System and method for detecting people entering and leaving field

A system for detecting people entering and leaving a field, comprising:

• a receiver, arranged above an entrance;
• and
• a main console, coupled to the receiver;
• wherein the receiver receives measurement signals transmitted by a transmitter equipped on a person, obtains a signal strength indication (RSSI) of the transmitter and phase information of the transmitter according to the measurement signals;
• the main console receives the RSSI and the phase information from the receiver, obtains an arrival angle (AoA) of the transmitter relative to the receiver based on the phase information, and obtains a position of the person based on the RSSI and the AoA;
• and the main console determines whether the person passes through or does not pass through the entrance according to all positions obtained within a time interval;
• wherein the step of determining whether the person passes through or does not pass through the entrance according to all positions obtained within the time interval by the main console further comprises:
• determining that the person passes through the entrance by the main console when there is a first position located on a first side of the entrance and there is a second position located on a second side of the entrance among all the positions obtained within the time interval;
• and
• determining that the person has not passed through the entrance by the main console when all the positions obtained within the time interval are located on the same side of the entrance.