquisition distance measuring signal;

Concrete, carry out fast fourier transform FFT to the time-domain signal through single antenna reception, the ranging sub-carrier of the frequency-region signal obtained after the conversion obtains distance measuring signal, distance measuring signal is made up of at least two symbols in time domain;

Step 102, carry out phase compensation;

Concrete, carry out phase compensation respectively to the sequence of other symbols except first outer symbol, offset is that the equivalent phase of CP (CyclicPrefix, Cyclic Prefix) length postpones;

Step 103, be weighted merging;

Concrete, merging is weighted to the sequence that sequence and other each symbols of first symbol obtain after phase compensation, obtains the sequence after merging;

Wherein, the weights of weighting are positioned between (0,1), and each weights sum equals 1, and is directly proportional to the data message amount that each symbol carries;

Step 104, carry out related operation, difference operation and FFT;

Concrete, in the code table stored, select local code successively, the sequence after utilizing the sequence of the local code selected and merging carries out related operation;

Difference operation and FFT are carried out to the sequence obtained after related operation, and calculates the power of each value in the sequence generated after difference operation and conversion;

Step 105, determine peak-to-average force ratio;

Concrete, according to the power of each value in the sequence generated after difference operation and FFT conversion, determine peak-to-average force ratio, peak-to-average force ratio is the ratio of the peak power that is respectively worth of the sequence generated after difference operation and conversion and average power;

Step 106, when large first threshold value of peak-to-average force ratio, determine receive time-domain signal in carry ranging code;

Concrete, when peak-to-average force ratio is greater than the first threshold value, determine to carry ranging code in the time-domain signal received, the first threshold value is not less than the threshold value corresponding to the default ranging code verification and measurement ratio upper limit.

Step 101 is when implementing, and distance measuring signal is made up of at least two symbols in time domain, and wherein, from time domain angle, other symbols be positioned at after first symbol are copies of first symbol; From frequency domain angle, the subcarrier that symbol occupies on frequency domain is identical.Therefore, distance measuring signal is subject to the process of independently white Gaussian noise impact after channel, can be regarded as same signal and experience twice different interference.According to random digital signal treatment theory, being carried out being added the signal to noise ratio after merging by the signal of experience S different white noise interference is original S times, and S is positive integer.Therefore, for distance measuring signal, two or more symbol carries out being added merging and signal to noise ratio corresponding for distance measuring signal can be enhanced about more than once on frequency domain.Such as, when distance measuring signal comprises two symbols, addition merging is carried out on frequency domain to two symbols and its signal to noise ratio can be improved 1 times, be about 3dB.

CP except other symbols of first outer symbol needs to be added on symbol ending, for other symbols, the phase place on frequency domain can be brought to deflect, therefore, can not be directly added by plural symbol, for solving this problem, step 102 is when implementing, the embodiment of the present invention proposes to carry out to each symbol the phase compensating method that length is CP, and concrete processing mode is as follows:

According to formula carry out phase compensation respectively to the sequence of other each symbols, wherein, i, j, k are positive integer, i>=2, and N is FFT window value, Y _i,krepresent the frequency domain value of a kth subcarrier of i-th symbol, Y ' _i,krepresent the frequency domain value after phase compensation of a kth subcarrier of i-th symbol, l _cpcP length, for the equivalent phase of CP length postpones, in other words, offset is

In distance measuring signal transmitting procedure, consider that distance measuring signal can exist the delay of certain hour when arriving receiving terminal, the information that first symbol carries may reduce to some extent, therefore, can arrange weights respectively to plural symbol, each symbol is added after being multiplied by corresponding weight value respectively again.As mentioned in step 103, the weights of weighting are directly proportional to the data message amount that each symbol carries.When implementing, in order to ensure the accuracy of the frequency domain sequence obtained after weighting merges, further can limit the weights of weighting, such as, can limit according to the weights of covering radius to weighting of community, place further, each weights are directly proportional to the covering radius of small-cell, place.Certainly, when implementing, the weights of weighting can also limit according to other cell environments or condition, can increase the accuracy of the sequence obtained after weighting merges.

For the method that clearer vivider explanation utilizes weights weighting to merge, existing two symbols are that example is described, and the ratio according to the data message amount that two symbols carry respectively establishes weights to two symbols, uses α respectively ₁, α ₂represent.Be added after the sequence that two symbols are corresponding is multiplied by corresponding weight value respectively, the combination type of acquisition is as follows: Y again _k=α ₁y _{1, k}+ α ₂y ' _{2, k}, wherein, Y _kthe sequence obtained after representing two symbol mergings.

According to the method that the embodiment of the present invention provides, the two or more symbol comprised by distance measuring signal carries out addition merging on frequency domain can improve signal to noise ratio, and then can solve mention in background technology cause ranging code verification and measurement ratio low because of low signal-to-noise ratio, thus make system be limited to the problem of up initial ranging code access detection, improve the performance of system.

Flow process as shown in Figure 1, step 104 implement time, carry out difference operation and FFT, embodiments provide one preferably execution mode, idiographic flow as shown in Figure 2:

Step 201, the frequency domain sequence after relevant is mapped to ranging sub-carrier;

Step 202, successively difference operation is carried out to the sequence that ranging sub-carrier carries;

Concrete, at a distance of the sequence for the ranging sub-carrier of n △ f carries by formula by formula $\begin{array}{c}x\[n\]=\underset{\left(k+n\right)\∈K}{\underset{k\∈K}{\mathrm{\Σ}}}{c}_k^{*}{Y}_k{H}_k\exp (-j\frac{2\mathrm{\π}k}{N}{l}_0)*{\left(c_{k+n}^{*}{Y}_{k+n}{H}_{k+n}\exp \right(-j\frac{2\mathrm{\π}(k+n)}{N}{l}_0\left)\right)}^{*}\\ =\underset{\left(k+n\right)\∈K}{\underset{k\∈K}{\mathrm{\Σ}}}{H}_k{H}_{k+n}^{*}\exp \left(j\frac{2{\mathrm{\πl}}_0}{N}n\right)\end{array}$ Carry out difference operation, obtain the sequence that length is M, wherein, 1≤n≤M, n, M are positive integer, and M is the largest interval of subcarrier, and △ f is the interval of adjacent two sub-intercarriers, and K represents the set that all ranging sub-carrier form, H _kand H _k+nfor channel correlation coefficient, c _kand c _k+nthe sequence that local code C is corresponding, l ₀be the time-domain signal received time inclined, N is the numerical value of system FFT window size, Y _krepresent the sequence obtained after merging is weighted to the sequence obtained after phase compensation of the sequence of a kth subcarrier of first symbol and a kth subcarrier of other each symbols, Y _k+nrepresent the sequence obtained after merging is weighted to the sequence obtained after phase compensation of the sequence of kth+n the subcarrier of first symbol and kth+n subcarrier of other each symbols;

Step 203, carry out zero padding and fast fourier transform;

Concrete, obtain after difference operation, length is mend N after the sequence of M _t-M individual 0 is N to the length formed after zero padding _tsequence be FFT, wherein, N _tbe positioned between (N/8, N), and N _tgo forward one by one in power side with 2.

Step 203 implement time, when local code be user send ranging code time, the sequence obtained after FFT computing is an accurate δ function waveform, and peak value is positioned at l ₀place, l ₀for inclined during user.

