CN104391298A - Digital delaying compensation device and method and achieving device and method - Google Patents

Abstract

The invention discloses a digital delaying compensation device and method and an achieving device and method. The digital delaying compensation device is used for compensating time delay between frequency modulation signals aiming at the broadband digital array radar aperture transition time. The device comprises a receiving module and a compensation module. The receiving module is used for receiving frequency modulation signals. The expression of the frequency modulation signals is provided as follows, wherein t stands for time, t0 stands for delay, S (t, t0) stands the modulation signals delayed for t0 from t, f0 stands for center frequency, B stands for signal bandwidth, and T0 stands for pulse width. The compensation module is used for compensating the frequency modulation signals. The expression of the frequency modulation signals is provided as follows, wherein the fi is the initial frequency, and the delay of the frequency modulation signals is compensated.

Description

A kind of digital delay compensation system and method, realize Apparatus and method for

Technical field

The present invention is mainly used in wideband digital array radar industry, the digital delay compensation method particularly relating to the wideband digital array radar aperture fill time belonging to electronic information technical field, apply this digital delay compensation method digital delay compensation system with realize the equipment that digital delay compensates.

Background technology

Phased-array radar has agility beam scanning fast and prompt change ability, can realize the advantages such as multiple goal intercepting and capturing, tracking, self-adaptation; And the signal of large instant bandwidth can improve the antijamming capability of phased-array radar, there is higher distance accuracy and resolution, be conducive to the imaging of target, recognition and classification.Therefore, wide band net technology is one of Main way of modern radar technology development.

But for the signal of large bandwidth, because problem is getted in the aperture of phased-array radar, traditional phase-moving method can cause the hyperchannel launching beam of different frequency inconsistent at the synthesis beam position in space, the space combination of broadband emission wave beam cannot be completed, the space combination of large bandwidth signal beam can only be realized by the method for compensation of delay.Analog delay line can reach the object of compensation delay, but it is expensive, quantified precision is limited and bulky, for modern times hundreds of array radar easily, is obviously worthless.And the space combination realizing launching beam on numeric field have cost low, control numerous features such as flexible.Therefore, can on numeric field, realize compensation of delay be also one of focus of current wide band net technical research.Along with the development of DDS chip technology, make the method realizing launching beam compensation of delay on numeric field become possibility, and higher compensation precision can be reached.

Summary of the invention

The technical matters that the present invention solves is that, in the time delay of numeric field fine compensation wideband correlation in wideband digital array radar system, resolving aperture gets over problem, realizes spatial beams synthesis and the scanning of wideband correlation.Therefore, the invention provides a kind of digital delay compensation system and digital delay compensation method of wideband digital array radar aperture fill time, realize the equipment of digital delay compensation, the digital delay compensation method of this equipment.

The present invention is achieved by the following technical solutions: a kind of digital delay compensation system, and it is for compensating the time delay between FM signal for wideband digital array radar aperture fill time, this digital delay compensation system comprises:

Receiver module, it is for receiving FM signal, and this FM signal expression formula is:

$\begin{array}{c}S(t,t_0)=\exp (2\mathrm{\π}\·((f_0-\frac{B}{2})\·(t-t_0)+\frac{B}{2T_0}\·{(t-t_0)}^2))\\ =\exp (2\mathrm{\π}\·((f_0-\frac{B}{2}-\frac{B\·t_0}{T_0})\·t+\frac{B}{2T_0}\·t^2)-2\mathrm{\π}\·((f_0-\frac{B}{2})\·t_0-\frac{B}{2T_0}\·{t_0}^2))\end{array},$ Wherein, t is the time, t ₀for time delay, S (t, t ₀) be t time delay t ₀this FM signal, f ₀centered by frequency, B is signal bandwidth, T ₀for pulse width;

Compensating module, it is for compensating this FM signal, and this FM signal expression formula is rewritten as:

wherein, f _ifor original frequency, for initial phase, make then the time delay of this FM signal is compensated.

