【正文】 %% function of theoretical BER%**************************************************************************%==========================================================================% Description: Approach in the relay node with AF% Usage: H = RayleighCH(mu,sigma)% Inputs:% SNR_SD: SNR without cooperation% CH_sd,CH_sr,CH_rd % : Rayleigh Fading coefficient of Channel S_in_R % POW_S_sd,POW_N_sd,POW_S_rd,POW_N_rd% : Signal and Noise Power of Channels S_to_D S_to_R and R_to_D% Outputs:% theoretical_BER: BER approximation theory% ========================================================================= function theoretical_BER = Theo_ber( varargin )%% According to the numbers of input parameter to determine AF or DF model,than calculate the SNR if nargin == 1 % SD % for SD SNR SNR_SD = varargin{1}。 POW_S_sd = 1。 sig = 10^(SNR_SD/10)。 POW_N_sd = POW_S_sd / sig。 gamma_sd = ( POW_S_sd * (abs(SNR_SD))^2 ) / POW_N_sd。 gamma_rd = 0。 elseif nargin == 6 % DF CH_sd = varargin{1}。 CH_rd = varargin{2}。 POW_S_sd = varargin{3}。 POW_N_sd = varargin{4}。 POW_S_rd = varargin{5}。 POW_N_rd = varargin{6}。 % for DF SNR gamma_sd = ( POW_S_sd * (abs(CH_sd))^2 ) / POW_N_sd。 gamma_rd = ( POW_S_rd * (abs(CH_rd))^2 ) / POW_N_rd。 elseif nargin == 7 % AF CH_sd = varargin{1}。 CH_sr = varargin{2}。 CH_rd = varargin{3}。 POW_S_sd = varargin{4}。 POW_N_sd = varargin{5}。 POW_S_rd = varargin{6}。 POW_N_rd = varargin{7}。 % for AF SNR gamma_sd = ( POW_S_sd * (abs(CH_sd))^2 ) / POW_N_sd。 numerator = (POW_S_rd)^2 * (abs(CH_sr))^2 * (abs(CH_rd))^2。 denominator = ( POW_S_rd*(abs(CH_sr))^2+ POW_S_rd*(abs(CH_rd))^2+POW_N_rd ) * POW_N_rd。 gamma_rd = numerator / denominator。 end %% output SNRgamma = gamma_sd + gamma_rd。 %% output bpsk system39。s approximate theoretical BERtheoretical_BER = 1 / ( 2 * sqrt(pi*gamma) * exp(gamma) )。 % Approximation under high BER% theoretical_BER = erfc( sqrt(gamma) ) / 2。 % Actual value3. 合并方式—最大比合并%% function of the MRC%==========================================================================% Description: only suitable for the double receiving aerial% Usage: % AF: R_bine = Mrc(CH_sd,CH_sr,CH_rd,beta,POW_S_sd,POW_N_sd,POW_S_rd,POW_N_rd,signal_sd,signal_rd)% DF: R_bine = Mrc(CH_sd,CH_rd,POW_S_sd,POW_N_sd,POW_S_rd,POW_N_rd,signal_sd,signal_rd)% Inputs: % CH_sd,CH_sr,CH_rd% : Rayleigh Fading coefficient of Channels S_in_D S_in_R and R_in_D% POW_S_sd,POW_N_sd,POW_S_rd,POW_N_rd% : Signal and Noise Power of Channels S_to_D S_to_R and R_to_D% signal_sd,signal_rd% : Signal of Channels S_to_D and S_to_R R_to_D% beta: amplification factor% Outputs:% R_bine: Signal after MRC % =========================================================================function signal_bine = Mrc( varargin ) %% According to the numbers of input parameter to determine AF or DF model, than calculate the gain coefficientif nargin == 8 % DF CH_sd = varargin{1}。 CH_rd = varargin{2}。 POW_S_sd = varargin{3}。 POW_N_sd = varargin{4}。 POW_S_rd = varargin{5}。 POW_N_rd = varargin{6}。 signal_sd = varargin{7}。 signal_rd = varargin{8}。 % a_sd and a_rd are determined such that the SNR of the MRC output is maximized a_sd = CH_sd39。 * sqrt(POW_S_sd) / POW_N_sd。 a_rd = CH_rd39。 * sqrt(POW_S_rd) / POW_N_rd。 elseif nargin == 10 % AF CH_sd = varargin{1}。 CH_sr = varargin{2}。 CH_rd = varargin{3}。 beta = varargin{4}。 POW_S_sd = varargin{5}。 POW_N_sd = varargin{6}。 POW_S_rd = varargin{7}。 POW_N_rd = varargin{8}。 signal_sd = varargin{9}。 signal_rd = varargin{10}。 % a_sd and a_rd are determined such that the SNR of the MRC output is maximized a_sd = CH_sd39。 * sqrt(POW_S_sd) / POW_N_sd。 a_rd = (beta * sqrt(POW_S_rd) * CH_sr39。 * CH_rd39。) / ( (beta^2*(abs(CH_rd))^2+1) * POW_N_rd )。 end %% output after MRCsignal_bine = a_sd*signal_sd + a_rd*signal_rd。 4. AF仿真程序%% function of AF%==========================================================================% Description: Approach in the relay node with AF% Usage: H = RayleighCH(mu,sigma)% Inputs:% CH_sr: Rayleigh Fading coefficient of Channel S_in_R % POW_S: Signal power% POW_N: Noise power% signal_sr: Relay received the signal 39。signal_sr39。 from Source% Outputs:% beta: amplification factor% signal_AF: signal after AF,it39。ll be transmitted from Relay to Destination% =========================================================================function [beta,signal_AF] = AF(CH_sr,POW_S,POW_N,signal_sr) beta = sqrt( POW_S) / ( (abs(CH_sr))^2 * POW_S + POW_N )。 % amplification factor signal_AF = beta * signal_sr。 % Relay transmit the AF signal 39。signal_A5. DF仿真程序%% function of AF%==========================================================================% Description: Approach in the relay node with AF% Usage: H = RayleighCH(mu,sigma)% Inputs:% CH_sr: Rayleigh Fading coefficient of Channel S_in_R % POW_S: Signal power% POW_N: Noise power% signal_sr: Relay received the signal 39。signal_sr39。 from Source% Outputs:% beta: amplification factor% signal_AF: signal after AF,it39。ll be transmitted from Relay to Destination% =========================================================================function [beta,signal_AF] = AF(CH_sr,POW_S,POW_N,signal_sr) beta = sqrt( POW_S) / ( (abs(CH_sr))^2 * POW_S + POW_N )。 % amplification factor signal_AF = beta * signal_sr。 % Relay transmit the AF signal 39。signal_