CN106028442A - Signal capture method and device - Google Patents

Abstract

The embodiment of the invention discloses a signal capture method and device. The method and the device are applied to a time division and code division orthogonal frequency division multiplexing TC-OFDM system. The method comprises the steps of carrying out incoherent loss compensation on an incoherent integral result Z (n), judging whether the incoherent integral result after the incoherent loss compensation satisfies a preset threshold judging condition or not; and capturing signals if the preset threshold judging condition is satisfied. According to the method and the device, through combination of coherent/incoherent integrals and loss compensation of the incoherent integral result, the signals are captured; a relative capture peak can be effectively improved; the capture missing probability of weak signals can be reduced; therefore, the capture capability of the location receiver of the TC-OFDM system to the weak signals can be improved; and the weak signals can be captured effectively.

Description

A kind of signal acquisition methods and device

Technical field

The present invention relates to wireless communication technology field, be applied to time-division code division OFDM TC-particularly to one The signal acquisition methods of ofdm system and device.

Background technology

Along with the fast development of wireless network, location-based service (Location Based Service, LBS) the most gradually incorporates In daily life.At present, GLONASS (Global Navigation Satellite System, GNSS) accurate positional information can be provided for our outdoor activity.Along with gradually increasing of urban large-scale buildings, people's Activity space turns to indoor activity from outdoor, and therefore being accurately positioned under indoor environment becomes the most important.

Time-division code division OFDM (TC-OFDM) system is developed for being accurately positioned of indoor environment just, Wide area high accuracy indoor and outdoor location-based service can be provided.TC-OFDM system as most of high-accuracy position systems, be also with Based on CDMA (Code Division Multiple Access, CDMA), CDMA Signal averaging is believed in mobile broadcast On number, do not affecting on the premise of user receives mobile broadcasting, providing the user accurate location-based service.

In the signals transmission of TC-OFDM system, owing to barrier blocks and the reasons such as homogenous frequency signal interference, cause The signal intensity of TC-OFDM system weakens significantly.When the carrier-to-noise ratio (Carrier to Noise Ratio, CNR) of signal is less than During certain value, common parallel Code acquisition algorithm will be unable to faint TC-OFDM system signal be detected.

Summary of the invention

The embodiment of the invention discloses a kind of signal capture being applied to time-division code division OFDM TC-OFDM system Method and device, to improve the location receiver capture ability to weak signal of TC-OFDM system.

For reaching above-mentioned purpose, the embodiment of the invention discloses a kind of signal acquisition methods, be applied to time-division code division orthogonal Frequency division multiplexing TC-OFDM system, described method includes:

Receive TC-OFDM base station radio-frequency signal, described radiofrequency signal is carried out down coversion and low-pass filtering, obtains complex signal r(t)；

Described complex signal r (t) is carried out A/D conversion, obtains i road discrete digital intermediate-freuqncy signal i (n) and q road discrete digital Intermediate-freuqncy signal q (n)；

Described i road discrete digital intermediate-freuqncy signal i (n) and described q road discrete digital intermediate-freuqncy signal q (n) are carried out relevant long-pending Point, obtain power output V (n) that i road is relevant with q road；

Described power output V (n) is carried out non-coherent integration, obtains non-coherent integration results Z (n)；

According to described non-coherent integration results Z (n) is removed maximum and the value of second largest value, computed losses offset P_noise；

By described loss balancing value P_noiseDescribed non-coherent integration results Z (n) is carried out loss balancing, obtains loss balancing After non-coherent integration results Z ' (n)；And

Judge whether non-coherent integration results Z ' (n) after described loss balancing meets the thresholding decision condition preset；If Meet, then signal capture success.

Optionally, described by described loss balancing value P_noiseDescribed non-coherent integration results Z (n) is carried out loss balancing, Obtain non-coherent integration results Z ' (n) after loss balancing, including:

Described non-coherent integration results Z (n) is deducted loss balancing value P_noise, obtain after described loss balancing is incoherent Integral result Z ' (n).