As the further improvement of such scheme, this FM signal is linear FM signal or the broadband NLFM signal with certain rule.

The present invention also provides a kind of digital delay compensation method, and it is for compensating the time delay between FM signal for wideband digital array radar aperture fill time, this digital delay compensation method comprises the following steps:

Step one, receive FM signal, this FM signal expression formula is:

$\begin{array}{c}S(t,t_0)=\exp (2\mathrm{\π}\·((f_0-\frac{B}{2})\·(t-t_0)+\frac{B}{2T_0}\·{(t-t_0)}^2))\\ =\exp (2\mathrm{\π}\·((f_0-\frac{B}{2}-\frac{B\·t_0}{T_0})\·t+\frac{B}{2T_0}\·t^2)-2\mathrm{\π}\·((f_0-\frac{B}{2})\·t_0-\frac{B}{2T_0}\·{t_0}^2))\end{array},$ Wherein, t is the time, t ₀for time delay, S (t, t ₀) be t time delay t ₀this FM signal, f ₀centered by frequency, B is signal bandwidth, T ₀for pulse width;

Step 2, compensates this FM signal, and this FM signal expression formula is rewritten as:

wherein, f _ifor original frequency, for initial phase, make then the time delay of this FM signal is compensated.

As the further improvement of such scheme, this FM signal is linear FM signal or the broadband NLFM signal with certain rule.

The present invention also provides a kind of equipment realizing digital delay and compensate, it is for for the time delay between wideband digital array radar aperture fill time compensated linear FM signal, this equipment adopts DDS chip to produce linear FM signal, this DDS chip utilizes above-mentioned digital delay compensation method, when DDS chip produces linear FM signal, configure the initial phase word of DDS chip, original frequency word to meet realize the compensation of delay of wideband correlation.

As the further improvement of such scheme, the work clock of DDS chip is made to be f _{sYS_CLK}, frequency tuning precision is M position, and planet phasing precision is N position, only considers that the first power of phase place and time delay carries out compensation of delay, then the delay precision Δ t determined by frequency tuning precision and planet phasing precision _f, Δ t _pbe respectively:

$\begin{array}{c}{\mathrm{\Δt}}_F=\frac{f_{\mathrm{SYS}\_\mathrm{CLK}}}{2^M}\×\frac{T_0}{B}\\ \mathrm{\Δ}{t}_P=\frac{1}{(f_0-\frac{B}{2}){\×2}^N}\end{array},$ Get the delay precision value that in both, larger value can reach for DDS chip.

The present invention also provides a kind of digital delay compensation method, and it is applied to above-mentioned realization arbitrarily in the equipment of digital delay compensation, and this digital delay compensation method comprises the following steps:

The first step, calculates according to the array element distance of wideband digital array, scanning angle parameter the signal lag compensated required for each array element: time delay t ₀, centre frequency f ₀, signal bandwidth B, pulse width T ₀;

Second step, brings the signal lag of calculating into formula calculate the offset that each array element needs: original frequency f _iand initial phase

3rd step, is added the initial value of calibration with the offset of calculating and sends into DDS chip, carry out digitizing fine compensation, realize the space combination of wideband correlation launching beam in this scanning angle to wideband correlation time delay.

Beneficial effect of the present invention is:

1, compensate at the enterprising line delay of numeric field, in principle not by the restriction of signal bandwidth, be suitable for broadband or ultra-broadband digital array radar system;

2, the space combination of launching beam and the demand of scanning in wideband digital array radar system can be met;

3, the present invention can reach higher delay precision by carrying out regulating to the original frequency of DDS chip and initial phase, and is easy to Project Realization;

4, compensation of delay precision is relevant with the quantified precision of DDS chip to frequency word and phase place word, also has relation, can reach higher compensation precision with the centre frequency of signal, signal bandwidth, signal pulsewidth;

5, owing to being the change of original frequency by time-delay conversion, the actual signal bandwidth transmitted can be caused to decrease, but generally in systems in which, need the time delay compensated to be very little relative to signal pulsewidth, so the loss of bandwidth is also negligible;

6, for larger time delay, can first will the time-delay conversion compensated be needed to be the time delay that an integer DDS chip upgrades pulse, then use the method to carry out digital delay compensation to remaining residue time delay, the loss of the signal bandwidth that large time delay brings can be reduced;

7, can be applied in wideband digital array radar system, realize space combination and the scanning of wideband correlation launching beam.

