Patent ID: 11956014
Assignee: UNIVERSITA' DEGLI STUDI DI MILANO
Field: Telecommunications (Electrical engineering)
Classification: CPC H  G | IPC G  H

Claim 15:
16. The method according to claim 15, wherein:
the first electromagnetic radiation beam (F1) and the at least one second electromagnetic radiation beam (F2) are digitally amplitude modulated, in a binary manner, and the amplitudes of the first modulation function a(t) and the at least one second modulation function b(t) may take the logical values 0 or 1;
the method comprises the further step of detecting the received power or intensity (Q3) corresponding to the first main beam electrical signal (P1) or the second main beam electrical signal (P2), and comparing the power or intensity received with a minimum threshold;
the determined difference (Q2=ΔPab/k−ΔR/k′) may take a first expected value (ΔP10/k−ΔR/k′) which is dependent on the first angular momentum (L1), or a second expected value (ΔP01/k−ΔR/k′) which is dependent on the second angular momentum (L2), or a third expected value (ΔP11/k−ΔR/k′) which is dependent on a combination of the first and second angular momentums;
the step of demodulating, demultiplexing and demodulating the modulated information comprises:
recognizing that the first modulated beam (Fm1) carries information corresponding to 1 and the second modulated beam (Fm2) carries information corresponding to 0 if the determined difference (ΔPab/k−ΔR/k′) takes said first expected value (ΔP10/k−ΔR/k′);
recognizing that the first modulated beam (Fm1) carries information corresponding to 0 and the second modulated beam (Fm2) carries information corresponding to 1 if the determined difference (ΔPab/k−ΔR/k′) takes said second expected value (ΔP01/k−ΔR/k′);
recognizing that the first modulated beam (Fm1) carries information corresponding to 1 and the second modulated beam (Fm2) carries information corresponding to 1 if the determined difference (ΔPab/k−ΔR/k′) takes said third expected value (ΔP11/k−ΔR/k′);
recognizing that the first modulated beam (Fm1) carries information corresponding to 0 and the second modulated beam (Fm2) carries information corresponding to 0 if the received power or intensity (Q3) is lower than said minimum threshold.