CN102238123A - Ranging code detection method and device - Google Patents

Abstract

The invention discloses a ranging code detection method, which comprises the following steps of: performing fast Fourier transform (FFT) on a received time domain signal, and acquiring a ranging signal from a ranging sub-carrier of a frequency domain signal obtained by the transform, wherein the ranging signal consists of at least two symbols on a time domain; performing phase compensation and weighting combination on sequences of the other symbols except a first symbol to obtain a combined sequence; sequentially selecting local codes from a stored code table, performing a correlation operation, a differential operation and the FFT by utilizing a selected local code sequence and the combined sequence, calculating the power of the sequence generated by the FFT, and calculating the peak to average power ratio of the sequence; and when the peak to average power ratio is greater than a first threshold value, determining that the received time domain signal carries a ranging code. The invention discloses another ranging code detection method and ranging code detection devices. By the methods and the devices, the detection rate of the ranging code can be increased.

Description

Ranging code detecting method and device

Technical field

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

Background technology

IEEE (Institute of Electrical and Electronics Engineers, Institute of Electrical and Electronics Engineers) 802.16e be a kind of be the standard of mobile wide-band wire-less accessing system on basis with OFDMA (Orthogonal Frequency Division MultiplexingAccess, OFDM) technology.Range finding is a kind of process that is used to adjust mobile subscriber's carrier wave frequency deviation, timing offset and received power in the 802.16e agreement regulation OFDMA system.

Usually, the base station can specify time to allow the mobile subscriber find range, and this Resource Block is referred to as distance measurement zone (ranging region).802.16e agreement has been stipulated 4 kinds of distance measuring methods, one group of corresponding ranging code can be specified at different distance measuring methods in the base station, and this ranging code is a kind of CDMA (Code DivisionMultiple Access, code division multiple access inserts) sign indicating number.

When carrying out initial ranging, the mobile subscriber selects a ranging code to send at the distance measurement zone of appointment from the code table of base station appointment, is used for finishing the system parameters estimation of uplink distance measuring process and adjusting.The base station detects ranging code and the information such as calculating is inclined to one side at that time, frequency deviation that the mobile subscriber sends from the distance measuring signal that receives, feed back to the mobile subscriber who sends ranging code then.The mobile subscriber adjusts the transmission parameter of oneself again according to these information.

At present the ranging code detecting method that adopts mainly is that autocorrelation performance according to ranging code carries out, and can be divided into time domain correlation method and frequency domain correlation method.The former is meant that the base station is not FFT (FastFourier Transform, fast fourier transform) to the time domain data that receives, and directly carries out relevant, peak detection operation with local code; After the latter was meant that the base station is to the time domain data FFT conversion that receives, the value that extracts on the range finding subchannel was carried out related operation, IFFT operations such as (Inverse Fast Fourier Transform, inverse fast Fourier transforms) with local code again.

In actual practicality, problem such as amount of calculation is very big because the time domain correlation method exists, the interference that is subject to the data user and seldom being used.The thought of frequency domain correlation method is succinct, realizes that introducing simple, the IFFT computing makes amount of calculation be less than the time domain correlation method greatly again, so is used to carry out the detection of ranging code in the reality usually.

Weigh range finding detection algorithm performance two indexs are generally arranged: verification and measurement ratio and false alarm rate.False alarm rate is meant and detects the probability that the user does not have the ranging code of transmission.Along with various advanced technologies such as MIMO (Multiple-Input Multiple-Out-put, multiple-input and multiple-output), the utilization of beam forming technique beamforming etc., performance index such as the descending covering of base station, throughput have obtained significantly promoting, and the sensitivity of system's operate as normal (being signal to noise ratio) also further reduces.But the verification and measurement ratio of frequency domain correlation method under low signal-to-noise ratio is extremely low, makes systematic function be subject to up initial ranging sign indicating number and inserts detection.The ranging detection method that adopts has only been considered the application scenarios of signal to noise ratio more than 0dB mostly at present, does not take in for the situation of signal to noise ratio far below 0dB, and therefore performance is undesirable under low signal-to-noise ratio.In addition, a lot of ranging detection methods all are at AWGN (Additive white Gaussian noise, what additive white Gaussian noise) derivation was come out under the channel, and in the actual application environment, channel mostly is multidiameter fading channel, with the environment of detection method and do not match, can cause the verification and measurement ratio of ranging code is further descended.

Summary of the invention

The embodiment of the invention provides a kind of ranging code detecting method, and is extremely low in order to solve the verification and measurement ratio of ranging code detecting method under low signal-to-noise ratio that proposes in the prior art, makes systematic function be subject to up initial ranging sign indicating number and inserts the problem that detects, and comprising:

The time-domain signal that receives through single antenna is carried out fast fourier transform FFT, obtain distance measuring signal on the ranging sub-carrier of the frequency-region signal that obtains after the conversion, described distance measuring signal is made up of at least two symbols on time domain;

Sequence to other symbols of removing first outer symbol is carried out phase compensation respectively, and offset is that the equivalent phase of cyclic prefix CP length postpones;

The sequence that sequence and other each symbols of first symbol obtained after phase compensation is weighted merging, sequence after obtaining to merge, wherein the weights of weighting are positioned between (0,1), each weights sum equals 1, and is directly proportional with the data message amount of carrying on each symbol;

In the code table of having stored, select local code successively, utilize the sequence of the local code of selecting and the sequence after the merging to carry out related operation;

The sequence that obtains behind the related operation is carried out difference operation and FFT, and calculate the power of each value in the sequence that after difference operation and conversion, generates;

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

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

The embodiment of the invention also provides a kind of ranging code detecting method, and is extremely low in order to solve the verification and measurement ratio of ranging code detecting method under low signal-to-noise ratio that proposes in the prior art, makes systematic function be subject to up initial ranging sign indicating number and inserts the problem that detects, and comprising:

During a plurality of time-domain signal of receiving via many antennas, respectively each time-domain signal is all carried out the sequence of following operation to obtain to generate through difference operation: time-domain signal is carried out fast fourier transform FFT, obtain distance measuring signal on the ranging sub-carrier of the frequency-region signal that obtains after the conversion, described distance measuring signal is made up of at least two symbols on time domain; Sequence to other symbols of removing first outer symbol is carried out phase compensation respectively, and offset is that the equivalent phase of cyclic prefix CP length postpones; The sequence that sequence and other each symbols of first symbol obtained after phase compensation is weighted merging, sequence after obtaining to merge, wherein the weights of weighting are positioned between (0,1), each weights sum equals 1, and is directly proportional with the data message amount of carrying on each symbol; In the code table of having stored, select local code successively, utilize the sequence of the local code of selecting and the sequence after the merging to carry out related operation, and the sequence that obtains behind the related operation is carried out difference operation;

The sequence of a plurality of sequences that generate through difference operation of obtaining respectively is worth corresponding addition, obtains the sequence after the addition, and carry out FFT;

