cirshftt.m

DSP with Matlab by Proakis and Ingle

function y = cirshftt(x,m,N)

% Circular shift of m samples wrt size N in sequence x: (time domain)

% -------------------------------------------------------------------

% [y] = cirshftt(x,m,N)

% y = output sequence containing the circular shift

% x = input sequence of length <= N

% m = sample shift

% N = size of circular buffer

%  Method: y(n) = x((n-m) mod N)



% Check for length of x

if length(x) > N

        error('N must be >= the length of x')

end

x = [x zeros(1,N-length(x))];

n = [0:1:N-1];

n = mod(n-m,N);

y = x(n+1);