clear?all;
close?all;
fprintf（‘OFDM信道估計仿真\n\n‘）;
carrier_count=64;%-----------載波數目
num_symbol=50;%--------------OFDM符號個數
Guard=8;%--------------------循環前綴
pilot_Inter=8;%--------------導頻間隔
modulation_mode=16;%---------調制方式
SNR=[0:2:20];%-------------信噪比取值
NumLoop=15;%-----------------循環次數
num_bit_err=zeros（length（SNR）NumLoop）;
num_bit_err_dft=zeros（length（SNR）NumLoop）;
num_bit_err_ls=zeros（length（SNR）NumLoop）;
MSE=zeros（length（SNR）NumLoop）;
MSE1=zeros（length（SNR）NumLoop）;
MSE2=zeros（length（SNR）NumLoop）;
%%%%%%%%%%%%%%%%%%%%%%%主程序循環%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
for?c1=1:length（SNR）
????fprintf（‘\n\n\n仿真信噪比為%f\n\n‘SNR（c1））;
????for?num1=1:NumLoop
????????%---------------產生發送的隨機序列——————————————-
????????BitsLen=carrier_count*num_symbol;
????????BitsTx=randint（1BitsLen）;
????????%---------------符號調制---------------------------------------
????????Modulated_Sequence=qammod（BitsTxmodulation_mode）;
????????%---------------導頻格式---------------------------------------
????????pilot_len=carrier_count;
????????pilot_symbols=round（rand（1pilot_len））;
????????for?i=1:pilot_len
????????????if?pilot_symbols（1i）==0
????????????????pilot_symbols（1i）=pilot_symbols（1i）-1;
????????????else
????????????????pilot_symbols（1i）=pilot_symbols（1i）;
????????????end
????????end
????????pilot_symbols=pilot_symbols‘;
????????%----------------計算導頻和數據數目----------------------------
????????num_pilot=ceil（num_symbol/pilot_Inter）;
????????if?rem（num_symbolpilot_Inter）==0
????????????num_pilot=num_pilot+1;
????????end
????????num_data=num_symbol+num_pilot;
????????%----------------導頻位置計算----------------------------------
????????pilot_Indx=zeros（1num_pilot）;
????????Data_Indx=zeros（1num_pilot*（pilot_Inter+1））;
????????for?i=1:num_pilot-1
????????????pilot_Indx（1i）=（i-1）*（pilot_Inter+1）+1;
????????end
????????pilot_Indx（1num_pilot）=num_data;
????????for?j=0:num_pilot
????????????Data_Indx（1（1+j*pilot_Inter）:（j+1）*pilot_Inter）=（2+j*（pilot_Inter+1））:（（j+1）*（pilot_Inter+1））;
????????end
????????Data_Indx=Data_Indx（11:num_symbol）;
????????%----------------導頻插入-------------------------------------
????????piloted_ofdm_syms=zeros（carrier_countnum_data）;
????????piloted_ofdm_syms（:Data_Indx）=reshape（Modulated_Sequencecarrier_countnum_symbol）;
????????piloted_ofdm_syms（:pilot_Indx）=repmat（pilot_symbols1num_pilot）;
????????%----------------IFFT變換———————————————————
????????time_signal=sqrt（carrier_count）*ifft（piloted_ofdm_syms）;
????????%----------------加循環前綴------------------------------------
????????add_cyclic_signal=[time_signal（（carrier_count-Guard+1:carrier_count）:）;time_signal];
????????Tx_data_trans=reshape（add_cyclic_signal1（carrier_count+Guard）*num_data）;
????????%----------------信道處理--------------------------------------
????????Tx_signal_power=sum（abs（Tx_data_trans（:））.^2）/length（Tx_data_trans（:））;
????????noise_var=Tx_signal_power/（10^（SNR（c1）/10））