CN103581071B - The transmitting signal frequency deviation real-time correction method of high dynamic motion carrier and system thereof - Google Patents

Abstract

The present invention discloses transmitting signal frequency deviation real-time correction method and the system thereof of a kind of high dynamic motion carrier, belongs to the communications field. Wherein correction method is specially: first high dynamic motion carrier carries out catching to received signal, follows the tracks of, obtain the frequency deviation estimated value of Received signal strength, then convert out the frequency deviation of transmitting signal according to the proportionlity launching signal and Received signal strength carrier frequency and compensated in advance, make transmitting signal frequency deviation in the scope required. Invention also provides a kind of system according to aforesaid method, this system uses correction calculation module to carry out frequency offset calculation, and digital to analog converter DAC and voltage controlled oscillator VCO are controlled by the total frequency deviation value calculated, and the crystal oscillator frequency of signal is launched in control further. Use the present invention that high dynamic motion carrier can carry out launch signal frequency deviation to correct in real time.

Description

The transmitting signal frequency deviation real-time correction method of high dynamic motion carrier and system thereof

Technical field

The present invention relates to a kind of motion carrier transmitting signal that dynamically moved by height and carry out method and the system thereof that frequency deviation corrects in real time, belong to the communications field.

Background technology

For high-speed motion carrier, it to be communicated with terrestrial station, then need to use relay communications system, in relay communications system, owing to the usual movement velocity of traditional carrier is not high, for transmitting signal frequency deviation not requirement, but during carrier high-speed motion, bigger Doppler shift can be produced, it is possible to the passband of relaying wave filter can be exceeded, thus cause signal to be attenuated, affect terrestrial station to the reception of signal. Therefore for some high-speed motion carrier, it is necessary to transmitting signal frequency deviation is carried out pre-setting.

The method of traditional carrier signal frequency offset correction, all for Received signal strength, carries out frequency offset correction by modes such as the supplementary such as position, speed or signal detection.

And current communication terminal all has forward signal catches, follows the tracks of passage, can accurately estimate the frequency deviation of Received signal strength, this kind of frequency deviation estimated value can use as when Signal reception, data processing, if can utilize this kind of frequency deviation estimated value that high dynamic motion carrier is launched signal carry out real-time frequency deviation adjustment, the system that then may reach is to the frequency deviation requirement launching signal, but current frequency deviation correcting method does not effectively utilize the frequency deviation estimated value of this kind of Received signal strength, contribute for launching signal frequency deviation restriction.

Summary of the invention

In view of this, the present invention provides the transmitting signal frequency deviation real-time correction method of a kind of high dynamic motion carrier, it is possible to effectively utilize the frequency deviation estimated value of Received signal strength, has broken the restriction that high dynamic motion carrier is launched signal frequency deviation by communication system.

For achieving the above object, the basic thought of present method is: first high dynamic motion carrier carries out catching to received signal, follows the tracks of, obtain the frequency deviation estimated value of Received signal strength, then convert out the frequency deviation of transmitting signal according to the proportionlity launching signal and Received signal strength carrier frequency and compensated in advance, make transmitting signal frequency deviation in the scope required.

Specifically, the method comprises the steps:

Step one, high dynamic motion carrier catch Received signal strength, obtain the frequency deviation estimated value Dop of Received signal strength;

Transmitting information sets frame is formed transmitting signal and launches by step 2, high dynamic motion carrier, calculates signal transmission time T, signal transmission time T and launches signal group frame to complete to the transmitting moment launching signal; Obtaining the frequency deviation that in signal transmission time T, high dynamic motion carrier movement causes is:

$\mathrm{\ΔDop}=\frac{a}{3\×{10}^8}\×M\×T$

Wherein M is the frequency of Received signal strength, and a is the current movement velocity velocity of variation of high dynamic motion carrier;

Step 3, use frequency deviation estimated value Dop calculate to obtain and launch the total frequency deviation value of signal, total frequency deviation value FreqErr=Dop+ �� Dop;

Step 4, the total frequency deviation value FreqErr using step 3 to obtain control the input value D of digital to analog converter DAC_adjust:

$D_{\mathrm{adjust}}=\frac{2^{m}Y}{X}-\frac{\mathrm{FreqErr}}{P}\·\frac{Z}{N}\·\frac{2^m}{X}$

Wherein m is the bit wide of DAC, and the voltage output range of DAC is 0��X, unit is V; The frequency adjustment range of crystal oscillator is-N��N, unit is ppm; Voltage adjusting range is Y �� Z, unit is V; Received signal strength carrier frequency is P, unit is MHz;

Step 5, use above-mentioned DAC outputting analog signal control voltage controlled oscillator VCO, VCO output control launch signal crystal oscillator frequency, thus realize to transmitting signal frequency deviation control.