Ranging code is being detected in the process determined, channel coefficients also plays certain impact to verification and measurement ratio, if channel coefficients impact is excessive, also verification and measurement ratio can be reduced to a great extent, for solving this problem, the embodiment of the present invention utilizes the characteristic in coherence bandwidth to provide a kind of solution, its characteristic is: when two subcarriers of participation difference operation should be positioned within the coherence bandwidth of channel, the impact of channel coefficients can be eliminated by the difference operation between subcarrier, concrete solution is as follows: get two subcarriers that subcarrier spacing is less than coherence bandwidth and carry out difference operation, now, channel coefficients can be considered as approx identical, i.e. H _k=H _k+n, can obtain after difference operation: wherein, k (n) is that ranging sub-carrier integrates spacing in K as the right number of the carrier wave of n △ f, and △ f is the subcarrier spacing that 802.16e agreement specifies.

Get the subcarrier that interval is less than coherence bandwidth to calculate, with only get be spaced apart 1 subcarrier pair its carry out conjugate multiplication and eliminate compared with the influence of fading of channel, better performance can be obtained with a small amount of amount of calculation.

Flow process as shown in Figure 1, step 106 is when implementing, whether ranging code is comprised according in the comparative result determination time-domain signal of peak-to-average force ratio and the first threshold value, mention in background technology, weigh range finding detection algorithm performance and generally have two indices, verification and measurement ratio and false alarm rate, but, in existing ranging code detecting method, verification and measurement ratio and false alarm rate are directly proportional, verification and measurement ratio is high, corresponding false alarm rate also can improve, and verification and measurement ratio is low, corresponding alert rate also can reduce, lower false alarm rate cannot be obtained while ensureing high detection rate, for solving this problem, the embodiment of the present invention proposes the method in conjunction with the first threshold value and the second threshold value determination ranging code, it is specific as follows: after confirmation peak-to-average force ratio is greater than the first threshold value, before determining to carry ranging code in the time-domain signal received, determine that peak-to-peak ratio is greater than the second threshold value, wherein, the ratio of the average of the peak power that peak-to-peak is more corresponding with each local code than the peak power that the sequence for generating after difference operation and conversion is respectively worth, second threshold value is not less than the threshold value corresponding to the alert code check lower limit of default ranging code.

During enforcement, the first threshold value value depends on signal to noise ratio and concrete channel circumstance, and preferably, the span of the first threshold value is (12,16), usually, can ensure higher verification and measurement ratio when carrying out value in (12,16).

In addition, the second threshold value depends on signal to noise ratio and concrete channel circumstance too, and preferably, the span of the second threshold value is (3,6), can ensure lower false alarm rate when usually carrying out value in (3,6).

Adopt the method in conjunction with the first threshold value and the second threshold value determination ranging code, overcome and simple rely on the verification and measurement ratio that causes when peak-to-average force ratio detects ranging code and the conflicting problem of false alarm rate, can ensure to obtain lower false alarm rate while raising verification and measurement ratio.

During enforcement, except the method in conjunction with the first threshold value and the second threshold value determination ranging code, namely utilize peak-to-average force ratio and peak-to-peak than the method determining ranging code, also may there is the method that other determine ranging code, can ensure to obtain lower false alarm rate while raising verification and measurement ratio.

For solving the problems of the technologies described above, the second ranging code detecting method that the embodiment of the present invention provides, be applicable to the application scenarios utilizing multiple antennas Received signal strength, concrete handling process as shown in Figure 3, comprising:

Step 301, receive via multiple antennas multiple time-domain signal time, all proceed as follows to obtain the sequence generated through difference operation respectively to each time-domain signal;

Concrete, carry out fast fourier transform FFT to time-domain signal, the ranging sub-carrier of the frequency-region signal obtained after the conversion obtains distance measuring signal, distance measuring signal is made up of at least two symbols in time domain; Carry out phase compensation respectively to the sequence of other symbols except first outer symbol, offset is that the equivalent phase of cyclic prefix CP length postpones; Merging is weighted to the sequence that sequence and other each symbols of first symbol obtain after phase compensation, obtain the sequence after merging, the weights of wherein weighting are positioned between (0,1), each weights sum equals 1, and is directly proportional to the data message amount that each symbol carries; In the code table stored, select local code successively, the sequence after utilizing the sequence of the local code selected and merging carries out related operation, and carries out difference operation to the sequence obtained after related operation;

Step 302, the multiple sequences of sequences generated through difference operation obtained respectively are worth corresponding addition, obtain the sequence after being added, and carry out FFT;

Step 303, calculate the power of sequence obtained after FFT conversion, and determine peak-to-average force ratio, peak-to-average force ratio is the ratio of the peak power that is respectively worth of the sequence generated after difference operation and conversion and average power;

Step 304, when peak-to-average force ratio is greater than the first threshold value, determine receive time-domain signal in carry ranging code, the first threshold value is not less than the threshold value corresponding to the default ranging code verification and measurement ratio upper limit.

Step 301 is when implementing, and distance measuring signal is made up of at least two symbols in time domain, and wherein, from time domain angle, other symbols be positioned at after first symbol are copies of first symbol; From frequency domain angle, the subcarrier that symbol occupies on frequency domain is identical.

For range finding symbol, the CP of second symbol is added on symbol ending, therefore relative first symbol, the phase place on frequency domain can be brought to deflect, therefore, can not directly two symbols be added, for solving this problem, see step 301, the embodiment of the present invention proposes to carry out to each symbol the phase compensating method that length is CP, and concrete processing mode is as follows:

According to formula carry out phase compensation respectively to the sequence of other each symbols, wherein, i, j, k are positive integer, i>=2, and N is FFT window value, Y _i,krepresent the frequency domain value of a kth subcarrier of i-th symbol, Y ' _i,krepresent the frequency domain value after phase compensation of a kth subcarrier of i-th symbol, l _cpcP length, for the equivalent phase of CP length postpones, in other words, offset is

In distance measuring signal transmitting procedure, consider that distance measuring signal can exist the delay of certain hour when arriving receiving terminal, the information that first symbol carries may reduce to some extent, therefore, can arrange weights respectively to plural symbol, each symbol is added after being multiplied by corresponding weight value respectively again.As mentioned in step 103, the weights of weighting are directly proportional to the data message amount that each symbol carries.When implementing, in order to ensure the accuracy of the frequency domain sequence obtained after weighting merges, further can limit the weights of weighting, such as, can limit according to the weights of covering radius to weighting of community, place further, each weights are directly proportional to the covering radius of small-cell, place.Certainly, when implementing, the weights of weighting can also limit according to other cell environments or condition, can increase the accuracy of the sequence obtained after weighting merges.

For the method that clearer vivider explanation utilizes weights weighting to merge, be now described for two symbols, the ratio according to the data message amount that two symbols carry respectively establishes weights to two symbols, uses α respectively ₁, α ₂represent.Be added after the frequency domain sequence of two symbols is multiplied by corresponding weight value respectively, the combination type of acquisition is as follows: Y again _k=α ₁y _{1, k}+ α ₂y ' _{2, k}, wherein, Y _kthe frequency domain sequence obtained after representing two symbol mergings.

