CN103581071A - High-dynamic motion carrier transmitted signal frequency offset real-time correction method and system - Google Patents

Abstract

The invention discloses a high-dynamic motion carrier transmitted signal frequency offset real-time correction method and system, and belongs to the communication field. The correction method particularly includes the steps that firstly, a high-dynamic motion carrier captures and tracks a received signal to obtain a frequency offset estimated value of the received signal, then frequency offset of a transmitted signal is computed and compensated in advance according to the proportional relation of the carrier frequency of the transmitted signal and the carrier frequency of the received signal, and therefore the frequency offset of the transmitted signal is within a required scope. According to the correction method, the high-dynamic motion carrier transmitted signal frequency offset real-time correction system is provided at the same time. A correction computing module is used in the correction system to conduct frequency offset computing, the computed total frequency offset value controls a DAC and a VCO, and the crystal oscillator frequency of the transmitted signal is further controlled. According to the high-dynamic motion carrier transmitted signal frequency offset real-time correction method and system, transmitted signal frequency offset real-time correction on the high-dynamic motion carrier can be achieved.

Description

Transmit frequency deviation real-time correction method and the system thereof of high dynamic motion carrier

Technical field

The present invention relates to a kind of to height dynamically moving motion carrier transmit and carry out method and the system thereof of frequency deviation real time correction, belong to the communications field.

Background technology

For high-speed motion carrier, Qi Yaoyu ground station communicates, need to use relay communications system, in relay communications system, because the common movement velocity of traditional carrier is not high, for transmitting, frequency deviation does not require, yet during carrier high-speed motion, can produce larger Doppler frequency deviation, likely can exceed the passband of relaying filter, thereby cause signal to be attenuated, affect the reception of ground station to signal.Therefore for some high-speed motion carrier, need to carry out pre-adjustment to the frequency deviation that transmits.

The method of traditional carrier signal frequency offset correction, all pin to received signal, carries out frequency offset correction by modes such as the supplementarys such as position, speed or input.

And current communication terminal all has, forward signal is caught, tracking channel, can accurately estimate the frequency deviation that receives signal, when can be used as signal reception, data processing, this frequency deviation estimated value uses, if can utilize this kind of frequency deviation estimated value to transmit and carry out real-time frequency deviation adjustment high dynamic motion carrier, the system that may reach is to the frequency deviation requirement transmitting, yet current frequency deviation correcting method does not effectively utilize the frequency deviation estimated value of this reception signal, in order to transmit, frequency deviation restriction is contributed.

Summary of the invention

In view of this, the invention provides a kind of frequency deviation real-time correction method that transmits of high dynamic motion carrier, can effectively utilize the frequency deviation estimated value that receives signal, broken communication system to the transmit restriction of frequency deviation of high dynamic motion carrier.

For achieving the above object, the basic thought of this method is: first high dynamic motion carrier is caught to received signal, followed the tracks of, obtain the frequency deviation estimated value that receives signal, then according to transmitting, convert out the frequency deviation transmitting and compensated in advance with the proportionate relationship that receives signal(-) carrier frequency, making to transmit frequency deviation in the scope requiring.

Particularly, the method comprises the steps:

Step 1, high dynamic motion carrier are caught reception signal, obtain the frequency deviation estimated value Dop that receives signal;

Step 2, high dynamic motion carrier form transmitting information framing to transmit and launch, and calculate signal transmission time T, and signal transmission time T is that the framing that transmits completes to the x time transmitting; The frequency deviation that in picked up signal T launch time, high dynamic motion carrier movement causes is:

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

Wherein M is for receiving the frequency of signal, and a is the current movement velocity rate of change of high dynamic motion carrier;

Step 3, use frequency deviation estimated value Dop calculate and obtain total frequency deviation value that transmits, total frequency deviation value FreqErr=Dop+ △ Dop;

Total frequency deviation value FreqErr that step 4, use step 3 obtain controls the input value D of digital to analog converter DAC _adjust:

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

The bit wide that wherein m is DAC, the voltage output range of DAC is that 0～X, unit are V; The frequency adjustment range of crystal oscillator for-N～N, unit be ppm; Voltage adjusting range is that Y ± Z, unit are V; Reception signal(-) carrier frequency is that P, unit are MHz;

Step 5, use above-mentioned DAC outputting analog signal to control voltage controlled oscillator VCO, the crystal oscillator frequency transmitting is controlled in the output of VCO, thereby realize, the frequency deviation that transmits is controlled.

