通讯/手机编程

开发平台：
Windows_Unix

parameter_Jakes.m：源码内容
							%--------------------------------------------------------------------
% parameter_Jakes.m -------------------------------------------------
%
% Program for the computation of the discrete Doppler frequencies,
% Doppler coefficients and Doppler phases by using the Jakes power
% spectral density.
%
% Used m-files: LPNM_opt_Jakes.m, fun_Jakes.m,
% grad_Jakes.m, acf_mue.m
%--------------------------------------------------------------------
% [f_i_n,c_i_n,theta_i_n]=parameter_Jakes(METHOD,N_i,sigma_0_2,...
% f_max,PHASE,PLOT)
%--------------------------------------------------------------------
% Explanation of the input parameters:
%
% METHOD:
% |----------------------------------------------|------------------|
% | Methods for the computation of the discrete | Input |
% | Doppler frequencies and Doppler coefficients | |
% |----------------------------------------------|------------------|
% |----------------------------------------------|------------------|
% | Method of equal distances (MED) | 'ed_j' |
% |----------------------------------------------|------------------|
% | Mean square error method (MSEM) | 'ms_j' |
% |----------------------------------------------|------------------|
% | Method of equal areas (MEA) | 'ea_j' |
% |----------------------------------------------|------------------|
% | Monte Carlo method (MCM) | 'mc_j' |
% |----------------------------------------------|------------------|
% | Lp-norm method (LPNM) | 'lp_j' |
% |----------------------------------------------|------------------|
% | Method of exact Doppler spread (MEDS) | 'es_j' |
% |----------------------------------------------|------------------|
% | Jakes method (JM) | 'jm_j' |
% |----------------------------------------------|------------------|
%
% N_i: number of harmonic functions
% sigma_0_2: average power of the real deterministic Gaussian
% process mu_i(t)
% f_max: maximum Doppler frequency
%
% PHASE:
% |----------------------------------------------|------------------|
% | Methods for the computation of the Doppler | Input |
% | phases | |
% |----------------------------------------------|------------------|
% |----------------------------------------------|------------------|
% | Random Doppler phases | 'rand' |
% |----------------------------------------------|------------------|
% | Permuted Doppler phases | 'perm' |
% |----------------------------------------------|------------------|
%
% % PLOT: plot of the ACF and the PSD of mu_i(t), if PLOT==1
% function [f_i_n,c_i_n,theta_i_n]=parameter_Jakes(METHOD,N_i,...
% sigma_0_2,f_max,PHASE,PLOT)
METHOD='ms_j'
N_i=25
sigma_0_2=1
f_max=120
PHASE=0.4
PLOT=1
if nargin<6,
error('Not enough input parameters')
end
sigma_0=sqrt(sigma_0_2);
% Method of equal distances (MED)
if METHOD=='ed_j',
n=(1:N_i)';
f_i_n=f_max/(2*N_i)*(2*n-1);