According to the method that the embodiment of the present invention provides, the two or more symbol comprised by distance measuring signal carries out addition merging on frequency domain can improve signal to noise ratio, and then can solve mention in background technology cause ranging code verification and measurement ratio low because of low signal-to-noise ratio, thus make system be limited to the problem of up initial ranging code access detection, improve the performance of system.

Flow process as shown in Figure 3, step 301 and step 302 are when implementing, difference operation is carried out to the ranging sub-carrier after mapping, sequential value correspondence on the multiple antennas generated through difference operation is added, obtain the sequence after being added, determine the corresponding power of each point in the sequence after being added, calculate peak-to-average force ratio, concrete processing mode as shown in Figure 4, comprising:

Step 401, the sequence mapping obtained after related operation returned corresponding ranging sub-carrier;

Step 402, successively difference operation is carried out to the sequence that ranging sub-carrier carries;

Concrete, successively at a distance of the sequence for the ranging sub-carrier of n △ f carries by formula $\begin{array}{c}x\[n\]=\underset{\left(k+n\right)\∈K}{\underset{k\∈K}{\mathrm{\Σ}}}{c}_k^{*}{Y}_k{H}_k\exp (-j\frac{2\mathrm{\π}k}{N}{l}_0)*{\left(c_{k+n}^{*}{Y}_{k+n}{H}_{k+n}\exp \right(-j\frac{2\mathrm{\π}(k+n)}{N}{l}_0\left)\right)}^{*}\\ =\underset{\left(k+n\right)\∈K}{\underset{k\∈K}{\mathrm{\Σ}}}{H}_k{H}_{k+n}^{*}\exp \left(j\frac{2{\mathrm{\πl}}_0}{N}n\right)\end{array}$ Carry out difference operation, obtain the sequence that length is M, wherein, 1≤n≤M, n, M are positive integer, and M is the largest interval of subcarrier, and △ f is the interval of adjacent two sub-intercarriers, and K represents the set that all ranging sub-carrier form, H _kand H _k+nfor channel correlation coefficient, c _kand c _k+nthe sequence that local code C is corresponding, l ₀inclined when being the time-domain signal received, N is system FFT window size, Y _krepresent the sequence obtained after merging is weighted to the sequence obtained after phase compensation of the sequence of a kth subcarrier of first symbol and a kth subcarrier of other each symbols, Y _k+nrepresent the sequence obtained after merging is weighted to the sequence obtained after phase compensation of the sequence of kth+n the subcarrier of first symbol and kth+n subcarrier of other each symbols;

Step 403, the add operation of execution phase;

Concrete, sequence correspondence after the difference of the multiple antennas generated through difference operation be added, obtaining after addition, length is the sequence of M;

Step 404, zero padding carry out fast fourier transform;

Concrete, obtain after difference operation, length is mend N after the sequence of M _t-M individual 0 is N to the length formed after zero padding _tsequence be FFT, wherein, N _tbe positioned between (N/8, N), and N _tgo forward one by one in power side with 2.

Step 403 implement time, when local code be user send ranging code time, the sequence obtained after FFT computing is an accurate δ function waveform, and peak value is positioned at l ₀place, l ₀for inclined during user.

Step 402 is when implementing, the sequence pair of the multiple antennas generated through difference operation should be added, obtain after being added, that length is M frequency division sequence, avoid and mention as in other ranging code detecting methods, a FFT computing (or IFFT computing) is all carried out to the data of every root antenna, significantly can reduce amount of calculation, saving resource.

Ranging code is being detected in the process determined, channel coefficients also plays certain impact to verification and measurement ratio, if channel coefficients impact is excessive, also verification and measurement ratio can be reduced to a great extent, for solving this problem, the embodiment of the present invention utilizes the characteristic in coherence bandwidth to provide a kind of solution, its characteristic is: when two subcarriers of participation difference operation should be positioned within the coherence bandwidth of channel, the impact of channel coefficients can be eliminated by the difference operation between subcarrier, concrete solution is as follows: get two subcarriers that subcarrier spacing is less than coherence bandwidth and carry out difference operation, now, channel coefficients can be considered as approx identical, i.e. H _k=H _k+n, now, wherein, k (n) is that ranging sub-carrier integrates spacing in K as the right number of the carrier wave of n △ f, and △ f is the subcarrier spacing that 802.16e agreement specifies.

Get the subcarrier that interval is less than coherence bandwidth to calculate, with only get be spaced apart 1 subcarrier pair its carry out conjugate multiplication and eliminate compared with the influence of fading of channel, better performance can be obtained with a small amount of amount of calculation.。

Flow process as shown in Figure 3, step 304 is when implementing, whether ranging code is comprised according in the comparative result determination time-domain signal of peak-to-average force ratio and the first threshold value, mention in background technology, weigh range finding detection algorithm performance and generally have two indices, verification and measurement ratio and false alarm rate, but, in existing ranging code detecting method, verification and measurement ratio and false alarm rate are directly proportional, verification and measurement ratio is high, corresponding false alarm rate also can improve, and verification and measurement ratio is low, corresponding false alarm rate also can reduce, lower false alarm rate cannot be obtained while ensureing high detection rate, for solving this problem, the embodiment of the present invention proposes the method in conjunction with the first threshold value and the second threshold value determination ranging code, it is specific as follows: after confirmation peak-to-average force ratio is greater than the first threshold value, before determining to carry ranging code in the time-domain signal received, determine that peak-to-peak ratio is greater than the second threshold value, wherein, the ratio of the average of the peak power that peak-to-peak is more corresponding with each local code than the peak power that the sequence for generating after difference operation and conversion is respectively worth, second threshold value is not less than the threshold value corresponding to the alert code check lower limit of default ranging code.

During enforcement, the first threshold value value depends on signal to noise ratio and concrete channel circumstance, and preferably, the span of the first threshold value is (12,16), usually, can ensure higher verification and measurement ratio when carrying out value in (12,16).

In addition, the second threshold value depends on signal to noise ratio and concrete channel circumstance too, and preferably, the span of the second threshold value is (3,6), can ensure lower false alarm rate when usually carrying out value in (3,6).

Adopt the method in conjunction with the first threshold value and the second threshold value determination ranging code, overcome and simple rely on the verification and measurement ratio that causes when peak-to-average force ratio detects ranging code and the conflicting problem of false alarm rate, can ensure to obtain lower false alarm rate while raising verification and measurement ratio.

During enforcement, except the method in conjunction with the first threshold value and the second threshold value determination ranging code, namely utilize peak-to-average force ratio and peak-to-peak than the method determining ranging code, also may there is the method that other determine ranging code, can ensure to obtain lower false alarm rate while raising verification and measurement ratio.

Now be described with a specific embodiment, in this example, for 4 antennas receptions, 10M system, namely, synchronously can receive four time-domain signals during enforcement, ranging sub-carrier accounts for 144 in 1024 all subcarriers, and each distance measuring signal comprises two symbols, be respectively symbol 1, symbol 2, CP length is the size N of 128, system FFT windows is 1024, the local code number be stored in code table is 64, and concrete implementing procedure refers to Fig. 5

Step 501, each antenna receive time-domain signal, transform to frequency domain by FFT, complete the phase compensation of symbol 2, with the weighting merging treatment of symbol 1;

Step 502, get local code and carry out related operation; Concrete, get local code C _m(0≤m<64), C _m=(c _{m, 0}, c _{m, 1}... c _{m, 143}) and Y _i,kcarry out related operation, obtain the sequence after being correlated with right carry out difference operation and carry out multiple antennas merging; Difference sequence after being combined carries out FFT conversion, sequence of calculation power, obtains its power peak and average;

Step 503, carry out the judgement of ranging code according to power peak and average, and inclined when obtaining.

