在matlab中看瑞利分布

%----------Input Section----------------

N=1000000 %Number of samples to generate

variance = 1% Variance of underlying Gaussian random variables

%---------------------------------------

%Independent Gaussian random variables with zero mean and unit variance

x = randn(1, N)

y = randn(1, N)

%Rayleigh fading envelope with the desired variance

r = sqrt(variance*(x.^2 + y.^2))

%Define bin steps and range for histogram plotting

step = 0.1range = 0:step:5

%Get histogram values and approximate it to get the pdf curve

h = hist(r, range)

approxPDF = h/(step*sum(h))%Simulated PDF from the x and y samples

%Theoritical PDF from the Rayleigh Fading equation

theoretical = (range/variance).*exp(-range.^2/(2*variance))

plot(range, approxPDF,'b*'耐吵, range, theoretical,'r')

title('方差1.0时瑞利悔亩巧概率密度函数仿真值和理论值')

legend('概率密度仿真碧键值','概率密度函数理论值')

xlabel('r')

ylabel('P(r)')

grid

%PDF of phase of the Rayleigh envelope

theta = atan(y./x)

figure(2)

hist(theta)%Plot histogram of the phase part

%Approximate the histogram of the phase part to a nice PDF curve

[counts,range] = hist(theta,100)

step=range(2)-range(1)

approxPDF = counts/(step*sum(counts))%Simulated PDF from the x and y samples

bar(range, approxPDF,'b')

hold on

plotHandle=plot(range, approxPDF,'r')

set(plotHandle,'LineWidth',3.5)

axis([-2 2 0 max(approxPDF)+0.2])

hold off

title('瑞利概率密度函数相位分布仿真 ')

xlabel('\theta ')

ylabel('P(\theta)')

grid

“P1取值范围0~0.1，服从正态分布？”

正态分布应该有两个参数（均值和方差）决定，范围很谈枣难说，理论上什么值都可能，只是概率比较小。瑞利分布缺大也存伏侍竖在类似问题。

正态分布用randn或normrnd；

瑞利分布用函数raylrnd；

均匀分布用函数rand或unifrnd。

直接把密度分布腔歼的函颂基数套进去

填参数

s=sigma^2

选点野圆谨

x=0:0.01:5

f= x/s.*exp(-x.^2/s)

plot(x,f)

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