kalman_estimate.m

OFDM系统的仿真代码MATLAB环境下

function [h, M] = kalman_estimate(initial_cir, y, num_ofdm)
% h0: a vector which describes the CIR of the pilot frequency in the first
% ofdm symbol. It is an initial values of the kalman estimator.
% num_ofdm: describes the number of the ofdm symbols in a single packet.
% h: a vector which describes the predicted CIR in the corresponding pilot
% frequency in every ofdm symbol.
% M: a vector which describes the MMS of the kalman estimator.
a = 1;
Q = 0.0001;
pilot = 1;
u = 0.01;

global sim_consts;

for i = 1:sim_consts.NumPilotSubc
    h2 = initial_cir(i);
    M2 = 1;
    for j = 1:num_ofdm
        h1 = a*h2;
        M1 = a.^2*M2+Q;
        K = M1*pilot/(u+M1);
        h0 = h1+K*(y(i,j)-h1);
        M0 = (1-K)*M1;
        h2 = h0;
        M2 = M0;
        h(i,j) = h0;
        M(i,j) = M0;
    end
end