Concrete, step 501, when implementing, specifically comprises:

The time domain data received is transformed to frequency domain through FFT, obtains frequency domain data;

From frequency domain data, extract the data on ranging subcarrier, obtain ranging frequency domain data, use Y _{i, j, k}represent, wherein i, j, k represent reception antenna sequence number, ranging symbol sequence number and ranging subcarrier physics sequence number respectively;

To the data Y of second ranging symbol _{i, 2, k}according to Y _k=α ₁y _{1, k}+ α ₂y ' _{2, k}carry out the partial compensation for the time of 128, with Y ' _{i, 2, k}represent the sequence after partial compensation for the time:

To Y ' _{i, 2, k}be multiplied by symbol 2 weights α ₂, add the frequency domain data Y of symbol 1 _{i, 1, k}be multiplied by symbol 1 weights α ₁, obtain a new sequence Y _i,k, Y _i,k=α ₁y _{i, 1, k}+ α ₂y ' _{i, 2, k}.

Concrete, step 502, when implementing, specifically comprises:

To local code C _mwith Y _i,kthe sequence of carrying out related operation carries out difference operation process, that is, wherein 1≤n≤M, M is the maximum sub-carrier number of conjugation difference, according to channel condition setting, can obtain by aforesaid operations the sequence that a data length is M;

Process according to above step respectively 4 reception antenna data, obtaining 4 length is the sequence of M;

These 4 sequences are merged, obtains sequence that a length is M and mended 0 to N _t, N _t=256, obtain sequence Z ' _n, 0≤n<256, merges formula as follows: $Z_{n-1}^{\&prime;}=\left\{\begin{array}{cc}\underset{i=0}{\overset{L-1}{\&Sigma;}}{Z}_{i,n},& 1\&le;n\&le;M\\ 0,& M<n<N_t\end{array}\right.;$

To Z _ncarry out the FFT conversion of 256, obtain sequence after a conversion, calculate the power of this sequence, and obtain its average power P _{m, avg}, be stored in average memory; Find out its power peak P _{m, peak}and position pos _m, be stored in peak memory with in peak memory;

All aforesaid operations is carried out to all local code C, obtains 64 P _avg, and pos _m.

Concrete, step 503, when implementing, specifically comprises:

For current candidate code C _m, take out its peak power P _{m, peak}with average power P _{m, avg}, calculate peak-to-average force ratio PAPR _m: ${\mathrm{PAPR}}_m=\frac{P_{m,peak}}{P_{m,avg}};$

Take out the peak value of every other code in this frame, and obtain the average of these peak values with the peak value P of Candidate key Cm _{m, peak}divided by obtain peak-to-peak and compare PTP _m, calculating formula is as follows:

$\stackrel{\&OverBar;}{P_{peak}}=\frac{1}{63}\underset{n\&NotEqual;m}{\underset{0\&le;n<63}{\mathrm{\&Sigma;}}}{P}_{n,peak}$

${\mathrm{PTP}}_m=\frac{P_{m,peak}}{\stackrel{\&OverBar;}{P_{peak}}};$

Use PAPR _mcompare with the first threshold T H1, PTP _mcompare with the second threshold T H2, if PAPR _m>TH1 and PTP _m>TH2, then this Candidate key is regarded as the ranging code that user sends, and forwards next step process to; Otherwise then directly process next local code.

Based on same inventive concept, the embodiment of the present invention additionally provides a kind of ranging code checkout gear, and concrete structure as shown in Figure 6, comprising:

Compensating module 601, for carrying out fast fourier transform FFT to the time-domain signal through single antenna reception, the ranging sub-carrier of the frequency-region signal obtained after the conversion obtains distance measuring signal, distance measuring signal is made up of at least two symbols in time domain; Carry out phase compensation respectively to the sequence of other symbols except first outer symbol, offset is that the equivalent phase of cyclic prefix CP length postpones;

Weighting block 602, sequence for obtaining after phase compensation sequence and other each symbols of first symbol is weighted merging, obtain the sequence after merging, wherein the weights of weighting are positioned at (0,1) between, each weights sum equals 1, and is directly proportional to the data message amount that each symbol carries;

Computing module 603, for selecting local code successively in the code table stored, the sequence after utilizing the sequence of the local code selected and merging carries out related operation; Difference operation and FFT are carried out to the sequence obtained after related operation, and calculates the power of each value in the sequence generated after difference operation and conversion; According to the power of value each in the sequence generated after difference operation and conversion, determine peak-to-average force ratio, peak-to-average force ratio is the ratio of the peak power that is respectively worth of the sequence generated after difference operation and conversion and average power;

First determination module 604, for when peak-to-average force ratio is greater than the first threshold value, determine to carry ranging code in the time-domain signal received, the first threshold value is not less than the threshold value corresponding to the default ranging code verification and measurement ratio upper limit.

In one embodiment, compensating module 601 can be specifically for: according to formula carry out phase compensation respectively to the sequence of other each symbols, wherein, i, j, k are positive integer, i>=2, and N is FFT window value, Y _i,krepresent the frequency domain value of a kth subcarrier of i-th symbol, Y ' _i,krepresent the frequency domain value after phase compensation of a kth subcarrier of i-th symbol, l _cpcP length, for the equivalent phase of CP length postpones.

In one embodiment, weighting block 602 can be further used for: according to the weights of the covering radius determination weighting of community, single antenna place, wherein, and the weights of weighting are directly proportional to the covering radius of community, single antenna place.

In one embodiment, structure as shown in Figure 7, computing module 603 specifically comprises:

First mapping submodule 701, for returning by the sequence mapping obtained after related operation to corresponding ranging sub-carrier;

First difference subspace module 702, for successively at a distance of for the sequence that carries in the ranging sub-carrier of n △ f is by formula $\begin{array}{c}x\&lsqb;n\&rsqb;=\underset{\left(k+n\right)\&Element;K}{\underset{k\&Element;K}{\mathrm{\&Sigma;}}}{c}_k^{*}{Y}_k{H}_k\exp (-j\frac{2\mathrm{\&pi;}k}{N}{l}_0)*{\left(c_{k+n}^{*}{Y}_{k+n}{H}_{k+n}\exp \right(-j\frac{2\mathrm{\&pi;}(k+n)}{N}{l}_0\left)\right)}^{*}\\ =\underset{\left(k+n\right)\&Element;K}{\underset{k\&Element;K}{\mathrm{\&Sigma;}}}{H}_k{H}_{k+n}^{*}\exp \left(j\frac{2{\mathrm{\&pi;l}}_0}{N}n\right)\end{array}$ Carry out difference operation, obtain the sequence that length is M, wherein, 1≤n≤M, n, M are positive integer, and M is the largest interval of subcarrier, and △ f is the interval of adjacent two sub-intercarriers, and K represents the set that all ranging sub-carrier form, H _kand H _k+nfor channel correlation coefficient, c _kand c _k+nthe sequence that local code C is corresponding, l ₀be the time-domain signal received time inclined, N is system FFT window size, Y _krepresent the sequence obtained after merging is weighted to the sequence obtained after phase compensation of the sequence of a kth subcarrier of first symbol and a kth subcarrier of other each symbols, Y _k+nrepresent the sequence obtained after merging is weighted to the sequence obtained after phase compensation of the sequence of kth+n the subcarrier of first symbol and kth+n subcarrier of other each symbols;

First transformation submodule 703, for obtain after difference operation, length is mend N after the sequence of M _t-M individual 0 is N to the length formed after zero padding _tsequence be FFT, wherein, N _tbe not less than M, be positioned between (N/8, N), and N _tthe value power side that equals 2.

