lpnm_opt_jakes.m

一些非常有用的MATLAB源码,对于提高编程水平和学习通信理论知识还有帮助.

%--------------------------------------------------------------------
% LPNM_opt_Jakes.m --------------------------------------------------
%
% Program for the computation of the discrete Doppler frequencies 
% employing the Jakes PSD by using a numerical optimization method.
%
% Used m-files: parameter_Jakes.m, fun_Jakes.m,
%                           grad_Jakes.m, acf_mue.m
%--------------------------------------------------------------------
% [f_i_n,c_i_n]=LPNM_opt_Jakes(N,f_max,sigma_0_2,p,N_i,PLOT)
%--------------------------------------------------------------------
% Explanation of the input parameters:
%
% N: length of vector tau
% f_max: maximum Doppler frequency
% sigma_0_2: average power of the real Gaussian process mu_i(t)
% p: parameter of the Lp-norm (here: p=2,4,6,...)
% N_i: number of harmonic functions
% PLOT: display of the intermediate optimization results, if PLOT==1

function [f_i_n,c_i_n]=LPNM_opt_Jakes(N,f_max,sigma_0_2,p,N_i,PLOT)

tau=linspace(0,N_i/(2*f_max),N);
Jo=sigma_0_2*besselj(0,2*pi*f_max*tau);
c_i_n=sqrt(sigma_0_2)*sqrt(2/N_i)*ones(N_i,1);

save data Jo tau N_i c_i_n p PLOT

% Initial values:
[f_i_n,dummy1,dummy2]=parameter_Jakes('es_j',N_i,...
                      sqrt(sigma_0_2),f_max,'none',0);
o=foptions;
o(1)=1;
o(1)=0;
o(2)=1e-9;
o(14)=N_i/10*200;
o(9)=0;

xo=f_i_n;

x=fminu('fun_Jakes',xo,o,'grad_Jakes');

load x

f_i_n=x;