| 摘要 |
A radio communications method, includes carrying out, by a transmitter: generating or receiving digital symbols to be transmitted; generating, every S digital symbols generated/received (with S integer higher than three), a corresponding multi-mode digital signal; generating a multi-frame digital signal comprising successive, non-overlapped time frames, each of which has the predefined time length and carries a respective multi-mode digital signal generated; and transmitting a radio frequency signal carrying the multi-frame digital signal. The radio communications method further includes carrying out, by a receiver: receiving the radio frequency signal transmitted by the transmitter; processing the received radio frequency signal to obtain a corresponding incoming digital signal; performing, on the basis of the incoming digital signal, carrier synchronization, clock synchronization, and frame synchronization; and extracting, on the basis of the carrier, clock and frame synchronizations. |
| 主权项 |
1. A radio communications method comprising carrying out, by a transmitter, the following steps:
a) generating or receiving digital symbols to be transmitted, said digital symbols having a given symbol rate associated with a corresponding symbol period; b) generating, every S digital symbols generated/received, a corresponding multi-mode digital signal, which
has a predefined time length shorter than S times the symbol period,has a predefined bandwidth larger than the Nyquist bandwidth corresponding to the given symbol rate, andcarries said S digital symbols by means of orbital angular momentum modes comprising
a main mode, that is an orbital angular momentum mode with topological charge equal to zero and that carries P of said S digital symbols, andone or more twisted modes carrying the other S-P digital symbols, wherein each twisted mode is an orbital angular momentum mode with a respective topological charge different than zero and is time-shifted with respect to the main mode; c) generating a multi-frame digital signal comprising successive, non-overlapped time frames, each of which has the predefined time length and carries a respective multi-mode digital signal generated; and d) transmitting a radio frequency signal carrying the multi-frame digital signal; wherein S is an integer higher than three, and P is an integer higher than zero and lower than S; the method further comprising carrying out, by a receiver, the following steps: e) receiving the radio frequency signal transmitted by the transmitter (3); f) processing the received radio frequency signal so as to obtain a corresponding incoming digital signal; g) performing on the basis of the incoming digital signal
carrier synchronization thereby recovering frequency and/or phase carrier used by the transmitter (3) to generate the multi-mode digital signals,clock synchronization thereby recovering the symbol rate and sampling time instants of the multi-mode digital signals generated by the transmitter (3), andframe synchronization thereby detecting successive, non-overlapped portions of the incoming digital signal corresponding to the successive, non-overlapped time frames of the multi-frame digital signal generated by the transmitter (3); and h) extracting, on the basis of the carrier, clock and frame synchronizations performed, the S digital symbols respectively carried by each detected incoming digital signal portion by means of the orbital angular momentum modes. |