In one embodiment, the first difference subspace module 702 can be further used for: when subcarrier spacing is less than coherence bandwidth, H _k=H _k+n, now, wherein, k (n) is that ranging sub-carrier integrates spacing in K as the right number of the carrier wave of n △ f.

In one embodiment, structure as shown in Figure 8, ranging code checkout gear can also comprise:

Second determination module 801, for determining that peak-to-peak ratio is greater than the second threshold value, wherein, the ratio of the average of the peak power that described peak-to-peak is more corresponding with each local code than the peak power that the sequence for generating after difference operation and conversion is respectively worth, described second threshold value is not less than the threshold value corresponding to the alert code check lower limit of default ranging code.

Based on same inventive concept, the embodiment of the present invention additionally provides another ranging code checkout gear, and concrete structure as shown in Figure 9, comprising:

Obtain module 901, for receive via multiple antennas multiple time-domain signal time, all proceed as follows to obtain the sequence generated through difference operation to each time-domain signal respectively: carry out fast fourier transform FFT to time-domain signal, the ranging sub-carrier of the frequency-region signal obtained after the conversion obtains distance measuring signal, and described distance measuring signal is made up of at least two symbols in time domain; Carry out phase compensation respectively to the sequence of other symbols except first outer symbol, offset is that the equivalent phase of cyclic prefix CP length postpones; Merging is weighted to the sequence that sequence and other each symbols of first symbol obtain after phase compensation, obtain the sequence after merging, the weights of wherein weighting are positioned between (0,1), each weights sum equals 1, and is directly proportional to the data message amount that each symbol carries; In the code table stored, select local code successively, the sequence after utilizing the sequence of the local code selected and merging carries out related operation, and carries out difference operation to the sequence obtained after related operation;

Summation module 902, for the sequence of the multiple sequences through difference operation generation obtained respectively is worth corresponding addition, obtains the sequence after being added, and carries out FFT; Calculate the power of sequence obtained after FFT conversion, determine peak-to-average force ratio, described peak-to-average force ratio is the ratio of the peak power that is respectively worth of the sequence generated after difference operation and conversion and average power;

3rd determination module 903, for when peak-to-average force ratio is greater than the first threshold value, determine to carry ranging code in the time-domain signal received, described first threshold value is not less than the threshold value corresponding to the default ranging code verification and measurement ratio upper limit.

In one embodiment, obtain module 901 can be further used for: according to formula carry out phase compensation respectively to the sequence of other each symbols, wherein, i, j, k are positive integer, i>=2, and N is FFT window value, Y _i,krepresent the frequency domain value of a kth subcarrier of i-th symbol, Y ' _i,krepresent the frequency domain value after phase compensation of a kth subcarrier of i-th symbol, l _cpcP length, for the equivalent phase of CP length postpones.

In one embodiment, obtain module 901 can be further used for: according to the weights of the covering radius determination weighting of community, multiple antennas place, wherein, the weights of weighting are directly proportional to the covering radius of community, multiple antennas place.

In one embodiment, structure as shown in Figure 10, obtaining module 901 can comprise:

Second mapping submodule 1001, for returning by the sequence mapping obtained after related operation to corresponding ranging sub-carrier;

Second difference subspace module 1002, for successively at a distance of for the sequence that carries in the ranging sub-carrier of n △ f is by formula $\begin{array}{c}x\&lsqb;n\&rsqb;=\underset{\left(k+n\right)\&Element;K}{\underset{k\&Element;K}{\mathrm{\&Sigma;}}}{c}_k^{*}{Y}_k{H}_k\exp (-j\frac{2\mathrm{\&pi;}k}{N}{l}_0)*{\left(c_{k+n}^{*}{Y}_{k+n}{H}_{k+n}\exp \right(-j\frac{2\mathrm{\&pi;}(k+n)}{N}{l}_0\left)\right)}^{*}\\ =\underset{\left(k+n\right)\&Element;K}{\underset{k\&Element;K}{\mathrm{\&Sigma;}}}{H}_k{H}_{k+n}^{*}\exp \left(j\frac{2{\mathrm{\&pi;l}}_0}{N}n\right)\end{array}$ Carry out difference operation, obtain the sequence that length is M, wherein, 1≤n≤M, n, M are positive integer, and M is the largest interval of subcarrier, and △ f is the interval of adjacent two sub-intercarriers, and K represents the set that all ranging sub-carrier form, H _kand H _k+nfor channel correlation coefficient, c _kand c _k+nthe sequence that local code C is corresponding, l ₀be the time-domain signal received time inclined, N is system FFT window size, Y _krepresent the sequence obtained after merging is weighted to the sequence obtained after phase compensation of the sequence of a kth subcarrier of first symbol and a kth subcarrier of other each symbols, Y _k+nrepresent the sequence obtained after merging is weighted to the sequence obtained after phase compensation of the sequence of kth+n the subcarrier of first symbol and kth+n subcarrier of other each symbols.

In one embodiment, the second difference subspace module 1002 can be further used for: when described subcarrier spacing is less than coherence bandwidth, H _k=H _k+n, now, wherein, k (n) is that ranging sub-carrier integrates spacing in K as the right number of the carrier wave of n △ f.

In one embodiment, structure as shown in figure 11, summation module 902 can comprise:

Be added submodule 1101, for obtain after difference operation, length is that the sequence of the sequence of M is respectively worth corresponding addition, obtain the sequence after being added, the sequence length after described addition is M;

Second transformation submodule 1102, for obtain after addition, length is mend N after the sequence of M _t-M individual 0 is N to the length formed after zero padding _tsequence be FFT, wherein, N _tbe not less than M, be positioned between (N/8, N), and N _tthe value power side that equals 2.

In one embodiment, structure as shown in figure 12, ranging code checkout gear can also comprise:

4th determination module 1201, for determining that peak-to-peak ratio is greater than the second threshold value, wherein, the ratio of the average of the peak power that peak-to-peak is more corresponding with each local code than the peak power that the sequence for generating after difference operation and conversion is respectively worth, the second threshold value is not less than the threshold value corresponding to the alert code check lower limit of default ranging code.

According to the method that the embodiment of the present invention provides, the two or more symbol comprised by distance measuring signal carries out addition merging on frequency domain can improve signal to noise ratio, and then can solve mention in background technology cause ranging code verification and measurement ratio low because of low signal-to-noise ratio, thus make system be limited to the problem of up initial ranging code access detection, improve the performance of system.

Further, adopt the method in conjunction with the first threshold value and the second threshold value determination ranging code, overcome and simple rely on the verification and measurement ratio that causes when peak-to-average force ratio detects ranging code and the conflicting problem of false alarm rate, can ensure to obtain lower false alarm rate while raising verification and measurement ratio.