Optionally, described loss balancing value P_noiseCalculated by below equation:

${P^{\′}}_{noise}=\frac{{\mathrm{\Σ}}_{n=1}^{len}Z\left(n\right)-max\left(Z\right(n\left)\right)-\sec ond\left(Z\right(n\left)\right)}{len-2}$

P_noise=α P '_noise

Wherein, max (Z (n)) represents the maximum in described non-coherent integration results Z (n), and second (Z (n)) represents institute Stating the second largest value in non-coherent integration results Z (n), len represents GOLD code code length, and α is default constant.

Optionally, described described non-coherent integration results Z (n) is deducted loss balancing value P_noise, obtain described loss and mend Non-coherent integration results Z ' (n) after repaying, including:

The maximum max (Z (n)) of described non-coherent integration results Z (n) is deducted loss balancing value P_noise, obtain first Non-coherent integration results Z ' after loss balancing₁(n)；

The second largest value second (Z (n)) of described non-coherent integration results Z (n) is deducted loss balancing value P_noise, obtain Non-coherent integration results Z ' after two loss balancings₂(n)。

Optionally, described judge whether non-coherent integration results Z ' (n) after described loss balancing meets the thresholding preset Decision condition, including:

Judge the non-coherent integration results Z ' after described first loss balancing₁Non-after (n) and described second loss balancing Coherent integration results Z '₂The ratio of (n) and detection threshold value R_thMagnitude relationship, if described ratio is more than or equal to described detection door Limit value R_th, then thresholding decision condition is met.

For reaching above-mentioned purpose, the embodiment of the invention discloses a kind of signal capture device, be applied to time-division code division orthogonal Frequency division multiplexing TC-OFDM system, comprising:

Receive unit, be used for receiving TC-OFDM base station radio-frequency signal；

First converting unit, for described radiofrequency signal is carried out down coversion and low-pass filtering, obtains complex signal r (t)；

Second converting unit, for described complex signal r (t) is carried out A/D conversion, obtains i road discrete digital intermediate-freuqncy signal i (n) and q road discrete digital intermediate-freuqncy signal q (n)；

Coherent integration unit, for described i road discrete digital intermediate-freuqncy signal i (n) and described q road discrete digital intermediate frequency letter Number q (n) carries out coherent integration, obtains power output V (n) that i road is relevant with q road；

Non-coherent integration unit, for described power output V (n) is carried out non-coherent integration, obtains non-coherent integration knot Really Z (n)；

Computing unit, for according to removing maximum and the value of second largest value in described non-coherent integration results Z (n), calculating and damage Consumption offset P_noise；

Loss balancing unit, is used for by described loss balancing value P_noiseDescribed non-coherent integration results Z (n) is lost Compensate, obtain non-coherent integration results Z ' (n) after loss balancing；

Judging unit, whether non-coherent integration results Z ' (n) after judging described loss balancing meets the door preset Limit decision condition；

Signal capture unit, if non-coherent integration results Z ' (n) after described loss balancing meets the thresholding preset Decision condition, then signal capture success.

Optionally, described loss balancing unit specifically for:

Described non-coherent integration results Z (n) is deducted loss balancing value P_noise, obtain after described loss balancing is incoherent Integral result Z ' (n).

Optionally, described computing unit, specifically for:

According to following formula computed losses offset P_noise:

${P^{\′}}_{noise}=\frac{{\mathrm{\Σ}}_{n=1}^{len}Z\left(n\right)-max\left(Z\right(n\left)\right)-\sec ond\left(Z\right(n\left)\right)}{len-2}$

P_noise=α P '_noise

Wherein, max (Z (n)) represents the maximum in described non-coherent integration results Z (n), and second (Z (n)) represents institute Stating the second largest value in non-coherent integration results Z (n), len represents GOLD code code length, and α is default constant.

