Signal processing apparatus and signal processing method

Abstract

One aspect of the present invention provides a signal processing apparatus including: filter processors, the number of the filter processors depending on the number of spatial modes of a received optical signal; a sum operator that outputs a sum of outputs of a plurality of the filter processors; an IFFT processor that performs inverse Fourier transform on the sum; an output signal selector that outputs a signal including only a predetermined part of an output of the IFFT processor; an error signal output that outputs, as an error signal, a difference between an output of the output signal selector and a desired signal; and an FFT processor that performs Fourier transform on signals including the error signal, in which the filter processors update a filter weight coefficient by using a signal obtained by performing multiplication only on a predetermined part for an output of the FFT processor and a signal obtained by performing processing including Fourier transform on the received optical signal, and the filter processors output a signal obtained by performing multiplication only on a predetermined part for the filter weight coefficient and the received optical signal.

Dependencies are inferred from the claim text.