Patent ID: 7302007

Claim:
A signal transmission and receiving apparatus for transmitting and receiving a PSK modulated signal or a QAM modulated signal, the apparatus comprising a transmission apparatus and a receiving apparatus, said transmission apparatus comprising: a modulator operable to modulate a data stream to an n-level PSK modulated signal or an n-level QAM modulated signal, wherein n is an integer, wherein the modulator is operable to select a value of n from a plurality of values of n; and a transmitter operable to transmit the n-level PSK modulated signal or the n-level QAM modulated signal; wherein the transmission power of the n-level PSK modulated signal or the n-level QAM modulated signal is determined according to information representing the selected value of n; said receiving apparatus comprising: a demodulator operable to demodulate the n-level PSK modulated signal or the n-level QAM modulated signal to a demodulated data stream.