关键词: 射频识别, 室内定位, 旋转天线, RSSI测距, 椭圆模型, 三边定位算法

Abstract: The traditional RFID indoor positioning system based on the distance measurement of RSSI needs to use multiple antennas simultaneously, which makes the cost of RFID positioning system expensive. However, the RFID rotating antenna positioning method using only one antenna needs to long-term search for a tag to measure the maximum signal strength, which causes that the system is unable to operate stably for a long period of time. In order to solve the problem, the system obtains the equal signal strength of different angles by rotating RFID antenna. Then the intersection points of two elliptical models are obtained by traversal methods. In this way the positioning function is achieved. At last the performance of the proposed algorithm is tested on the hardware device. The result indicates that the error of position is 0.754?m. Compared with the traditional RSSI positioning algorithm, the cost of proposed RFID indoor positioning system can be reduced about 36.19%. At the same time, the problem of heating easily of the reader is solved.

Key words: Radio Frequency Identification（RFID）, indoor localization, rotable antenna, Received Signal Strength Indication （RSSI） distance measurement, three edge location algorithm