1. Show that two codes constructed by the algorithm for OVSF codes have the desired orthogonality properties. Do OVSF codes apply to asynchronous systems?
2. Prove the autocorrelation property of Eq. (5.31) for m-sequences.
3. To show that scramblers based on tn-sequences are not very good encryption devices, determine the minimum number of consecutive bits that would need to be known to reconstruct the initial state. (Assume that the generating polynomial is known.)