Let P1 and P2 two distinct output signals that are generated by a common input signal S. If you want to estimate S using multichannel blind system identification algorithms, you have to specify the channel length L. How can I determine the best choice for L?
If I understand correctly, the Akaike Information Criterion leads to the following algorithm:
Fix an L. Calculate S from P1 and P2 (and L) and determine the impulse responses h1 and h2. Then calculate the estimated signals P1est and P2est from S and h1 and h2 resp. The Criterion is therefore given by the sum of the errors e1i and e2i at the sample points i=1:length(P1)=N, divided by 2N, minus the penalty term of the Akaike Information Criterion. Repeat the calculations for other choices of L and compare the resulted values of the criterion.
This is a possibility to determine the optimal choice of L, but this needs a lot of computations and it is expensive. Is there not an easier way to determine the best choice for L?