Calculate the power of the sequence that obtains after the FFT conversion, determine peak-to-average force ratio, described peak-to-average force ratio is the peak power of each value of the sequence that generates and the ratio of average power after difference operation and conversion;

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

The embodiment of the invention also provides a kind of ranging code checkout gear, and is extremely low in order to solve the verification and measurement ratio of ranging code detecting method under low signal-to-noise ratio that proposes in the prior art, makes systematic function be subject to up initial ranging sign indicating number and inserts the problem that detects, and comprising:

Compensating module is used for the time-domain signal that receives through single antenna is carried out fast fourier transform FFT, obtains distance measuring signal on the ranging sub-carrier of the frequency-region signal that obtains after the conversion, and described distance measuring signal is made up of at least two symbols on time domain; Sequence to other symbols of removing first outer symbol is carried out phase compensation respectively, and offset is that the equivalent phase of cyclic prefix CP length postpones;

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

Computing module is used for selecting local code successively at the code table of having stored, utilizes the sequence of the local code of selecting and the sequence after the merging to carry out related operation; The sequence that obtains behind the related operation is carried out difference operation and FFT, and calculate the power of each value in the sequence that after difference operation and conversion, generates; Calculate the power of the sequence that obtains after the FFT conversion, determine peak-to-average force ratio, described peak-to-average force ratio is the peak power of each value of the sequence that generates and the ratio of average power after difference operation and conversion;

First determination module is used for carrying ranging code when peak-to-average force ratio during greater than first threshold value in the time-domain signal of determining to receive, and described first threshold value is not less than the default pairing threshold value of the ranging code verification and measurement ratio upper limit.

The embodiment of the invention provides a kind of ranging code checkout gear, and is extremely low in order to solve the verification and measurement ratio of ranging code method under low signal-to-noise ratio that proposes in the prior art, makes systematic function be subject to up initial ranging sign indicating number and inserts the problem that detects, and comprising:

Obtain module, during a plurality of time-domain signal of being used for receiving via many antennas, respectively each time-domain signal is all carried out the sequence of following operation to obtain to generate through difference operation: time-domain signal is carried out fast fourier transform FFT, obtain distance measuring signal on the ranging sub-carrier of the frequency-region signal that obtains after the conversion, described distance measuring signal is made up of at least two symbols on time domain; Sequence to other symbols of removing first outer symbol is carried out phase compensation respectively, and offset is that the equivalent phase of cyclic prefix CP length postpones; The sequence that sequence and other each symbols of first symbol obtained after phase compensation is weighted merging, sequence after obtaining to merge, wherein the weights of weighting are positioned between (0,1), each weights sum equals 1, and is directly proportional with the data message amount of carrying on each symbol; In the code table of having stored, select local code successively, utilize the sequence of the local code of selecting and the sequence after the merging to carry out related operation, and the sequence that obtains behind the related operation is carried out difference operation;

Summation module, the sequence that is used for a plurality of sequences that generate through difference operation that will obtain respectively is worth corresponding addition, obtains the sequence after the addition, and carries out FFT; Calculate the power of the sequence that obtains after the FFT conversion, determine peak-to-average force ratio, described peak-to-average force ratio is the peak power of each value of the sequence that generates and the ratio of average power after difference operation and conversion;

The 3rd determination module is used for carrying ranging code when peak-to-average force ratio during greater than first threshold value in the time-domain signal of determining to receive, and described first threshold value is not less than the default pairing threshold value of the ranging code verification and measurement ratio upper limit.

The method that provides according to the embodiment of the invention, two above symbols that distance measuring signal is comprised carry out addition and merge and can improve signal to noise ratio on frequency domain, and then can solve mention in the background technology cause the ranging code verification and measurement ratio low because of low signal-to-noise ratio, thereby make system be subject to up initial ranging sign indicating number and insert the problem that detects, improve the performance of system.

Description of drawings

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

Fig. 2 for the embodiment of the invention provide relevant after frequency domain sequence in the flow chart of first kind of definite method of power of each frequency domain value correspondence;

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

Fig. 4 for the embodiment of the invention provide relevant after frequency domain sequence in the flow chart of second kind of definite method of power of each frequency domain value correspondence;

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

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

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

Second kind of structural representation of first kind of ranging code checkout gear that Fig. 8 provides for the embodiment of the invention;

First kind of structural representation of second kind of ranging code checkout gear that Fig. 9 provides for the embodiment of the invention;

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

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

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

Embodiment

Prior art mentions in order to solve, the verification and measurement ratio of frequency domain correlation method under low signal-to-noise ratio is extremely low, make systematic function be subject to up initial ranging sign indicating number and insert the problem that detects, the embodiment of the invention provides two kinds of ranging code detecting methods, a kind of application scenarios that utilizes the single antenna received signal that is applicable to, another kind is applicable to the application scenarios that utilizes many antenna receiving signals.

For solving the problems of the technologies described above, first kind of ranging code detecting method that the embodiment of the invention provides is applicable to the application scenarios that utilizes the single antenna received signal, and concrete handling process comprises as shown in Figure 1:

Step 101, obtain distance measuring signal;

Concrete, the time-domain signal that receives through single antenna is carried out fast fourier transform FFT, on the ranging sub-carrier of the frequency-region signal that obtains after the conversion, obtain distance measuring signal, distance measuring signal is made up of at least two symbols on time domain;

Step 102, carry out phase compensation;

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

Step 103, be weighted merging;

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

Wherein, the weights of weighting are positioned between (0,1), and each weights sum equals 1, and are directly proportional with the data message amount of carrying on each symbol;

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

Concrete, in the code table of having stored, select local code successively, utilize the sequence of the local code of selecting and the sequence after the merging to carry out related operation;

The sequence that obtains behind the related operation is carried out difference operation and FFT, and calculate the power of each value in the sequence that after difference operation and conversion, generates;

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

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

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

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

Step 101 is when implementing, and distance measuring signal is made of at least two symbols on time domain, and wherein, on the time domain angle, other symbols that are positioned at behind first symbol are copies of first symbol; On the frequency domain angle, the subcarrier that symbol occupies on frequency domain is identical.Therefore, distance measuring signal can be regarded as same signal and experience twice different interference through being subjected to the process of independent Gaussian white noise influence behind the channel.According to the random digital signal treatment theory, the signal to noise ratio that S different white noise interference signals of experience are carried out after addition merges is original S times, and S is a positive integer.Therefore, for distance measuring signal, two above symbols carry out addition and merge and the signal to noise ratio of distance measuring signal correspondence can be enhanced about more than once on frequency domain.For example, when distance measuring signal comprises two symbols, two symbols are carried out addition merge and its signal to noise ratio can be improved 1 times on frequency domain, be about 3dB.

