Filtering :: Galois Field Computations (Communications Toolbox)

Communications Toolbox

Filtering

To filter a Galois vector, use the filter function. It behaves like the ordinary MATLAB filter function when given exactly three input arguments.

The code and diagram below give the impulse response of a particular filter over GF(2).

m = 1; % Work in GF(2).
b = gf([1 0 0 1 0 1 0 1],m); % Numerator
a = gf([1 0 1 1],m); % Denominator
x = gf([1,zeros(1,19)],m);
y = filter(b,a,x); % Filter x.
figure; stem(y.x); % Create stem plot.
axis([0 20 -.1 1.1])

Signal Processing Operations in Galois Fields

Convolution