SU789883A1 - Fourier-walsh spectrum analyzer - Google Patents

Description

one

The invention relates to radio measurements and can be used to analyze radar and radio navigation signals.

Analyzers are known that contain a 5 Walsh function generator, a voltage-code converter, multipliers, and a calculator flj.

However, the accuracy of their analysis is insufficient, which is due to the lack of accurate synchronization between pulses.

The purpose of the invention is to improve the accuracy of the analysis.

This goal is achieved by having a Fourier-Walsh spectrum analyzer containing a Walsh function generator, a voltage-code converter, a multiplier, the inputs of which are connected to the outputs of these blocks, and an arithmetic unit, one input of which is connected to the output of the voltage converter the code additionally contains a delay block and a coincidence block, one input of which is connected to the output25 of the multiplier, and the other to the input of the Walsh function generator through the delay block, while the output of the coincidence block is connected to the second input ap fmeticheskogo block, and Bloch yield 30

is connected to one of the inputs of the voltage-code converter.

On the drawing, xy is a structural diagram of the analyzer.

It contains a voltage-to-code converter 1, a Walsh function generator 2, an arithmetic unit 3, a signal sign conversion unit 4 consisting of a multiplier. 5, a delay block 7, and a match block 8. The last two blocks constitute the sampler of 6 Walsh functions.

The analyzer works as follows.

The input analog signal arrives at the input of the voltage-code converter (PNK) 1. The parallel binary code from the output of PNK 1 is fed to the information inputs of the arithmetic unit 3, and the code characterizing the sign of the input signal is fed to block 4 by the multiplier 5. the other input of the multiplier 5 receives a signal from the output of the generator 2 functions. Walsh. Multiplier 5 is a modulo-two cymplator and provides multiplication of the input signal and Walsh function.

This device requires the orthogonality of the Walsh functions

It is detected by gating signals from the multiplier output by 5 delayed clock pulses TI in block 8 coincidence. Delay value per block

7 selects more than the duration of transients in generator 2, affecting the non-orthogonality of the Walsh functions, but less than half the period of the input pulses TI. In this case, the transition to discrete Walsh functions having an extremely high degree of orthogonality is practically carried out, and the requirements for constructing a diagram of the generator 2 Walsh functions are made much easier.

To increase the reliability of the device and eliminate the uncontrollable parasitic delay of the multiplier 5, gating the Walsh functions in the device is not technically done by direct gating.

signals from the output of generator 2, and gating signals from the output of multiplier 5, which is logically equivalent, but allows you to further improve the speed of the device.

The code of the sign from the output of block 4 is fed to the input of the arithmetic unit 3. The code of the sign from the output of the block of coincidence 8 at the time of arrival of the pulses TI is fed to the input of the arithmetic block 3. The information inputs of block 3 receive a parallel binary code from the output of the PNK 1. Arithmetic unit 3 performs the functions of a subtractor accumulator.

In this device, it performs the following operations:

a) receiving and transmitting numbers in parallel code;

b) addition and subtraction of numbersJ

c) storing the result of performing the operations of addition and subtraction and reading them at the moment of time, defined as the moment of the end of an interval of duration T.

To do this, at the end of the orthogonality interval of the Walsh functions from the output of the generator 2 to the installation

input unit 3 receives the appropriate signal.

Thus, the proposed analyzer ensures synchronization of input signals with their decomposition interval. The accuracy of this synchronization, and consequently the accuracy of the measurement of the spectral components, is practically independent of the type and structure of the signals and makes it possible to analyze a wide class of radio signals with a frequency of filling up to microwave frequencies.

The use of the proposed spectrum analyzer, for example, as part of a receiving indicator, provides the environment5 with a non-quadratic estimate of the radionavigation parameter with an accuracy of 0.02 ISS, which is currently unattainable by other methods.

Claims (1)

Invention Formula A Fourier-Walsh spectrum analyzer comprising a Walsh function generator, a voltage-code converter, a multiplier whose inputs are connected to the outputs of said blocks, and an arithmetic unit, one input of which is connected to the output of a voltage-code converter, characterized in that increase the accuracy of the analysis, it additionally contains a delay block and a coincidence block, one input of which is connected to the multiplier output, and another 5 to the input of the Walsh function generator through a delay block, while the output of the coincidence block is n to the second input of the arithmetic unit, and the output of the delay unit is connected to one 0 from the voltage converter inputs. Sources of information taken into account during the examination 1. USSR Author's Certificate No. 432547, cl. G About 3 3/00, 1975. F (i) 6 7U