瑞利衰落信道，是一种无线电信号传播环境的统计模型。这种模型假设信号通过无线信道之后，其信号幅度是随机的，即“衰落”，并且其包络服从瑞利分布。这一信道模型能够描述由电离层和对流层反射的短波信道，以及建筑物密集的城市环境。-Rayleigh fading channels, the statistical model of a radio signal propagation environment. This model assumes that after the signal through the radio channel, the signal amplitude is random, ie, the " fading"　and the envelope of the Rayleigh distribution. This channel model is able to describe the HF channel reflected by the ionosphere and troposphere, as well as building a dense urban environment.