Video image transmission via mobile satellite channels

This paper deals with transmitting CCITT H.261 standard compressed moving-images (64 kbits/sec) through shadowed mobile satellite channels. Concatenated codes consisting of 8PSK trellis inner codes and Reed-Solomon (or BCH) outer codes are used to achieve large coding gains with small bandwidth expansion in the presence of frequency-nonselective slow fading. Pilot symbol-aided techniques have been found to be suitable for the transmission of digital signals over mobile satellite channels. An improved pilot symbol assisted DFALP (decision feedback adaptive linear prediction) algorithm is presented and used to estimate fading channel state information. Monte Carlo simulations show that our 40.5 kBd system yields near error free image transmission at average channel signal to noise ratio (Eb/No) between 10-13 dB over light-to-average shadowed Rician channels. The trade off between BER performance and delay due to interleaving is investigated