Matlab中关于信道chan = rayleighchan(ts,fd,tau,pdb)中的变量

各位大侠:
在matlab中,瑞利信道的函数chan = rayleighchan(ts,fd,tau,pdb)中,pdb is a vector of average path gains.有谁知道这个变量的意义,呵呵.
谢谢

读matlab的文档，里面已经写的很详尽了，而且给出了参考文献
使用软件的时候一定要学会利用软件开发者提供的文档，
否则MATLAB的开发工程师会伤心死的 :)

呵呵,兄弟,help文档已经看了若干遍了,还是不清楚.如果你清楚的话,老你给解释一下;否则,我们都听听高手的吧.
我再把问题的关键重复一下:pdb is a vector of average path gains, each specified in dB.这个变量的物理意义是什么?
0dB代表什么意思?
按照计算ak的步骤,里面有一个欧米嘎,那个变量是怎么计算的?
欧米嘎=E{|ak|2},那么ak 服从什么分布,按权来做?还是和延时相同,认为是等概分布?
谢谢

可以认为pdb表示某径对信号功率的放大倍数，不同的径有不同的放大倍数。

下面这一段不知道你看到没有 :)
Communications Toolbox=>Fading Channels=>Configure Channel Objects
The average path gains in the channel object indicate the average
power gain of  each FADING PATH. In practice, an average path gain
value is a large negative dB. However, computer models typically use
average path gains between -20dB and 0 dB.
The dB values in a vector of average path gains often decay roughly
linearly as a function of delay, but the specific delay profile depends
on the propagation environment.
To ensure that the expected value of the path gains' total power is 1,
you can normalize path gains via the channel object's NormalizePathGains
property.