Simulation, Design and Testing of Wireless Data Acquisition RF Systems for Capsule Endoscopy

This paper presents an aggregation of simulated and designed radio frequency (RF)-based models for a wireless data acquisition system. The model consists of key units that were simulated with SIMULINK. We employed a path loss scenario based on the popular log-normal model to investigate the relationship between signal power transmitted, distance between transmitter and receiver, and the bit error rate generated in the channel. The performance of the RF unit through additive white Gaussian noise (AWGN) channel was examined by estimating the average bit error rate (BER) for a certain carrier frequency. The effect of the multi-path fading in a lossy medium (applicable to the human gastro intestinal (GI) tract) was also considered. The receiver model was operating about 10-20 cm from the transmitter whereby the power emanating from the transmitter antenna is essentially omnidirectional. Taking advantage of the 433 MHz free band, input power 1 W, and signal energy-noise power spectral density (Es/No) = 20 dB corresponding to the linear region of the target transceiver. Finally a laboratory model was built in order to confirm the simulated results.