第二章.zip_传感器阵列_传感器阵列波束优化设计与应用_波束优化_波束图设计_阵列设计

%%传感器阵列波束优化设计与应用 %%20170813 %%20170815改 %%myuzhao %% clc; clear ; close all; %扫描计算范围 freq =1000; %信号频率 f=freq; fs = 10000; % 采样频率 c0 = 344; lamd=c0/freq; snapshots_N=5000; % %阵元位置 element_num=10; d_lamda=1/2;%阵元间距d与波长lamda的关系 d=d_lamda*c0/f*[0:1:element_num-1]; %%扫描参数设置 theta0=10*pi/180; theta1=linspace(-90,90,10000); theta=theta1*pi/180; % snr=0; % s=10^(snr/20)*exp(1i*2*pi*freq*[1/fs:1/fs:snapshots_N/fs]); % aps=exp(1i*2*pi*freq*d'*sin(theta0)/c0)*s; wp=exp(1i*2*pi*freq*d'*sin(theta0)/c0)/element_num; ap=exp(1i*2*pi*freq*d'*sin(theta)/c0); p=ap'*wp; energy_cbf_P=20*log10(abs(p)); figure plot(theta1,energy_cbf_P) xlabel('方位/(^o)') ylabel('波束/dB') ylim([-70 3]) grid on title('波束图') %%纯信号时波束扫描方位谱 snr=0; s=10^(snr/20)*exp(1i*2*pi*freq*[1/fs:1/fs:snapshots_N/fs]); aps=exp(1i*2*pi*freq*d'*sin(theta0)/c0)*s; R=aps*aps'/snapshots_N; wp=exp(1i*2*pi*freq*d'*sin(theta)/c0)/element_num; p=diag(wp'*R*wp); energy_cbf_P=10*log10(abs(p)); figure plot(theta1,energy_cbf_P) xlabel('方位/(^o)') ylabel('波束/dB') ylim([-70 3]) grid on title('纯信号时波束扫描方位谱') %%SNR=30dB信噪比时波束扫描方位谱 snr=30; s=10^(snr/20)*exp(1i*2*pi*freq*[1/fs:1/fs:snapshots_N/fs]); aps=exp(1i*2*pi*freq*d'*sin(theta0)/c0)*s; noise=1/sqrt(2)*(randn(element_num,snapshots_N)+1i*randn(element_num,snapshots_N)); aps=aps+noise; R=aps*aps'/snapshots_N; wp=exp(1i*2*pi*freq*d'*sin(theta)/c0)/element_num; p=diag(wp'*R*wp); energy_cbf_P=10*log10(abs(p)); figure plot(theta1,energy_cbf_P) xlabel('方位/(^o)') ylabel('波束/dB') ylim([-10 33]) grid on title('SNR=30dB时波束扫描方位谱') %%不同方位时波束阵增益 10*logM ap=exp(1i*2*pi*freq*d'*sin(theta0)/c0); pn=eye(10,10); wp=exp(1i*2*pi*freq*d'*sin(theta)/c0); pn=diag(wp'*pn*wp); ps=diag((wp'*ap)*(ap'*wp)); G=abs(ps./pn); G_dB=10*log10(G); figure plot(theta1,G_dB) xlabel('方位/(^o)') ylabel('阵增益/dB') title('不同方位时波束阵增益') ylim([-50 13]) grid on