Communication device and distance measurement method

A communication device comprising:

• a phase characteristic acquisition unit that acquires a phase characteristic with respect to a frequency of a signal propagation path with another communication device;
• and
• a distance calculation unit that calculates a distance to the another communication device on a basis of the phase characteristic, wherein
• the phase characteristic acquisition unit acquires the phase characteristic by changing the frequency by a frequency change pattern including at least an upward-side change and a downward- side change,
• the phase characteristic acquisition unit performs an ascending order characteristic acquisition process of acquiring the phase characteristic by changing the frequency by an ascending order change pattern for changing the frequency in a predetermined frequency band in ascending order and a descending order characteristic acquisition process of acquiring the phase characteristic by changing the frequency by a descending order change pattern for changing the frequency in the predetermined frequency band in descending order, and
• the distance calculation unit calculates the distance on a basis of the phase characteristic acquired in the ascending order characteristic acquisition process and the phase characteristic acquired in the descending order characteristic acquisition process.

A non-transitory computer readable medium storing a program for controlling a communication device, the program being executable by a processor to perform operations comprising:

• acquires a phase characteristic with respect to a frequency of a signal propagation path with another communication device;
• calculating a distance to the another communication device on a basis of the phase characteristic;
• and
• changing the frequency by a frequency change pattern including at least an upward-side change and a downward-side change, the frequency change pattern being executed as an ascending-order frequency sweep and a descending-order frequency sweep performed in sequence.

A non-transitory computer readable medium storing a program for controlling a communication device, the program being executable by a processor to perform operations comprising:

• acquiring a phase characteristic with respect to a frequency of a signal propagation path with another communication device;
• calculating a distance to the another communication device on a basis of the phase characteristic;
• changing the frequency by a frequency change pattern including at least an upward-side change and a downward-side change;
• performing an ascending order characteristic acquisition process of acquiring the phase characteristic by changing the frequency by an ascending order change pattern for changing the frequency in a predetermined frequency band in ascending order and a descending order characteristic acquisition process of acquiring the phase characteristic by changing the frequency by a descending order change pattern for changing the frequency in the predetermined frequency band in descending order;
• and
• calculating the distance on a basis of the phase characteristic acquired in the ascending order characteristic acquisition process and the phase characteristic acquired in the descending order characteristic acquisition process.