A new kind of two-dimensional optical orthogonal code named ESPC/OCS is constructed,which uses the extend square prime code (ESPC) for time spreading and the one-coincidence sequence(OCS) for wavelength hopping. The performance of ESPC/OCS is analyzed and the mean value of cross-correlation is deduced. Meanwhile the bit error ratio (BER) for codes is simulated and compared. The simulation results show that given p and q,the BER of ESPC/OCS is reduced,and the capacity is enlarged,when the number of hopping codes p is increased. Given OCS (given q and d),when p is changed,only the capacity is changed,but the BER is almost the same. The performance of ESPC/OCS is better than that of PC/ OCS.
We present a scheme for multiparty quantum remote secret conference （MQRSC） with pure entangled states, not maximally entangled multipartite quantum systems. The conferees first share a private quantum key, a sequence of pure entangled states and then use them to encode and decode the secret messages. The conferees exploit the decoy-photon technique to ensure the security of the transmission of qubits. This MQRSC scheme is more feasible and efficient than others.
