Communication device, information processing method, and storage medium

An information processing method, comprising:

• wirelessly receiving a signal from another communication device;
• correlating a first signal with a second signal at a designated interval, the second signal corresponding to the first signal and being received in a case where the other communication device transmits a signal including a pulse as the first signal;
• converting a correlation computation result that is a result of correlating the first signal with the second signal at the designated interval into a format including a matrix product of an expanded modal matrix and an expanded signal vector, the expanded modal matrix being a matrix including a plurality of elements indicating the correlation computation result obtained when assuming that the second signal is received at respective set times, the expanded signal vector being a vector including a plurality of elements, each of which indicates whether or not there is the second signal received at each of the set times and amplitude and a phase of the second signal;
• and
• estimating reception time of the second signal on a basis of the set times corresponding to the plurality of elements of the expanded signal vector,
• wherein an interval between the set times is shorter than the designated interval.

A non-transitory storage medium having a program stored therein, the program causing a computer to function as

• a controller configured to
• correlate a first signal with a second signal at a designated interval, the second signal corresponding to the first signal and being received by a wireless communicator that wirelessly receives a signal from another communication device in a case where the other communication device transmits a signal including a pulse as the first signal,
• convert a correlation computation result that is a result of correlating the first signal with the second signal at the designated interval into a format including a matrix product of an expanded modal matrix and an expanded signal vector, the expanded modal matrix being a matrix including a plurality of elements indicating the correlation computation result obtained when assuming that the second signal is received at respective set times, the expanded signal vector is a vector including a plurality of elements, each of which indicates whether or not there is the second signal received at each of the set times and amplitude and a phase of the second signal, and
• estimate reception time of the second signal on a basis of the set times corresponding to the plurality of elements of the expanded signal vector,
• wherein an interval between the set times is shorter than the designated interval.