HI,
When i implement Turbo code in MATLAB and plot the graph for BER of each iteration(I computed BER after every iteration and i performed 10 iteration), i thought the plot should be monotonically decrease and reach minimum. . But to my surprise, i am getting randomly increasing and decreasing plot..
Can anybody help , y this occurs and spot the error...
To my knowledge my algo is right and i am getting good results for some other set of data..
i think you should use a very larger number of iterations to get the right result.
According to Monte Carlo simulation method , to estimate a given BER, the number of iterations must be very larger than 1/BER and as a rule of thumb we can choose N>10/BER
for example , if you want to estimate a BER of 1e-5 then you must at least have N=1000,000 iterations.
first of all i m bit shocked to read that u have implemented iterative decoding on MATLAB. because it involves lot of memory access, indirections and pointers are unavoidable in the implementation of decoding.
i wonder to wat extent the code is correct.
recently i have developed turbo encoder and decoder on C. as for as algo is concerned it is working fine, but because the turbo decoder wants soft bits as inputs right now i m focused on soft demapper.
once i m done with that i will surely get back to ur issue.