Optionally, described loss balancing unit, specifically for:

The maximum max (Z (n)) of described non-coherent integration results Z (n) is deducted loss balancing value P_noise, obtain first Non-coherent integration results Z ' after loss balancing₁(n)；

The second largest value second (Z (n)) of described non-coherent integration results Z (n) is deducted loss balancing value P_noise, obtain Non-coherent integration results Z ' after two loss balancings₂(n)。

Optionally, described judging unit specifically for:

Judge the non-coherent integration results Z ' after described first loss balancing₁Non-after (n) and described second loss balancing Coherent integration results Z '₂The ratio of (n) and detection threshold value R_thMagnitude relationship, if described ratio is more than or equal to described detection door Limit value R_th, then thresholding decision condition is met.

The signal acquisition methods being applied to time-division code division OFDM TC-OFDM system that the embodiment of the present invention provides And device, combine by relevant/non-coherent integration and non-coherent integration results is carried out loss balancing, signal is caught Obtain, it is possible to be effectively improved and relatively capture peak value, reduce the leakage probability of weak signal, thus the location improving TC-OFDM system connects The receipts machine capture ability to weak signal, it is achieved the effective capture to weak signal.

Accompanying drawing explanation

In order to be illustrated more clearly that the embodiment of the present invention or technical scheme of the prior art, below will be to embodiment or existing In having technology to describe, the required accompanying drawing used is briefly described, it should be apparent that, the accompanying drawing in describing below is only this Some embodiments of invention, for those of ordinary skill in the art, on the premise of not paying creative work, it is also possible to Other accompanying drawing is obtained according to these accompanying drawings.

The schematic flow sheet of a kind of signal acquisition methods that Fig. 1 provides for the embodiment of the present invention；

Fig. 2 is to be captured as power measurements under different signal to noise ratio；

The structural representation of a kind of signal capture device that Fig. 3 provides for the embodiment of the present invention.

Detailed description of the invention

Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is carried out clear, complete Describe, it is clear that described embodiment is only a part of embodiment of the present invention rather than whole embodiments wholely.Based on Embodiment in the present invention, it is every other that those of ordinary skill in the art are obtained under not making creative work premise Embodiment, broadly falls into the scope of protection of the invention.

The schematic flow sheet of a kind of signal acquisition methods that Fig. 1 provides for the embodiment of the present invention, this signal acquisition methods should For time-division code division OFDM TC-OFDM system, comprise the steps:

S101: receive TC-OFDM base station radio-frequency signal, described radiofrequency signal is carried out down coversion and low-pass filtering, obtains Complex signal r (t).

Wherein, described complex signal r (t) can be expressed from the next:

$r\left(t\right)=aD\left(t\right)S(t-\mathrm{\τ})e^{j\[2\mathrm{\π}(f_{IF}+f_d)(t-\mathrm{\τ})+{\mathrm{\θ}}_{IF}\]}+n\left(t\right)$

Wherein, t express time, a represents signal amplitude, and D (t) represents numeric data code, and S (t-τ) represents GOLD code, and τ represents biography Sowing time prolongs, f_IFRepresent residual carrier frequency, f_dRepresent the intermediate frequency frequency deviation that Doppler and crystal oscillator deviation cause, θ_IFRepresent carrier wave first phase Position, n (t) represents noise signal.

S102: described complex signal r (t) is carried out A/D conversion, obtains i road discrete digital intermediate-freuqncy signal i (n) and q road is discrete Digital medium-frequency signal q (n).

Wherein, i road discrete digital intermediate-freuqncy signal i (n) and q road discrete digital intermediate-freuqncy signal q (n) can be respectively by following formula table Show:

I (n)=aD (n-τ) S (n-τ) sin (2 π (f_IF+f_d)t(n)+θ_IF)+n_i(n)

Q (n)=aD (n-τ) S (n-τ) cos (2 π (f_IF+f_d)t(n)+θ_IF)+n_q(n)

Wherein, n represents the discrete time, and a represents signal amplitude, and D (n-τ) represents numeric data code, and S (n-τ) represents GOLD code, τ represents propagation delay, f_IFRepresent residual carrier frequency, f_dRepresent the intermediate frequency frequency deviation that Doppler and crystal oscillator deviation cause, θ_IFRepresent Carrier wave initial phase, n_iN () represents i road noise signal, n_qN () represents q road noise signal, noise signal meets white Gaussian noise and divides Cloth.

