Method, apparatus and system for measuring nonlinear correlation parameters of nonlinear device
A method, an apparatus and a system to measure nonlinear correlation parameters of a nonlinear device, a processor to, perform band-stop filtering on a signal to be measured to generate a notch signal, and calculate a first nonlinear correlation parameter of the nonlinear device when the signal to be measured is transmitted according to a first output signal of the nonlinear device after the notch signal is input into the nonlinear device; calculate gain compression correction coefficients according to a second output signal of the nonlinear device after the first input signal is input into the nonlinear. The first input signal and the signal to be measured may have identical power and different signal probability distribution. The processor is to correct the first nonlinear correlation parameter according to the gain compression correction coefficients to obtain a second nonlinear correlation parameter of the nonlinear device when the signal to be measured is transmitted.
1. An apparatus to measure nonlinear correlation parameters of a nonlinear device, comprising:
a memory; and
a processor coupled to the memory to control execution of a process to,
perform band-stop filtering on a signal to be measured to generate a notch signal, and calculate a first nonlinear correlation parameter of the nonlinear device when the signal to be measured is transmitted according to a first output signal of the nonlinear device after the notch signal is input into the nonlinear device;
calculate gain compression correction coefficients according to a second output signal of the nonlinear device after a first input signal is input into the nonlinear device, the first input signal and the signal to be measured having identical power and different signal probability distribution; and
correct the first nonlinear correlation parameter according to the gain compression correction coefficients to obtain a second nonlinear correlation parameter of the nonlinear device when the signal to be measured is transmitted.
2. The apparatus according to claim 1 , wherein,
the first nonlinear correlation parameter or the second nonlinear correlation parameter comprises: a power-to-noise ratio.
3. The apparatus according to claim 1 , wherein,
the signal probability distribution of the first input signal comprises:
signal probability distribution obtained according to a part of the signal to be measured that is filtered by the band-stop filtering; or
signal probability distribution obtained according to Gaussian distribution.
4. The apparatus according to claim 1 , wherein,
the gain compression correction coefficient comprises:
a first coefficient and a second coefficient,
wherein,
the first coefficient denotes a ratio of a root-mean-square amplitude or modulus of a linear item in a third output signal of the nonlinear device after the signal to be measured is input into the nonlinear device to a root-mean-square amplitude or modulus of the signal to be measured, and
the second coefficient denotes a ratio of a root-mean-square amplitude or modulus of a linear item in the second output signal to a root-mean-square amplitude or modulus of the first input signal.
5. The apparatus according claim 4 , wherein to calculate the first and second coefficients, the process is to:
calculate a ratio of power of the third output signal to power of the signal to be measured as the first coefficient; and
calculate a ratio of power of the second output signal to power of the first input signal as the second coefficient.
6. The apparatus according claim 4 , wherein to calculate the first and second coefficients, the process is to:
calculate a ratio of power of the first output signal to power of the notch signal as the first coefficient; and
calculate a ratio of power of a fourth output signal to power of a second input signal as the second coefficient;
wherein the second input signal is obtained by performing the band-stop filtering on the first input signal, and the nonlinear device outputs the fourth output signal after the second input signal is input into the nonlinear device.
7. The apparatus according claim 4 , wherein the process is to:
calculate power of a linear term in the third output signal and power of a linear term in the second output signal based on the first nonlinear correlation parameter or a second nonlinear correlation parameter obtained after a previous time of correction;
calculate the first coefficient according to the power of the signal to be measured and the power of the linear term in the third output signal, and calculate the second coefficient according to the power of the first input signal and the power of the linear term in the second output signal; and
correct the first nonlinear correlation parameter or the second nonlinear correlation parameter obtained after the previous time of correction according to the calculated first coefficient and the second coefficient, so as to obtain a second nonlinear correlation parameter after a current time of correction,
when the second nonlinear correlation parameter after this time of correction satisfies a set condition, determining the calculated first coefficient and the second coefficient as the gain compression correction coefficients, and taking the second nonlinear correlation parameter after the current time of correction as the second nonlinear related coefficient.
