Signal generating method, signal generating unit, and non-transitory recording medium storing computer program

A signal generating unit that generates a visible light signal to be transmitted by way of a luminance change of a light source included in a transmitter, the signal generating unit comprising:

• a processor;
• and
• a memory storing thereon a computer program, which when executed by the processor, causes the processor to perform operations including:
• determining, as a method for transmitting the visible light signal from the transmitter, one of a single-frame transmitting method for transmitting data as one frame and a multiple-frame transmitting method for transmitting the data while dividing the data into a plurality of frames;
• when the multiple-frame transmitting method is determined to be the method for transmitting visible light signal, generating partition type information indicating a type of data to be transmitted, and generating combination data by adding the partition type information to the data to be transmitted;
• generating the plurality of frames, each of which includes each of a plurality of data parts, by dividing the combination data into the plurality of data parts;
• generating the visible light signal by adding a preamble that is data indicating a head of a frame to the head of each of the plurality of frames;
• and
• outputting the visible light signal to the transmitter,
• wherein
• in the generation of the visible light signal, a first preamble is added to the head of the frame located at a last position in an array of the plurality of frames as the preamble, and
• a second preamble different from the first preamble is added to the head of the frame located at a position that is not the last position in the array as the preamble.

A non-transitory recording medium having a computer program stored thereon, the computer program causing a processor which is included in a transmitter having a light source which transmits a visible light signal by change in luminance, to execute operations comprising:

• determining, as a method for transmitting the visible light signal from the transmitter, one of a single-frame transmitting method for transmitting data as one frame and a multiple-frame transmitting method for transmitting the data while dividing the data into a plurality of frames;
• when the multiple-frame transmitting method is determined to be the method for transmitting visible light signal, generating partition type information indicating a type of data to be transmitted, and generating combination data by adding the partition type information to the data to be transmitted;
• generating the plurality of frames each of which includes each of a plurality of data parts by dividing the combination data into the plurality of data parts;
• generating the visible light signal by adding a preamble, which is data indicating a head of a frame, to the head of each of the plurality of frames;
• and
• outputting the visible light signal to the transmitter,
• wherein
• in the generation of the visible light signal, a first preamble is added to the head of the frame located at a last position in an array of the plurality of frames as the preamble, and
• a second preamble different from the first preamble is added to the head of the frame located at a position that is not the last position in the array as the preamble.