c_i_n=2*sigma_0/sqrt(pi)*(asin(n/N_i)-asin((n-1)/N_i)).^0.5;
K=1;
% Mean square error method (MSEM)
elseif METHOD=='ms_j',
n=(1:N_i)';
f_i_n=f_max/(2*N_i)*(2*n-1);
Tp=1/(2*f_max/N_i);
t=linspace(0,Tp,5E3);
Jo=besselj(0,2*pi*f_max*t);
c_i_n=zeros(size(f_i_n));
for k=1:length(f_i_n),
c_i_n(k)=2*sigma_0*...
sqrt(1/Tp*( trapz( t,Jo.*...
cos(2*pi*f_i_n(k)*t )) ));
end
K=1;
% Method of equal areas (MEA)
elseif METHOD=='ea_j'
n=(1:N_i)';
f_i_n=f_max*sin(pi*n/(2*N_i));
c_i_n=sigma_0*sqrt(2/N_i)*ones(size(n));
K=1;
% Monte Carlo method (MCM)
elseif METHOD=='mc_j'
n=rand(N_i,1);
f_i_n=f_max*sin(pi*n/2);
c_i_n=sigma_0*sqrt(2/N_i)*ones(size(n));
K=1;
% Lp-norm method (LPNM)
elseif METHOD=='lp_j',
if exist('fminu')~=2
disp([' =====> This method requires ',...
'the Optimization Toolbox !!'])
return
else
N=1E3;
p=2; % Norm
s_o=1;
[f_i_n,c_i_n]=LPNM_opt_Jakes(N,f_max,sigma_0,p,N_i,s_o);
K=1;
end
% Method of exact Doppler spread (MEDS)
elseif METHOD=='es_j',
n=(1:N_i)';
f_i_n=f_max*sin(pi/(2*N_i)*(n-1/2));
c_i_n=sigma_0*sqrt(2/(N_i))*ones(size(f_i_n));
K=1;
% Jakes method (JM)
elseif METHOD=='jm_j',
n=1:N_i-1;
f_i_n=f_max*[[cos(pi*n/(2*(N_i-1/2))),1]',...
[cos(pi*n/(2*(N_i-1/2))),1]'];
c_i_n=2*sigma_0/sqrt(N_i-1/2)*[[sin(pi*n/(N_i-1)),1/2]',...
[cos(pi*n/(N_i-1)),1/2]'];
K=1;
theta_i_n=zeros(size(f_i_n));
PHASE='none';
else
error('Method is unknown')
end
% Computation of the Doppler phases:
if PHASE=='rand',
theta_i_n=rand(N_i,1)*2*pi;
elseif PHASE=='perm',
n=(1:N_i)';
Z=rand(size(n));
[dummy,I]=sort(Z);
theta_i_n=2*pi*n(I)/(N_i+1);
end;
if PLOT==1,
if METHOD=='jm_j'
subplot(2,3,1)
stem([-f_i_n(N_i:-1:1,1);f_i_n(:,1)],...
1/4*[c_i_n(N_i:-1:1,1);c_i_n(:,1)].^2)
title('i=1')
xlabel('f (Hz)')
ylabel('PSD')
subplot(2,3,2)
stem([-f_i_n(N_i:-1:1,2);f_i_n(:,2)],...
1/4*[c_i_n(N_i:-1:1,2);c_i_n(:,2)].^2)
title('i=2')
xlabel('f (Hz)')
ylabel('PSD')
tau_max=N_i/(K*f_max);
tau=linspace(0,tau_max,500);
r_mm=sigma_0^2*besselj(0,2*pi*f_max*tau);
r_mm_tilde1=acf_mue(f_i_n(:,1),c_i_n(:,1),tau);
subplot(2,3,4)
plot(tau,r_mm,'r-',tau,r_mm_tilde1,'g--')
title('i=1')
xlabel('tau (s)')
ylabel('ACF')
r_mm_tilde2=acf_mue(f_i_n(:,2),c_i_n(:,2),tau);
subplot(2,3,5)
plot(tau,r_mm,'r-',tau,r_mm_tilde2,'g--')
title('i=2')
xlabel('tau (s)')
ylabel('ACF')
subplot(2,3,3)
stem([-f_i_n(N_i:-1:1,1);f_i_n(:,1)],...
1/4*[c_i_n(N_i:-1:1,1);c_i_n(:,1)].^2+...
1/4*[c_i_n(N_i:-1:1,2);c_i_n(:,2)].^2)
title('i=1,2')
xlabel('f (Hz)')
ylabel('PSD')
subplot(2,3,6)
plot(tau,2*r_mm,'r-',tau,r_mm_tilde1+r_mm_tilde2,'g--')
title('i=1,2')
xlabel('tau (s)')
ylabel('ACF')
else
subplot(1,2,1)
stem([-f_i_n(N_i:-1:1);f_i_n],...
1/4*[c_i_n(N_i:-1:1);c_i_n].^2)
xlabel('f/Hz')
ylabel('LDS')
tau_max=N_i/(K*f_max);
tau=linspace(0,tau_max,500)
r_mm=sigma_0^2*besselj(0,2*pi*f_max*tau);
r_mm_tilde=acf_mue(f_i_n,c_i_n,tau);
subplot(1,2,2)
plot(tau,r_mm,'r-',tau,r_mm_tilde,'g--')
xlabel('tau (s)')
ylabel('ACF')
end
end

						