Diversidade cooperativa adaptativa aplicada a redes de sensores sem fio cognitivas.

Abstract

Wireless sensor networks (WSNs) are becoming popular in many applications, such as industrial, civilian, multimedia, etc. The need to improve the performance of such systems can be attained by using the adaptive cooperative diversity (SCA) technique, which is basically a cross-layer design that combines Truncated ARQ at the link layer and cooperative diversity at the physical layer. In addition, the LEACH protocol has the advantage of utilizing randomized rotation of local cluster-heads to evenly distribute the energy load among the sensors in the network. This dissertation proposes an integrated system, SCA with LEACH and evaluates its performance with LEACH with Truncated ARQ system. A comparison is obtained based on network lifetime and packet loss rate of the system under varying propagation scenarios, number of retransmissions, initial energy by node, packet length and network size. The performance of image transmissions using both techniques is also evaluated. Simulation results show better performances for the proposed system.