Wireless communication system, wireless communication apparatus and directivity determination method

A wireless communication apparatus that is communicatively connected to a wireless transmitter, the wireless communication apparatus comprising:

• a reception antenna unit that receives a signal which is transmitted from the wireless transmitter;
• a memory storing instructions;
• and
• a processor configured to implement the instructions and execute a plurality of tasks, including:
• in a first step,
• a setting task that sets M pieces of reception directivity in the reception antenna unit in a manner that is scannable, where M is an integer that is equal to or greater than 2;
• a measurement task that measures a reception parameter at each of the M pieces of reception directivity during an interval in which a signal is not transmitted from the wireless transmitter;
• and
• a storing task that stores a first result of the measurement of the reception parameter into the memory, wherein the first result of the measurement includes interference plus noise;
• and
• in a second step,
• a reception control task that determines k pieces of transmission directivity which correspond to high-ranking k results, respectively, of the measurements that have a great reception parameter, based on a result of measurement of a reception parameter relating to reception of a first signal that is transmitted while scanning L pieces of transmission directivity from the wireless transmitter, where k is a predetermined integer value and L is an integer that is equal to or greater than 2,
• wherein the measurement task measures a reception parameter relating to reception of a second signal that is transmitted at any one of the k pieces of transmission directivity from the wireless transmitter while the M pieces of reception directivity are scanned, and stores a second result of the measurement of the reception parameter in the memory, wherein the second result of the measurement includes both the second signal and the interference plus noise, and
• wherein the reception control task calculates a Signal to Interference plus Noise Ratio (SINR) of each of the M pieces of reception directivity based on a comparison between the first result of the measurement obtained in the first step and the second result of the measurement obtained in the second step, and determines a reception directivity having an SINR exceeding a prescribed value, among the M pieces of reception directivity, for use in data communication.

A directivity determination method in a wireless communication system in which a wireless transmitter and a wireless receiver are connected communicatively, the directivity determination method comprising:

• in a first step,
• by the wireless receiver, measuring a reception parameter while scanning M pieces of reception directivity during an interval in which a signal is not transmitted from the wireless transmitter, where M is an integer that is equal to or greater than 2, and retaining a first result of the measurement which includes interference plus noise;
• and
• in a second step,
• by the wireless transmitter, transmitting a first signal to the wireless receiver while scanning L pieces of transmission directivity, where L is an integer that is equal to or greater than 2;
• by the wireless receiver, measuring a reception parameter relating to reception of the first signal that is transmitted at each of the L pieces of transmission directivity, determining k pieces of transmission directivity that correspond to high-ranking k results, respectively, of the measurements that have a great reception parameter, where k is a predetermined integer value <L, and reporting the determined k pieces of transmission directivity to the wireless transmitter;
• by the wireless transmitter, forming any one of the k pieces of transmission directivity and transmitting a second signal to the wireless receiver;
• by the wireless receiver, measuring a reception parameter relating to reception of the second signal that is transmitted by the wireless transmitter, while scanning the M pieces of reception directivity, and retaining a second result of the measurement which includes both the second signal and the interference plus noise;
• and
• calculating a Signal to Interference plus Noise Ratio (SINR) of each of the M pieces of reception directivity based on a comparison between the first result of the measurement obtained in the first step and the second result of the measurement obtained in the second step, and determining a reception directivity having an SINR exceeding a prescribed value, among the M pieces of reception directivity, for use in data communication.