Present a modified particle filter ( pf ) algorithm based on the los / nlos binary state information of propagation environment using the numerical method of the probability density function ( pdf ) about the hybrid noise . the key idea is using numerical method to calculate the hybrid noise pdf , and integrating binary environment information to get filtering result 2 .給出了應用粒子濾波器改進直達波與非直達波混合環境中移動終端跟蹤性能的新算法,特色是利用數值方法計算混合噪聲密度函數,結合二元環境信息完成濾波估計。