%?script?for?computing?the?BER?for?BPSK?modulation?in?a
%?Rayleigh?fading?channel?with?Alamouti?Space?Time?Block?Coding
%?Two?transmit?antenna?1?Receive?antenna

clear
N?=?10^6;?%?number?of?bits?or?symbols
Eb_N0_dB?=?[0:25];?%?multiple?Eb/N0?values

for?ii?=?1:length（Eb_N0_dB）

????%?Transmitter
????ip?=?rand（1N）>0.5;?%?generating?01?with?equal?probability
????s?=?2*ip-1;?%?BPSK?modulation?0?->?-1;?1?->?0

????%?Alamouti?STBC?
????sCode?=?zeros（2N）;
????sCode（:1:2:end）?=?（1/sqrt（2））*reshape（s2N/2）;?%?[x1?x2??...]
????sCode（:2:2:end）?=?（1/sqrt（2））*（kron（ones（1N/2）[-1;1]）.*flipud（reshape（conj（s）2N/2）））;?%?[-x2*?x1*?....]

????h?=?1/sqrt（2）*[randn（1N）?+?j*randn（1N）];?%?Rayleigh?channel
????hMod?=?kron（reshape（h2N/2）ones（12））;?%?repeating?the?same?channel?for?two?symbols????

????n?=?1/sqrt（2）*[randn（1N）?+?j*randn（1N）];?%?white?gaussian?noise?0dB?variance

????%?Channel?and?noise?Noise?addition
????y?=?sum（hMod.*sCode1）?+?10^（-Eb_N0_dB（ii）/20）*n;

????%?Receiver
????yMod?=?kron（reshape（y2N/2）ones（12））;?%?[y1?y1?...?;?y2?y2?...]
????yMod（2:）?=?conj（yMod（2:））;?%?[y1?y1?...?;?y2*?y2*...]
?
????%?forming?the?equalization?matrix
????hEq?=?zeros（2N）;
????hEq（:[1:2:end]）?=?reshape（h2N/2）;?%?[h1?0?...?;?h2?0...]
????hEq（:[2:2:end]）?=?kron（ones（1N/2