S103: described i road discrete digital intermediate-freuqncy signal i (n) and described q road discrete digital intermediate-freuqncy signal q (n) are carried out phase Dry integration, obtains power output V (n) that i road is relevant with q road.

Wherein it is possible to first by described i road discrete digital intermediate-freuqncy signal i (n) and described q road discrete digital intermediate-freuqncy signal q (n) It is added again after being multiplied with local code para-position respectively by parallel serial conversion module, obtains coherent integration results I ' (n), Q ' (n), then will Coherent integration results I ' (n), Q ' (n) carry out quadratic sum process after serioparallel exchange module, and the power obtaining i, q two-way relevant is defeated Go out V (n).

Wherein, coherent integration results I ' (n), Q ' (n) can be expressed from the next:

$I^{\′}\left(n\right)={\Σ}_{k=0}^{N-1}i\left(k\right)C\left(k\right)=I\left(n\right)+n_I=aD\left(n\right)R\left(\mathrm{\τ}\right)\sin c\left(f_e{T}_{coh}\right)\cos \left({\mathrm{\φ}}_e\right)+n_I$

$Q^{\′}\left(n\right)={\mathrm{\Σ}}_{k=0}^{N-1}q\left(k\right)C\left(k\right)=Q\left(n\right)+n_Q=aD\left(n\right)R\left(\mathrm{\τ}\right)\sin c\left(f_e{T}_{coh}\right)cos\left({\mathrm{\φ}}_e\right)+n_Q$

Wherein, n represents the discrete time, and k represents and represents the time of integration, N code length, and C (k) represents local code, and a represents signal Amplitude, R (τ) represents corresponding auto-correlation function, f_eRepresent frequency error, T_cohRepresent the time of integration, φ_eRepresent phase error, n_IRepresent i road noise signal, n_QRepresent q road noise signal.

Wherein, power output V (n) can be expressed from the next:

$\begin{array}{c}V\left(n\right)={\left(I\right(n)+n_I)}^2+{\left(Q\right(n)+n_Q)}^2=\left(I^2\right(n)+Q^2(n)+(2I\left(n\right)n_I+2Q\left(n\right)n_Q)+(n_I^2+\\ n_Q^2\left)\right)\end{array}$

Wherein, n_IAnd n_QIt it is all the normal noise that average is zero, variance is equal；Section 1 on the right side of second equal sign is for connecing By the auto-correlation performance number of signal, the average of Section 2 is zero, Section 3Average be not equal to zero.

Power output V (n) can be further represented as:

$V\left(n\right)=\left(I^2\right(n)+Q^2(n\left)\right)+(n_I^2+n_Q^2)=a^2{R}^2\left(\mathrm{\τ}\right){\mathrm{sinc}}^2\left(f_e{T}_{coh}\right)+(n_I^2+n_Q^2)$

Wherein, n represents the discrete time, and a represents that signal amplitude, R (τ) represent corresponding auto-correlation function, f_eRepresent frequency Rate error, T_cohRepresent the time of integration, φ_eRepresent phase error, n_IRepresent i road noise signal, n_QRepresent q road noise signal.

S104: described power output V (n) is carried out non-coherent integration, obtains non-coherent integration results Z (n).

Wherein, non-coherent integration results Z (n) can be expressed from the next:

$Z\left(n\right)={\mathrm{\Σ}}_{l=0}^{x-1}V\left(n\right)={\mathrm{\Σ}}_{l=0}^{x-1}\left(I_l^2\right(n)+Q_l^2(n\left)\right)+{\mathrm{\Σ}}_{l=0}^{x-1}(n_{I,l}^2+n_{Q,l}^2)$

Wherein, x represents that integral number of times, l represent that integration variable, n represent the discrete time.

