Research On The Technology Of Optical Wireless Links Intra-Satellite Communications

Optical wireless links intra-satellite communications (OWLS) is a new renovation for the satellites. Comparing to the usual wired communications and the wireless RF (Radio Frequency) communications in the satellites, OWLS will have the advantages of low volume, low mass, low power, high speed, high EMC (Electro Magnetic Compatibility) and simplification of the AIT.Optical wireless communications rely on the development of the infrared wireless communications and the optoelectronic components. But OWLS must solve some problems, such as the rad-hard components, the suitable wireless LAN et al., before it is used in the satellite'environments. The paper present the key technology of the optical wireless intra-satellites communications in the second part, such as the simulation of the optical wireless links, the optical wireless LAN, the modulation and demodulation, the rad-hard optoelectronic components.Next, the optical wireless links in the satellites is analyzed and the different material's impact to the optical wireless links is demonstrated in the third part. There are many loads in the satellites. So it's hard to set a line-of-sight (LOS) wireless optical links in the on-board computer to the loads' communications or in the load to load communications. A nondirected-non-LOS links (or a diffuse links) may be the best choice for the optical wireless intra-satellites communications. Moute-Carlo ray tracing is a important way to study the optical wireless links in the satellites. The paper use a software to study different satellites' material's reflection to the infrared links, and also calculate the number of the emitters to different material's diffuse links. Then principle on design the optical wireless links is discussed.Last, demonstration of optical wireless links intra-satellites is presented. The experiment used rad-hard emitters and receivers to found a optical wireless LAN. And the point to point wireless communication can reach 3 meters. There also used a microcontroller to implement the protocol of the wireless links. The system transmits the temperature information from the slave units to the master unit. Also in the system uses two kinds of links, the line-of-sight(LOS) and the non-line-of-sight(Non-LOS), to investigate the optical wireless links in the satellite'communications.