Upper bound for a hybrid sum over Galois rings with applications to aperiodic correlation of some q-ary sequences

An upper bound for a hybrid exponential sum over Galois rings is derived. This bound is then used to obtain an upper bound for the maximum aperiodic correlation of some sequence families over Galois rings. The bound is of the order of /spl radic/qlnq where q-1 is the period of the sequences