OTFS_modulation.m

%
% Copyright (c) 2018, Raviteja Patchava, Yi Hong, and Emanuele Viterbo, Monash University
% All rights reserved.
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% Redistribution and use in source and binary forms, with or without
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% 1. Redistributions of source code must retain the above copyright notice, this
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% 2. Redistributions in binary form must reproduce the above copyright notice,
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%    - Latest version of this code may be downloaded from: https://ecse.monash.edu/staff/eviterbo/
%    - Freely distributed for educational and research purposes
%%
function s = OTFS_modulation(N,M,x)
%% OTFS Modulation: 1. ISFFT, 2. Heisenberg transform
% X1=ifft(x);
% X2=X1.';
% X3=fft(X1);
% X4=fft(X2);
X = fft(ifft(x).').'/sqrt(M/N); %%%ISFFT
s_mat = ifft(X.')*sqrt(M); % Heisenberg transform
s = s_mat(:);
end