%===================================================================
%10/30/04?Sun?Jie-ting?ECUST
%===================================================================
%?Alamouti.m
%?==========
%?Description:?This?m-file?simulates?the?SER?performance?of?Alamouti
%??????????????space-time?shceme?using?maximum?likelihood?decoding
%?Usage:??ser_ml=Alamouti（Nrmax_snrmax_err_symbolsymbol_per_frame）
%?Inputs:
%?????????Nr:?the?number?of?receiving?antennaeither?1?or?2
%?????????max_snr:?simulation?from?0?to?max_snr
%?????????max_err_symbol:?the?simulation?will?stop?when?the?number?of
%?????????????????????????received?error?symbols?exceeds?max_err_symbol
%?????????symbol_per_frame:?the?number?of?symbols?to?transmit?in?a?data
%????????????????????????????frame?and?we?assume?the?channel?fading
%????????????????????????????coefficients?will?keep?the?same?the?data
%????????????????????????????frame?transmitting?period.Becasue?of?2?Tx
%????????????????????????????antenna?symbol_per_frame?must?be?even
%?Outputs:
%?????????ser_ml:?symbol-error-ratio?of?each?snr
%?======================================================================
function?ser_ml=Alamouti（Nrmax_snrmax_err_symbolsymbol_per_frame）;
%clc;
%發(fā)射天線數(shù)，固定為2
if?mod（symbol_per_frame2）?==?0
????Nt?=?2;
????tot_frame_tx=zeros（1max_snr+1）;
????tot_err_symbol?=zeros（1max_snr+1）;
????tot_frame_tx?=?zeros（1max_snr+1）;
????for?snr=0:max_snr
????????while?tot_err_symbol（snr+1）????????????tot_frame_tx（snr+1）?=?tot_frame_tx（snr+1）+1;
????????????%生成偽隨機(jī)二進(jìn)制待發(fā)送序列
????????????psudo_bit_sequence?=?rand（1symbol_per_frame?*?2）>0.5;
????????????%二進(jìn)制信道與QPSK信號的轉(zhuǎn)換
????????????qpsk_sequence?=?QpskMapping（psudo_bit_sequence）;
????????????%噪聲能量（已歸一化）
%???????????sig?=?sqrt（0.5/（10^（snr/10）））;
????????????sig?=?sqrt（1/（10^（snr/10）））;
????????????%生成加性高斯噪聲
????????????addtional_gaussian_noise???=???sig?*?（randn（NrNtsymbol_per_frame）?+?j*randn（NrNtsymbol_per_frame））;
????????????%生成具有瑞利分布特性的信道衰落系數(shù)
????????????H=RayleighCH（NrNt）;
????????????for?k=1:2:symbol_per_frame-1
????????????????X=[qpsk_sequence（k）?-conj（qpsk_sequence（k+1））;?qpsk_sequence（k+1）?conj（qpsk_sequence（k））];
????????????????%接收信號
????????????????R=H*X?+?addtional_gaussian_noise（::k）;
????????????????%接收信號的合成（利用發(fā)送矩陣的正交性對信道衰落矩陣進(jìn)行正交化處理），由Alamoui碼原理可知，信號合成方式因接收天線數(shù)目而異
????????????????switch?Nr
????????????????????case?1
????????????????????????s0=conj（H（1））*R（1）+H（2）*conj（R（2））;
????????????????????????s1=conj（H（2））*R（1）-H（1）*conj（R（2））;
????????????????????case?2
????????????????????????s0=conj（H（11））*R（11）+H（12）*conj（R（12））+conj（H（21））*R（21）+H（22）*conj（R（22））;??
????????????????????????s1=conj（H（12））*R（11）-H（11）*conj（R（12））+conj（H（22））*R（21）-H（21）*conj（R（22））;
????????????????end
????????????????S=[s0?s1];
????????????????%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%????
????????????????%??????????最大似然譯碼??????????%
????????????????%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
???

?屬性????????????大小?????日期????時間???名稱
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?????目錄??????????0??2005-06-19?13:19??Alamouti

?????文件???????1164??2005-06-19?13:43??Alamouti\程序說明.txt

?????文件????????754??2005-06-19?11:36??Alamouti\RayleighCH.m

?????文件???????1504??2005-06-19?12:49??Alamouti\QpskMapping.m

?????文件???????4099??2005-06-19?13:32??Alamouti\Alamouti.m

?????文件?????225238??2004-09-28?20:03??Alamouti\a?simple?transmit?diversity?technique?for?wireless?communications.pdf

?????文件???????1463??2005-06-19?13:40??Alamouti\SimAlamouti.m

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???????????????234222????????????????????7