The CP that removes other symbols of first outer symbol need be added on the symbol ending, for other symbols, can bring the phase place deflection on the frequency domain, therefore, can not directly plural symbol be carried out addition, for addressing this problem, step 102 is when implementing, the embodiment of the invention proposes each symbol is carried out the phase compensating method that length is CP, and concrete processing mode is as follows:

According to formula

Sequence to other each symbols is carried out phase compensation respectively, and wherein, i, j, k are positive integer, i 〉=2, and N is the FFT window value, Y _{I, k}The frequency domain value of representing k subcarrier of i symbol, Y _{I, k}The frequency domain value after phase compensation of k subcarrier of i symbol of ' expression, l _CpBe CP length,

Be the equivalent phase delay of CP length, in other words, offset is

In the distance measuring signal transmission course, consider that can there be the delay of certain hour in distance measuring signal when arriving receiving terminal, the information of carrying on first symbol may reduce to some extent, therefore, can weights be set respectively to plural symbol, each symbol multiply by addition again after the corresponding weight value respectively.As mentioning in the step 103, the data message amount of carrying on the weights of weighting and each symbol is directly proportional.When implementing, accuracy for the frequency domain sequence that guarantees to obtain after weighting merges can further limit the weights of weighting, for example, can be further limit according to the covering radius of sub-district, the place weights to weighting, each weights is directly proportional with the covering radius of sub-district, place.Certainly, when implementing, the weights of weighting can also limit according to other cell environments or condition, and the accuracy that can increase the sequence that obtains after weighting merges gets final product.

Be the method that clearer vivider explanation utilizes the weights weighting to merge, existing two symbols are that example describes, and according to the ratio of the data message amount of carrying on two symbols two symbols are respectively established weights, use α respectively ₁, α ₂Expression.The sequence of two symbol correspondences multiply by addition again after the corresponding weight value respectively, and the combination type of acquisition is as follows: Y _k=α ₁Y _{1, k}+ α ₂Y _{2, k}', wherein, Y _kRepresent the sequence that obtains after two symbols merge.

The method that provides according to the embodiment of the invention, two above symbols that distance measuring signal is comprised carry out addition and merge and can improve signal to noise ratio on frequency domain, and then can solve mention in the background technology cause the ranging code verification and measurement ratio low because of low signal-to-noise ratio, thereby make system be subject to up initial ranging sign indicating number and insert the problem that detects, improve the performance of system.

Flow process as shown in Figure 1, step 104 is carried out difference operation and FFT when implementing, the embodiment of the invention provides a kind of preferred implementation, idiographic flow as shown in Figure 2:

Step 201, the frequency domain sequence after will being correlated with are mapped to ranging sub-carrier;

Step 202, successively the sequence of carrying on the ranging sub-carrier is carried out difference operation;

Concrete, at a distance of for the sequence of carrying on the ranging sub-carrier of n Δ f by formula

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 Δ f is for facing the interval of two sub-intercarriers mutually, and K represents the set that all ranging sub-carrier are formed, H _kAnd H _K+nBe channel coefficient correlation, C _kAnd C _K+nBe the sequence of local code C correspondence, l ₀Be the time-domain signal that receives the time inclined to one side, N is the numerical value of the FFT of system window size;

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

Concrete, obtain after the difference operation, length mends N after being the sequence of M _t-M 0, is N to the length that forms after the zero padding _tSequence be FFT, wherein, N _tBe positioned between (N/8, N), and N _tPower power with 2 goes forward one by one.

Step 203 when implementing, when local code be the user send ranging code the time, the sequence that obtains after the FFT computing is an accurate δ function waveform, peak value is positioned at l ₀The place, l ₀Inclined to one side during for the user.

Ranging code is being detected in definite process, channel coefficients also plays certain influence to verification and measurement ratio, if the channel coefficients influence is excessive, also can reduce verification and measurement ratio to a great extent, for addressing this problem, the embodiment of the invention utilizes the characteristic in the coherence bandwidth that a kind of solution is provided, its characteristic is: when two subcarriers that participate in difference operation should be positioned within the coherence bandwidth of channel, can eliminate the influence of channel coefficients by the difference operation between subcarrier, concrete solution is as follows: get subcarrier spacing and carry out difference operation less than two subcarriers of coherence bandwidth, at this moment, it is identical to be considered as channel coefficients approx, i.e. H _k=H _K+n, can get through after the difference operation: Wherein, k (n) is that spacing is the right number of carrier wave of n Δ f among the ranging sub-carrier collection K, and Δ f is the subcarrier spacing of 802.16e agreement regulation.

The subcarrier of getting at interval less than coherence bandwidth calculates, and is spaced apart 1 subcarrier and it is carried out conjugate multiplication eliminates the influence of fading of channel and compare with only getting, and can obtain more performance with a spot of amount of calculation.

Flow process as shown in Figure 1, step 106 is when implementing, determine whether comprise ranging code in the time-domain signal according to the comparative result of the peak-to-average force ratio and first threshold value, mention in the background technology, weigh range finding detection algorithm performance two indexs are generally arranged, 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, the verification and measurement ratio height, corresponding false alarm rate also can improve, and verification and measurement ratio is low, corresponding alert rate also can reduce, can't when guaranteeing the high detection rate, obtain lower false alarm rate, for addressing this problem, the embodiment of the invention has proposed to determine in conjunction with first threshold value and second threshold value method of ranging code, specific as follows: after confirming that peak-to-average force ratio is greater than first threshold value, carry before the ranging code in the time-domain signal of determining to receive, determine that the peak-to-peak ratio is greater than 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 of each value of sequence that is through difference operation and generates after changing, second threshold value is not less than presets the pairing threshold value of ranging code police's code check lower limit.

During enforcement, the first threshold value value depends on signal to noise ratio and concrete channel circumstance, and is more excellent, and the span of first threshold value is (12,16), usually, can guarantee the higher detection rate when carrying out value in (12,16).

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

The method of ranging code is determined in employing in conjunction with first threshold value and second threshold value, overcome the verification and measurement ratio and the conflicting problem of false alarm rate that cause when simple dependence peak-to-average force ratio detects ranging code, can when improving verification and measurement ratio, guarantee to obtain lower false alarm rate.

During enforcement, remove the method for determining ranging code in conjunction with first threshold value and second threshold value, promptly utilize peak-to-average force ratio and peak-to-peak method, also may have other methods of determining ranging code, can guarantee when improving verification and measurement ratio that can obtain lower false alarm rate gets final product than definite ranging code.

