RU64385U1 - ELECTRIC SIGNAL CURRENT ENERGY SPECTRUM - Google Patents

Abstract

The utility model relates to spectrum analyzers and can be used in signal detection systems, in particular radar systems, as well as systems using radio waves or electromagnetic wave radiation other than radio waves. The shaper of the current energy spectrum of the electric signal contains a storage device (memory), the input of which is the input of the device, the first and second multipliers, the first and second adders, an inverter, the adder-drive, the output of which is the output of the device. The input of the memory is connected to the first and second inputs of the first multiplier, and the output is connected to the first and second inputs of the second multiplier; the output of the first multiplier is connected to the first input of the first adder, to the second input of which the output of the accumulator-accumulator is connected. The output of the second multiplier through an inverter is connected to the first input of the second adder, the second input of which is connected to the output of the first adder, and the output to the input of the accumulator adder. The memory device is configured for sequential access of the FIFO type. 1 s.p. f-ly, 1 ill.

Description

The utility model relates to spectrum analyzers and can be used in signal detection systems, in particular radar systems, as well as systems using radio waves or electromagnetic wave radiation other than radio waves.

In radio measurement technology, spectrum analyzers of the frequency spectrum of electromagnetic signals are widely used. Closest to the utility model is a device for implementing a method for determining the energy spectrum of a noise electric signal, comprising an input signal sampler and a spectrum analyzer that has two outputs, one of which is connected to a series unit for calculating the real part of the spectrum, a unit for summing the real part of the spectrum, and the first quadrator, and the second one - with the sequentially connected unit for calculating the imaginary part of the spectrum, the summing unit imaginary the first part of the spectrum and the second quadrator; the outputs of the quadrants are connected to the adder.

In this device, the input noise voltage is sampled with the formation of n sets of samples, which are sequentially in time with an interval Δt fed to the input of a spectrum analyzer made on fast Fourier transform processors (FFT). From its output, positive and negative values of the real and imaginary parts of the spectrum are separately generated, each of which is subsequently summed up, the summation results are squared and fed into the adder, which generates a signal representing the energy spectrum of the noise electrical signal:

.

In this case, the signal energy increases in proportion to the number of summations, and the interference energy increases in proportion to the square root of the number of summations, thereby increasing the signal-to-noise ratio [1].

The reasons that impede the obtaining of the technical result indicated below when using the known device for determining the energy spectrum of a noise electric signal are as follows. Providing the detection of a continuous harmonic signal against a background of normal stationary noise interference, the device does not allow to determine the position of various pulsed pulses

signals of finite duration on the time axis of sampling. The need for multiple FFT calculations determines the complexity of the hardware implementation of the device and the significant cost of time for calculations.

The essence of the utility model is as follows.

The technical result achieved by its implementation is to expand the functionality of the known device by obtaining the current energy spectrum of a discretized electrical signal and simplifying its hardware implementation.

The specified technical result is achieved by the fact that in the known device for determining the energy spectrum containing the first and second quadrators, the first adder, according to a utility model, a storage device (memory), an inverter, a second adder, an adder-drive are introduced, while the first and second quadrators are made in the form of multipliers; the input of the memory, which is the input of the device, is connected to the first and second inputs of the first multiplier, and the output is connected to the first and second inputs of the second multiplier; the output of the first multiplier is connected to the first input of the first adder, to the second input of which the output of the accumulator-accumulator is connected; the output of the second multiplier through the inverter is connected to the first input of the second adder, the second input of which is connected to the output of the first adder, and the output to the input of the adder-drive, the output of which is the output of the device.

The memory device is configured for sequential access of the FIFO type.

The utility model is illustrated by the drawing, which shows the structural diagram of the shaper of the current energy spectrum (TPP) of the electrical signal.

Shaper TPP (figure 1) contains a storage device (memory) 1, the first 2 ₁ and second 2 ₂ multipliers, an inverter 3, the first 4 ₁ and second 4 ₂ adders, the adder-drive 5. The input of the memory 1, which is the input of the device, is connected with the first and second inputs of the first multiplier 2 ₁ , and the output with the first and second inputs of the second multiplier 2 ₂ . The output of the first multiplier 2 _{1 is} connected to the first input of the first adder 4 ₁ , to the second input of which the output of the accumulator-accumulator 5 is connected. The output of the second multiplier 2 ₂ through an inverter 3 is connected to the first input of the second adder 4 ₂ , the second input of which is connected to the output of the first adder 4 ₁ , and the output - with the first input of the adder-drive 5, the second input of which is reset, and its output is the output of the device.

The device is made on known elements of digital technology. In particular, memory 1 can be made in the form of a register with series-connected memory cells and parallel transfer of their contents and direct access to the first and last memory cell with the possibility of sequential access of the "first

entered - the first left "(FIFO) [2]. In general, the thermal power generator can be performed on FPGAs of type EP1S10 from ALTERA [3].

The theoretical prerequisite for obtaining a TES of an electric signal is a known position, according to which the signal energy for the time interval T is determined by the expression:

Using Parseval's equation, expression (1) can be written using the Fourier transform of a time function that describes the signal, or using its representation in the form of a Fourier series [4].

Representation of Parseval equality through a spectrum of functions:

Representation of the Parseval equality through the coefficients of the Fourier series of the function:

where x (t) is the function describing the signal;

S [ω] is the Fourier transform for the continuous-time function x (t),

And _i are the coefficients of the Fourier series of the function x (t).

