ifft_cp_tx_blk.m

汪裕民的OFDM关键技术与应用中仿真MIMO-OFDM的源代码

function ofdm_symbol = ifft_cp_tx_blk(inp_symbol,num_subc,guard_interval);
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%----------------------------
% 每个传输模块的IFFT和循环前缀
%----------------------------
%   输入：
%       inp_symbol      所有子载波的输入符号
%       num_subc        子载波数
%       guard_interval  OFDM符号的保护间隔
%   输出：
%       ofdm_symbol     加入IFFT和保护前缀的OFDM符号
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

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 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];