Wherein, what non-coherent integration was cumulative is the energy work rate amplitude of noise, thus can cause incoherent loss.

S105: according to removing maximum and the value of second largest value, computed losses offset in described non-coherent integration results Z (n) P_noise。

S106: by described loss balancing value P_noiseDescribed non-coherent integration results Z (n) is carried out loss balancing, is damaged Non-coherent integration results Z ' (n) after consumption compensation.

Wherein, loss balancing may comprise steps of:

Described non-coherent integration results Z (n) is deducted loss balancing value P_noise, obtain after described loss balancing is incoherent Integral result Z ' (n).

Wherein, described loss balancing value P_noiseCalculated by below equation:

${P^{\′}}_{noise}=\frac{{\mathrm{\Σ}}_{n=1}^{len}Z\left(n\right)-max\left(Z\right(n\left)\right)-\sec ond\left(Z\right(n\left)\right)}{len-2}$

P_noise=α P '_noise

Wherein, max (Z (n)) represents the maximum in described non-coherent integration results Z (n), and second (Z (n)) represents institute Stating the second largest value in non-coherent integration results Z (n), len represents GOLD code code length, and α is default constant.

It should be noted that α is default constant, in certain error allowed band, approximate evaluation can be carried out with this constant Irrelevant integral result (is designated as P ' except the value of maximum and second largest value_noise) and this loss balancing value P_noiseBetween linear Relation, and then, can be according to P '_noiseObtain this loss balancing value P_noise。

Also, it should be noted the embodiment of the present invention is not required to be defined the concrete numerical value of α, the skill in this area The concrete condition that art personnel are referred in the empirical value that obtained according to lot of experimental data and actual application is carried out rationally Setting.

Wherein, described described non-coherent integration results Z (n) is deducted loss balancing value P_noise, obtain described loss balancing After non-coherent integration results Z ' (n), may comprise steps of:

The maximum max (Z (n)) of described non-coherent integration results Z (n) is deducted loss balancing value P_noise, obtain first Non-coherent integration results Z ' after loss balancing₁(n)；

The second largest value second (Z (n)) of described non-coherent integration results Z (n) is deducted loss balancing value P_noise, obtain Non-coherent integration results Z ' after two loss balancings₂(n)。

S107: judge whether non-coherent integration results Z ' (n) after described loss balancing meets the thresholding preset and judge bar Part, if meeting, then signal capture success.

Wherein, described judge described loss balancing after non-coherent integration results Z ' (n) whether meet the thresholding preset and sentence Fixed condition may comprise steps of:

Judge the non-coherent integration results Z ' after described first loss balancing₁Non-after (n) and described second loss balancing Coherent integration results Z '₂The ratio of (n) and detection threshold value R_thMagnitude relationship, if described ratio is more than or equal to described detection door Limit value R_th, then thresholding decision condition is met.

In a kind of implementation, can capture GOLD code in such a way, detailed process is as follows: with local GOLD Code does with the signal received and mates, and such as, has 100 groups of Gold codes, and the radiofrequency signal received contains certain in system One group of GOLD code, during capture, local system does not do matching operation with the signal received by all of GOLD code division, when Occur the when of peak value (identical GOLD code-phase coupling just can go out peak value), determine which group comprise in the signal received is GOLD code, determines the phase place of GOLD code this moment simultaneously.Certainly, a kind of capture GOLD code and GOLD code are the most only listed The specific implementation of phase place, the present invention need not be defined it, and any feasible implementation all can apply to this Invention.

From the above embodiments, what the embodiment of the present invention provided is applied to time-division code division OFDM TC- The signal acquisition methods of ofdm system, is combined by relevant/non-coherent integration and non-coherent integration results carries out loss and mend Repay, signal is captured, it is possible to be effectively improved and relatively capture peak value, reduce the leakage probability of weak signal, thus improve TC- The location receiver of the ofdm system capture ability to weak signal, it is achieved the effective capture to weak signal.