Based on the transmitting signal frequency deviation real-time correction method of above-mentioned high dynamic motion carrier, invention also provides the transmitting signal frequency deviation System with Real-Time of a kind of high dynamic motion carrier, this system can be incorporated on high dynamic motion carrier, and mate mutually with function module each on carrier, thus break the restriction that high dynamic motion carrier is launched signal frequency deviation by communication system.

For achieving the above object, the concrete scheme of native system is: this system is placed on high dynamic motion carrier, it is characterised in that, this system comprises SPI switch, DAC and VCO, and sets up correction calculation function in transmitting processing module;

High dynamic motion carrier has radio frequency module, baseband processing module and launches processing module, and wherein radio frequency module catches Received signal strength, and baseband processing module processes to received signal, obtains the Dop of Received signal strength; Dop is sent to transmitting processing module;

Transmitting processing module is obtained the transmitting information of high dynamic motion carrier and carries out group frame formation transmitting signal and launched by radio frequency module; Calculating total frequency deviation value FreqErr=Dop+ �� Dop, wherein, �� Dop is the frequency deviation that in signal transmission time T, high dynamic motion carrier movement causesSignal transmission time T is transmitting signal group frame and completes to the transmitting moment launching signal, and M is the frequency of Received signal strength, and a is the current movement velocity velocity of variation of high dynamic motion carrier;

According to above-mentioned total frequency deviation value FreqErr, launch the adjustment input value D that processing module calculates DAC_adjust:

$D_{\mathrm{adjust}}=\frac{2^{m}Y}{X}-\frac{\mathrm{FreqErr}}{P}\·\frac{Z}{N}\·\frac{2^m}{X}$

Wherein m is the bit wide of DAC, and the voltage output range of DAC is 0��X, unit is V; The frequency adjustment range of crystal oscillator is-N��N, unit is ppm; Voltage adjusting range is Y �� Z, unit is V; Received signal strength carrier frequency is P, unit is MHz;

SPI switch controls break-make according to FreqErr value, if the value of FreqErr is within the scope of the maximum skew of emission signal frequency, then launches processing module control SPI switch and is in shutoff state; If FreqErr is beyond the maximum skew scope of emission signal frequency, then launches processing module control SPI switch and it is in connection state;

DAC, when SPI switch is in connection state, receives D_adjust, and according to D_adjustCarrying out analog output, analog output is to VCO;

The crystal oscillator of radio frequency module in high dynamic motion carrier is controlled by VCO according to analog quantity.

Useful effect:

1, present method is the method that the transmitting signal frequency deviation of a kind of high dynamic motion carrier corrects in real time. Its main function is by catching to received signal, follows the tracks of, detect out the frequency deviation of signal, then convert out the frequency deviation of transmitting signal according to the proportionlity of Received signal strength with transmitting signal-carrier frequency and compensated in advance, make transmitting signal frequency deviation in the scope required, efficiently utilize the frequency deviation estimated value of Received signal strength so that high dynamic motion carrier is more effective to the control launching signal frequency deviation.

2, based on aforesaid method, invention also provides a kind of frequency deviation System with Real-Time launching signal, this system is by having the module of certain function, high dynamic motion carrier is carried out Signal reception, follow the tracks of the frequency deviation estimated value obtaining Received signal strength, and DAC and VCO is controlled by the frequency deviation estimated value according to Received signal strength, thus control crystal oscillator frequency and reach the object that signal frequency deviation is launched in control, this system can be incorporated on high dynamic motion carrier, and mate mutually with function module each on carrier, thus broken the restriction that high dynamic motion carrier is launched signal frequency deviation by communication system.

Accompanying drawing explanation

Fig. 1 is the frequency deviation System with Real-Time structure iron launching signal based on high dynamic motion carrier.

Embodiment

Develop simultaneously embodiment below in conjunction with accompanying drawing, describe the present invention.

