Signal analysis apparatus, control circuit, storage medium, and signal analysis method

A control circuit for controlling a signal analysis apparatus that outputs a plurality of sampling sequences obtained by adding, to respective signals obtained by branching a target signal into a plurality of branches, different delay times and by sampling each of the signals at a sampling rate lower than a Nyquist rate, converts each of the plurality of sampling sequences from a time domain signal to a frequency domain signal, collectively performs phase compensation processing and processing for multiplying the sampling sequences by coefficients that cancel phase rotation caused by delay time differences between the sampling sequences, the phase compensation processing corresponding to sub-Nyquist zones of each of the sampling sequences converted into a frequency domain signal, and estimates a frequency of the target signal by determining a sub-Nyquist zone in which the target signal has been folded, the control circuit causing the signal analysis apparatus to perform:

• selecting a frequency group with a higher estimated spectrum amplitude value based on a sum of values for each of the sub-Nyquist zones, the values being obtained by multiplication of the sampling sequences by the corresponding coefficients;
• and
• performing separation processing for separation of at least one of a cause of an error or an error portion in the target signal by using the selected frequency group.

A non-transitory storage medium with a program stored thereon, the program being for controlling a signal analysis apparatus that outputs a plurality of sampling sequences obtained by adding, to respective signals obtained by branching a target signal into a plurality of branches, different delay times and by sampling each of the signals at a sampling rate lower than a Nyquist rate, converts each of the plurality of sampling sequences from a time domain signal to a frequency domain signal, collectively performs phase compensation processing and processing for multiplying the sampling sequences by coefficients that cancel phase rotation caused by delay time differences between the sampling sequences, the phase compensation processing corresponding to sub-Nyquist zones of each of the sampling sequences converted into a frequency domain signal, and estimates a frequency of the target signal by determining a sub-Nyquist zone in which the target signal has been folded, the program causing the signal analysis apparatus to perform:

• selecting a frequency group with a higher estimated spectrum amplitude value based on a sum of values for each of the sub-Nyquist zones, the values being obtained by multiplication of the sampling sequences by the corresponding coefficients;
• and
• performing separation processing for separation of at least one of a cause of an error or an error portion in the target signal by using the selected frequency group.

A signal analysis method comprising:

• outputting a plurality of sampling sequences obtained by adding, to respective signals obtained by branching a target signal into a plurality of branches, different delay times and by sampling each of the signals at a sampling rate lower than a Nyquist rate;
• converting each of the plurality of sampling sequences from a time domain signal to a frequency domain signal;
• collectively performing phase compensation processing and processing for multiplying the sampling sequences by coefficients that cancel phase rotation caused by delay time differences between the sampling sequences, the phase compensation processing corresponding to sub-Nyquist zones of each of the sampling sequences converted into a frequency domain signal;
• estimating a frequency of the target signal by determining a sub-Nyquist zone in which the target signal has been folded;
• selecting a frequency group with a higher estimated spectrum amplitude value based on a sum of values for each of the sub-Nyquist zones, the values being obtained by multiplication of the sampling sequences by the corresponding coefficients;
• and
• performing separation processing for separation of at least one of a cause of an error or an error portion in the target signal by using the selected frequency group.