We study synchronization of electrically coupled three parameter Rose-Hindmarsh neurons when steady external currents are applied. We show that full synchronization (perfect phase-locking with zero phase-difference) is not possible for a network of two coupled neurons unless both neurons are subject to external currents of the same value. Then, after a looser definition of synchronization, we present simulation results at several points in the stimulus space. In a network of four coupled neurons with applied currents to only two of these neurons, by studying the distance between those two neurons which do not experience the external currents, we observe the presence of various synchronization topologies in the stimulus space as the weight configuration is varied.

In this study, a hybrid approach that employs a genetic algorithm (GA) and a multistage detector (MSD) for the multiuser detection problem in a code-division multiple-access communications system is proposed. Using this approach: (1) the GA is used as the first stage of the MSD to provide a good initial point for successive stages of the MSD and (2) the MSD is embedded into the GA as a "genetic operator" to improve further the fitness of the population at each generation. Such a hybridization of the GA with the MSD reduces its computational complexity by providing faster convergence. In addition, a better initial data estimate supplied by the GA improves the performance of the MSD, and the embedded MSD improves the performance of the GA. Simulation results for the synchronous and asynchronous cases are provided to show that the approach is promising.