The frequency deviation real-time correction method that transmits based on above-mentioned high dynamic motion carrier, the present invention provides a kind of frequency deviation System with Real-Time that transmits of high dynamic motion carrier simultaneously, this system can be incorporated on high dynamic motion carrier, and with carrier on each functional module match, thereby broken communication system to the transmit restriction of frequency deviation of high dynamic motion carrier.

For achieving the above object, the concrete scheme of native system is: this system is placed on high dynamic motion carrier, it is characterized 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 transmitting processing module, and wherein radio-frequency module is caught reception signal, and baseband processing module is processed to received signal, obtains the Dop that receives signal; Dop is sent to transmitting processing module;

Transmitting processing module is obtained the transmitting information of high dynamic motion carrier and is carried out framing and forms to transmit and launch by radio-frequency module; Calculate total frequency deviation value FreqErr=Dop+ △ Dop, wherein, △ Dop is the frequency deviation that in signal transmission time T, high dynamic motion carrier movement causes

signal transmission time T is the framing that transmits and completes to the x time transmitting, and M is for receiving the frequency of signal, and a is the current movement velocity rate of change of high dynamic motion carrier;

According to above-mentioned total frequency deviation value FreqErr, transmitting processing module is calculated the adjustment input value D of DAC _adjust:

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

The bit wide that wherein m is DAC, the voltage output range of DAC is that 0～X, unit are V; The frequency adjustment range of crystal oscillator for-N～N, unit be ppm; Voltage adjusting range is that Y ± Z, unit are V; Reception signal(-) carrier frequency is that P, unit are MHz;

SPI switch is controlled break-make according to FreqErr value, if the value of FreqErr within the scope of the peak excursion of emission signal frequency, is launched processing module, controls SPI switch in off state; If FreqErr has exceeded the peak excursion scope of emission signal frequency, launch processing module and control SPI switch in on-state;

DAC during in on-state, receives D at SPI switch _adjust, and according to D _adjustcarry out analog output, analog output is to VCO;

VCO controls the crystal oscillator of radio-frequency module in high dynamic motion carrier according to analog quantity.

Beneficial effect:

1, this method is a kind of method of the frequency deviation real time correction that transmits of high dynamic motion carrier.Its major function is by catching, following the tracks of to received signal, detect the frequency deviation of signal, then according to receiving signal, convert out the frequency deviation transmitting and compensated in advance with the proportionate relationship of the carrier frequency that transmits, make to transmit frequency deviation in the scope requiring, effectively utilize the frequency deviation estimated value that receives signal, made high dynamic motion carrier more effective to the control of the frequency deviation that transmits.

2, based on said method, the present invention provides a kind of frequency deviation System with Real-Time transmitting simultaneously, this system is by having the module of certain function, high dynamic motion carrier is carried out to signal reception, the frequency deviation estimated value that receives signal is obtained in tracking, and according to the frequency deviation estimated value that receives signal, DAC and VCO are controlled, thereby control crystal oscillator frequency and reach the object of controlling the frequency deviation that transmits, this system can be incorporated on high dynamic motion carrier, and with carrier on each functional module match, thereby broken communication system to the transmit restriction of frequency deviation of high dynamic motion carrier.

Accompanying drawing explanation

The frequency deviation System with Real-Time structure chart of Fig. 1 for transmitting based on high dynamic motion carrier.

Embodiment

Below in conjunction with the accompanying drawing embodiment that develops simultaneously, describe the present invention.

The invention provides a kind of frequency deviation real-time correction method transmitting based on high dynamic motion carrier, the basic thought of the method is: first high dynamic motion carrier is caught to received signal, followed the tracks of, obtain the frequency deviation estimated value that receives signal, then according to transmitting, calculate and convert out the frequency deviation transmitting and compensated in advance with the proportionate relationship that receives signal(-) carrier frequency, make to transmit frequency deviation in the scope requiring.

Embodiment 1,

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

Step 1, high dynamic motion carrier are caught reception signal, thereby and carry out to received signal mixing, relevant and loop tracks is obtained the frequency deviation estimated value Dop that receives signal.

Step 2, high dynamic motion carrier form transmitting and launching of reference format by transmitting information framing, and the framing that transmits is completed to the x time transmitting and is designated as signal transmission time T.

Wherein above-mentioned transmitting information comprises the data that oneself state data and transducer gather.

Consider the speed of high dynamic motion carrier, in the signal transmission time T of high dynamic motion carrier, its motion can affect to the frequency deviation that transmits equally, therefore, need 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 for receiving the frequency of signal, and a is the current movement velocity rate of change of high dynamic motion carrier.

