Extended Games-Chan algorithm for the 2-adic complexity of FCSR-sequences

Binary sequences generated by feedback shift registers with carry operation (FCSR) share many of the important properties enjoyed by sequences generated by linear feedback shift registers. We present an FCSR analog of the (extended) Games?Chan algorithm, which efficiently determines the linear complexity of a periodic binary sequence with period length T=2n or pn, where p is an odd prime and 2 is a primitive element modulo p2. The algorithm to be presented yields an upper bound for the 2-adic complexity, an FCSR analog of the linear complexity, of a pn-periodic binary sequence.