SIGNAL GENERATION APPARATUS AND METHOD

1 . A signal generation apparatus, comprising:

a memory; and

a processor coupled to the memory to control execution of a process to:

perform dispersion processing on a two-dimensional reference signal to obtain a two-dimensional dispersion signal;

perform at least one time of equiprobability processing, perturbation processing and isospectral processing on a two-dimensional input signal according to the two-dimensional dispersion signal; and

output a two-dimensional isospectral equiprobability signal generated, when an equiprobability processed signal according to the equiprobability processing or an isospectral processed signal according to the isospectral processing satisfies a predetermined condition,

wherein, in the equiprobability processing, the two-dimensional dispersion signal and the two-dimensional input signal are classified, so that numbers of constellation points of the two-dimensional input signal and the two-dimensional dispersion signal of same classes are identical, and the classified two-dimensional input signal and two-dimensional dispersion signal are sorted, so that the equiprobability processed signal maintain joint probability distribution.

2 . The signal generation apparatus according to claim 1 , wherein the equiprobability processing whereby the two-dimensional dispersion signal and the two-dimensional input signal are classified comprises:

in each class, sorting the two-dimensional input signal and the two-dimensional dispersion signal, respectively;

in each class, replacing the two-dimensional input signal with the two-dimensional dispersion signal; and

recovering the replaced two-dimensional input signal to be of original time position coordinates, so as to obtain the equiprobability processed signal.

3 . The signal generation apparatus according to claim 2 , wherein the classifying the two-dimensional dispersion signal and the two-dimensional input signal comprises:

classifying the two-dimensional dispersion signal into M classes by using a decision field to which the two-dimensional reference signal correspond, and counting a number of constellation points of the two-dimensional dispersion signal in each class; and

sorting and classifying the two-dimensional input signal into M classes by amplitudes and/or phases, so that a number of constellation points of the two-dimensional input signal in the same class is identical to the number of constellation points of the two-dimensional dispersion signal;

where, M is a positive integer.

4 . The signal generation apparatus according to claim 2 , wherein the sorting the two-dimensional input signal and the two-dimensional dispersion signal, respectively, comprises:

sorting the two-dimensional input signal and the two-dimensional dispersion signal respectively by modulo values, or,

sorting the two-dimensional input signal and the two-dimensional dispersion signal respectively by angles.

5 . The signal generation apparatus according to claim 2 , wherein the replacing the two-dimensional input signal with the two-dimensional dispersion signal comprises:

directly replacing the two-dimensional input signal with the two-dimensional dispersion signal; or,

replacing the two-dimensional input signal one by one with the two-dimensional dispersion signal by using a minimum Euclidean distance as a criterion.

6 . The signal generation apparatus according to claim 2 , wherein the equiprobability processing further comprises:

for a case where a training sequence and a pilot symbol are inserted into the two-dimensional reference signal, performing time position locking before the classifying.

7 . The signal generation apparatus according to claim 1 , wherein,

in the perturbation processing, a perturbation amplitude is variable.

8 . The signal generation apparatus according to claim 1 , wherein,

the isospectral processing comprises unilateral isospectral processing and bilateral isospectral processing.

9 . A signal generation apparatus, comprising:

a memory; and

a processor coupled to the memory to control execution of a process to:

perform dispersion processing on a two-dimensional reference signal to obtain a two-dimensional dispersion signal;

perform at least one time of equiprobability processing, perturbation processing and isospectral processing on a two-dimensional input signal according to the two-dimensional dispersion signal; and

output generated two-dimensional isospectral equiprobability signal when an equiprobability processed signal according to the equiprobability processing or an isospectral processed signal according to the isospectral processing satisfies a predetermined condition,

wherein in the equiprobability processing, the two-dimensional dispersion signal and the two-dimensional reference signal are decomposed first, amplitude sorting, amplitude replacement and time sorting are respectively performed on I-path signal and Q-path signal obtained after decomposition, and I-path signal and Q-path signal obtained after the time sorting are combined to obtain a equiprobability signal.

10 . A measurement apparatus for nonlinear system noises, comprising:

a memory; and

a processor coupled to the memory to control execution of a process to:

acquire two-dimensional isospectral equiprobability signal of a bilateral band notch and two-dimensional isospectral equiprobability signal of a unilateral band notch, the two-dimensional isospectral equiprobability signal of the bilateral band notch and the two-dimensional isospectral equiprobability signal of the unilateral band notch being generated by the signal generation apparatus as claimed in claim 1 ;

measure a first power-to-noise ratio of the nonlinear system by using the two-dimensional isospectral equiprobability signal of the bilateral band notch;

measure a second power-to-noise ratio of the nonlinear system by using the two-dimensional isospectral equiprobability signal of the unilateral band notch; and

calculate a power-to-noise ratio of the nonlinear system introduced by IQ imbalance according to the first power-to-noise ratio and the second power-to-noise ratio.