The present invention provides a kind of frequency deviation real-time correction method launching signal based on high dynamic motion carrier, the basic thought of the method is: first high dynamic motion carrier carries out catching to received signal, follows the tracks of, obtain the frequency deviation estimated value of Received signal strength, then calculate, according to the proportionlity launching signal and Received signal strength carrier frequency, the frequency deviation converting out transmitting signal and compensated in advance, make transmitting signal frequency deviation in the scope required.

Embodiment 1,

Based on above-mentioned basic thought, the method specifically comprises the steps:

Step one, high dynamic motion carrier catch Received signal strength, and carry out to received signal mixing, relevant and loop tracks thus obtain the frequency deviation estimated value Dop of Received signal strength.

Step 2, high dynamic motion carrier are by the transmitting signal launching information sets frame formation standard format and launch, and complete to the transmitting moment launching signal to be designated as signal transmission time T by launching signal group frame.

The data that wherein above-mentioned transmitting information oneself state data and sensor gather.

Then consider that the speed of high dynamic motion carrier is very fast, in the signal transmission time T of high dynamic motion carrier, transmitting signal frequency deviation can be affected by its motion equally, consequently, it is desirable to calculate the frequency deviation �� Dop that in signal transmission time T, high dynamic motion carrier movement causes:

$\mathrm{\ΔDop}=\frac{a}{3\×{10}^8}\×M\×T$

Wherein M is the frequency of Received signal strength, and a is the current movement velocity velocity of variation of high dynamic motion carrier.

Step 3, use frequency deviation estimated value Dop calculate to obtain and launch the total frequency deviation value of signal, total frequency deviation value FreqErr=Dop+ �� Dop;

Step 4, the total frequency deviation value FreqErr using step 3 to obtain control the input value D of digital to analog converter DAC_adjust:

$D_{\mathrm{adjust}}=\frac{2^{m}Y}{X}-\frac{\mathrm{FreqErr}}{P}\·\frac{Z}{N}\·\frac{2^m}{X}$

Wherein m is the bit wide of DAC, and the voltage output range of DAC is 0��X, and unit is V, and the frequency adjustment range of crystal oscillator is-N��N, and unit is ppm, and voltage adjusting range is Y �� Z, and unit is V; Received signal strength carrier frequency is P, and unit is MHz.

Step 5, use above-mentioned DAC outputting analog signal control voltage controlled oscillator VCO thus realize to transmitting signal frequency deviation control.

Embodiment 2,

Based on the method that embodiment 1 provides, invention also provides a kind of specially for the transmitting signal frequency deviation System with Real-Time of high dynamic motion carrier, the modular design of this system is mated mutually with the function module of high dynamic motion carrier, can be incorporated on high dynamic motion carrier, high dynamic motion carrier wherein itself has radio frequency module, receives baseband processing module, launch the function module such as processing module and sensor, wherein radio frequency module has crystal oscillator.

The present embodiment is provided frequency deviation System with Real-Time to comprise SPI switch, digital to analog converter DAC and voltage controlled oscillator VCO, and sets up correction calculation function in transmitting processing module. Launching the input that processing module connects DAC by SPI switch, the output of DAC connects the input of VCO, and the output of VCO connects the crystal oscillator in radio frequency module. The integrated structure of this system and high dynamic motion carrier is as shown in Figure 1. Then within the system, each functions of modules is as follows:

Radio frequency module

Radio frequency module, as the reception of native system and transmission channel, has crystal oscillator in it, therefore when carrying out signal and launch, radio frequency module adjusts emission signal frequency according to crystal oscillator frequency; After the signal that radio frequency module satellite receiver is sent, Received signal strength is sent to reception baseband processing module.

Receive baseband processing module

Receive baseband processing module mainly to process to received signal, namely to adopting the technology such as existing signal capture, mixing and signal are relevant, loop tracks, carry out receiving to received signal, mixing, relevant and loop tracks, thus obtain the frequency deviation estimated value Dop of Received signal strength, and Dop is sent to transmitting processing module.

Sensor

Sensor and the reception parallel operation of baseband processing module, sensor can obtain the state data of high dynamic motion carrier, the data such as the attitude data of such as carrier, carrier remaining fuel amounts or engine temperature; After wherein sensor obtains state data, need above state data carry out the group process such as frame and packing, forming standard signal form gives radio frequency module to carry out the transmitting of signal, and therefore sensor needs to be sent to obtained state data and launches processing module and carry out the group process such as frame and packing.