For solving the problems of the technologies described above, second kind of ranging code detecting method that the embodiment of the invention provides is applicable to the application scenarios that utilizes many antenna receiving signals, and concrete handling process comprises as shown in Figure 3:

Step 301, receive via many antennas a plurality of time-domain signal the time, respectively each time-domain signal is all carried out the sequence of following operation to obtain to generate through difference operation;

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

The sequence of step 302, a plurality of sequences that generate through difference operation that will obtain respectively is worth corresponding addition, obtains the sequence after the addition, and carries out FFT;

Step 303, calculate the power of the sequence that obtains after the FFT conversion, and definite peak-to-average force ratio, peak-to-average force ratio is the peak power of each value of sequence of generating and the ratio of average power after difference operation and conversion;

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

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

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

According to formula

Sequence to other each symbols is carried out phase compensation respectively, and wherein, i, j, k are positive integer, i 〉=2, and N is the FFT window value, Y _{I, k}The frequency domain value of representing k subcarrier of i symbol, Y _{I, k}The frequency domain value after phase compensation of k subcarrier of i symbol of ' expression, l _CpBe CP length, Be the equivalent phase delay of CP length, in other words, offset is

In the distance measuring signal transmission course, consider that can there be the delay of certain hour in distance measuring signal when arriving receiving terminal, the information of carrying on first symbol may reduce to some extent, therefore, can weights be set respectively to plural symbol, each symbol multiply by addition again after the corresponding weight value respectively.As mentioning in the step 103, the data message amount of carrying on the weights of weighting and each symbol is directly proportional.When implementing, accuracy for the frequency domain sequence that guarantees to obtain after weighting merges can further limit the weights of weighting, for example, can be further limit according to the covering radius of sub-district, the place weights to weighting, each weights is directly proportional with the covering radius of sub-district, place.Certainly, when implementing, the weights of weighting can also limit according to other cell environments or condition, and the accuracy that can increase the sequence that obtains after weighting merges gets final product.

Be the method that clearer vivider explanation utilizes the weights weighting to merge, existing is that example describes with two symbols, according to the ratio of the data message amount of carrying on two symbols two symbols is respectively established weights, uses α respectively ₁, α ₂Expression.The frequency domain sequence of two symbols multiply by addition again after the corresponding weight value respectively, and the combination type of acquisition is as follows: Y _k=α ₁Y _{1, k}+ α ₂Y _{2, k}', wherein, Y _kRepresent the frequency domain sequence that obtains after two symbols merge.

The method that provides according to the embodiment of the invention, two above symbols that distance measuring signal is comprised carry out addition and merge and can improve signal to noise ratio on frequency domain, and then can solve mention in the background technology cause the ranging code verification and measurement ratio low because of low signal-to-noise ratio, thereby make system be subject to up initial ranging sign indicating number and insert the problem that detects, improve the performance of system.

Flow process as shown in Figure 3, step 301 and step 302 are when implementing, ranging sub-carrier after the mapping is carried out difference operation, will be through the corresponding addition of the sequential value on a plurality of antennas that difference operation generates, obtain the sequence after the addition, determine the corresponding power of each point in the sequence after the addition, calculate peak-to-average force ratio, concrete processing mode comprises as shown in Figure 4:

Step 401, the sequence that obtains behind the related operation is shone upon back corresponding ranging sub-carrier;

Step 402, successively the sequence of carrying on the ranging sub-carrier is carried out difference operation;

Concrete, successively at a distance of for the sequence of carrying on the ranging sub-carrier of n Δ f by formula

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 Δ f is for facing the interval of two sub-intercarriers mutually, and K represents the set that all ranging sub-carrier are formed, H _kAnd H _K+nBe channel coefficient correlation, C _kAnd C _K+nBe the sequence of local code C correspondence, l ₀Inclined to one side when being the time-domain signal that receives, N is the FFT of a system window size;

Step 403, the add operation of execution phase;

Concrete, will sequence correspondence addition after the difference of a plurality of antennas that difference operation generates, obtain after the addition, length is the sequence of M;

Step 404, zero padding are also carried out fast fourier transform;

Concrete, obtain after the difference operation, length mends N after being the sequence of M _t-M 0, is N to the length that forms after the zero padding _tSequence be FFT, wherein, N _tBe positioned between (N/8, N), and N _tPower power with 2 goes forward one by one.

Step 403 when implementing, when local code be the user send ranging code the time, the sequence that obtains after the FFT computing is an accurate δ function waveform, peak value is positioned at l ₀The place, l ₀Inclined to one side during for the user.

Step 402 is when implementing, the corresponding addition of the sequence of a plurality of antennas that will generate through difference operation, obtain after the addition, length is the frequency division sequence of M, avoided mentioning as in other ranging code detecting methods, the data of every antenna are all carried out a FFT computing (or IFFT computing), can reduce amount of calculation significantly, save resource.

Ranging code is being detected in definite process, channel coefficients also plays certain influence to verification and measurement ratio, if the channel coefficients influence is excessive, also can reduce verification and measurement ratio to a great extent, for addressing this problem, the embodiment of the invention utilizes the characteristic in the coherence bandwidth that a kind of solution is provided, its characteristic is: when two subcarriers that participate in difference operation should be positioned within the coherence bandwidth of channel, can eliminate the influence of channel coefficients by the difference operation between subcarrier, concrete solution is as follows: get subcarrier spacing and carry out difference operation less than two subcarriers of coherence bandwidth, at this moment, it is identical to be considered as channel coefficients approx, i.e. H _k=H _K+n, at this moment, Wherein, k (n) is that spacing is the right number of carrier wave of n Δ f among the ranging sub-carrier collection K, and Δ f is the subcarrier spacing of 802.16e agreement regulation.

The subcarrier of getting at interval less than coherence bandwidth calculates, and is spaced apart 1 subcarrier and it is carried out conjugate multiplication eliminates the influence of fading of channel and compare with only getting, and can obtain more performance with a spot of amount of calculation.。

Flow process as shown in Figure 3, step 304 is when implementing, determine whether comprise ranging code in the time-domain signal according to the comparative result of the peak-to-average force ratio and first threshold value, mention in the background technology, weigh range finding detection algorithm performance two indexs are generally arranged, 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, the verification and measurement ratio height, corresponding false alarm rate also can improve, and verification and measurement ratio is low, corresponding false alarm rate also can reduce, can't when guaranteeing the high detection rate, obtain lower false alarm rate, for addressing this problem, the embodiment of the invention has proposed to determine in conjunction with first threshold value and second threshold value method of ranging code, specific as follows: after confirming that peak-to-average force ratio is greater than first threshold value, carry before the ranging code in the time-domain signal of determining to receive, determine that the peak-to-peak ratio is greater than 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 of each value of sequence that is through difference operation and generates after changing, second threshold value is not less than presets the pairing threshold value of ranging code police's code check lower limit.

During enforcement, the first threshold value value depends on signal to noise ratio and concrete channel circumstance, and is more excellent, and the span of first threshold value is (12,16), usually, can guarantee the higher detection rate when carrying out value in (12,16).

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

The method of ranging code is determined in employing in conjunction with first threshold value and second threshold value, overcome the verification and measurement ratio and the conflicting problem of false alarm rate that cause when simple dependence peak-to-average force ratio detects ranging code, can when improving verification and measurement ratio, guarantee to obtain lower false alarm rate.

During enforcement, remove the method for determining ranging code in conjunction with first threshold value and second threshold value, promptly utilize peak-to-average force ratio and peak-to-peak method, also may have other methods of determining ranging code, can guarantee when improving verification and measurement ratio that can obtain lower false alarm rate gets final product than definite ranging code.

