Evaluating a time-domain signal

A signal evaluator for evaluating a first time-domain signal received from a single source by one or more antennas, wherein the time domain signal is processed with a Fourier-related transform with overlapping input frames to indirectly or directly provide a first frequency-domain signal being made up of frames of frequency-domain coefficients, wherein only one part, of the real part and the imaginary part from the Fourier-related transform, is included in the first frequency-domain signal, wherein a first part is the part, real or imaginary, that is included in the frequency-domain signal and a second part is the part, real or imaginary, that is not included in the frequency-domain signal, the signal evaluator comprising:

• a processor;
• and
• a memory storing instructions that, when executed by the processor, cause the signal evaluator to:
• receive the first frequency-domain signal;
• obtain a reference frequency-domain signal;
• and
• determine a first cross-correlation between the received first frequency-domain signal and the reference frequency-domain signal by cross-correlating the received first frequency-domain signal and the reference frequency-domain signal.