Further, get the subcarrier that interval is less than coherence bandwidth to calculate, with only get be spaced apart 1 subcarrier pair its carry out conjugate multiplication and eliminate compared with the influence of fading of channel, computation amount, decrease the complexity of calculating, reduce taking resource, can saving resource, improve resource utilization, better performance can be obtained with a small amount of amount of calculation.

Further, the frequency domain value correspondence of the multiple frequency division sequences generated through difference operation is added, obtain after being added, that length is M frequency division sequence, avoid and mention as in other ranging code detecting methods, the each sequence obtained after difference operation all carries out a FFT computing, significantly can reduce amount of calculation, saving resource.

Obviously, those skilled in the art can carry out various change and modification to the present invention and not depart from the spirit and scope of the present invention.Like this, if these amendments of the present invention and modification belong within the scope of the claims in the present invention and equivalent technologies thereof, then the present invention is also intended to comprise these change and modification.

Claims (26)

1. a ranging code detecting method, is characterized in that, comprising:

Carry out fast fourier transform FFT to the time-domain signal through single antenna reception, the ranging sub-carrier of the frequency-region signal obtained after the conversion obtains distance measuring signal, described distance measuring signal is made up of at least two symbols in time domain;

Carry out phase compensation respectively to the sequence of other symbols except first outer symbol, offset is that the equivalent phase of cyclic prefix CP length postpones;

Merging is weighted to the sequence that sequence and other each symbols of first symbol obtain after phase compensation, obtain the sequence after merging, the weights of wherein weighting are positioned between (0,1), each weights sum equals 1, and is directly proportional to the data message amount that each symbol carries;

In the code table stored, select local code successively, the sequence after utilizing the sequence of the local code selected and merging carries out related operation;

Difference operation and FFT are carried out to the sequence obtained after related operation, and calculates the power of each value in the sequence generated after difference operation and conversion;

According to the power of value each in the sequence generated after difference operation and conversion, determine peak-to-average force ratio, described peak-to-average force ratio is the ratio of peak power and average power, and described peak power is the maximum in the power of each value in sequence, and described average power is the mean value of the power of each value in sequence;

When peak-to-average force ratio is greater than the first threshold value, determine to carry ranging code in the time-domain signal received, described first threshold value is not less than the threshold value corresponding to the default ranging code verification and measurement ratio upper limit;

Wherein, carry out phase compensation respectively to the sequence of other symbols except first outer symbol, offset is that the equivalent phase of cyclic prefix CP length postpones, and comprising:

According to formula carry out phase compensation respectively to the sequence of other each symbols, wherein, i, j, k are positive integer, i>=2, and N is FFT window value, Y _i,krepresent the frequency domain value of a kth subcarrier of i-th symbol, Y ' _i,krepresent the frequency domain value after phase compensation of a kth subcarrier of i-th symbol, l _cpcP length, for the equivalent phase of CP length postpones.

2. the method for claim 1, is characterized in that, the weights of described weighting are directly proportional to the covering radius of community, described single antenna place.

3. the method as described in any one of claim 1-2, is characterized in that, carries out difference operation and FFT, specifically comprise the sequence obtained after related operation:

The sequence mapping obtained after related operation is returned corresponding ranging sub-carrier;

Successively at a distance of for the sequence that carries in the ranging sub-carrier of n △ f is by formula $x\&lsqb;n\&rsqb;=\underset{\left(k+n\right)\&Element;K}{\underset{k\&Element;K}{\mathrm{\&Sigma;}}}{c}_k^{*}{Y}_k{H}_k\exp (-j\frac{2\mathrm{\&pi;}k}{N}{l}_0)*{\left(c_{k+n}^{*}{Y}_{k+n}{H}_{k+n}\exp \right(-j\frac{2\mathrm{\&pi;}(k+n)}{N}{l}_0\left)\right)}^{*}$ Carry out difference operation, obtain

$=\underset{\left(k+n\right)\&Element;K}{\underset{k\&Element;K}{\mathrm{\&Sigma;}}}{H}_k{H}_{k+n}^{*}\exp \left(j\frac{2{\mathrm{\&pi;l}}_0}{N}n\right)$

Length is the sequence of M, and wherein, 1≤n≤M, n, M are positive integer, and M is the largest interval of subcarrier, and △ f is the interval of adjacent two sub-intercarriers, and K represents the set that all ranging sub-carrier form, H _kand H _k+nfor channel correlation coefficient, c _kand c _k+nthe sequence that local code C is corresponding, l ₀be the time-domain signal received time inclined, Y _krepresent the sequence obtained after merging is weighted to the sequence obtained after phase compensation of the sequence of a kth subcarrier of first symbol and a kth subcarrier of other each symbols, Y _k+nrepresent the sequence obtained after merging is weighted to the sequence obtained after phase compensation of the sequence of kth+n the subcarrier of first symbol and kth+n subcarrier of other each symbols;

Obtain after difference operation, length is mend N after the sequence of M _t-M individual 0 is N to the length formed after zero padding _tsequence be FFT, wherein, N _tbe not less than M, be positioned between (N/8, N), and N _tthe value power side that equals 2.

4. method as claimed in claim 3, is characterized in that, when described subcarrier spacing is less than coherence bandwidth, and H _k=H _k+n, now, wherein, k (n) is that ranging sub-carrier integrates spacing in K as the right number of the carrier wave of n △ f.

5. the method as described in any one of claim 1-2, is characterized in that, described first threshold value is positioned between (12,16).

6. the method as described in any one of claim 1-2, is characterized in that, after confirmation peak-to-average force ratio is greater than the first threshold value, before determining to carry ranging code in the time-domain signal received, also comprises:

Determine that peak-to-peak ratio is greater than the second threshold value, wherein, the ratio of the average of the peak power that described peak-to-peak is more corresponding with each local code than the peak power that the sequence for generating after difference operation and conversion is respectively worth, described second threshold value is not less than the threshold value corresponding to the alert code check lower limit of default ranging code.

7. method as claimed in claim 6, it is characterized in that, described second threshold value is positioned between (3,6).

8. a ranging code detecting method, is characterized in that, comprising:

During the multiple time-domain signal received via multiple antennas, all proceed as follows to obtain the sequence generated through difference operation to each time-domain signal respectively: carry out fast fourier transform FFT to time-domain signal, the ranging sub-carrier of the frequency-region signal obtained after the conversion obtains distance measuring signal, and described distance measuring signal is made up of at least two symbols in time domain; Carry out phase compensation respectively to the sequence of other symbols except first outer symbol, offset is that the equivalent phase of cyclic prefix CP length postpones; Merging is weighted to the sequence that sequence and other each symbols of first symbol obtain after phase compensation, obtain the sequence after merging, the weights of wherein weighting are positioned between (0,1), each weights sum equals 1, and is directly proportional to the data message amount that each symbol carries; In the code table stored, select local code successively, the sequence after utilizing the sequence of the local code selected and merging carries out related operation, and carries out difference operation to the sequence obtained after related operation;

The multiple sequences generated through difference operation obtained respectively are worth corresponding addition, obtain the sequence after being added, and carry out FFT;

Calculate the power of sequence obtained after FFT conversion, determine peak-to-average force ratio, described peak-to-average force ratio is the ratio of the peak power that is respectively worth of the sequence generated after difference operation and conversion and average power;

When peak-to-average force ratio is greater than the first threshold value, determine to carry ranging code in the time-domain signal received, described first threshold value is not less than the threshold value corresponding to the default ranging code verification and measurement ratio upper limit;

Wherein, carry out phase compensation respectively to the sequence of other symbols except first outer symbol, offset is that the equivalent phase of cyclic prefix CP length postpones, and comprising:

According to formula carry out phase compensation respectively to the sequence of other each symbols, wherein, i, j, k are positive integer, i>=2, and N is FFT window value, Y _i,krepresent the frequency domain value of a kth subcarrier of i-th symbol, Y ' _i,krepresent the frequency domain value after phase compensation of a kth subcarrier of i-th symbol, l _cpcP length, for the equivalent phase of CP length postpones.

