说明：  瑞利衰落信道（Rayleigh fading channel）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。
(Rayleigh fading channel, Rayleigh fading channel) is a statistical model of radio signal propagation environment. This model assumes that the signal through a wireless channel, its signal amplitude is random, or "decline", and its envelope obey Rayleigh distribution. )