In mobile ad hoc networks(MANETs),if a muhihop route breaks,route maintenance is typicallyperformed to establish a new route which causes high control overhead and long packet delay.To decreasethe time of recovery and the overhead of maintenance,a new route maintenance mechanism in which themaintenance is confined to the vicinity of the broken link is proposed.This mechanism patches brokenroute through some other nodes in which only nodes near the broken link(s)may need to be substitutedand the rest of nodes can be retained on the route.The broken link can be repaired without consideringits relative position in the whole path,so the ability of dealing with link failure is improved obviously.Simulation results show that the proposed strategy improves network performance significantly,such as inmerits of control overhead and packet delay.
Direct sequence spread spectrum transmission can be realized at low SNR,and has low probability of detection.It is aly problem how to obtain the original users' signal in a non-cooperative context.In practicality, the DS/CDMA sources received are linear convolute mixing.A more complex multichannel blind deconvolution MBD algorithm is required to achieve better source separation.An improved MBD algorithm for separating linear convolved mixtures of signals in CDMA system is proposed.This algorithm is based on minimizing the average squared cross-output-channel-correlation.The mixture coefficients are totally unknown,while some knowledge about temporal model exists.Results show that the proposed algorithm can bring about the exactness and low computational complexity.
