Synchronization and Sampling in Wireless Adaptive Signal Processing Systems

Abstract

This paper deals with the synchronization in wireless adaptive signal processingsystems. Wireless communication offers high flexibility, however, the distributedstructure of wireless systems requires the synchronization of the subsystems. Thesynchronization becomes particularly important if the signal bandwidth is in thekHz range, and it is inevitable in distributed control systems. The demand on thesynchronization is presented through the introduction of awireless active noise con-trol system. In this system wireless sensors (microphones)receive the signal, and themain signal processing algorithm is implemented on a central unit which producesthe signal for the actuators (loudspeakers). In spite of thespecial application, thesystem has a general structure, so the results are valid for other adaptive systems.First a PLL like algorithm is described for the synchronization of the sampling ina wireless real-time signal processing system, then a higher-level synchronizationis introduced for a distributed Fourier-analyzer based noise control system. Theeffectiveness of the algorithms is demonstrated by measurement results.