A WFMT Dowulink Transmitter for Low Earth Orbit Satellite

This paper discusses the performance of the satellite downlink transmitter that uses a wavelet based filtered multi-tone (WFMT) modulation. The novel WFMT modulation was proposed for improving characteristics of OFDM multicarrier systems but also can be successfully used in satellite communications. In this paper, we discuss the advantages of WFMT modulation in comparison with OFDM so as low sensitivity to narrowband RF interference and lower peak-to-average power ratio. It is shown that modern GaAs solid-state power amplifiers are well suited for transmission of multicarrier signals. An effect of non-linear distortion on power added efficiency (PAE) of the RF power amplifier is discussed. Effect of clipping of WFMT signal on the error performance is described. It is shown that error correction block codes can significantly improve PAR characteristics of the communication system. The power efficiency of WFMT satellite transmitter is significantly higher that in case of OFDM.