hi all,Below is the QPSK i have done to calculate the BER. However, the dectection part is wrong. Can anyone advise what is the correct syntax. Appreciate the help greatly. Thanks %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%% % MATLAB Code for QPSK % performs the calculatation of the BER for the given value of SNR_db numSym; % Generate number of symbols to send bits_per_symbol=2; N=bits_per_symbol*numSym; M=4; % QPSK modulation. 1 symbol consists 2 bits SNR_db=1:0.5:13; % SNR range for per bit rand('state',12345) randn('state',54321) BER = zeros(1,prod(size(SNR_db))); % generate BER metric dimension the same as SNR_db for count=1:length(SNR_db) msg_orig=randsrc(numSym,1,[1:M]); QPSK=[1+i -1+i -1-i 1-i]; tx_signal=QPSK([msg_orig]); noise=sqrt(1/(2*log(M)*10^(SNR_db(count)/10)))*(rand(1,numSym) +j*rand(1,numSym)); rx_signal=tx_signal+noise rx_signal=rx_signal(:) a=[ 1 2 3 4]'; c=complex(a); decis=c([rx_signal-1]) end |

# QPSK for BER performance

Started by ●December 13, 2003