How to check the performance of viterbi algorithm i.e. What is the theoretical expression for Pe vs SNR graph for viterbi algorithm?

Moreover, How is SNR (or Es/No) defined? Do we add noise to each channel (path) seperately or to the sum?

The exact expression for the BER with a Viterbi algorithm is quite difficult to compute (there is no closed form expression or even an infinite series that can be numerically computed). However, we can obtain good lower bounds at high SNR. We can also obtain upper bounds. The relative easy bound to compute would be the lower bound based on computing the minimum Euclidean distance error event just like the example I worked out in class for three tap channel. There are some what easy ways to find this using the MATLAB program that you have already written for the Viterbi Algorithm, it is a bit difficult to explain this here.

As for the noise, there is often some confusion among the origin of what we call as noise in our model. This is thermal noise which has nothing to do with the individual paths that the transmitted signals take to get to the receiver. Read the section on thermal noise from Thermal noise and see that this noise occurs in the electronic circuitry at the receiver. So, you will NOT add noise to each path, but only once to the received signals.

What is the difference between the steps 5 and 6 in the task list? Are there two ways of computing BER - with using and without using Montecarlo simulations?

Is there any difference in the implementation of viterbi if the inputs and tap coefficients are complex and not real?

No, there should be no difference in the implementation. However, make sure you compute the branch metric properly as the square of the magnitude of the difference between what you observe at that time instant and what the noiseless output along that branch should be.

Hi,

How should we upload the m-files to the web? Moreover, should it be up to Tuesday that we turn in our reports?

Will we get to know our project scores before exam?

It is unlikely. If you want to talk to me about your performance, you can come by on Friday. I think I will do most of the grading only over the weekend or right after the finals.