Launch processing module

Launch processing module and mainly carry out signal processing: launch the signal format that state data are carried out organizing frame, packing formation standard by processing module, and signal is sent to radio frequency module and launches.

Data processing is mainly: calculate the signal transmission time T in signal processing, and uses the Dop calculating acquisition from receiving baseband processing module to launch the total frequency deviation value of signal. Wherein signal transmission time T launches signal group frame to complete to launching signal to launch the time between the moment;

Why need to calculate signal transmission time, mainly consider the present invention institute for high dynamic motion carrier, it completes to launching during the moment also have motion launching signal group frame, and transmitting signal still can be caused comparatively objective frequency deviation by this motion.

Launch the correction calculation function in processing module

Its main function of correction calculation function is the adjustment input value D carrying out total frequency offset calculation and adjusting digital to analog converter DAC according to total frequency deviation_adjust:

Assume that the frequency deviation that high dynamic motion carrier movement causes within time T is �� Dop, then have:

$\mathrm{\ΔDop}=\frac{a}{3\×{10}^8}\×M\×T$

Wherein M is the frequency of Received signal strength, and a is the current movement velocity velocity of variation of high dynamic motion carrier; Then total frequency deviation value FreqErr=Dop+ �� Dop=k �� Dop; Wherein k is variation factor;

According to above-mentioned total frequency deviation value FreqErr, launch the adjustment input value D that processing module calculates digital to analog converter DAC simultaneously_adjust:

$D_{\mathrm{adjust}}=\frac{2^{m}Y}{X}-\frac{\mathrm{FreqErr}}{P}\·\frac{Z}{N}\·\frac{2^m}{X}$

Wherein m is the bit wide of DAC, and the voltage output range of DAC is 0��X, and unit is V, and the frequency adjustment range of crystal oscillator is-N��N, and unit is ppm, and voltage adjusting range is Y �� Z, and unit is V; Received signal strength carrier frequency is P, and unit is MHz.

SPI switch

SPI switch needs to control break-make according to FreqErr value, and situation is as follows:

If within the scope of the maximum skew that FreqErr is less, belong to emission signal frequency, then think and now do not need transmitting signal is carried out frequency offset correction, therefore launch processing module control SPI switch and be in shutoff state, launch the D that processing module calculates_adjustThen can not be passed in DAC;

If FreqErr is beyond the maximum skew scope of emission signal frequency, then think that now launching signal demand carries out frequency offset correction, therefore launch processing module control SPI switch and be in connection state, the D calculated_adjustThen can be passed in DAC.

Digital to analog converter DAC

DAC, when SPI switch is in connection state, receives D_adjust, and according to D_adjustCarrying out analog output, analog output is to VCO.

Voltage controlled oscillator VCO

VCO controls according to the crystal oscillator of the analog quantity radio frequency module that DAC exports, thus reaches the correction to emission signal frequency.

VCO is input as D_adjustAnalog quantity, then, after VCO processes, export the frequency control word being equivalent to have updated crystal oscillator, that is:

${\mathrm{FCW}}_{\mathrm{new}}={\mathrm{FCW}}_{\mathrm{old}}-\frac{\mathrm{FreqErr}}{f_s}\·2^{32}$

Wherein, FCW_oldFor not correcting the frequency control word of front system, f_sFor the sample frequency of DAC; FCW_oldInitial value according to launch signal frequency calculate.

Embodiment 3,

The frequency deviation System with Real-Time workflow that above-described embodiment 2 provides is:

First radio frequency module can carry out signal transmitting, and this transmitting signal is received by terrestrial station.

If terrestrial station needs to obtain carrier status information, then send communication signal to carrier, this communication signal is received by radio frequency module equally, Received signal strength is passed to reception baseband processing module by radio frequency module, receive baseband processing module Received signal strength and carry out catching to received signal, tracking etc. processes, thus obtains the frequency deviation estimated value of Received signal strength;

Launch processing module and there are signal group frame and correction calculation two kinds of functions, namely on the one hand can receiving sensor data and organize frame and form the form launching signal and issue radio frequency module and carry out signal transmitting; Carrier obtains total frequency deviation in the frequency deviation carrying out launching signal group frame and ballistic device motion causes then to use on the other hand frequency deviation estimated value to add, total frequency deviation, for controlling the crystal oscillator frequency of emission signal frequency, makes the frequency deviation of transmitting signal within the scope required.

