Demodulation apparatus for multi-carrier PSK signals which reduces inter-carier interference

The disclosed apparatus is suitable for use with continuous phase signals which have a phase transition period 9 in which the phase varies non-linearly between the phase of a previous symbol and the phase of the present symbol 10. The frequency is greater within the transition period 9 than within the data period 10. Interference between the transition period 9 of a low frequency carrier and the data period 10 of a higher frequency carrier is avoided by synchronising the symbol positions of respective carriers and performing demodulation using only the data periods 10, preferably using a FFT. The transition periods 9 are ignored and can therefore be considered guard intervals. The demodulation apparatus is also suitable for use with a combined amplitude/phase modulation scheme such as QAM.