%%%%%%%Cramer-Rao?bound?on?DOA?for?a?single?target
clear?all
clc
M=10;
snr=1;
i=sqrt（-1）;
syms?theta;???????????????????????????%定義一個符號變量theta
%atheta?=?zeros（M1）;??
for?m=1:M
????atheta（m1）=exp（-i*（m-1）*pi*sin（theta））;
end
atheta;??
dtheta=diff（atheta）;??????????????????%求導引矢量關于角度theta的一階微分
theta1?=?0;
theta2?=?（12*pi）/180;
theta3?=?linspace（theta1theta2）;
for?k=1:100
????theta=theta3（k）;
????athetanum=eval（atheta）;
????dthetanum=eval（dtheta）;????????????????????
????b?=?ones（M）;
????c?=?eye（M）;
????CRB1（k）=1/（2*snr*（M*dthetanum‘*b*dthetanum+athetanum‘*b*athetanum*（（norm（dthetanum））.^2）...
???????????????????????-M*（（（abs（athetanum‘*b*dthetanum））.^