Now describing with a specific embodiment, in this example, is example with the reception of 4 antennas, 10M system, promptly, can receive four time-domain signals synchronously 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 are 128, and the big or small N of system FFT window is 1024, the local code number that has been stored in the code table is 64, and concrete implementing procedure sees also Fig. 5

Step 501, each antenna receive time-domain signal, transform to frequency domain by FFT, finish the phase compensation of symbol 2, merge with the weighting of symbol 1 and handle;

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, k}Carry out related operation, the sequence Y after obtaining being correlated with _{I, k}C _{M, k} ^*To Y _{I, k}C _{M, k} ^*Carry out difference operation and carry out many antennas merging; Difference sequence after being combined is carried out the FFT conversion, and sequence of calculation power is obtained its power peak and average;

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

Concrete, step 501 specifically comprises when implementing:

The time domain data that receives is transformed to frequency domain through FFT, obtain frequency domain data;

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

Data Y to second ranging symbol _{I, 2, k}According to Y _k=α ₁Y _{1, k}+ α ₂Y _{2, k}' carry out 128 partial compensation for the time, use Y _{I, 2, k}Sequence behind the ' expression partial compensation for the time:

To Y _{I, 2, k}' multiply by symbol 2 weights α ₂, add the frequency domain data Y of symbol 1 _{I, 1, k}Multiply 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 specifically comprises when implementing:

To local code C _mWith Y _{I, k}Carry out the sequence of related operation and carry out the difference operation processing, that is,

1≤n≤M wherein, M is the maximum sub-carrier number of conjugation difference, sets according to channel condition, can obtain the sequence that a data length is M by aforesaid operations;

4 reception antenna data are handled the sequence that to obtain 4 length be M respectively according to above step;

These 4 sequences are merged, obtain sequence that a length is M and it is mended 0 to N _t, N _t=256, obtain sequence Z _n', 0≤n＜256, it is as follows to merge formula:

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

All local code C are all carried out aforesaid operations, obtain 64 P _Avg, and pos _m

Concrete, step 503 specifically comprises when implementing:

For current Candidate key C _m, take out its peak power P _{M, peak}With average power P _{M, avg}, calculate peak-to-average force ratio PAPR _m:

Take out the peak value of every other sign indicating number in this frame, and obtain the average of these peak values

Peak value P with Candidate key Cm _{M, peak}Divided by

Obtain peak-to-peak and compare PTP _m, calculating formula is as follows:

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

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

Use PAPR _mCompare PTP with the first threshold T H1 _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 the user sends, and forwards next step processing to; Otherwise then directly handle next local code.

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

Compensating module 601 is used for the time-domain signal that receives through single antenna is carried out fast fourier transform FFT, obtains distance measuring signal on the ranging sub-carrier of the frequency-region signal that obtains after the conversion, and distance measuring signal is made up of at least two symbols on time domain; Sequence to other symbols of removing first outer symbol is carried out phase compensation respectively, and offset is that the equivalent phase of cyclic prefix CP length postpones;

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

Computing module 603 is used for selecting local code successively at the code table of having stored, utilizes the sequence of the local code of selecting and the sequence after the merging to carry out related operation; The sequence that obtains behind the related operation is carried out difference operation and FFT, and calculate the power of each value in the sequence that after difference operation and conversion, generates; According to the power of each value in the sequence that after difference operation and conversion, generates, determine peak-to-average force ratio, peak-to-average force ratio is the sequence that generates the respectively peak power of value and the ratio of average power after difference operation and conversion;

First determination module 604 is used for carrying ranging code when peak-to-average force ratio during greater than first threshold value in the time-domain signal of determining to receive, and first threshold value is not less than the default pairing threshold value of the ranging code verification and measurement ratio upper limit.

In one embodiment, compensating module 601 can specifically be used for: according to formula

Sequence to other each symbols is carried out phase compensation respectively, and wherein, i, j, k are positive integer, i 〉=2, and N is the FFT window value, Y _{I, k}The frequency domain value of representing k subcarrier of i symbol, Y _{I, k}The frequency domain value after phase compensation of k subcarrier of i symbol of ' expression, l _CpBe CP length,

Equivalent phase delay for CP length.

In one embodiment, weighting block 602 can be further used for: determine the weights of weighting according to the covering radius of sub-district, single antenna place, wherein, the weights of weighting are directly proportional with the covering radius of sub-district, single antenna place.

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

First mapping submodule 701 is used for the sequence that obtains behind the related operation is shone upon back corresponding ranging sub-carrier;

The first difference subspace module 702, be used for successively at a distance of for the sequence of carrying on the ranging sub-carrier of n Δ f by formula

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 Δ f is for facing the interval of two sub-intercarriers mutually, and K represents the set that all ranging sub-carrier are formed, H _kAnd H _K+nBe channel coefficient correlation, C _kAnd C _K+nBe the sequence of local code C correspondence, l ₀Be the time-domain signal that receives the time inclined to one side, N is the FFT of a system window size;

First transformation submodule 703, be used for obtain after the difference operation, length mends N after being the sequence of M _t-M 0, is N to the length that forms after the zero padding _tSequence be FFT, wherein, N _tBe not less than M, be positioned between (N/8, N), and N _tThe value power power that equals 2.

In one embodiment, the first difference subspace module 702 can be further used for: when subcarrier spacing during less than coherence bandwidth, and H _k=H _K+n, at this moment,

Wherein, k (n) is that spacing is the right number of carrier wave of n Δ f among the ranging sub-carrier collection K.

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

Second determination module 801, be used for determining that the peak-to-peak ratio is greater than 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 of each value of sequence that is through difference operation and generates after changing, described second threshold value are not less than presets the pairing threshold value of ranging code police's code check lower limit.

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

Obtain module 901, during a plurality of time-domain signal of being used for receiving via many antennas, respectively each time-domain signal is all carried out the sequence of following operation to obtain to generate through difference operation: time-domain signal is carried out fast fourier transform FFT, obtain distance measuring signal on the ranging sub-carrier of the frequency-region signal that obtains after the conversion, described distance measuring signal is made up of at least two symbols on time domain; Sequence to other symbols of removing first outer symbol is carried out phase compensation respectively, and offset is that the equivalent phase of cyclic prefix CP length postpones; The sequence that sequence and other each symbols of first symbol obtained after phase compensation is weighted merging, sequence after obtaining to merge, wherein the weights of weighting are positioned between (0,1), each weights sum equals 1, and is directly proportional with the data message amount of carrying on each symbol; In the code table of having stored, select local code successively, utilize the sequence of the local code of selecting and the sequence after the merging to carry out related operation, and the sequence that obtains behind the related operation is carried out difference operation;

Summation module 902, the sequence that is used for a plurality of sequences that generate through difference operation that will obtain respectively is worth corresponding addition, obtains the sequence after the addition, and carries out FFT; Calculate the power of the sequence that obtains after the FFT conversion, determine peak-to-average force ratio, described peak-to-average force ratio is the peak power of each value of the sequence that generates and the ratio of average power after difference operation and conversion;

The 3rd determination module 903 is used for carrying ranging code when peak-to-average force ratio during greater than first threshold value in the time-domain signal of determining to receive, and described first threshold value is not less than the default pairing threshold value of the ranging code verification and measurement ratio upper limit.

