www.pudn.com > mimo_ofdm.rar > ifft_cp_tx_blk.m, change:2004-11-20,size:1003b

function ofdm_symbol = ifft_cp_tx_blk(inp_symbol,num_subc,guard_interval)
%------------------------------------------------------------
% IFFT and Circular Prefix Addition Block for Transmitter
% -------------------------------------------------------
% (EE359 Project: Andrew and Prateek)
% Inputs : 
%   inp_symbol     : Input Symbol from all the Subcarriers
%   num_subc       : Number of Subcarriers
%   guard_interval : Guard Interval based on OFDM Symbol  
% Outputs : 
%   ofdm symbol    : Output of IFFT and Guard Interval
% -----------------------------------------------------------


ofdm_symbol = ifft(inp_symbol,num_subc);

if (guard_interval > length(ofdm_symbol))
    error(' The guard interval is greater than the ofdm symbol duration ');
end

% The guard symbol is the copy of the end of the ofdm symbol to the beginning
% of the ofdm symbol.
guard_symbol = ofdm_symbol(end-guard_interval+1:end);

% Add the cyclic prefix to the ofdm symbol
ofdm_symbol = [guard_symbol ofdm_symbol];