Accompanying drawing explanation

Fig. 1 is that two paths of signals of the present invention adopts different compensation method synthesis result schematic block diagrams.

Embodiment

In order to make object of the present invention, technical scheme and advantage clearly understand, below in conjunction with accompanying drawing and embodiment, the present invention is further elaborated.Should be appreciated that specific embodiment described herein only in order to explain the present invention, be not intended to limit the present invention.

The present invention is directed to the aperture that the space combination of launching beam in existing wideband digital array radar system and scanning brings and get over problem, propose a kind of digital delay compensation method of wideband digital array radar aperture fill time.The method is easy to DDS chip and realizes, and dirigibility is high.For the wideband correlation that DDS produces, its original frequency and initial phase are adjustable, by the object regulating original frequency and initial phase to reach signal accurate delay, resolving aperture gets over problem, realizes spatial beams synthesis and the scanning of wideband correlation.

The digital delay compensation system corresponding to digital delay compensation method comprises receiver module, compensating module.

This receiver module is for receiving FM signal, and this FM signal expression formula is:

$\begin{array}{c}S(t,t_0)=\exp (2\mathrm{\π}\·((f_0-\frac{B}{2})\·(t-t_0)+\frac{B}{2T_0}\·{(t-t_0)}^2))\\ =\exp (2\mathrm{\π}\·((f_0-\frac{B}{2}-\frac{B\·t_0}{T_0})\·t+\frac{B}{2T_0}\·t^2)-2\mathrm{\π}\·((f_0-\frac{B}{2})\·t_0-\frac{B}{2T_0}\·{t_0}^2))\end{array},$ Wherein, t is the time, t ₀for time delay, S (t, t ₀) be t time delay t ₀this FM signal, f ₀centered by frequency, B is signal bandwidth, T ₀for pulse width.

This compensating module is used for compensating this FM signal, and this FM signal expression formula is rewritten as:

wherein, f _ifor original frequency, for initial phase, make then the time delay of this FM signal is compensated.

The signal compensated can be wideband correlation, but is not limited to wideband correlation, also can be that other has the broadband NLFM signal of certain rule.Because the signal compensated is wideband correlation or the broadband NLFM signal having certain rule, can the derivation of equation be passed through, will the time-delay conversion compensated be needed to be the change of original frequency and the change of initial phase.

During the application of this digital delay compensation system, its digital delay compensation method comprises the following steps:

Step one, receive FM signal, this FM signal expression formula is:

$\begin{array}{c}S(t,t_0)=\exp (2\mathrm{\π}\·((f_0-\frac{B}{2})\·(t-t_0)+\frac{B}{2T_0}\·{(t-t_0)}^2))\\ =\exp (2\mathrm{\π}\·((f_0-\frac{B}{2}-\frac{B\·t_0}{T_0})\·t+\frac{B}{2T_0}\·t^2)-2\mathrm{\π}\·((f_0-\frac{B}{2})\·t_0-\frac{B}{2T_0}\·{t_0}^2))\end{array},$ Wherein, t is the time, t ₀for time delay, S (t, t ₀) be t time delay t ₀this FM signal, f ₀centered by frequency, B is signal bandwidth, T ₀for pulse width;

Step 2, compensates this FM signal, and this FM signal expression formula is rewritten as:

wherein, f _ifor original frequency, for initial phase, make then the time delay of this FM signal is compensated.

The subsequent foundation illustratively compensated.

