通讯编程

开发平台：
Matlab

main1.m：源码内容
							%简单main函数，用来测试基本的协同过程
tic
nr_of_iterations=1000; %循环次数
SNR=[-10:2.5:15];%dB形式
use_direct_link=1;%直接传输
use_relay=1;%通过伙伴传输
P=2;%总功率为2
global signal;%发送信号的全局变量
signal=generate_signal_structure;%发送信号结构体，包括传输比特数、传输字符数、每个字符包含的比特数、信号的调制方式、发送信号的比特序列、
                                 %发送信号的字符序列,传输完毕后接收到的比特序列,用来求误码率.
signal(1).modulation_type='QPSK'
signal.nr_of_bits=2^10;
signal.position_x=-1;
siganl.position_y=0;
calculate_signal_parameter;%发送信号准备完毕
channel=generate_channel_structure;
channel(1).attenuation(1).pattern='Rayleigh';
channel.attenuation(1).block_length=1;
channel(2)=channel(1);
channel(3)=channel(1);
channel(1).attenuation.distance=1;
channel(2).attenuation.distance=0.75;
channel(3).attenuation.distance=0.25;
rx=generate_rx_structure;
rx(1).combining_type='ESNRC';
rx.rx_position_x=1;
rx.rx_position_y=0;
rx.sd_weight=2;
rx(2)=rx(1);%负责没有协同情况下的接收
global relay;
relay=generate_relay_structure;
relay(1).mode='AAF';       
relay.magic_genie=0;
relay.rx=rx(1);
h = waitbar(0,'Please wait...');
BER=zeros(size(SNR));
BER_1sender=zeros(size(SNR));
for iSNR=1:size(SNR,2)
    waitbar(iSNR/size(SNR,2));
    channel(1).noise(1).SNR=SNR(iSNR);
    channel(2).noise(1).SNR=SNR(iSNR);
    channel(3).noise(1).SNR=SNR(iSNR);  
    for it=1:nr_of_iterations
        %Reset receiver
        rx(1)=rx_reset(rx(1));
        rx(2)=rx_reset(rx(2));%负责非协同情况
        relay.rx=rx_reset(relay.rx);
        
        [channel(1)]=get_channel_muti_parameter(channel(1),signal.symbol_sequence,1);
        [noise_vector_sd,channel(1),asd]=get_channel_white_noise(channel(1),signal.symbol_sequence);
        
        [channel(2)]=get_channel_muti_parameter(channel(2),signal.symbol_sequence,1);
        [noise_vector_sr,channel(2),asr]=get_channel_white_noise(channel(2),signal.symbol_sequence);
        
        [channel(3)]=get_channel_muti_parameter(channel(3),signal.symbol_sequence,1);
        [noise_vector_rd,channel(3),ard]=get_channel_white_noise(channel(3),signal.symbol_sequence);
        
        %功率分配
        [Ps,Pr]=power_allocate(P,asd,asr,ard,'ESNRC','Best','AAF',rx(1).sd_weight);
        
        %direct link
        if(use_direct_link==1)
        [rx(1)]=add_PA_and_channel_effect(channel(1),signal.symbol_sequence,rx(1),Ps,noise_vector_sd);
        rx(1)=rx_correct_phaseshift(rx(1),channel(1).attenuation.phi);
        end
        
        
        %Multi-hop
        if (use_relay==1)
            %sender to relay
            [relay.rx]=add_PA_and_channel_effect(channel(2),signal.symbol_sequence,relay.rx,Ps,noise_vector_sr);
            relay=prepare_relay2send(relay,channel(2),Ps,Pr);
            %relay to destination
            [rx(1)]=add_PA_and_channel_effect(channel(3),relay.signal2send,rx(1),Pr,noise_vector_rd);
            switch relay.mode
                case 'AAF'
                    rx(1)=rx_correct_phaseshift(rx(1),channel(2).attenuation.phi+channel(3).attenuation.phi);
                case 'DAF'
                    rx(1)=rx_correct_phaseshift(rx(1),channel(3).attenuation.phi);
                otherwise
                    error(['Relay-mode unknown:',relay.mode]);
            end
        end
      
        
        %receiver
        [received_symbol,signal.received_bit_sequence]=rx_combine(rx(1),channel,use_relay,Ps);
        
        BER(iSNR)=BER(iSNR)+sum(not(signal.received_bit_sequence==signal.bit_sequence));
        
        %不协同情况，只有一条单链路
        [rx(2)]=add_PA_and_channel_effect(channel(1),signal.symbol_sequence,rx(2),P,noise_vector_sd);
        rx(2)=rx_correct_phaseshift(rx(2),channel(1).attenuation.phi);
        [received_single_symbol,single_received_bit_sequence]=rx_combine(rx(2),channel,0,P);
        BER_1sender(iSNR)=BER_1sender(iSNR)+sum(not(single_received_bit_sequence==signal.bit_sequence));
    end%end of iteration
    
    BER(iSNR)=BER(iSNR)./it./signal.nr_of_bits;
    BER_1sender(iSNR)=BER_1sender(iSNR)./it./signal.nr_of_bits;
    %计算只有单链路的理论ber
    SNR_avg(iSNR)=10^(SNR(iSNR)/10);
    single_link_theo_ber(iSNR)=ber(SNR_avg(iSNR),'QPSK','Rayleigh');
end; 
close(h);
%画出实际和理论误码率图
%figure,
%semilogy(SNR,single_link_theo_ber,'g-^');
semilogy(SNR,BER,'r-<');
%semilogy(SNR,BER,'g-+',SNR,BER_1sender,'r->');%SNR,single_link_theo_ber,'k-');
%legend('Combining type FRC:2:1 QPSK Rayleign','theory 2sender','theory single link');
xlabel('Eb/No (dB)');
ylabel('BER');
grid on;
hold on;

						