rrc.m

安捷仑的数字调制信号发生器E4438用于很多通信系统的开发过程中。本代码可以用于通过网络接口或GPIB接口向E4438下载被调制数据

% FILE: RRC.M
% Rev: 1/29/2002, 9/23/1996
% Author: Young-Seo Park
% This file evaluates Root Raised Cosine 
% rrc(t,a,Ts) = (4*a*cos((1+a)*pi*t/Ts) + (sin((1-a)*pi*t/Ts)./(t/Ts))) ./ (pi*(1-(4*a*t/Ts).^2))
% a = a + 1E-8 to remove discontinuity points 
% possible error is less than 1E-8 (=0.00000001) 

function 	y	=	rrc(t,a,Ts)
pc		=	1E-8;							% Very Small Number
ts		=	t/Ts;
a		=	a+pc;							% Remove discontinuity at not zero
ts1		=	ts+pc*(ts==0);					% Remove discontinuity at zero
y		=	( 4*a*cos((1+a)*pi*ts1) + (sin((1-a)*pi*ts1)./(ts1)) )...
			./ (pi*(1-(4*a*ts1).^2));
return; 									% End of function call.