A distributed channel and code assignment algorithm to reduce interference in a wireless sensor network

Recently, the use of frequency division has emerged as an effective way of increasing network performance and mitigating interference in wireless sensor networks (WSNs). This technique allows sensor nodes to simultaneously access the wireless channel and thus enhances the performance of sensors. The inherent characteristics of sensor nodes such as the limited battery power, computation capabilities make it important to design protocols to enable interference free communications. This thesis proposes a distributed channel allocation (DCA) algorithm to assign different frequency channels to interfering sensors. Simulation results shows that the proposed scheme achieves a much lower probability of collisions when compared to previous schemes. Gold codes are also proposed to reduce multiple access interference (MAI) in a direct sequence code division multiple access (DS-CDMA) WSN. Comparisons are made with a pure CDMA network, and simulation results show a reduction of interference with the employment of a small number of frequency channels.