8. The apparatus according to claim 7 , wherein,
when the second nonlinear correlation parameter after the current time of correction does not satisfy the set condition,
the second nonlinear correlation parameter after the current time of correction is taken as the second nonlinear correlation parameter after the previous time of correction, so that the first coefficient and the second coefficient are recalculated, and the second nonlinear correlation parameter after the previous time of correction is corrected.
9. A system nonlinear correlation parameters of a nonlinear device, comprising a nonlinear device and the apparatus for measuring nonlinear correlation parameters of the nonlinear device as claimed in claim 1 .
10. A method of measuring nonlinear correlation parameters of a nonlinear device, comprising:
performing band-stop filtering on a signal to be measured to generate a notch signal, and calculating a first nonlinear correlation parameter of the nonlinear device when the signal to be measured is transmitted according to a first output signal of the nonlinear device after the notch signal is input into the nonlinear device;
calculating gain compression correction coefficients according to a second output signal of the nonlinear device after a first input signal is input into the nonlinear device, the first input signal and the signal to be measured having identical power and different signal probability distribution; and
correcting the first nonlinear correlation parameter according to the gain compression correction coefficients to obtain a second nonlinear correlation parameter of the nonlinear device when the signal to be measured is transmitted.
11. The method according to claim 10 , wherein,
the first nonlinear correlation parameter or the second nonlinear correlation parameter comprises: a power-to-noise ratio.
12. The method according to claim 10 , wherein,
the signal probability distribution of the first input signal comprises:
signal probability distribution obtained according to a part of the signal to be measured that is filtered by the band-stop filtering; or
signal probability distribution obtained according to Gaussian distribution.
13. The method according to claim 10 , wherein,
the gain compression correction coefficient comprises:
a first coefficient and a second coefficient,
wherein,
the first coefficient denotes a ratio of a root-mean-square amplitude or modulus of a linear item in a third output signal of the nonlinear device after the signal to be measured is input into the nonlinear device to a root-mean-square amplitude or modulus of the signal to be measured, and
the second coefficient denotes a ratio of a root-mean-square amplitude or modulus of a linear item in the second output signal to a root-mean-square amplitude or modulus of the first input signal.
14. The method according to claim 13 , wherein the calculating gain compression correction coefficients comprises:
calculating a ratio of power of the third output signal to power of the signal to be measured as the first coefficient; and
calculating a ratio of power of the second output signal to power of the first input signal as the second coefficient.
15. The method according claim 13 , wherein the calculating gain compression correction coefficients comprises:
calculating a ratio of power of the first output signal to power of the notch signal as the first coefficient; and
calculating a ratio of power of a fourth output signal to power of the second input signal as the second coefficient;
wherein the second input signal is obtained by performing the band-stop filtering on the first input signal, and the nonlinear device outputs the fourth output signal after the second input signal is input into the nonlinear device.
16. The method according claim 13 , wherein the calculating gain compression correction coefficients comprises:
calculating power of a linear term in the third output signal and power of a linear term in the second output signal based on the first nonlinear correlation parameter or a second nonlinear correlation parameter obtained after a previous time of correction;
calculating the first coefficient according to the power of the signal to be measured and the power of the linear term in the third output signal, and calculating the second coefficient according to the power of the first input signal and the power of the linear term in the second output signal; and
correcting the first nonlinear correlation parameter or the second nonlinear correlation parameter obtained after the previous time of correction according to the calculated first coefficient and the second coefficient, so as to obtain a second nonlinear correlation parameter after a current time of correction,
when the second nonlinear correlation parameter after this time of correction satisfies a set condition, determining the calculated first coefficient and the second coefficient as the gain compression correction coefficients, and taking the second nonlinear correlation parameter after the current time of correction as the second nonlinear related coefficient.
17. The method according to claim 16 , wherein,
when the second nonlinear correlation parameter after the current time of correction does not satisfy the set condition,
the second nonlinear correlation parameter after this time of correction is taken as the second nonlinear correlation parameter after the previous time of correction, so that the first coefficient and the second coefficient are recalculated, and the second nonlinear correlation parameter after the previous time of correction is corrected.