Filter coefficient calculation device, signal generation device including the same, filter coefficient calculation method, and signal generation method

Patent metadata

Field	Value
Publication number	US-10778192-B2
Application number	US-201816166738-A
Country	US
Kind code	B2
Filing date	Oct 22, 2018
Priority date	Oct 30, 2017
Publication date	Sep 15, 2020
Grant date	Sep 15, 2020

Abstract

A filter coefficient calculation device includes a function unit that has a plurality of functions to be executed by an FIR filter, a function selection unit that selects one or a plurality of functions from among the plurality of functions, and a filter coefficient calculation unit that calculates a filter coefficient in the selected one or plurality of functions, and is configured such that the function unit includes a first transfer function calculation unit, a second transfer function calculation unit, and a third transfer function calculation unit which calculate a transfer function of the FIR filter in the respective functions, and the filter coefficient calculation unit performs inverse Fourier transform on the transfer function in the selected one function or a product of the transfer functions in the plurality of functions to obtain an impulse response of the FIR filter and calculates the impulse response as the filter coefficient.

First claim

What is claimed is:

1. A signal generation device comprising:
a signal generator configured to generate a signal for testing a test target device; and
a finite impulse response filter comprising a number of taps, and which has a plurality of predetermined functions executable by the finite impulse response filter depending on one or more filter coefficients corresponding to the number of taps, configured to:
set the one or more filter coefficients in the finite impulse response filter,
receive the signal from the signal generator,
perform one or more functions of the plurality of predetermined functions on the signal to generate a processed signal, and
output the processed signal to the test target device;

at least one processor configured to:
calculate a plurality of transfer functions of the finite impulse response filter, each of the plurality of transfer functions corresponding to one of the plurality of predetermined functions of the finite impulse response filter; and

a selector configured to:
receive each of the plurality of transfer functions as inputs, and
select any combination of the plurality of transfer functions;

wherein the processor is further configured to calculate a product of the selected transfer functions, and
to perform an inverse Fourier transform on the product of the selected transfer functions to obtain an impulse response of the finite impulse response filter as the one or more filter coefficients.

2. The signal generation device according to claim 1 , wherein the at least one processor is further configured to:
add an emphasis function to the signal generated by the signal generator,
add a function of simulating a channel through which the signal passes to the signal output to the test target device, or
add a function of exerting influence of intersymbol interference on the signal output to the test target device.

3. The signal generation device according to claim 2 , wherein the at least one processor is configured to add the function of simulating the channel on the basis of scattering parameters of the test target device.

4. The signal generation device according to any one of claim 1 , further comprising:
a display device configured to:
detect a selection operation of a user selecting one or more of the plurality of functions, and

output a signal indicating the selected one or more of the plurality of functions to the at least one processor.

5. The signal generation device according to claim 4 , wherein the display device includes a display configured to display a setting state of the selected one or more of the plurality of functions.

6. A signal generation method comprising:
a filter coefficient calculation step for a finite impulse response filter comprising a number of taps that has a plurality of predetermined functions executable by the finite impulse response filter depending on one or more filter coefficients corresponding to the number of taps;
a signal generation step of generating a signal by a signal generator for testing a test target device;
a filter coefficient setting step of setting the one or more filter coefficients calculated by the filter coefficient calculation step in the finite impulse response filter; and
a signal output step of receiving the signal from the signal generator and causing the finite impulse response filter to perform the predetermined function or functions on the signal to generate and output a processed signal to the test target device,
wherein the filter coefficient calculation step comprises:
a transfer function calculation step of calculating a plurality of transfer functions, each of the plurality of the transfer functions corresponds to each of the plurality of the predetermined functions of the finite impulse response filter;
a selection step of receiving each of the plurality of transfer functions as inputs to a selector, and selecting any combination of the plurality of the transfer functions; and
a filter coefficient calculation step of calculating a product of the selected transfer functions and performing inverse Fourier transform on the product of the selected transfer functions to obtain an impulse response of the finite impulse response filter as the one or more filter coefficients.

7. The signal generation method according to claim 6 , further comprising at least one of:
an emphasis function step of adding emphasis function to the signal;
a channel emulator function step of adding a function of simulating a channel through which the signal passes to the signal output to the test target device; or
an intersymbol interference function step of adding a function of exerting influence of intersymbol interference on the signal output to the test target device.

8. The signal generation method according to claim 7 , wherein the channel emulator function step adds the function of simulating the channel on the basis of scattering parameters of the test target device.

9. The signal generation method according to any one of claim 6 , further comprising:
a display step of detecting a selection operation of causing a user to select one or the plurality of functions to display the detected selection operation,
wherein a signal indicating one or the plurality of functions selected by the selection operation of the user is output to the selection step.

10. The signal generation method according to claim 9 , wherein the display step displays a setting state of one or the plurality of functions selected by the selection operation of the user.

Assignees

• Anritsu Corp

Inventors

• Hosaka Yasuo

Classifications

• H04B17/0085 Primary

  using test signal generators · CPC title

• H03H17/06 Primary

  Non-recursive filters · CPC title

• H03H21/0012

  Digital adaptive filters · CPC title

• H04L1/0033

  arrangements specific to the transmitter · CPC title

• H03H17/0294

  Variable filters; Programmable filters · CPC title