Lossless coding scheme for data acquisition under limited communication bandwidth

Wireless data acquisition system (WDAS) is widely used in many application fields. Due to the conflict between bandwidth constraint and large amount of real-time data with high sampling frequency or multi-channel sampling, it is a challenging problem to transmit data to the back-end processing server timely and effectively. A novel and simple lossless source coding scheme, called PVA (Pre-processing and Valid word length Adaptive coding), is proposed for WDAS under limited communication bandwidth. The proposed coding scheme improves the utilization of communication bandwidth and realizes the real-time compression and transmission by the technique of common binary fields finding, repeating fields reducing and data stream recombination. PVA scheme also improves the precision of the measured signals compared to the normal oversampling method under the same bandwidth. It is thus effective for the applications which are in high demand of fidelity. The experiments on vibration and electroencephalography (EEG) signals show that the proposed PVA scheme is effective and valuable in WDAS.