A New Twist on Radio Waves
By now, you’d expect that communications engineers would have explored every trick in their century-old effort to cram more data into a limited number of frequencies.
But researchers in Italy and Sweden have shown that there is still uncharted territory. A little-explored quantum property, they claim , has the potential to boost the number of channels available in a single-frequency microwave link, perhaps as much as elevenfold.
In early March the researchers simultaneously transmitted two radio beams at exactly the same frequency between two of Venice’s islands, a distance of 442 meters. The signals were received and decoded as clearly as if they’d been sent at two different frequencies. Ordinarily, coding schemes require either different frequencies to distinguish the signals or the division of a channel into time slots.
The new trick hinges on using a quantum state...