A reduced complexity digital multicarrier demodulator for satellite communication systems

The design of a completely digital multicarrier demodulator (MCD) for application in advanced satellite communication systems is presented. The proposed MCD has two parts: the demultiplexer (DEMUX) and the coherent demodulator (DEMOD). In particular, the DEMUX has been implemented according to the analytic signal approach leading to a per-channel structure that avoids any digital product modulator and any block processor. It has the specific feature to relax the filter specifications, thus achieving a lower implementation complexity with respect to other per-channel approaches. Further, the analytic signal approach is directly matched to the per-channel implementation of the demodulators; therefore, a certain degree of integration of the DEMUX and DEMOD functions can be obtained, thus lowering the overall system complexity. In conclusion, the digital MCD system described represents an appropriate solution for advanced digital communication systems interfacing FDMA and TDM links and, in particular, it has been carried out aiming at its possible implementation by custom or semicustom VLSI digital circuits.