www.gusucode.com > phased 案例源码 matlab代码程序 > phased/PropagateWidebandSignalLOSChannelExample.m
%% Propagate Wideband Signal in LOS Channel % Propagate a wideband signal in a line-of-sight (LOS) channel from a radar % at _(0,0,0)_ meters to a target at _(60,0,0)_ meters in medium fog. Set % the fog liquid water density to 0.05 $g/m^3$. Assume rain is falling % at 5 mm/hr. The signal carrier frequency is 20 GHz. The signal is a sum % of four cw tones at 19.75, 19.875, 20.125, and 20.25 GHz. Set the % signal duration to 0.5 microsecond and the sample rate to 2.0 GHz. Assume % the radar is stationary and the target approaches the radar at 40 m/s. % The atmospheric temperature is 12°C and the dry air pressure is % 101.300 kPa. %% % Set the signal parameters and create the transmitted signal. c = physconst('LightSpeed'); fs = 2e9; freq = [-0.25,-.125,0.0,0.125,0.25]*1e9; fc = 20.0e9; dt = 1/fs; t = [0:dt:.5e-6]; sig = sum(exp(1i*2*pi*t.'*freq),2); %% % Specify the atmosphere parameters and create the |phased.WidebandChannel| % System object(TM). lwd = 0.05; rainrate = 5.0; dap = 101300.0; temp = 12.0; sWBLOS = phased.WidebandLOSChannel('SampleRate',fs,'PropagationSpeed',c,... 'SpecifyAtmosphere',true,'OperatingFrequency',fc,'RainRate',rainrate,... 'LiquidWaterDensity',lwd,'Temperature',temp,'DryAirPressure',dap); %% % Specify the radar and target positions and velocities. xradar = [0,0,0].'; vradar = [0,0,0].'; xtgt = [60,0,0].'; vtgt = [-40,0,0].'; %% % Propagated the signal using the |step| method. prop_sig = step(sWBLOS,sig,xradar,xtgt,vradar,vtgt); %% % Plot the propagated signal. For a target range of 60 m, the propagation % delay is 0.20 μs as shown in the plot. plot(t*1e6,real(prop_sig)) grid xlabel('Time (\mu sec)') ylabel('Amplitude')