Improved pilot symbol-aided transmission technique for hybrid satellite and terrestrial mobile systems

In the hybrid satellite and terrestrial mobile systems, robust transmission techniques are required to compensate the signal distortion introduced in the fading channels. The pilot symbol-aided techniques have been proved to be suitable for the transmission of digital signals over satellite mobile and terrestrial mobile channels. In the paper, an improved pilot symbol-aided transmission technique suitable for the hybrid systems is proposed. The proposed technique uses the distortion information in data symbols as well as in pilot symbols for multipath fading compensation. Monte Carlo simulations have been carried out to investigate the effects of the proposed technique on the bit-error rate (BER) performances of 16PSK and 16QAM signals in satellite mobile and terrestrial mobile channels. Results have shown that, at high signal-to-noise ratios (SNRs), an improvement of more than two orders of magnitude in the BER performance can be obtained by the proposed technique, relative to those only using the pilot symbols