关键词: 定位, 接收信号强度指示器（RSSI）, 天线全向性, 无损卡尔曼滤波（UKF）

Abstract: By analyzing antenna omni-directional problem in RSSI values-based ranging technique, it proposes location algorithm based on the Unscented Kalman Filter（UKF）. It uses the RSSI values-based ranging model for distance measurement, and uses the Unscented Kalman filter algorithm to estimate node coordinates. Since the RSSI value measurement and ranging model parameters affected by the environment, it uses Gaussian filter to optimize the RSSI value and uses linear regression algorithm to optimize the environmental parameters. Compared with the Maximum Likelihood estimation method（ML）, experimental results show that this method can effectively reduce the positioning error and improve accuracy.

Key words: localization, Received Signal Strength Indicator（RSSI）, antenna omni-directional, Unscented Kalman Filter（UKF）