function?output_frame?=?demodulation（input_modu?index）
%?demodulation?for?IEEE802.11a
%?Input:????input_modu?complex?values?representing?constellation?points
%???????????index
%?Output:???output_frame?output?bit?stream?（data?unit?is?one?bit）

%?In?this?version?increase?the?quatilization?levels?into?8.
%?note:?Matlab?index?starts?from?1
Q_length=length（input_modu）;
QAM_input_I?=?real（input_modu）;
QAM_input_Q?=?imag（input_modu）;
output_frame?=?zeros（1length（input_modu）*index）;
switch?index
case?1
????BPSK_Demodu_I?=?[0?1];??????%f（m）=（m+1）/2?+?1?so?I=-1?--->?1?I=1?--->?2
????idx?=?find（QAM_input_I>1）;
????QAM_input_I（idx）?=?1;
????idx?=?find（QAM_input_I<-1）;
????QAM_input_I（idx）?=?-1;
????output_frame?=?BPSK_Demodu_I（round（（QAM_input_I+1）/2）?+?1）;
case?2
????QPSK_Demodu_IQ?=?[0?1];?????%f（m）=（m+1）/2?+?1?so?I=-1?--->?1?I=1?--->?2
????idx?=?find（QAM_input_I>1）;
????QAM_input_I（idx）?=?1;
????idx?=?find（QAM_input_I<-1）;
????QAM_input_I（idx）?=?-1;
????idx?=?find（QAM_input_Q>1）;
????QAM_input_Q（idx）?=?1;
????idx?=?find（QAM_input_Q<-1）;
????QAM_input_Q（idx）?=?-1;
????output_frame（1:2:end）?=?QPSK_Demodu_IQ（round（（QAM_input_I+1）/2）?+?1）;
????output_frame（2:2:end）?=?QPSK_Demodu_IQ（round（（QAM_input_Q+1）/2）?+?1）;
case?3
????remapping=[0?0?0;0?0?1;0?1?0;0?1?1;1?0?0;1?0?1;1?1?0;1?1?1].‘;
????for?i=1:Q_length
????phase_det=[2????a=find（phase_det）;
????output_frame（（1+（i-1）*3）:（3+（i-1）*3））=remapping（（1+（a-1）*3）:（3+（a-1）*3））;
????end
case?4
????QAM_16_Demodu_IQ?=?[0?1?3?2];???%f（m）=（m+3）/2?+?1?so?I=-3?--->?1?I=1?--->?3
????idx?=?find（QAM_input_I>3）;
????QAM_input_I（idx）?=?3;
????idx?=?find（QAM_input_I<-3）;
????QAM_input_I（idx）?=?-3;
????idx?=?find（QAM_input_Q>3）;
????QAM_input_Q（idx）?=?3;
????idx?=?find（QAM_input_Q<-3）;
????QAM_input_Q（idx）?=?-3;
????tmp?=?round（（QAM_input_I+3）/2）?+?1;
????output_frame（1:4:end）?=?bitget（QAM_16_Demodu_IQ（tmp）2）;
????output_frame（2:4:end）?=?bitget（QAM_16_Demodu_IQ（tmp）1）;
????tmp?=?round（（QAM_input_Q+3）/2）?+?1;
????output_frame（3:4:end）?=?bitget（QAM_16_Demodu_IQ（tmp）2）;
????output_frame（4:4:end）?=?bitget（QAM_16_Demodu_IQ（tmp）1）;
case??5
?????remapping=[0?0?0?0?0;0?0?0?0?1;0?0?0?1?0;0?0?0?1?1;0?0?1?0?0;0?0?1?0?1;0?0?1?1?0;0?0?1?1?1;
????????????????0?1?0?0?0;0?1?0?0?1;0?1?0?1?0;0?1?0?1?1;0?1?1?0?0;0?1?1?0?1;0?1?1?1?0;0?1?1?1?1;
????????????????1?0?0?0?0;1?0?0?0?1;1?0?0?1?0;1?0?0?1?1;1?0?1?0?0;1?0?1?0?1;1?0?1?1?0;1?0?1?1?1;
????????????????1?1?0?0?0;1?1?0?0?1;1?1?0?1?0;1?1?0?1?1;1?1?1?0?0;1?1?1?0?1;1?1?1?1?0;1?1?1?1?1].‘;
????for?i=1:Q_length
????phase_det=[4