FIR Filter Verstärkung größer 1?

function [fw,h]=fir(M,h,fs,step)

%Autor: Tobias Markus

%FIR Filter with M koeffizients

%fs is the sampling frequency and 

%h is the koefficent vector must have the size

%of M. And step defines the steps between 0Hz and fs

n=0;

m=0;

sum =0;

f=[0:step:fs/2];

hz=[];

% Calculating the transfer function

while m < (fs/(2*step)+1)

while n < M

  sum = sum +h(n+1)*exp(-j*n*(2*pi*f(m+1))/fs);

n=n+1;

end

hz(m+1)= sum;

sum=0;

m=m+1;

n=0;

end

h=hz;

fw=f;

endfunction

h=[];

h(1)=-0.045;

h(2)=0;

h(3)=0.075;

h(4)=0.159;

h(5)=0.225;

h(6)=0.25;

h(7)=0.225;

h(8)=0.159;

h(9)=0.075

h(10)=0

h(11)=-0.045

fs=16000;

M=11;

step=10;

f=[];

w=[];

[f,w]=fir(M,h,fs,step);

plot(f,abs(w));