RU2012152893A - METHOD FOR SIGNAL ARRIVAL TIME MEASUREMENT AND DEVICE FOR ITS IMPLEMENTATION - Google Patents

Abstract

1. A method of measuring the time of arrival of a signal with two-position angular manipulation, including receiving a signal, analog-to-digital conversion of the received signal into a first digital data stream representing the signal as a series of values of the time function, converted into digital form, using the fast Fourier transform (FFT) for two signals, representing both signals as a series of discrete values of the spectrum S (k), where k is an integer index variable that varies within the data length, ai = 1,2 is an index variable, meaning I am the serial number of the digital data stream to be converted using the FFT to the spectrum values, the mutual multiplication of the spectrum values of one of the signals with the complex conjugate values of the spectrum of another signal, generating a cross spectrum, the calculation of the discrete cross-correlation function (DCF) of the signal using the inverse FFT, time determination the arrival (VP) of the signal as an argument of the maximum DKKF signal, characterized in that the quadrature decomposition of the first digital data stream relative to nominal the central frequency of the modulated signal into the corresponding stream, the set of in-phase and quadrature samples, the obtained in-phase and quadrature samples are independently low-pass filtered with a cutoff frequency corresponding to the manipulation speed of the modulating signal, and the set of current signal phases will be obtained as arguments of complex numbers, the real part of which use the corresponding filtered in-phase samples, and as the imaginary - the corresponding filtered quadrature samples

Claims (5)

1. A method of measuring the time of arrival of a signal with two-position angular manipulation, including receiving a signal, analog-to-digital conversion of the received signal into a first digital data stream representing the signal as a series of values of the time function, converted into digital form, using the fast Fourier transform (FFT) for two signals representing the two signals as a series of discrete spectral values S _i (k), where k -tselochislennaya index variable, changing within the data length, ai = 1,2 - index variable, mean the next serial number of the digital data stream converted using the FFT to the spectrum values, the mutual multiplication of the spectrum values of one of the signals with the complex conjugate values of the spectrum of another signal, generating a cross spectrum, the calculation of the discrete cross-correlation function (DCF) of the signal using the inverse FFT, time determination the arrival (VP) of the signal as an argument of the maximum DKKF signal, characterized in that the quadrature decomposition of the first digital data stream relative to the nominal the central frequency of the modulated signal corresponding to the specified stream, the set of in-phase and quadrature samples, the obtained in-phase and quadrature samples are independently low-pass filtered with a cut-off frequency corresponding to the modulation signal manipulation speed, and the set of current signal phases will be obtained as arguments of complex numbers, the real part of which use the corresponding filtered in-phase samples, and as the imaginary - the corresponding filtered quadrature samples signal Ety, delay set received current signal phases on the duration of the modulation signal symbol, subtracting modulo 2π from each of the resultant current phase corresponding to the value of the delayed current signal phase, and the resulting differential digital data stream is converted using FFT values of the first spectrum S ₁ (k) form a two-level modulating signal and differentially decode, map each symbol of the differential-decoded signal to the corresponding number of samples of the converted o into the digital form of the received signal relative to the time scale of the receiving position by repeating the values of the differential-decoded signal with increasing its sampling frequency to the sampling frequency of the digitalized received signal and thus form a second digital data stream that is converted using FFT into values second spectrum S ₂ (k). 2. The method of measuring the time of arrival of a signal according to claim 1, characterized in that for a signal for which the duration of the signal symbol is not a multiple of the sampling frequency of the analog-to-digital conversion of the received signal, the filtered in-phase and quadrature samples are additionally decimated and interpolated to provide a frequency multiplicity of the first digital samples data stream signal symbol duration. 3. The method of measuring the time of arrival of a signal according to claim 1 or 2, characterized in that to the left and to the right of the maximum argument DKKF signal select L points of the specified function, the DKKF values for the selected points and maximum points are combined in the order of time following in a column vector c, a unit is used to form a column vector v _{0 of} the same dimension as the vector c, corresponding to the selected DQFF points, the arguments are expressed through the index variable l = 0, ± 1, ..., ± L, where the indices l with a negative sign correspond to the times to the maximum point of the DQF , zero and subscript l corresponds to the maximum point DKKF and indices l with positive sign correspond to times when the maximum point DKKF arguments selected DKKF points are ordered as well as vector components, and combined into the column vector v _1, the squares of the components of the vector v ₁ similarly combined in column vector v ₂ , a specified value of the VI $${\widehat{\tau }}_M$$

determined by the following rule $${\widehat{\tau }}_M=\frac{\left(S^2-NQ\right)v_{\mathrm{one}}^{T}c}{2{\left(NS{v}_2-S^2{v}_0\right)}^{T}c}{T}_s$$

, where N = 2L + 1 is the dimension of the generated vectors, the superscript ^T denotes the transpose of the vector, T _s is the signal sampling period, $$v_{\mathrm{one}}^{T}c$$

- a scalar product of the vectors v ₁ and, S ratio is determined by the expression $$S=\frac{L\left(L+\mathrm{one}\right)\left(2L+\mathrm{one}\right)}{3}$$

, the coefficient Q is determined by another expression $$Q=\frac{2{\left(L+\mathrm{one}\right)}^5}{5}-{\left(L+\mathrm{one}\right)}^{\mathrm{four}}+\frac{2{\left(L+\mathrm{one}\right)}^3}{3}-\frac{L+\mathrm{one}}{\mathrm{fifteen}}$$

, a (NSv ₂ -S ² v ₀ ) ^T c is the scalar product of the difference vector (NSv ₂ -S ² v ₀ ) with the vector с. 4. A device for implementing a method for measuring the time of arrival of a signal with on-off angle manipulation, comprising a signal receiving means, the input of which is an input to a measuring device connected to an analog-to-digital converter (ADC), a first FFT processor, a cross-spectrum calculator, and a second processor FFT and the device for determining the arguments of the maximum of the discrete cross-correlation function (DCF) of the signal, the output of which is the output of the measuring device, while to the second input of the subtraction a third FFT processor is connected to the cross-spectral array, characterized in that between the ADC output and the input of the first FFT processor, a quadrature signal decomposition device, a first low-pass filter (LPF), a read-only memory device (ROM) AA, and a subtraction device modulo 2π are connected, between the second output of the quadrature decomposition device of the signal and the second input of the ROM, a second low-pass filter is turned on, the subtractive input of the subtractor is connected to the output of the ROM through a delay element for the duration of the signal symbol, and the input Etego FFT processor is connected to the output of the two-level modulation signal generator via series connected differential decoder expander and sampling frequency. 5. A device for implementing the method of measuring the time of arrival of a signal with on-off angle manipulation according to claim 4, characterized in that an arithmetic device is additionally connected to the output of the device for determining the maximum argument of the discrete cross-correlation signal function.