function [y1,y2]=rise_cos(x1,x2,fd,fs)
[yf, tf]=rcosine(fd,fs, 'fir/sqrt');
[yo1, to1]=rcosflt(x1, fd,fs,'filter/Fs',yf);
[yo2, to2]=rcosflt(x2, fd,fs,'filter/Fs',yf);
y1=yo1;
y2=yo2;