Signal is launched complete, and SPI switch should be made to disconnect, and for receive carriers signal, until needing to launch signal, crystal oscillator frequency is adjusted by recycling Received signal strength, and so forth.

In sum, these are only the better embodiment of the present invention, it is not intended to limit protection scope of the present invention. Within the spirit and principles in the present invention all, any amendment of doing, equivalent replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (2)

1. the transmitting signal frequency deviation real-time correction method of high dynamic motion carrier, it is characterised in that, the method specifically comprises the steps:

Step one, high dynamic motion carrier catch Received signal strength, obtain the frequency deviation estimated value Dop of Received signal strength;

Transmitting information sets frame is formed transmitting signal and launches by step 2, high dynamic motion carrier, calculates signal transmission time T, described signal transmission time T and launches signal group frame to complete to the transmitting moment launching signal; Obtaining the frequency deviation that in signal transmission time T, high dynamic motion carrier movement causes is:

$\mathrm{\Δ}Dop=\frac{a}{3\×{10}^8}\×M\×T$

Wherein M is the frequency of Received signal strength, and a is the current movement velocity velocity of variation of high dynamic motion carrier;

Step 3, use frequency deviation estimated value Dop calculate to obtain and launch the total frequency deviation value of signal, total frequency deviation value FreqErr=Dop+ �� Dop;

Step 4, the total frequency deviation value FreqErr using step 3 to obtain control the input value D of digital to analog converter DAC_adjust:

$D_{adjust}=\frac{2^{m}Y}{X}-\frac{FreqErr}{P}\·\frac{Z}{N}\·\frac{2^m}{X}$

Wherein m is the bit wide of DAC, and the voltage output range of DAC is 0��X, unit is V; The frequency adjustment range of crystal oscillator is-N��N, unit is ppm; Voltage adjusting range is Y �� Z, unit is V; Received signal strength carrier frequency is P, unit is MHz;

Step 5, using above-mentioned DAC outputting analog signal to voltage controlled oscillator VCO, the output of VCO controls the crystal oscillator frequency of described transmitting signal, thus realizes transmitting signal frequency deviation control.

2. the transmitting signal frequency deviation System with Real-Time of high dynamic motion carrier, this system is placed on high dynamic motion carrier, it is characterised in that, this system comprises SPI switch, DAC and VCO, and sets up correction calculation function in transmitting processing module;

Described high dynamic motion carrier has radio frequency module, baseband processing module and launches processing module, and wherein radio frequency module catches Received signal strength, and baseband processing module processes to received signal, obtains the Dop of Received signal strength; Dop is sent to transmitting processing module;

Transmitting processing module is obtained the oneself state data of high dynamic motion carrier and carries out group frame formation transmitting signal and launched by radio frequency module; Calculating total frequency deviation value FreqErr=Dop+ �� Dop, wherein, �� Dop is the frequency deviation that in time signal T launch time, high dynamic motion carrier movement causesSignal transmission time T is transmitting signal group frame and completes to the transmitting moment launching signal, and M is the frequency of Received signal strength, and a is the current movement velocity velocity of variation of high dynamic motion carrier;

According to above-mentioned total frequency deviation value FreqErr, launch the adjustment input value D that processing module calculates DAC_adjust:

$D_{adjust}=\frac{2^{m}Y}{X}-\frac{FreqErr}{p}\·\frac{Z}{N}\·\frac{2^m}{X}$

Wherein m is the bit wide of DAC, and the voltage output range of DAC is 0��X, unit is V; The frequency adjustment range of crystal oscillator is-N��N, unit is ppm; Voltage adjusting range is Y �� Z, unit is V; Received signal strength carrier frequency is P, unit is MHz;

Described SPI switch controls break-make according to FreqErr value, if the value of FreqErr is within the scope of the maximum skew of emission signal frequency, then launches processing module control SPI switch and is in shutoff state; If FreqErr is beyond the maximum skew scope of emission signal frequency, then launches processing module control SPI switch and it is in connection state;

Described DAC, when SPI switch is in connection state, receives D_adjust, and according to D_adjustCarrying out analog output, analog output is to VCO;

The crystal oscillator of radio frequency module in high dynamic motion carrier is controlled by described VCO according to analog quantity.