Implementation of reception and real-time decoding of ASDM encoded and wirelessly transmitted signals

Abstract

This paper describes an implementation of reception and real-time decoding of Asynchronous Sigma-Delta modulator (ASDM) encoded and wirelessly (On-off keying) transmitted signals. By using Fast reconstruction algorithm it is possible to reconstruct the original signal ≈ 25 times faster than by Classical reconstruction algorithm, if the signal lenght is 1 second, and ≈ 61, ≈ 130 and ≈ 228 times faster, if the length of the signal is 2, 4 and 8 seconds, respectively. Developed overall system consists of 3 parts - superheterodyne receiver, digitizer, PC with adaptive data reconstruction algorithm. Real-time decoding algorithm, which consist of data acquistion, filtering, processing, reconstruction and vizualization is implemented in LabView as a virtual instrument with graphical user interface (GUI).