Digital radio communication system utilizing quadrature modulated carrier waves

A digital radio communication system comprising a transmitter and a receiver, said transmitter including:

• a modulator for generating a linear quadrature modulated carrier signal, the carrier signal having signal points which are defined on a complex amplitude plane according to binary digital signals to be transmitted, said signal points defining traces each of which is non-intersective with and spaced from the origin of the complex amplitude plane;
• and
• a linear power amplifier adapted to amplify the output of said modulator, said power amplifier including means for compensating non-linearity of the amplified signal,
• said receiver including:
• an amplitude limiter for hard limiting a received linear quadrature modulated carrier signal, said carrier signal having signal points which are defined on a complex amplitude plane according to binary digital signals to be transmitted, said signal points defining traces each of which is non-intersective with and spaced from the origin of the complex amplitude plane;
• a demodulator which determines the instantaneous angular velocity of the received signal according to the hard limited signal applied from said amplitude limiter and which integrates the instantaneous angular velocity during a time duration which corresponds to one period of the binary digital signal, said demodulator detecting an actual phase variation between two consecutive received signal points;
• and
• a decision circuit for determining a correct phase variation between the two consecutive received signal points.