Fig. 2 is to be captured as power test, i.e. under the conditions of arbitrary signal to noise ratio, to TC-OFDM signal under different signal to noise ratio Carrying out 500 continuous capture operations, wherein detection threshold sets R_th=1.5, capture before and after record non-coherent integration loss balancing Successfully percentage rate.From figure 2 it can be seen that through non-coherent integration compensate after be captured as power than compensate before high.Therefore, The modified model catching method using relevant/non-coherent integration to combine can effectively reduce leakage probability, it is achieved to weak signal Capture.

The structural representation of a kind of signal capture device that Fig. 3 provides for the embodiment of the present invention, with the flow process phase shown in Fig. 1 Correspondence, this signal capture device is applied to time-division code division OFDM TC-OFDM system, comprising:

Receive unit 301, be used for receiving TC-OFDM base station radio-frequency signal；

First converting unit 302, for described radiofrequency signal is carried out down coversion and low-pass filtering, obtains complex signal r (t)；

Second converting unit 303, for described complex signal r (t) is carried out A/D conversion, obtains i road discrete digital intermediate frequency letter Number i (n) and q road discrete digital intermediate-freuqncy signal q (n)；

Coherent integration unit 304, in described i road discrete digital intermediate-freuqncy signal i (n) and described q road discrete digital Frequently signal q (n) carries out coherent integration, obtains power output V (n) that i road is relevant with q road；

Non-coherent integration unit 305, for described power output V (n) is carried out non-coherent integration, obtains non-coherent integration Result Z (n)；

Computing unit 306, for according to removing maximum and the value of second largest value in described non-coherent integration results Z (n), calculating Loss balancing value P_noise。

Loss balancing unit 307, for described non-coherent integration results Z (n) is carried out loss balancing, obtains loss balancing After non-coherent integration results Z ' (n)；

Judging unit 308, whether non-coherent integration results Z ' (n) after judging described loss balancing meets default Thresholding decision condition.

Signal capture unit 309, if non-coherent integration results Z ' (n) after described loss balancing meets the door preset Limit decision condition, then signal capture success.

Concrete, described loss balancing unit specifically for:

Described non-coherent integration results Z (n) is deducted loss balancing value P_noise, obtain after described loss balancing is incoherent Integral result Z ' (n).

Concrete, described computing unit, specifically for:

According to following formula computed losses offset P_noise:

${P^{\′}}_{noise}=\frac{{\mathrm{\Σ}}_{n=1}^{len}Z\left(n\right)-max\left(Z\right(n\left)\right)-\sec ond\left(Z\right(n\left)\right)}{len-2}$

P_noise=α P '_noise

Wherein, max (Z (n)) represents the maximum in described non-coherent integration results Z (n), and second (Z (n)) represents institute Stating the second largest value in non-coherent integration results Z (n), len represents GOLD code code length, and α is default constant.

Concrete, described loss balancing unit, specifically for:

The maximum max (Z (n)) of described non-coherent integration results Z (n) is deducted loss balancing value P_noise, obtain first Non-coherent integration results Z ' after loss balancing₁(n)；

The second largest value second (Z (n)) of described non-coherent integration results Z (n) is deducted loss balancing value P_noise, obtain Non-coherent integration results Z ' after two loss balancings₂(n)。

Concrete, described judging unit specifically for:

Judge the non-coherent integration results Z ' after described first loss balancing₁Non-after (n) and described second loss balancing Coherent integration results Z '₂The ratio of (n) and detection threshold value R_thMagnitude relationship, if described ratio is more than or equal to described detection door Limit value R_th, then thresholding decision condition is met.

From the above embodiments, what the embodiment of the present invention provided is applied to time-division code division OFDM TC- The signal capture device of ofdm system, is combined by relevant/non-coherent integration and non-coherent integration results carries out loss and mend Repay, signal is captured, it is possible to be effectively improved and relatively capture peak value, reduce the leakage probability of weak signal, thus improve TC- The location receiver of the ofdm system capture ability to weak signal, it is achieved the effective capture to weak signal.