Step 3, use frequency deviation estimated value Dop calculate and obtain total frequency deviation value that transmits, total frequency deviation value FreqErr=Dop+ △ Dop;

Total frequency deviation value FreqErr that step 4, use step 3 obtain controls the input value D of digital to analog converter DAC _adjust:

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

The bit wide that wherein m is DAC, 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; Reception signal(-) carrier frequency is P, and unit is MHz.

Thereby step 5, use above-mentioned DAC outputting analog signal to control voltage controlled oscillator VCO to realize the frequency deviation that transmits is controlled.

Embodiment 2,

The method providing based on embodiment 1, the present invention provides a kind of special frequency deviation System with Real-Time that transmits for high dynamic motion carrier simultaneously, the functional module of the modular design of this system and high dynamic motion carrier matches, can be incorporated on high dynamic motion carrier, wherein on high dynamic motion carrier, itself there is radio-frequency module, receive baseband processing module, transmitting processing module and sensor functional module, wherein in radio-frequency module, there is crystal oscillator.

The present embodiment provides 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.Transmitting processing module connects the input of 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 as shown in Figure 1., in this system, each functions of modules is as follows:

Radio-frequency module

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

Receive baseband processing module

Receiving baseband processing module is mainly to process to received signal, to adopting the technology such as existing signal capture, mixing and signal correction, loop tracks, receive to received signal, mixing, relevant and loop tracks, thereby obtain the frequency deviation estimated value Dop that receives signal, and Dop is sent to transmitting processing module.

Transducer

Transducer runs parallel with receiving baseband processing module, and transducer can obtain the status data of high dynamic motion carrier, such as the data such as attitude data, carrier residual fuel amount or engine temperature of carrier; Wherein transducer obtains after status data, above status data need to be carried out to the processing such as framing and packing, form standard signal form and give radio-frequency module to carry out the transmitting of signal, so transducer need to be sent to obtained status data transmitting processing module and carries out the processing such as framing and packing.

Transmitting processing module

Transmitting processing module is mainly carried out signal processing: transmitting processing module is carried out the signal format of framing, packing formation standard to status data, and signal is sent to radio-frequency module launches.

Data processing is mainly: calculate the signal transmission time T in signal processing, and use from the Dop that receives baseband processing module and calculate and obtain total frequency deviation value that transmits.Wherein signal transmission time T is that the framing that transmits completed to the time transmitting between x time;

Why need to calculate signal transmission time, be mainly consider the present invention for high dynamic motion carrier, it completes during x time and also has motion at the framing that transmits, this motion still can cause to transmitting comparatively objectively frequency deviation.

Correction calculation function in transmitting processing module

Its major function of correction calculation function is the adjustment input value D that carries out total frequency offset calculation and adjust digital to analog converter DAC according to total frequency deviation _adjust:

Suppose that the frequency deviation that high dynamic motion carrier movement causes in time T is △ Dop, have:

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

Wherein M is for receiving the frequency of signal, and a is the current movement velocity rate of change of high dynamic motion carrier; Total frequency deviation value FreqErr=Dop+ △ Dop=k * Dop; Wherein k is variation coefficient;

According to above-mentioned total frequency deviation value FreqErr, transmitting processing module is calculated the adjustment input value D of digital to analog converter DAC simultaneously _adjust:

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

The bit wide that wherein m is DAC, 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; Reception signal(-) carrier frequency is P, and unit is MHz.

SPI switch

SPI switch need to be controlled break-make according to FreqErr value, and situation is as follows:

If within the scope of the peak excursion that FreqErr is less, belong to emission signal frequency, think and now do not need to carry out transmitting frequency offset correction, therefore launch processing module and control SPI switch in off state, the D that transmitting processing module is calculated _adjustcan not be passed in DAC;

If FreqErr has exceeded the peak excursion scope of emission signal frequency, thinking now transmits need to carry out frequency offset correction, therefore launches processing module and controls SPI switch in on-state, the D calculating _adjustcan be passed in DAC.

Digital to analog converter DAC

DAC during in on-state, receives D at SPI switch _adjust, and according to D _adjustcarry out analog output, analog output is to VCO.

Voltage controlled oscillator VCO

VCO controls the crystal oscillator of radio-frequency module according to the analog quantity of DAC output, thereby reaches the correction to emission signal frequency.

VCO is input as D _adjustanalog quantity,, after VCO processes, output has been equivalent to upgrade the frequency control word of crystal oscillator, that is:

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

Wherein, FCW _oldfor the frequency control word of system before not proofreading and correct, f _ssample frequency for DAC; FCW _oldinitial value according to the frequency that transmits, 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 transmits and is received by ground station.

