Hamming distance and error detection/correction properties.

Question

Hi guys,

Let's assume I want to have a possibility of detecting 4-bit errors and recovering 2-bit errors. What the Hamming distance should be then?

I wonder if it should be d = Max{2r+1, r+1} or d = s + r, where s is 4 and r is 2?

Thanks in advance for the reply!

Cheers