It should be noted that in this article, the relational terms of such as first and second or the like is used merely to a reality Body or operation separate with another entity or operating space, and deposit between not necessarily requiring or imply these entities or operating Relation or order in any this reality.And, term " includes ", " comprising " or its any other variant are intended to Comprising of nonexcludability, so that include that the process of a series of key element, method, article or equipment not only include that those are wanted Element, but also include other key elements being not expressly set out, or also include for this process, method, article or equipment Intrinsic key element.In the case of there is no more restriction, statement " including ... " key element limited, it is not excluded that Including process, method, article or the equipment of described key element there is also other identical element.

Each embodiment in this specification all uses relevant mode to describe, identical similar portion between each embodiment Dividing and see mutually, what each embodiment stressed is the difference with other embodiments.Real especially for device For executing example, owing to it is substantially similar to embodiment of the method, so describe is fairly simple, relevant part sees embodiment of the method Part illustrate.

One of ordinary skill in the art will appreciate that all or part of step realizing in said method embodiment is can Completing instructing relevant hardware by program, described program can be stored in computer read/write memory medium, The storage medium obtained designated herein, such as: ROM/RAM, magnetic disc, CD etc..

The foregoing is only presently preferred embodiments of the present invention, be not intended to limit protection scope of the present invention.All Any modification, equivalent substitution and improvement etc. made within the spirit and principles in the present invention, are all contained in protection scope of the present invention In.

Claims (10)

1. a signal acquisition methods, it is characterised in that be applied to time-division code division OFDM TC-OFDM system, described Method includes:

Receive TC-OFDM base station radio-frequency signal, described radiofrequency signal is carried out down coversion and low-pass filtering, obtains complex signal r (t)；

Described complex signal r (t) is carried out A/D conversion, obtains i road discrete digital intermediate-freuqncy signal i (n) and q road discrete digital intermediate frequency Signal q (n)；

Described i road discrete digital intermediate-freuqncy signal i (n) and described q road discrete digital intermediate-freuqncy signal q (n) are carried out coherent integration, Power output V (n) relevant with q road to i road；

Described power output V (n) is carried out non-coherent integration, obtains non-coherent integration results Z (n)；

According to described non-coherent integration results Z (n) is removed maximum and the value of second largest value, computed losses offset P_noise；

By described loss balancing value P_noiseDescribed non-coherent integration results Z (n) is carried out loss balancing, after obtaining loss balancing Non-coherent integration results Z ' (n)；And

Judge whether non-coherent integration results Z ' (n) after described loss balancing meets the thresholding decision condition preset；If meeting, Then signal capture success.

Method the most according to claim 1, it is characterised in that described by described loss balancing value P_noiseTo described incoherent Integral result Z (n) carries out loss balancing, obtains non-coherent integration results Z ' (n) after loss balancing, including:

Described non-coherent integration results Z (n) is deducted loss balancing value P_noise, obtain the non-coherent integration after described loss balancing Result Z ' (n).

Method the most according to claim 2, it is characterised in that described loss balancing value P_noiseCalculated by below equation Go out:

${P^{\′}}_{noise}=\frac{{\mathrm{\Σ}}_{n=1}^{len}Z\left(n\right)-\max \left(Z\left(n\right)\right)-\sec ond\left(Z\left(n\right)\right)}{len-2}$

P_noise=α P '_noise

Wherein, max (Z (n)) represents that the maximum in described non-coherent integration results Z (n), second (Z (n)) represent described non- Second largest value in coherent integration results Z (n), len represents GOLD code code length, and α is default constant.