In one embodiment, obtaining module 901 can be further used for: according to formula

Sequence to other each symbols is carried out phase compensation respectively, and wherein, i, j, k are positive integer, i 〉=2, and N is the FFT window value, Y _{I, k}The frequency domain value of representing k subcarrier of i symbol, Y _{I, k}The frequency domain value after phase compensation of k subcarrier of i symbol of ' expression, l _CpBe CP length,

Equivalent phase delay for CP length.

In one embodiment, obtaining module 901 can be further used for: determine the weights of weighting according to the covering radius of sub-district, many antennas place, wherein, the weights of weighting are directly proportional with the covering radius of sub-district, many antennas place.

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

Second mapping submodule 1001 is used for the sequence that obtains behind the related operation is shone upon back corresponding ranging sub-carrier;

The second difference subspace module 1002, be used for successively at a distance of for the sequence of carrying on the ranging sub-carrier of n Δ f by formula

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 Δ f is for facing the interval of two sub-intercarriers mutually, and K represents the set that all ranging sub-carrier are formed, H _kAnd H _K+nBe channel coefficient correlation, C _kAnd C _K+nBe the sequence of local code C correspondence, l ₀Be the time-domain signal that receives the time inclined to one side, N is the FFT of a system window size.

In one embodiment, the second difference subspace module 1002 can be further used for: when described subcarrier spacing during less than coherence bandwidth, and H _k=H _K+n, at this moment,

Wherein, k (n) is that spacing is the right number of carrier wave of n Δ f among the ranging sub-carrier collection K.

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

Addition submodule 1101, be used for after difference operation, obtaining, length is that the sequence of the sequence of M respectively is worth corresponding addition, obtains the sequence after the addition, the sequence length after the described addition is M;

Second transformation submodule 1102, be used for obtain after the addition, length mends N after being the sequence of M _t-M 0, is N to the length that forms after the zero padding _tSequence be FFT, wherein, N _tBe not less than M, be positioned between (N/8, N), and N _tThe value power power that equals 2.

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

The 4th determination module 1201, be used for determining that the peak-to-peak ratio is greater than 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 of each value of sequence that is through difference operation and generates after changing, second threshold value are not less than presets the pairing threshold value of ranging code police's code check lower limit.

The method that provides according to the embodiment of the invention, two above symbols that distance measuring signal is comprised carry out addition and merge and can improve signal to noise ratio on frequency domain, and then can solve mention in the background technology cause the ranging code verification and measurement ratio low because of low signal-to-noise ratio, thereby make system be subject to up initial ranging sign indicating number and insert the problem that detects, improve the performance of system.

Further, the method of ranging code is determined in employing in conjunction with first threshold value and second threshold value, overcome the verification and measurement ratio and the conflicting problem of false alarm rate that cause when simple dependence peak-to-average force ratio detects ranging code, can when improving verification and measurement ratio, guarantee to obtain lower false alarm rate.

Further, the subcarrier of getting at interval less than coherence bandwidth calculates, be spaced apart 1 subcarrier and it is carried out conjugate multiplication eliminate the influence of fading of channel and compare with only getting, computation amount, reduced the complexity of calculating, reduced, can save resource the taking of resource, improve resource utilization, can obtain more performance with a spot of amount of calculation.

Further, the corresponding addition of the frequency domain value of a plurality of frequency division sequences that will generate through difference operation, obtain after the addition, length is the frequency division sequence of M, avoided mentioning as in other ranging code detecting methods, each sequence that obtains after difference operation is all carried out a FFT computing, can reduce amount of calculation significantly, save resource.

Obviously, those skilled in the art can carry out various changes and modification to the present invention and not break away from the spirit and scope of the present invention.Like this, if of the present invention these are revised and modification belongs within the scope of claim of the present invention and equivalent technologies thereof, then the present invention also is intended to comprise these changes and modification interior.

Claims (30)

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

The time-domain signal that receives through single antenna is carried out fast fourier transform FFT, obtain distance measuring signal on the ranging sub-carrier of the frequency-region signal that obtains after the conversion, described distance measuring signal is made up of at least two symbols on time domain;

Sequence to other symbols of removing first outer symbol is carried out phase compensation respectively, and offset is that the equivalent phase of cyclic prefix CP length postpones;

The sequence that sequence and other each symbols of first symbol obtained after phase compensation is weighted merging, sequence after obtaining to merge, wherein the weights of weighting are positioned between (0,1), each weights sum equals 1, and is directly proportional with the data message amount of carrying on each symbol;

In the code table of having stored, select local code successively, utilize the sequence of the local code of selecting and the sequence after the merging to carry out related operation;

The sequence that obtains behind the related operation is carried out difference operation and FFT, and calculate the power of each value in the sequence that after difference operation and conversion, generates;

Power according to each value in the sequence that after difference operation and conversion, generates, 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 the sequence, and described average power is the mean value of the power of value respectively in the sequence;

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

2. the method for claim 1 is characterized in that, the sequence of other symbols of removing first outer symbol is carried out phase compensation respectively, and offset is that the equivalent phase of cyclic prefix CP length postpones, and comprising:

According to formula

Sequence to other each symbols is carried out phase compensation respectively, and wherein, i, j, k are positive integer, i 〉=2, and N is the FFT window value, Y _{I, k}The frequency domain value of representing k subcarrier of i symbol, Y _{I, k}The frequency domain value after phase compensation of k subcarrier of i symbol of ' expression, l _CpBe CP length,

Equivalent phase delay for CP length.

3. the method for claim 1 is characterized in that, the weights of described weighting are directly proportional with the covering radius of sub-district, described single antenna place.

4. as each described method of claim 1-3, it is characterized in that, the sequence that obtains behind the related operation carried out difference operation and FFT, specifically comprise:

The sequence that obtains behind the related operation is shone upon back corresponding ranging sub-carrier;

Successively at a distance of for the sequence of carrying on the ranging sub-carrier of n Δ f by formula

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

$=\underset{(k+n)\&Element;K}{\underset{k\&Element;K}{\mathrm{\&Sigma;}}}{H}_k{H}_{k+n}^{*}\exp \left(j\frac{2\mathrm{\&pi;}{l}_0}{N}n\right)$ 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 Δ f is for facing the interval of two sub-intercarriers mutually, and K represents the set that all ranging sub-carrier are formed, H _kAnd H _K+nBe channel coefficient correlation, C _kAnd C _K+nBe the sequence of local code C correspondence, l ₀Be the time-domain signal that receives the time inclined to one side;

Obtain after the difference operation, length mends N after being the sequence of M _t-M 0, is N to the length that forms after the zero padding _tSequence be FFT, wherein, N _tBe not less than M, be positioned between (N/8, N), and N _tThe value power power that equals 2.

