High Reliable Orbital Angular Momentum Wireless Communications for Space Information Networks

Space wireless communications have been developing for several decades, along with traditional orthogonal resources such as frequency and time widely explored. To further increase the capacity of space information networks, new orthogonal resources are highly expected to be used for space wireless communications. In recent years, electromagnetic (EM) waves carrying orbital angular momentum (OAM), which is a kind of nonplanar EM waves (NEWs), received much attention due to their orthogonal beam structures. However, for space wireless communications, reliability is very crucial, thus challenging the utilization of OAM wireless communications for space information networks. In this paper, we propose the cosine weighting function based NEWs wireless transmission, which is a kind of high reliable OAM based wireless communications, for space information networks. At first, we give the system model of the cosine function based NEWs wireless transmission. Then, we derive the electric fields and array factors of the cosine based NEWs. After that, the orthogonality among cosine based different NEWs-modes is proved. Following that, the analyses for modulation/demodulation, received bit-error-rate, and corresponding capacity are given. Simulation results validate that cosine based NEWs are more reliable than traditional OAM beams for space wireless communications.