通讯/手机编程

开发平台：
Matlab

This_one.m：源码内容
							 
%%%%%%%%%%%%%%%%%%%%%%%%%METHOD%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
%(a) Generate random binary sequence of +1抯 and -1抯.
%(b) Given different Power to the source and the relay as well
%(c) Multiply the symbols with the channel and then add white Gaussian noise.
%(d) At any receiver, equalize (divide) the received symbols with the known channel
%(e) Perform hard-decision-decoding and count the bit errors
%(f) Plot the power given to both source(Ps) and relay(Pr) with both SNR and BER
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
               %Total Power available PT=Ps+Pr=100dB
clear
N = 100; % bit stream
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%SOURCE_NODE%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
ip = rand(1,N)>0.5; % generating 0,1 with equal probability
s = 2*ip-1; % BPSK modulation 0 -> -1; 1 -> 0 
Ps=linspace(1,100,N);%Power given to the source(in dB)
for j=1:length(Ps)
    
%%%%%%%%%%%%%%%%%%%%%%%%%%%%DIFINING_CHANNEL_AND_NOISE%%%%%%%%%%%%%%%%%%%%%
    
   n = 1/sqrt(2)*(randn(1,N) + 1i*randn(1,N)); % white gaussian noise, 0dB variance 
   h = 1/sqrt(2)*(randn(1,N) + 1i*randn(1,N)); % Rayleigh channel
   ys=sqrt(Ps(j)).*h.*+ n;%Signal and noise added together(broadcasted in the first time slot)
   SNR1=(Ps(j).*h.^2)./n;%SNR_Souce-Relay,Souce-destination-link
   
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%RELAY_NODE%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
                      %Pr=100-Ps Power given to the relay
% equalization
   yHat = ys./sqrt(Ps(j)).*h;
% hard-decision-decoding
   ipHat = real(yHat)>0;% signal at the relay after decoding
s1=2*ipHat-1;%BPSK modulation(before sending in the second time slot)
yr= sqrt(100-Ps(j)).*h.*s1+ n; %signal broadcasted by the relay in the second time slot
SNR2=((100-Ps(j)).*h.^2)./n;%SNR_Relay-Destination-link
%%%%%%%%%%%%%%%%%%%%%%%%%DESTINATION_NODE%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
yd=ys+yr;
SNR3=max(SNR1,SNR2);% Selection_combining(SC)
SNR_RC=SNR1+SNR2;%Ratio_combining
% equalization 
   yHat_dest =ys./sqrt(Ps(j)).*h+yr./sqrt(80-Ps(j)).*h;
% hard-decision-decoding
ipHat_dest=real(yHat_dest)>0;
% counting the errors
   nErr(j) = size(find((ip- ipHat_dest)),2);
end
BER=real(nErr/N);%bit error rate
%plotting
close all
figure
subplot(2,1,1)
plot(Ps,SNR3,'r')
xlabel('Ps,Pr')
ylabel('SNR')
hold on
plot(100-Ps,SNR3,'g')
legend('Source-Power','Relay-Power')
grid on
subplot(2,1,2)
plot(Ps,BER,'r')
hold on
plot(100-Ps,BER,'g')
xlabel('Ps,Pr')
ylabel('BER')
grid on
legend('Source-Power','Relay-Power')
%%%%%%%%%%%%%%%%%%%%%%%RATION_COMBINING%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%plotting
% close all
% figure
% subplot(2,1,1)
% plot(Ps,SNR_RC,'r--')
% xlabel('Ps,Pr')
% ylabel('SNR-RC')
% hold on
% plot(100-Ps,SNR_RC,'g--')
% legend('Source-Power;SNR-RC','Relay-Power;SNR-RC')
% grid on
% subplot(2,1,2)
% plot(Ps,SNR3,'r')
% hold on
% plot(100-Ps,SNR3,'g')
% xlabel('Ps,Pr')
% ylabel('SNR3')
% grid on
% legend('Source-Power;SNR3','Relay-Power;SNR3')

						