5. method as claimed in claim 4 is characterized in that, when described subcarrier spacing during less than coherence bandwidth, and H _k=H _K+n, at this moment,

Wherein, k (n) is that spacing is the right number of carrier wave of n Δ f among the ranging sub-carrier collection K.

6. as each described method of claim 1-3, it is characterized in that described first threshold value is positioned between (12,16).

7. as each described method of claim 1-3, it is characterized in that, after confirming that peak-to-average force ratio is greater than first threshold value, carry before the ranging code in the time-domain signal of determining to receive, also comprise:

Determine that the peak-to-peak ratio is greater than 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 of each value of sequence that is through difference operation and generates after changing, described second threshold value are not less than presets the pairing threshold value of ranging code police's code check lower limit.

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

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

During a plurality of time-domain signal of receiving via many antennas, respectively each time-domain signal is all carried out the sequence of following operation to obtain to generate through difference operation: time-domain signal is carried out fast fourier transform FFT, obtain distance measuring signal on the ranging sub-carrier of the frequency-region signal that obtains after the conversion, described distance measuring signal is made up of at least two symbols on time domain; Sequence to other symbols of removing first outer symbol is carried out phase compensation respectively, and offset is that the equivalent phase of cyclic prefix CP length postpones; The sequence that sequence and other each symbols of first symbol obtained after phase compensation is weighted merging, sequence after obtaining to merge, wherein the weights of weighting are positioned between (0,1), each weights sum equals 1, and is directly proportional with the data message amount of carrying on each symbol; In the code table of having stored, select local code successively, utilize the sequence of the local code of selecting and the sequence after the merging to carry out related operation, and the sequence that obtains behind the related operation is carried out difference operation;

The a plurality of sequences that generate through difference operation that obtain respectively are worth corresponding addition, obtain the sequence after the addition, and carry out FFT;

Calculate the power of the sequence that obtains after the FFT conversion, determine peak-to-average force ratio, described peak-to-average force ratio is the peak power of each value of the sequence that generates and the ratio of average power after difference operation and conversion;

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

10. method as claimed in claim 9 is characterized in that, the sequence of other symbols of removing first outer symbol is carried out phase compensation respectively, and offset is that the equivalent phase of cyclic prefix CP length postpones, and comprising:

According to formula

Sequence to other each symbols is carried out phase compensation respectively, and wherein, i, j, k are positive integer, i 〉=2, and N is the FFT window value, Y _{I, k}The frequency domain value of representing k subcarrier of i symbol, Y _{I, k}The frequency domain value after phase compensation of k subcarrier of i symbol of ' expression, l _CpBe CP length,

Equivalent phase delay for CP length.

11. method as claimed in claim 9 is characterized in that, the weights of described weighting are directly proportional with the covering radius of sub-district, described many antennas place.

12., it is characterized in that as each described method of claim 9-11, the sequence that obtains behind the related operation is carried out difference operation, specifically comprise:

The sequence that obtains behind the related operation is shone upon back corresponding ranging sub-carrier;

Successively at a distance of for the sequence of carrying on the ranging sub-carrier of n Δ f by formula

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

$=\underset{(k+n)\&Element;K}{\underset{k\&Element;K}{\mathrm{\&Sigma;}}}{H}_k{H}_{k+n}^{*}\exp \left(j\frac{2\mathrm{\&pi;}{l}_0}{N}n\right)$ 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 Δ f is for facing the interval of two sub-intercarriers mutually, and K represents the set that all ranging sub-carrier are formed, H _kAnd H _K+nBe channel coefficient correlation, C _kAnd C _K+nBe the sequence of local code C correspondence, l ₀Be the time-domain signal that receives the time inclined to one side.

13. method as claimed in claim 12 is characterized in that, when described subcarrier spacing during less than coherence bandwidth, and H _k=H _K+n, at this moment,

Wherein, k (n) is that spacing is the right number of carrier wave of n Δ f among the ranging sub-carrier collection K.

14. method as claimed in claim 12 is characterized in that, the sequence of a plurality of sequences that generate through difference operation of obtaining respectively is worth corresponding addition, obtains the sequence after the addition, and carries out FFT, comprising:

After difference operation, obtain, length is that the sequence of a plurality of sequences of M respectively is worth corresponding addition, obtains the sequence after the addition, the sequence length after the described addition is M;

Obtain after the addition, length mends N after being the sequence of M _t-M 0, is N to the length that forms after the zero padding _tSequence be FFT, wherein, N _tBe not less than M, be positioned between (N/8, N), and N _tThe value power power that equals 2.

15., it is characterized in that described first threshold value is positioned between (12,16) as each described method of claim 9-11.

16., it is characterized in that as each described method of claim 9-11, after confirming that peak-to-average force ratio is greater than first threshold value, carry before the ranging code in the time-domain signal of determining to receive, also comprise:

Determine that the peak-to-peak ratio is greater than 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 of each value of sequence that is through difference operation and generates after changing, described second threshold value are not less than presets the pairing threshold value of ranging code police's code check lower limit.

17. method as claimed in claim 16 is characterized in that, described second threshold value is positioned between (3,6).

18. a ranging code checkout gear is characterized in that, comprising:

Compensating module is used for the time-domain signal that receives through single antenna is carried out fast fourier transform FFT, obtains distance measuring signal on the ranging sub-carrier of the frequency-region signal that obtains after the conversion, and described distance measuring signal is made up of at least two symbols on time domain; Sequence to other symbols of removing first outer symbol is carried out phase compensation respectively, and offset is that the equivalent phase of cyclic prefix CP length postpones;

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

Computing module is used for selecting local code successively at the code table of having stored, utilizes the sequence of the local code of selecting and the sequence after the merging to carry out related operation; The sequence that obtains behind the related operation is carried out difference operation and FFT, and calculate the power of each value in the sequence that after difference operation and conversion, generates; According to the power of each value in the sequence that after difference operation and conversion, generates, determine peak-to-average force ratio, described peak-to-average force ratio is the sequence that generates the respectively peak power of value and the ratio of average power after difference operation and conversion;

First determination module is used for carrying ranging code when peak-to-average force ratio during greater than first threshold value in the time-domain signal of determining to receive, and described first threshold value is not less than the default pairing threshold value of the ranging code verification and measurement ratio upper limit.

19. device as claimed in claim 18 is characterized in that, described compensating module specifically is used for: according to formula

Sequence to other each symbols is carried out phase compensation respectively, and wherein, i, j, k are positive integer, i 〉=2, and N is the FFT window value, Y _{I, k}The frequency domain value of representing k subcarrier of i symbol, Y _{I, k}The frequency domain value after phase compensation of k subcarrier of i symbol of ' expression, l _CpBe CP length,

Equivalent phase delay for CP length.

20. device as claimed in claim 18, it is characterized in that, described weighting block is further used for: determine the weights of described weighting according to the covering radius of sub-district, described single antenna place, wherein, the weights of described weighting are directly proportional with the covering radius of sub-district, described single antenna place.

