1. A signal receiving apparatus comprising: a first setting module configured to set a rising or falling of an arbitrary high pulse in a detection interval of a pulse-position modulation signal as a starting point; a calculator configured to calculate a sampling period based on intervals between a plurality of high pulses in the detection interval; a detector configured to set a multiple of the sampling period from the starting point as reference points in the detection interval and to detect positions where the plurality of high pulses are generated from each of the reference points; a generator configured to generate a histogram for the positions where the plurality of high pulses are generated; a determination module configured to determine positions obtained by adding a value of a peak in the histogram to each of the reference points as sampling points in a to-be-reproduced signal interval of the pulse-position modulation signal; and a reproduction module configured to reproduce the to-be-reproduced signal interval based on the sampling points.