Method the most according to claim 3, it is characterised in that described described non-coherent integration results Z (n) is deducted loss Offset P_noise, obtain non-coherent integration results Z ' (n) after described loss balancing, including:

The maximum max (Z (n)) of described non-coherent integration results Z (n) is deducted loss balancing value P_noise, obtain the first loss Non-coherent integration results Z ' after compensation₁(n)；

The second largest value second (Z (n)) of described non-coherent integration results Z (n) is deducted loss balancing value P_noise, obtain the second damage Non-coherent integration results Z ' after consumption compensation₂(n)。

Method the most according to claim 4, it is characterised in that the non-coherent integration knot after the described loss balancing of described judgement Really whether Z ' (n) meets the thresholding decision condition preset, including:

Judge the non-coherent integration results Z ' after described first loss balancing₁Incoherent long-pending after (n) and described second loss balancing Divide result Z '₂The ratio of (n) and detection threshold value R_thMagnitude relationship, if described ratio is more than or equal to described detection threshold value R_th, then thresholding decision condition is met.

6. a signal capture device, it is characterised in that be applied to time-division code division OFDM TC-OFDM system, its bag Include:

Receive unit, be used for receiving TC-OFDM base station radio-frequency signal；

First converting unit, for described radiofrequency signal is carried out down coversion and low-pass filtering, obtains complex signal r (t)；

Second converting unit, for described complex signal r (t) is carried out A/D conversion, obtains i road discrete digital intermediate-freuqncy signal i (n) With q road discrete digital intermediate-freuqncy signal q (n)；

Coherent integration unit, for described i road discrete digital intermediate-freuqncy signal i (n) and described q road discrete digital intermediate-freuqncy signal q N () carries out coherent integration, obtain power output V (n) that i road is relevant with q road；

Non-coherent integration unit, for described power output V (n) is carried out non-coherent integration, obtains non-coherent integration results Z (n)；

Computing unit, for according to removing maximum and the value of second largest value in described non-coherent integration results Z (n), computed losses is mended Repay value P_noise；

Loss balancing unit, is used for by described loss balancing value P_noiseDescribed non-coherent integration results Z (n) carries out loss mend Repay, obtain non-coherent integration results Z ' (n) after loss balancing；

Judging unit, whether non-coherent integration results Z ' (n) after judging described loss balancing meets the thresholding preset is sentenced Fixed condition；

Signal capture unit, if non-coherent integration results Z ' (n) after described loss balancing meets the thresholding preset and judges Condition, then signal capture success.

Device the most according to claim 6, it is characterised in that described loss balancing unit specifically for:

Described non-coherent integration results Z (n) is deducted loss balancing value P_noise, obtain the non-coherent integration after described loss balancing Result Z ' (n).

Device the most according to claim 7, it is characterised in that described computing unit, specifically for:

According to following formula computed losses offset P_noise:

${P^{\′}}_{noise}=\frac{{\mathrm{\Σ}}_{n=1}^{len}Z\left(n\right)-\max \left(Z\left(n\right)\right)-\sec ond\left(Z\left(n\right)\right)}{len-2}$

P_noise=α P '_noise

Wherein, max (Z (n)) represents that the maximum in described non-coherent integration results Z (n), second (Z (n)) represent described non- Second largest value in coherent integration results Z (n), len represents GOLD code code length, and α is default constant.

Device the most according to claim 8, it is characterised in that described loss balancing unit, specifically for:

The maximum max (Z (n)) of described non-coherent integration results Z (n) is deducted loss balancing value P_noise, obtain the first loss Non-coherent integration results Z ' after compensation₁(n)；

The second largest value second (Z (n)) of described non-coherent integration results Z (n) is deducted loss balancing value P_noise, obtain the second damage Non-coherent integration results Z ' after consumption compensation₂(n)。

Device the most according to claim 9, it is characterised in that described judging unit specifically for:

Judge the non-coherent integration results Z ' after described first loss balancing₁Incoherent long-pending after (n) and described second loss balancing Divide result Z '₂The ratio of (n) and detection threshold value R_thMagnitude relationship, if described ratio is more than or equal to described detection threshold value R_th, then thresholding decision condition is met.