21., it is characterized in that described computing module specifically comprises as each described device of claim 18-20:

First mapping submodule is used for the sequence that obtains behind the related operation is shone upon back corresponding ranging sub-carrier;

The first difference subspace module, be used for successively at a distance of for the sequence of carrying on the ranging sub-carrier of n Δ f by formula $x\left[n\right]=\underset{(k+n)\&Element;K}{\underset{k\&Element;K}{\mathrm{\&Sigma;}}}{c}_k^{*}{Y}_k{H}_k\exp (-j\frac{2\mathrm{\&pi;k}}{N}{l}_0)*{\left(c_{k+n}^{*}{Y}_{k+n}{H}_{k+n}\exp (-j\frac{2\mathrm{\&pi;}(k+n)}{N}{l}_0)\right)}^{*}$

$=\underset{(k+n)\&Element;K}{\underset{k\&Element;K}{\mathrm{\&Sigma;}}}{H}_k{H}_{k+n}^{*}\exp \left(j\frac{2\mathrm{\&pi;}{l}_0}{N}n\right)$ 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 Δ f is for facing the interval of two sub-intercarriers mutually, and K represents the set that all ranging sub-carrier are formed, H _kAnd H _K+nBe channel coefficient correlation, C _kAnd C _K+nBe the sequence of local code C correspondence, l ₀Be the time-domain signal that receives the time inclined to one side;

First transformation submodule, be used for obtain after the difference operation, length mends N after being the sequence of M _t-M 0, is N to the length that forms after the zero padding _tSequence be FFT, wherein, N _tBe not less than M, be positioned between (N/8, N), and N _tThe value power power that equals 2.

22. device as claimed in claim 21 is characterized in that, the described first difference subspace module is further used for: when described subcarrier spacing during less than coherence bandwidth, and H _k=H _K+n, at this moment,

Wherein, k (n) is that spacing is the right number of carrier wave of n Δ f among the ranging sub-carrier collection K.

23. as each described device of claim 18-20, it is characterized in that, also comprise:

Second determination module, be used for determining that the peak-to-peak ratio is greater than 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 of each value of sequence that is through difference operation and generates after changing, described second threshold value are not less than presets the pairing threshold value of ranging code police's code check lower limit.

24. a ranging code checkout gear is characterized in that, comprising:

Obtain module, during a plurality of time-domain signal of being used for receiving via many antennas, respectively each time-domain signal is all carried out the sequence of following operation to obtain to generate through difference operation: time-domain signal is carried out fast fourier transform FFT, obtain distance measuring signal on the ranging sub-carrier of the frequency-region signal that obtains after the conversion, described distance measuring signal is made up of at least two symbols on time domain; Sequence to other symbols of removing first outer symbol is carried out phase compensation respectively, and offset is that the equivalent phase of cyclic prefix CP length postpones; The sequence that sequence and other each symbols of first symbol obtained after phase compensation is weighted merging, sequence after obtaining to merge, wherein the weights of weighting are positioned between (0,1), each weights sum equals 1, and is directly proportional with the data message amount of carrying on each symbol; In the code table of having stored, select local code successively, utilize the sequence of the local code of selecting and the sequence after the merging to carry out related operation, and the sequence that obtains behind the related operation is carried out difference operation;

Summation module, the sequence that is used for a plurality of sequences that generate through difference operation that will obtain respectively is worth corresponding addition, obtains the sequence after the addition, and carries out FFT; Calculate the power of the sequence that obtains after the FFT conversion, determine peak-to-average force ratio, described peak-to-average force ratio is the peak power of each value of the sequence that generates and the ratio of average power after difference operation and conversion;

The 3rd determination module is used for carrying ranging code when peak-to-average force ratio during greater than first threshold value in the time-domain signal of determining to receive, and described first threshold value is not less than the default pairing threshold value of the ranging code verification and measurement ratio upper limit.

25. device as claimed in claim 24 is characterized in that, described acquisition module specifically is used for: according to formula Sequence to other each symbols is carried out phase compensation respectively, and wherein, i, j, k are positive integer, i 〉=2, and N is the FFT window value, Y _{I, k}The frequency domain value of representing k subcarrier of i symbol, Y _{I, k}The frequency domain value after phase compensation of k subcarrier of i symbol of ' expression, l _CpBe CP length,

Equivalent phase delay for CP length.

26. device as claimed in claim 24, it is characterized in that, described acquisition module is further used for: determine the weights of described weighting according to the covering radius of sub-district, described many antennas place, wherein, the weights of described weighting are directly proportional with the covering radius of sub-district, described many antennas place.

27., it is characterized in that described acquisition module comprises as each described device of claim 24-26:

Second mapping submodule is used for the sequence that obtains behind the related operation is shone upon back corresponding ranging sub-carrier;

The second difference subspace module, be used for successively at a distance of for the sequence of carrying on the ranging sub-carrier of n Δ f by formula $x\left[n\right]=\underset{(k+n)\&Element;K}{\underset{k\&Element;K}{\mathrm{\&Sigma;}}}{c}_k^{*}{Y}_k{H}_k\exp (-j\frac{2\mathrm{\&pi;k}}{N}{l}_0)*{\left(c_{k+n}^{*}{Y}_{k+n}{H}_{k+n}\exp (-j\frac{2\mathrm{\&pi;}(k+n)}{N}{l}_0)\right)}^{*}$

$=\underset{(k+n)\&Element;K}{\underset{k\&Element;K}{\mathrm{\&Sigma;}}}{H}_k{H}_{k+n}^{*}\exp \left(j\frac{2\mathrm{\&pi;}{l}_0}{N}n\right)$ 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 Δ f is for facing the interval of two sub-intercarriers mutually, and K represents the set that all ranging sub-carrier are formed, H _kAnd H _K+nBe channel coefficient correlation, C _kAnd C _K+nBe the sequence of local code C correspondence, l ₀Be the time-domain signal that receives the time inclined to one side, N is the FFT window number.

28. device as claimed in claim 27 is characterized in that, the described second difference subspace module is further used for: when described subcarrier spacing during less than coherence bandwidth, and H _k=H _K+n, at this moment,

Wherein, k (n) is that spacing is the right number of carrier wave of n Δ f among the ranging sub-carrier collection K.

29. device as claimed in claim 27 is characterized in that, described summation module comprises:

The addition submodule, be used for after difference operation, obtaining, length is that the sequence of the sequence of M respectively is worth corresponding addition, obtains the sequence after the addition, the sequence length after the described addition is M;

Second transformation submodule, be used for obtain after the addition, length mends N after being the sequence of M _t-M 0, is N to the length that forms after the zero padding _tSequence be FFT, wherein, N _tBe not less than M, be positioned between (N/8, N), and N _tThe value power power that equals 2.

30. as each described device of claim 24-26, it is characterized in that, also comprise:

The 4th determination module, be used for determining that the peak-to-peak ratio is greater than 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 of each value of sequence that is through difference operation and generates after changing, described second threshold value are not less than presets the pairing threshold value of ranging code police's code check lower limit.

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