Random Variables with Nakagami - m distribution.

How can i generate random variables having distribution Nakagami-m ? such that parameter 'm' is user defined.

Thank you.

[Pawan Kumar]

clc;

clear all;

N = 10^7;

M = 2;

g = sin(pi/M)^2;

hmod = modem.pskmod(M);

hdemod = modem.pskdemod(M);

int = randi([0 M-1],1,N);

symb = modulate(hmod,int);

snr_dB = 0:3:30;

snr = 10.^(snr_dB/10);

sze = zeros(size(snr_dB));

jmath = sqrt(-1);

sigm = 1; % channel variance

m = 1.5; % Nakagami-m parameter

thta = 0 + (pi-0).*rand(1,N); % uniform phase

y = gamrnd(m, sigm/m, 1, N); % amplitude having Gamma distribution

h = sqrt(y).*exp(-1i*thta); % Samples for Nakagami-m distribution

n = sqrt(1/2)* (randn(1,N)+jmath*randn(1,N)); % Noise

for j1 = 1:length(snr_dB) j1

   r          =  sqrt(snr(j1))*h.*symb + n;     % received signal
   rhat       =  r.*exp(-jmath*angle(h));  % fading phase compensation
   Det_r      =  demodulate(hdemod,rhat);   % demodulation
   nerr_r     =  size(find(int-Det_r),2);  % number of errors for given snr level
   Pe_sim(j1) =  nerr_r/N;           % error rate

   Pe_ana(j1) =  1/pi*quad(@(t) (1+g*snr(j1)./(m*sin(t).^2)).^(-m) , 0, (M-1)*pi/M);

end

figure;

semilogy(snr_dB,Pe_sim,'-.ok');

hold on;

semilogy(snr_dB,Pe_ana,'-+k');

xlabel('SNR (dB)'); ylabel('Average symbol error rate');

legend('Simulation', 'Analytical');