Wireless multimedia system over SST channels
P. Steyn, J.S. Kunicki · 2002
Supplementary signal transmission (SST) channels are used for low rate data and audio transmission. SST uses sections of bandwidth of conventional FM and is an under-utilized channel in South Africa. Data on radio channels are easily corrupted by channel noise. To address this problem for SST, forward error correction (FEC) coding is essential for data protection and consequently convolutional codes, with and without interleaving, are implemented and tested for performance on the SST channel. The authors present a wireless multimedia system using the SST channel. This system has been conceptualized with distant education in mind and is based on "slide show-like" lectures. To accomplish this, text and/or JPEG images accompanied by a real-time audio signal are sent over the SST channel. This paper mainly concentrates on the effects of errors on JPEG images as well as the effect of FEC coding on recovery of data corrupted by SST channel noise. The system is experimentally implemented and data files are transmitted and received with real time FEC coding. Selected bit error rate (BER) measurements of the SST channel are presented to provide an additional characterisation of the transmission medium used.