Combined trellis shaping and coding to control the envelope of a bandlimited PSK-signal

A combined coded and trellis shaped modulation scheme is proposed to reduce the envelope fluctuations of a bandlimited 8-PSK system and hence to mitigate distortions introduced by nonlinearities in the transmission path. The method of trellis shaping is used to influence the symbol transitions of the transmitted signal. Thus, transitions with large phase differences causing strong fluctuations in the envelope of the bandlimited modulated signal can be avoided. The restoration of the spectral sidelobes due to nonlinear distortion is considerably reduced. Additional coding leads to a bit error rate comparable to that of conventional QPSK.<<ETX>>