9. method as claimed in claim 8, it is characterized in that, the weights of described weighting are directly proportional to the covering radius of community, described multiple antennas place.

10. the method as described in any one of claim 8-9, is characterized in that, carries out difference operation, specifically comprise the sequence obtained after related operation:

The sequence mapping obtained after related operation is returned corresponding ranging sub-carrier;

Successively at a distance of for the sequence that carries in the ranging sub-carrier of n △ f is by formula $x\&lsqb;n\&rsqb;=\underset{\left(k+n\right)\&Element;K}{\underset{k\&Element;K}{\mathrm{\&Sigma;}}}{c}_k^{*}{Y}_k{H}_k\exp (-j\frac{2\mathrm{\&pi;}k}{N}{l}_0)*{\left(c_{k+n}^{*}{Y}_{k+n}{H}_{k+n}\exp \right(-j\frac{2\mathrm{\&pi;}(k+n)}{N}{l}_0\left)\right)}^{*}$ Carry out difference operation, obtain

$=\underset{\left(k+n\right)\&Element;K}{\underset{k\&Element;K}{\mathrm{\&Sigma;}}}{H}_k{H}_{k+n}^{*}\exp \left(j\frac{2{\mathrm{\&pi;l}}_0}{N}n\right)$

Length is the sequence of M, and wherein, 1≤n≤M, n, M are positive integer, and M is the largest interval of subcarrier, and △ f is the interval of adjacent two sub-intercarriers, and K represents the set that all ranging sub-carrier form, H _kand H _k+nfor channel correlation coefficient, c _kand c _k+nthe sequence that local code C is corresponding, l ₀be the time-domain signal received time inclined, Y _krepresent the sequence obtained after merging is weighted to the sequence obtained after phase compensation of the sequence of a kth subcarrier of first symbol and a kth subcarrier of other each symbols, Y _k+nrepresent the sequence obtained after merging is weighted to the sequence obtained after phase compensation of the sequence of kth+n the subcarrier of first symbol and kth+n subcarrier of other each symbols.

11. methods as claimed in claim 10, is characterized in that, when described subcarrier spacing is less than coherence bandwidth, and H _k=H _k+n, now, wherein, k (n) is that ranging sub-carrier integrates spacing in K as the right number of the carrier wave of n △ f.

12. methods as claimed in claim 11, is characterized in that, the sequence of the multiple sequences through difference operation generation obtained respectively is worth corresponding addition, obtains the sequence after being added, and carry out FFT, comprising:

Obtain after difference operation, length is that the sequence of multiple sequences of M is respectively worth corresponding addition, obtain the sequence after being added, the sequence length after described addition is M;

Obtain after addition, length is mend N after the sequence of M _t-M individual 0 is N to the length formed after zero padding _tsequence be FFT, wherein, N _tbe not less than M, be positioned between (N/8, N), and N _tthe value power side that equals 2.

13. methods as described in any one of claim 8-9, it is characterized in that, described first threshold value is positioned between (12,16).

14. methods as described in any one of claim 8-9, is characterized in that, after confirmation peak-to-average force ratio is greater than the first threshold value, before determining to carry ranging code in the time-domain signal received, also comprise:

Determine that peak-to-peak ratio is greater than the second threshold value, wherein, the ratio of the average of the peak power that described peak-to-peak is more corresponding with each local code than the peak power that the sequence for generating after difference operation and conversion is respectively worth, described second threshold value is not less than the threshold value corresponding to the alert code check lower limit of default ranging code.

15. methods as claimed in claim 14, it is characterized in that, described second threshold value is positioned between (3,6).

16. 1 kinds of ranging code checkout gears, is characterized in that, comprising:

Compensating module, for carrying out fast fourier transform FFT to the time-domain signal through single antenna reception, the ranging sub-carrier of the frequency-region signal obtained after the conversion obtains distance measuring signal, described distance measuring signal is made up of at least two symbols in time domain; Carry out phase compensation respectively to the sequence of other symbols except first outer symbol, offset is that the equivalent phase of cyclic prefix CP length postpones;

Weighting block, is weighted merging for the sequence obtained after phase compensation sequence and other each symbols of first symbol, obtains the sequence after merging, wherein the weights of weighting are positioned at (0,1) between, each weights sum equals 1, and is directly proportional to the data message amount that each symbol carries;

Computing module, for selecting local code successively in the code table stored, the sequence after utilizing the sequence of the local code selected and merging carries out related operation; Difference operation and FFT are carried out to the sequence obtained after related operation, and calculates the power of each value in the sequence generated after difference operation and conversion; According to the power of value each in the sequence generated after difference operation and conversion, determine peak-to-average force ratio, described peak-to-average force ratio is the ratio of the peak power that is respectively worth of the sequence generated after difference operation and conversion and average power;

First determination module, for when peak-to-average force ratio is greater than the first threshold value, determine to carry ranging code in the time-domain signal received, described first threshold value is not less than the threshold value corresponding to the default ranging code verification and measurement ratio upper limit;

Wherein, described compensating module specifically for: according to formula carry out phase compensation respectively to the sequence of other each symbols, wherein, i, j, k are positive integer, i>=2, and N is FFT window value, Y _i,krepresent the frequency domain value of a kth subcarrier of i-th symbol, Y ' _i,krepresent the frequency domain value after phase compensation of a kth subcarrier of i-th symbol, l _cpcP length, for the equivalent phase of CP length postpones.

17. devices as claimed in claim 16, it is characterized in that, described weighting block is further used for: the weights determining described weighting according to the covering radius of community, described single antenna place, and wherein, the weights of described weighting are directly proportional to the covering radius of community, described single antenna place.

