Sulav Timsina
Newbie level 2
I am writing a matlab code about convolutional encoder. I have created trellis for 4,8,16 and 32 states and their corresponding viterbi decoder(using vitdec matlab function). My system goes like this:
Trellis Encoder-->DPSK Modulator-->Rayleigh fading Channel + awgn Noise-->DPSK Demodulator-->Viterbi Decoder
For the 4 state trellis it is fine,but as I go on increasing the states of trellis encoder, the BER increases.But actually by theory it should decrease. I think I have problem with passing arguments in the vitdec function (may be problem with track back length). I have presented my matlab code here. Please suggest,why the error is increasing with the increasing of states.
Matlab Code:
https://pastebin.com/ykw75iVm
Or file in txt.Change the extension to .m and run it:
sulavWorkingSTTCmanystate..txt
Trellis Encoder-->DPSK Modulator-->Rayleigh fading Channel + awgn Noise-->DPSK Demodulator-->Viterbi Decoder
For the 4 state trellis it is fine,but as I go on increasing the states of trellis encoder, the BER increases.But actually by theory it should decrease. I think I have problem with passing arguments in the vitdec function (may be problem with track back length). I have presented my matlab code here. Please suggest,why the error is increasing with the increasing of states.
Matlab Code:
https://pastebin.com/ykw75iVm
Or file in txt.Change the extension to .m and run it:
sulavWorkingSTTCmanystate..txt