The right-hand sides of expressions (2) and (3) are used to formulate the criterion of signal-to-noise energy ratios in the classical multichannel version of constructing a range-determining device. But from the Parseval equality it also follows that the energy of a pulse signal in the time domain at time t on the interval of its existence T can be calculated by the formula:

Using expression (4), it is possible to determine the TES of the signal x (t) on the interval t ₁ ≤t≥t _{2 by the} discrete values of the function E _x (iΔt, N), that is, in digital form expression (1) for the TES is represented as:

where E _i - readings of the current energy spectrum,

x _i - ADC output samples (elements of a numerical array)

T ₁ ≤i≥T ₂ ;

T ₁ = t ₁ / Δt; T ₂ = t ₂ / Δt; (the character "/" is an integer division)

Δt is the sampling interval of the analog-to-digital converter;

N is the number of samples of the function that describes the signal.

This expression can be represented in a simple recursive form:

where E ₀ = 0, T ₁ ≤i> T ₂ ;

For example, when T ₁ = 1, T ₂ = L, N = 10, the sequence of obtaining TES readings is represented as follows:

The first TES sample is obtained by direct summation of the squares of the first ten samples of the L - sequence. The second TES reference can be obtained by subtracting from the value of the 1st TES reference the square of the 1st reference from the L - sequence and adding the square of the 11th reference of this sequence. The third TES reference can be obtained by subtracting from the value of the 2nd TES reference the square of the 2nd reference from the L - sequence and adding the square of the 12th reference of this sequence, and so on; (the i-th TES reference can be obtained by subtracting from the value of the (i-1) th TES reference the square of the i-th reference from the L-sequence and adding the square of the (N + i) -th reference of this sequence, etc. by same rule before calculating the last (L-9) th sample.

Shaper TPP electric signal operates as follows. A numerical sequence that characterizes, for example, the output sampled signal of the receiver, is fed to the input of memory 1 and to the first and second inputs of the first multiplier 2 ₁ . The memory 1 has a register of N memory cells previously zeroed. At each step, in accordance with the organization of memory on a first-come-first-go basis (FIFO), in the register of memory cells of memory 1, their contents are overwritten from the previous cell to the next cell, and the previous contents of the last N-th memory cell of the register are not saved . The calculation of the next step of counting the numerical value of thermal power plants, as shown in the table (for example, with N = 4), is performed

for the time a new countdown arrives. For this, in parallel with the input number arriving at the first multiplier 2 ₁ , the first and second inputs of the second multiplier 2 ₂ receive a number from the N-th cell of the memory register 1. The result of multiplication from the output of the first multiplier 2 ₁ goes to the input of the first adder 4 ₁ whose second input is the table

Step 0 0 0 0 0 E ₀ = 00 + 00 + 00 + 00 Step 1 x ₁ 0 0 0 E ₁ = E ₀ + x ₁ x ₁ -00 Step 2 x ₂ x ₁ 0 0 E ₂ = E ₁ + x ₂ x ₂ -00 Step 3 x ₃ x ₂ x ₃ 0 E ₃ = E ₂ + x ₃ x ₃ -00 Step 4 x ₄ x ₃ x ₂ x ₁ E ₄ = E ₃ + x ₄ x ₄ -x ₁ x ₁ Step 5 x ₅ x ₄ x ₃ x ₂ E ₅ = E ₄ + x ₅ x ₅ -x ₂ x ₂ Step 6 x ₆ x ₅ x ₄ x ₃ E ₆ = E ₅ + x ₆ x ₆ -x ₃ x ₃

receives a numerical value from the output of the accumulator-accumulator 5. The result, representing the sum of two numbers, from the output of the first adder 4 _{1 is} fed to the first input of the second adder 4 ₂ , the second input of which receives a numerical value from the output of inverter 3, obtained by inversion (by changing the sign number) of the result obtained from the output of the second multiplier 2 ₂ . From the output of the second adder 4 _{2, the} result of the summation is fed to the input of the adder-accumulator 5, the number obtained in it is the output of the adder-accumulator 5 and the output of the TPP device, representing successive readings of the TPP.

Since the elements of a numerical array can correspond to different physical processes, and the array itself can be of different dimensions (vector, matrix, tensor, etc.), the declared generator of thermal electric power stations is also applicable in systems using different electromagnetic waves as information sources, than radio waves. For example, if there is a numerical matrix that displays surface smoothness in the optical range, then using this TES generator, setting various values of the parameter N, you can determine the coordinates of the anomalies corresponding to this parameter in the matrix and, therefore, on the surface under study.

Information sources:

1. RU 2236687, G01R 23/16, H04B 1/10, G01S 3/80, 2004.

2. Novozhilov O.P. Fundamentals of digital technology / study guide. - M .: IP Radio-Soft, 2004, pp. 322-327.

3. www.Altera.com.

4. Denisenko A.N. Signals. Theoretical radio engineering. Reference manual. - M., Hotline - Telecom, 2005, p. 28-29.

Claims (2)

1. The shaper of the current energy spectrum of the electrical signal containing the first and second quadrators, the first adder, characterized in that the input memory (memory), inverter, second adder, the adder-drive, while the first and second quadrators are made in the form of multipliers, input The memory device, which is the input of the device, is connected to the first and second inputs of the first multiplier, and the output is connected to the first and second inputs of the second multiplier; the output of the first multiplier is connected to the first input of the first adder, to the second input of which the output of the accumulator-accumulator is connected; the output of the second multiplier through the inverter is connected to the first input of the second adder, the second input of which is connected to the output of the first adder, and the output to the input of the adder-drive, the output of which is the output of the device. 2. The shaper according to claim 1, characterized in that the memory is made with the possibility of sequential access of the FIFO type.