Synchronization and sampling in wireless adaptive signal processing systems

Abstract

This paper deals with the synchronization in wireless adaptive signal processing systems. Wireless communication offers high flexibility, however, the distributed structure of wireless systems requires the synchronization of the subsystems. The synchronization becomes particularly important if the signal bandwidth is in the kHz range, and it is inevitable in distributed control systems. The demand on the synchronization is presented through the introduction of a wireless active noise control system. In this system wireless sensors (microphones) receive the signal, and the main signal processing algorithm is implemented on a central unit which produces the signal for the actuators (loudspeakers). In spite of the special application, the system 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 in a wireless real-time signal processing system, then a higher-level synchronization is introduced for a distrib uted Fourier-analyzer based noise control system. The effectiveness of the algorithms is demonstrated by measurement results.