For linear FM signal, centre frequency is f ₀, signal bandwidth is B, and pulse width is T ₀, time delay is t ₀linear FM signal expression formula be:

$\begin{array}{c}S(t,t_0)=\exp (2\mathrm{\π}\·((f_0-\frac{B}{2})\·(t-t_0)+\frac{B}{2T_0}\·{(t-t_0)}^2))\\ =\exp (2\mathrm{\π}\·((f_0-\frac{B}{2}-\frac{B\·t_0}{T_0})\·t+\frac{B}{2T_0}\·t^2)-2\mathrm{\π}\·((f_0-\frac{B}{2})\·t_0-\frac{B}{2T_0}\·{t_0}^2))\end{array},$

If time delay t ₀be 0, then have: $S(t,0)=\exp (2\mathrm{\π}\·((f_0-\frac{B}{2})\·t+\frac{B}{2T_0}\·t^2))$

Two formulas relatively above, can find out that original frequency and the initial phase of the linear FM signal after time delay all change, so the time delay between compensated linear FM signal can be carried out by the method compensating original frequency and initial phase, make signal can be added synthesis by homophase.If the original frequency compensated is f _i, initial phase is then the expression formula of linear FM signal can be rewritten as:

If make then the time delay of linear FM signal can obtain fine compensation.Traditional phased-array radar carrys out compensation delay by means of only phase control, and its precondition should meet to such an extent as to need the frequency of compensation can ignore by contrast, if other parameters remain unchanged, signal bandwidth B is less, and this condition more easily meets.Meanwhile, compensation of phase comprise time delay t ₀first power and quadratic component, in nonlinear relationship.When signal bandwidth B is less, and time delay t ₀time very little (being equivalent to beam position deflection angle little), expression formula in t ₀ ²item can be ignored, compensation of phase with time delay t ₀be approximately linear relationship.In this case, to Digital Array Radar, the signal lag nt of the n-th array element ₀, by simple signal phase compensate.Visible, the method of traditional phase control compensation delay is only applicable to the situation of narrow band signal, low-angle beam scanning, when signal bandwidth is wider, scanning angle is larger, when nonlinear terms in frequency compensated part and phase compensation can not be ignored, then need to carry out to original frequency and initial phase the object that fine compensation just can reach compensation of delay simultaneously.

Digital delay compensation system and digital delay compensation method, when specific implementation, can adopt hardware device to realize, as realized the equipment that digital delay compensates.This equipment adopts DDS chip to produce linear FM signal, and this DDS chip utilizes above-mentioned digital delay compensation method, when DDS chip produces linear FM signal, configures the initial phase word of DDS chip, original frequency word to meet realize the compensation of delay of wideband correlation.

The work clock of DDS chip is made to be f _{sYS_CLK}, frequency tuning precision is M position, and planet phasing precision is N position, only considers that the first power of phase place and time delay carries out compensation of delay, then the delay precision Δ t determined by frequency tuning precision and planet phasing precision _f, Δ t _pbe respectively:

$\begin{array}{c}{\mathrm{\Δt}}_F=\frac{f_{\mathrm{SYS}\_\mathrm{CLK}}}{2^M}\×\frac{T_0}{B}\\ \mathrm{\Δ}{t}_P=\frac{1}{(f_0-\frac{B}{2}){\×2}^N}\end{array},$ Get the delay precision value that in both, larger value can reach for DDS chip.

That is, when utilizing DDS chip to produce linear FM signal, initial phase word CPOW0, original frequency word CFTW0 need be configured, stop the registers such as frequency word CFTW1, upwards sweep frequency stepping word RDW.So, the compensation of delay of wideband correlation can be realized easily by configuration initial phase word and original frequency word.Suppose that the work clock of DDS chip is f _{sYS_CLK}, frequency tuning precision is M position, and planet phasing precision is N position, only considers that the first power of phase place and time delay carries out compensation of delay, then the delay precision Δ t determined by frequency tuning precision and planet phasing precision _f, Δ t _pbe respectively

$\begin{array}{c}{\mathrm{\Δt}}_F=\frac{f_{\mathrm{SYS}\_\mathrm{CLK}}}{2^M}\×\frac{T_0}{B}\\ \mathrm{\Δ}{t}_P=\frac{1}{(f_0-\frac{B}{2}){\×2}^N}\end{array},$ Get the delay precision value that in both, larger value can reach for DDS chip.

