An efficient receiver architecture for burst reception at very low SNR

In interactive satellite communication systems, adaptive coding and modulation is a suitable countermeasure to mitigate the high fade dynamics of frequency ranges like the Ka-band. Consequently, receivers that support operation at low and very low SNR are required. in this paper, we present such a receiver structure dedicated for burst reception in a MF-TDMA system, as it is typically adopted in the return link of satellite systems. The receiver tackles the phase, frequency and timing synchronization problem arising at low SNR. This is achieved by a combination of simple algorithms, which estimate frequency offsets on a pre- and postamble structure as well as jointly with a Turbo decoder. On top of that, payload cyclic redundancy check is used to test a number of frequency and timing hypotheses. This is done such that the computational complexity is in the order to that of classical receiver architectures in higher SNR regions. By means of Monte Carlo simulations, we could show that there were practically no degradations due to frequency and timing offsets. The burst error rate performance of the proposed system with all the synchronization units in operation was at least equal to that obtained over ideal AWGN.