18. devices as described in any one of claim 16-17, it is characterized in that, described computing module specifically comprises:

First mapping submodule, for returning by the sequence mapping obtained after related operation to corresponding ranging sub-carrier;

First difference subspace module, for successively at a distance of for the sequence that carries in the ranging sub-carrier of n △ f is by formula $x\&lsqb;n\&rsqb;=\underset{\left(k+n\right)\&Element;K}{\underset{k\&Element;K}{\mathrm{\&Sigma;}}}{c}_k^{*}{Y}_k{H}_k\exp (-j\frac{2\mathrm{\&pi;}k}{N}{l}_0)*{\left(c_{k+n}^{*}{Y}_{k+n}{H}_{k+n}\exp \right(-j\frac{2\mathrm{\&pi;}(k+n)}{N}{l}_0\left)\right)}^{*}$ Carry out difference operation,

$=\underset{\left(k+n\right)\&Element;K}{\underset{k\&Element;K}{\mathrm{\&Sigma;}}}{H}_k{H}_{k+n}^{*}\exp \left(j\frac{2{\mathrm{\&pi;l}}_0}{N}n\right)$

Be the sequence of M to length, wherein, 1≤n≤M, n, M are positive integer, and M is the largest interval of subcarrier, and △ f is the interval of adjacent two sub-intercarriers, and K represents the set that all ranging sub-carrier form, H _kand H _k+nfor channel correlation coefficient, c _kand c _k+nthe sequence that local code C is corresponding, l ₀be the time-domain signal received time inclined, Y _krepresent the sequence obtained after merging is weighted to the sequence obtained after phase compensation of the sequence of a kth subcarrier of first symbol and a kth subcarrier of other each symbols, Y _k+nrepresent the sequence obtained after merging is weighted to the sequence obtained after phase compensation of the sequence of kth+n the subcarrier of first symbol and kth+n subcarrier of other each symbols;

First transformation submodule, for obtain after difference operation, length is mend N after the sequence of M _t-M individual 0 is N to the length formed after zero padding _tsequence be FFT, wherein, N _tbe not less than M, be positioned between (N/8, N), and N _tthe value power side that equals 2.

19. devices as claimed in claim 18, is characterized in that, described first difference subspace module is further used for: when described subcarrier spacing is less than coherence bandwidth, H _k=H _k+n, now, wherein, k (n) is that ranging sub-carrier integrates spacing in K as the right number of the carrier wave of n △ f.

20. devices as described in any one of claim 16-17, is characterized in that, also comprise:

Second determination module, for determining that peak-to-peak ratio is greater than the second threshold value, wherein, the ratio of the average of the peak power that described peak-to-peak is more corresponding with each local code than the peak power that the sequence for generating after difference operation and conversion is respectively worth, described second threshold value is not less than the threshold value corresponding to the alert code check lower limit of default ranging code.

21. 1 kinds of ranging code checkout gears, is characterized in that, comprising:

Obtain module, for receive via multiple antennas multiple time-domain signal time, all proceed as follows to obtain the sequence generated through difference operation to each time-domain signal respectively: carry out fast fourier transform FFT to time-domain signal, the ranging sub-carrier of the frequency-region signal obtained after the conversion obtains distance measuring signal, and described distance measuring signal is made up of at least two symbols in time domain; Carry out phase compensation respectively to the sequence of other symbols except first outer symbol, offset is that the equivalent phase of cyclic prefix CP length postpones; Merging is weighted to the sequence that sequence and other each symbols of first symbol obtain after phase compensation, obtain the sequence after merging, the weights of wherein weighting are positioned between (0,1), each weights sum equals 1, and is directly proportional to the data message amount that each symbol carries; In the code table stored, select local code successively, the sequence after utilizing the sequence of the local code selected and merging carries out related operation, and carries out difference operation to the sequence obtained after related operation;

Summation module, for the sequence of the multiple sequences through difference operation generation obtained respectively is worth corresponding addition, obtains the sequence after being added, and carries out FFT; Calculate the power of sequence obtained after FFT conversion, determine peak-to-average force ratio, described peak-to-average force ratio is the ratio of the peak power that is respectively worth of the sequence generated after difference operation and conversion and average power;

3rd determination module, for when peak-to-average force ratio is greater than the first threshold value, determine to carry ranging code in the time-domain signal received, described first threshold value is not less than the threshold value corresponding to the default ranging code verification and measurement ratio upper limit;

Wherein, described acquisition module specifically for: according to formula carry out phase compensation respectively to the sequence of other each symbols, wherein, i, j, k are positive integer, i>=2, and N is FFT window value, Y _i,krepresent the frequency domain value of a kth subcarrier of i-th symbol, Y ' _i,krepresent the frequency domain value after phase compensation of a kth subcarrier of i-th symbol, l _cpcP length, for the equivalent phase of CP length postpones.

22. devices as claimed in claim 21, it is characterized in that, described acquisition module is further used for: the weights determining described weighting according to the covering radius of community, described multiple antennas place, and wherein, the weights of described weighting are directly proportional to the covering radius of community, described multiple antennas place.

23. devices as described in any one of claim 21-22, it is characterized in that, described acquisition module comprises:

Second mapping submodule, for returning by the sequence mapping obtained after related operation to corresponding ranging sub-carrier;

Second difference subspace module, for successively at a distance of for the sequence that carries in the ranging sub-carrier of n △ f is by formula $x\&lsqb;n\&rsqb;=\underset{\left(k+n\right)\&Element;K}{\underset{k\&Element;K}{\mathrm{\&Sigma;}}}{c}_k^{*}{Y}_k{H}_k\exp (-j\frac{2\mathrm{\&pi;}k}{N}{l}_0)*{\left(c_{k+n}^{*}{Y}_{k+n}{H}_{k+n}\exp \right(-j\frac{2\mathrm{\&pi;}(k+n)}{N}{l}_0\left)\right)}^{*}$ Carry out difference operation,

$=\underset{\left(k+n\right)\&Element;K}{\underset{k\&Element;K}{\mathrm{\&Sigma;}}}{H}_k{H}_{k+n}^{*}\exp \left(j\frac{2{\mathrm{\&pi;l}}_0}{N}n\right)$

Be the sequence of M to length, wherein, 1≤n≤M, n, M are positive integer, and M is the largest interval of subcarrier, and △ f is the interval of adjacent two sub-intercarriers, and K represents the set that all ranging sub-carrier form, H _kand H _k+nfor channel correlation coefficient, c _kand c _k+nthe sequence that local code C is corresponding, l ₀be the time-domain signal received time inclined, N is FFT window number, Y _krepresent the sequence obtained after merging is weighted to the sequence obtained after phase compensation of the sequence of a kth subcarrier of first symbol and a kth subcarrier of other each symbols, Y _k+nrepresent the sequence obtained after merging is weighted to the sequence obtained after phase compensation of the sequence of kth+n the subcarrier of first symbol and kth+n subcarrier of other each symbols.

24. devices as claimed in claim 23, is characterized in that, described second difference subspace module is further used for: when described subcarrier spacing is less than coherence bandwidth, H _k=H _k+n, now, wherein, k (n) is that ranging sub-carrier integrates spacing in K as the right number of the carrier wave of n △ f.

25. devices as claimed in claim 23, it is characterized in that, described summation module comprises:

Be added submodule, for obtain after difference operation, length is that the sequence of the sequence of M is respectively worth corresponding addition, obtain the sequence after being added, the sequence length after described addition is M;

Second transformation submodule, for obtain after addition, length is mend N after the sequence of M _t-M individual 0 is N to the length formed after zero padding _tsequence be FFT, wherein, N _tbe not less than M, be positioned between (N/8, N), and N _tthe value power side that equals 2.

26. devices as described in any one of claim 21-22, is characterized in that, also comprise:

4th determination module, for determining that peak-to-peak ratio is greater than the second threshold value, wherein, the ratio of the average of the peak power that described peak-to-peak is more corresponding with each local code than the peak power that the sequence for generating after difference operation and conversion is respectively worth, described second threshold value is not less than the threshold value corresponding to the alert code check lower limit of default ranging code.