Suppose f _{sYS_CLK}=500MHz, M=32, N=16, f ₀=300MHz, T ₀=400 μ s, B=100MHz, then have Δ t _f≈ 0.5ps, Δ t _p≈ 0.06ps.So with this understanding, the delay precision that DDS chip can reach is 0.5ps, can meet actual system requirements.

Figure 1 shows that centre frequency 300MHz, bandwidth 100MHz, time wide 10 μ s, relative time delay 5ns the linear FM signal of two-way standard adopt the synthesis result of different compensation method.Be the method compensating centre frequency phase place, better, both sides net amplitude reduces gradually in centre frequency synthesis; Another kind is the method compensating original frequency and initial phase, and in Whole frequency band, synthesis is all fine, and signal amplitude is consistent.

This realizes the equipment of digital delay compensation in the specific implementation, and its specific implementation process realizing wideband correlation space combination and scanning is as described below:

The first step, calculates the signal lag compensated required for each array element according to the parameter such as array element distance, scanning angle, namely calculate according to the array element distance of wideband digital array, scanning angle parameter the signal lag compensated required for each array element: time delay t ₀, centre frequency f ₀, signal bandwidth B, pulse width T ₀;

Second step, the time delay of calculating is brought into original frequency and initial phase that aforementioned formula calculates the compensation of each array element needs, the signal lag being about to calculate brings formula into calculate the offset that each array element needs: original frequency f _iand initial phase

3rd step, is added the initial value of calibration with the offset of calculating and sends into DDS chip, carry out digitizing fine compensation, realize the space combination of wideband correlation launching beam in this scanning angle to wideband correlation time delay.

In sum, compensation of delay precision is relevant with the quantified precision of DDS chip to frequency word and phase place word, also has relation, can reach higher compensation precision with the centre frequency of signal, signal bandwidth, signal pulsewidth.The present invention compensates at the enterprising line delay of numeric field, in principle not by the restriction of signal bandwidth, is suitable for broadband or ultra-broadband digital array radar system.Owing to being the change of original frequency by time-delay conversion, the actual signal bandwidth transmitted can be caused to decrease, but generally in systems in which, need the time delay compensated to be very little relative to signal pulsewidth, so the loss of bandwidth is also negligible.For larger time delay, can first will the time-delay conversion compensated be needed to be the time delay that an integer DDS chip upgrades pulse, then use the method to carry out digital delay compensation to remaining residue time delay, the loss of the signal bandwidth that large time delay brings can be reduced.The present invention can also be applied in wideband digital array radar system, realizes space combination and the scanning of wideband correlation launching beam.

The foregoing is only preferred embodiment of the present invention, not in order to limit the present invention, all any amendments done within the spirit and principles in the present invention, equivalent replacement and improvement etc., all should be included within protection scope of the present invention.

Claims (7)

1. a digital delay compensation system, it, for compensating the time delay between FM signal for wideband digital array radar aperture fill time, is characterized in that: this digital delay compensation system comprises:

Receiver module, it is for receiving FM signal, and this FM signal expression formula is:

$\begin{array}{c}S(t,t_0)=\exp (2\mathrm{\π}\·((f_0-\frac{B}{2})\·(t-t_0)+\frac{B}{{2T}_0}\·{(t-t_0)}^2))\\ =\exp (2\mathrm{\π}\·((f_0-\frac{B}{2}-\frac{B\·t_0}{T_0})\·t+\frac{B}{{2T}_0}\·t^2)-2\mathrm{\π}\·((f_0-\frac{B}{2})\·t_0-\frac{B}{{2T}_0}\·{t_0}^2))\end{array},$ Wherein, t is the time, t ₀for time delay, S (t, t ₀) be t time delay t ₀this FM signal, f ₀centered by frequency, B is signal bandwidth, T ₀for pulse width;

Compensating module, it is for compensating this FM signal, and this FM signal expression formula is rewritten as:

wherein, f _ifor original frequency, for initial phase, make $f_i=\frac{B\·t_0}{T_0},$ then the time delay of this FM signal is compensated.

