Remember that cross correlation is a mean of linear system theory and not of information theory.. Correlation simply considers the time course, mutual information the information coded in the time course of the signal. What is your focus?

Werner

In the beginning i did not get the required correlation coefficient for my  ECG and BCG data, the values were too low -0.06 etc., but I tried this only because ECG and PPG signals were compared similarly (atleast HRV analysis). Hence thought mutual information could help but I was not sure.

Now i seem to get a good value for cross correlation coefficient itself. I had missed a peak or two in my previous analysis. :)