LTE_channel.rar_LTE MATLAB 代码_LTE 信道_LTE 信道_LTE信道

%% Function discription: %%------------------------------------------------------------------------- %% generate wireless channel for transmission, the supported channel here is PedA,PedB etc. %% you can reference to 3GPP TR 25.890 & 3GPP TS 36.101 for more details about such channel modes %%------------------------------------------------------------------------- % Author: Qinzhiyong % E-mail: braveching@gmail.com % Date: 27th October 2011 % @@input: channel_type -- type of wireless channel, % NTxSymbol -- the total number of Symbols to be transmited(including all subcarriers) % @@output: channel -- a struct which contains the multipath channel impulse response channel.h % & his FFT form channel.h_FFT function channel = LTE_channel(channel_type,NTxSymbol) global LTE_params % initial the parameters switch channel_type case {'PedA'} % ITU Pedestrian A channel channel.PDP_dB = [0 -9.7 -19.2 -22.8]; % Average power of multipaths [dB] channel.delays = [0 110*10^-9 190*10^-9 410*10^-9]; % delay of multipaths [s] figure; plot(channel.delays,channel.PDP_dB) xlabel('s') ylabel('dB') title('PDP for QPSK using OFDM in a PedA channel') case {'PedB'} % you can add channel data here after you refer to some 3GPP specifications metioned above channel.PDP_dB = [0 -0.9 -4.9 -8.0 -7.8 -23.9]; % Average power of multipaths [dB] channel.delays = [0 200*10^-9 800*10^-9 1200*10^-9 2300*10^-9 3700*10^-9]; % delay of multipaths [s] figure; plot(channel.delays,channel.PDP_dB) xlabel('s') ylabel('dB') title('PDP for QPSK using OFDM in a PedB channel') case {'VehA'} channel.PDP_dB = [0 -1 -9 -10 -15 -20]; % Average power of multipaths [dB] channel.delays = [0 310*10^-9 710*10^-9 1090*10^-9 1730*10^-9 2510*10^-9]; % delay of multipaths [s] figure; plot(channel.delays,channel.PDP_dB) xlabel('s') ylabel('dB') title('PDP for QPSK using OFDM in a VehA channel') case {'VehB'} channel.PDP_dB = [-2.5 0 -12.8 -10.0 -25.2 -16.0]; % Average power of multipaths [dB] channel.delays = [0 300*10^-9 8900*10^-9 12900*10^-9 17100*10^-9 20000*10^-9]; % delay of multipaths [s] figure; plot(channel.delays,channel.PDP_dB) xlabel('s') ylabel('dB') title('PDP for QPSK using OFDM in a VehB channel') case {'TU'} channel.PDP_dB = [-3.0 0.0 -2.0 -6.0 -8.0 -10.0]; % Average power of multipaths [dB] channel.delays = [0.0 0.2 0.6 1.6 2.4 5.0]*10^-6; % delay of multipaths [s] figure; plot(channel.delays,channel.PDP_dB) xlabel('s') ylabel('dB') title('PDP for QPSK using OFDM in a TU channel') case {'RA'} case {'HT'} channel.PDP_dB = [0.0 -2.0 -4.0 -7.0 -6.0 -12.0]; % Average power of multipaths [dB] channel.delays = [0.0 0.2 0.4 0.6 15.0 17.2]*10^-6; % delay of multipaths [s] figure; plot(channel.delays,channel.PDP_dB) xlabel('s') ylabel('dB') title('PDP for QPSK using OFDM in a HT channel') case {'EVehA'} % extended multipath channel model in 3GPP TS 36.101 added case {'ETU'} % extended multipath channel model in 3GPP TS 36.101 added case {'AWGN','flat_Rayleigh'} channel.Num_path = 1;% the number of Rayleigh paths,default is 1,if you want to % simulate multi-paths channel, you can use other channel model above otherwise error('Channel not supported'); end % generate channel matrix, assuming that the channel time corelation is independent switch channel_type case {'flat_Rayleigh'} channel.h = 1/sqrt(2)*(randn(NTxSymbol,channel.Num_path) + j*randn(NTxSymbol,channel.Num_path)); otherwise LTE_params.Fs = LTE_params.SubcarrierSpacing*LTE_params.Nfft; % sampling frequency channel.path_delays_samples = round(channel.delays*LTE_params.Fs); channel.num_faders = length(unique(channel.path_delays_samples)); % some taps merged by a specific sampling freq %because of the resolution, and can not distinguish every path channel.h_temp = 1/sqrt(2)*(randn(NTxSymbol,channel.num_faders) + 1i*randn(NTxSymbol,channel.num_faders)); distinct_path_delays_samples = unique(channel.path_delays_samples); channel.h = zeros(NTxSymbol,length(channel.delays)); for path_i = 1:channel.num_faders index = find(distinct_path_delays_samples(path_i)==channel.path_delays_samples); channel.h(:,index(1)) = sqrt(sum(10.^(channel.PDP_dB(index)./10))).* channel.h_temp(:,path_i); end end % computing and storing the frequency response of the channel, for equalization at recevier channel.h_FFT = fftshift(fft(channel.h,LTE_params.Nfft,2),2);