2. digital delay compensation system as claimed in claim 1, is characterized in that: this FM signal is linear FM signal or the broadband NLFM signal with certain rule.

3. a digital delay compensation method, it, for compensating the time delay between FM signal for wideband digital array radar aperture fill time, is characterized in that: this digital delay compensation method comprises the following steps:

Step one, receive FM signal, this FM signal expression formula is:

$\begin{array}{c}S(t,t_0)=\exp (2\mathrm{\π}\·((f_0-\frac{B}{2})\·(t-t_0)+\frac{B}{{2T}_0}\·{(t-t_0)}^2))\\ =\exp (2\mathrm{\π}\·((f_0-\frac{B}{2}-\frac{B\·t_0}{T_0})\·t+\frac{B}{{2T}_0}\·t^2)-2\mathrm{\π}\·((f_0-\frac{B}{2})\·t_0-\frac{B}{{2T}_0}\·{t_0}^2))\end{array},$ Wherein, t is the time, t ₀for time delay, S (t, t ₀) be t time delay t ₀this FM signal, f ₀centered by frequency, B is signal bandwidth, T ₀for pulse width;

Step 2, compensates this FM signal, and this FM signal expression formula is rewritten as:

wherein, f _ifor original frequency, for initial phase, make $f_i=\frac{B\·t_0}{T_0},$ then the time delay of this FM signal is compensated.

4. digital delay compensation method as claimed in claim 3, is characterized in that: this FM signal is linear FM signal or the broadband NLFM signal with certain rule.

5. the equipment realizing digital delay and compensate, it is for for the time delay between wideband digital array radar aperture fill time compensated linear FM signal, it is characterized in that: this equipment adopts DDS chip to produce linear FM signal, this DDS chip utilizes digital delay compensation method as claimed in claim 3, when DDS chip produces linear FM signal, configure the initial phase word of DDS chip, original frequency word to meet $f_i=\frac{B\·t_0}{T_0},$ realize the compensation of delay of wideband correlation.

6. realize the equipment that digital delay compensates as claimed in claim 5, it is characterized in that: make the work clock of DDS chip be f _{sYS_CLK}, frequency tuning precision is M position, and planet phasing precision is N position, only considers that the first power of phase place and time delay carries out compensation of delay, then the delay precision Δ t determined by frequency tuning precision and planet phasing precision _f, Δ t _pbe respectively:

$\begin{array}{c}{\mathrm{\Δt}}_F=\frac{f_{\mathrm{SYS}\_\mathrm{CLK}}}{2^M}\×\frac{T_0}{B}\\ {\mathrm{\Δt}}_P=\frac{1}{(f_0-\frac{B}{2})\×2^N}\end{array},$ Get the delay precision value that in both, larger value can reach for DDS chip.

7. a digital delay compensation method, it is applied to realizing as described in claim 5 or 6 and, in the equipment of digital delay compensation, it is characterized in that: this digital delay compensation method comprises the following steps:

The first step, calculates according to the array element distance of wideband digital array, scanning angle parameter the signal lag compensated required for each array element: time delay t ₀, centre frequency f ₀, signal bandwidth B, pulse width T ₀;

Second step, brings the signal lag of calculating into formula $f_i=\frac{B\·t_0}{T_0},$ calculate the offset that each array element needs: original frequency f _iand initial phase

3rd step, is added the initial value of calibration with the offset of calculating and sends into DDS chip, carry out digitizing fine compensation, realize the space combination of wideband correlation launching beam in this scanning angle to wideband correlation time delay.