How to do convolution of more than 2 signals? I keep on getting errors

I keep on getting errors like this : "Error using conv (line 35) SHAPE must be 'full', 'same', or 'valid'.

Error in mp2no3 (line 25) orig1 = conv(x1est,x2est,x3est);"

Answer 1

[Mohammad Abouali]

conv only accepts two signal at a time. you can not pass it three signal.