If ground station need to obtain carrier state information, to carrier, send signal of communication, this signal of communication is received by radio-frequency module equally, receive signal and be passed to reception baseband processing module by radio-frequency module, receive baseband processing module and receive the processing such as signal is also caught to received signal, tracking, thereby obtain the frequency deviation estimated value that receives signal;

Transmitting processing module has signal framing and two kinds of functions of correction calculation, on the one hand can receiving sensor data and framing form the form transmitting and issue radio-frequency module and carry out signal transmitting; The frequency deviation of using on the other hand frequency deviation estimated value to add that carrier causes in transmit framing and ballistic device motion obtains total frequency deviation, and total frequency deviation, for controlling the crystal oscillator frequency of emission signal frequency, makes the frequency deviation transmitting within the scope requiring.

Signal battery has fired, should make SPI switch disconnect, and for carrier, receives signal, until need to transmit, recycling receives signal crystal oscillator frequency is adjusted, and so forth.

In sum, these are only preferred embodiment of the present invention, be not intended to limit protection scope of the present invention.Within the spirit and principles in the present invention all, any modification of doing, be equal to replacement, improvement etc., within all should being included in protection scope of the present invention.

Claims (3)

1. the frequency deviation real-time correction method that transmits of high dynamic motion carrier, it is characterized in that, the method is specially: first high dynamic motion carrier is caught to received signal, followed the tracks of, obtain the frequency deviation estimated value that receives signal, then according to transmitting, convert out the frequency deviation transmitting and compensated in advance with the proportionate relationship that receives signal(-) carrier frequency, making to transmit frequency deviation in the scope requiring.

2. the frequency deviation real-time correction method that transmits of high dynamic motion carrier as claimed in claim 1, is characterized in that, the method specifically comprises the steps:

Step 1, high dynamic motion carrier are caught reception signal, obtain the frequency deviation estimated value Dop that receives signal;

Step 2, high dynamic motion carrier form transmitting information framing to transmit and launch, and calculate signal transmission time T, and described signal transmission time T is that the framing that transmits completes to the x time transmitting; The frequency deviation that in picked up signal T launch time, high dynamic motion carrier movement causes is:

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

Wherein M is for receiving the frequency of signal, and a is the current movement velocity rate of change of high dynamic motion carrier;

Step 3, use frequency deviation estimated value Dop calculate and obtain total frequency deviation value that transmits, total frequency deviation value FreqErr=Dop+ △ Dop;

Total frequency deviation value FreqErr that step 4, use step 3 obtain controls the input value D of digital to analog converter DAC _adjust:

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

The bit wide that wherein m is DAC, the voltage output range of DAC is that 0～X, unit are V; The frequency adjustment range of crystal oscillator for-N～N, unit be ppm; Voltage adjusting range is that Y ± Z, unit are V; Reception signal(-) carrier frequency is that P, unit are MHz;

Step 5, use above-mentioned DAC outputting analog signal to control voltage controlled oscillator VCO, the crystal oscillator frequency that the output of VCO transmits described in controlling, controls the frequency deviation that transmits thereby realize.

3. the frequency deviation System with Real-Time that transmits of high dynamic motion carrier, this system is placed on high dynamic motion carrier, it is characterized in that, and 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 transmitting processing module, and wherein radio-frequency module is caught reception signal, and baseband processing module is processed to received signal, obtains the Dop that receives signal; Dop is sent to transmitting processing module;

Transmitting processing module is obtained the oneself state data of high dynamic motion carrier and is carried out framing and forms to transmit and launch by radio-frequency module; Calculate 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 causes

signal transmission time T is the framing that transmits and completes to the x time transmitting, and M is for receiving the frequency of signal, and a is the current movement velocity rate of change of high dynamic motion carrier;

According to above-mentioned total frequency deviation value FreqErr, transmitting processing module is calculated the adjustment input value D of DAC _adjust:

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

The bit wide that wherein m is DAC, the voltage output range of DAC is that 0～X, unit are V; The frequency adjustment range of crystal oscillator for-N～N, unit be ppm; Voltage adjusting range is that Y ± Z, unit are V; Reception signal(-) carrier frequency is that P, unit are MHz;

Described SPI switch is controlled break-make according to FreqErr value, if the value of FreqErr within the scope of the peak excursion of emission signal frequency, is launched processing module, controls SPI switch in off state; If FreqErr has exceeded the peak excursion scope of emission signal frequency, launch processing module and control SPI switch in on-state;

Described DAC during in on-state, receives D at SPI switch _adjust, and according to D _adjustcarry out analog output, analog output is to VCO;

Described VCO controls the crystal oscillator of radio-frequency module in high dynamic motion carrier according to analog quantity.

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