Radio communications system and method based on time twisted waves

Radio communications method including carrying out, by a transmitter, transmission operations that comprise:

• generating first digital time signals related to a first Orbital Angular Momentum mode with topological charge equal to zero, wherein each first digital time signal includes respective first time samples carrying corresponding first digital symbols to be transmitted;
• applying a first transmission filter to the first digital time signals, thereby obtaining filtered first digital time signals;
• generating second digital time signals related to one or more second Orbital Angular Momentum modes with topological charge different than zero, wherein each second digital time signal includes respective second time samples carrying one or more respective second digital symbols by means of a phase, or amplitude and phase, modulation related to a respective second Orbital Angular Momentum mode with topological charge different than zero;
• applying a second transmission filter to the second digital time signals, thereby obtaining filtered second digital time signals;
• combining the filtered first and second digital time signals into combined digital time signals, all having one and the same predefined time length;
• and
• transmitting a radio frequency signal carrying, in successive, non-overlapped time frames having the predefined time length, the combined digital time signals;
• the radio communications method further including carrying out, by a receiver, reception operations that comprise:
• receiving the radio frequency signal transmitted by the transmitter;
• processing the received radio frequency signal so as to obtain a corresponding incoming digital signal;
• and
• processing said incoming digital signal so as to extract therefrom the first and second digital symbols carried thereby;
• wherein the first transmission filter and the second transmission filter have different filtering characteristics.