A quadrature phase-shift keying (QPSK) modulation is used to combine the L1OC and L1SC signals. The local minimum between 1,610 MHz and 1,614 MHz is caused by a notch filter onboard the satellite to ...

Quantum Key Distribution (QKD) enables information-theoretic secure communication based on quantum physics. A new study by Danish, Austrian, and Canadian researchers has demonstrated composable secure ...