Introduction » History » Version 2
Version 1 (ZHAI, Lili, 03/26/2017 09:45 AM) → Version 2/44 (ZHAI, Lili, 03/26/2017 10:00 AM)
h1. Introduction
The purpose is to reproduce the satellite channel emulation at RF level in the Satcom lab. The transmission link will be influenced as in a real environment. In the case of the channel emulator developed in the geo satellite system, the channels refer to the links from a terrestrial station, via a transparent satellite and finally to another terrestrial station. As shown in the Figure 1, it is a typical satellite access scheme for the connections of forward and return link channels. Each link is equipped with a PC, a modem EL470, a dish antenna. The forward link and return link communicate with each other through a geo satellite.
In this project, we remove all the elements between the two modems in order to make the emulation with NI hardware and LabVIEW software. The emulator generates the signal to make the two modems believe that the bi-directional satellite Internet access still works.
In general, hardware-based satellite channel emulators are around 100k euros on the market thus it is such a high price for the common customers. Compared to a realistic environment, emulator is much less costly. In fact, it is possible that the total price of the instruments is around 5k euros with controllable features of emulations in the lab. Another motivation to carry out the emulation is related to the bandwidth, given that, the bandwidth for the common satellite emulations on the market is up to 600MHz while it is accessible to reproduce it with only 5MHz.
As far as satellite emulation is concerned, it is increasingly significant to use the FPGA (Field Programmable Gate array) as a resource of software-define radio system (SDR). This implementation technology provides important advantages with higher performances, such as higher design flexibility and lower cost per channel.
The purpose is to reproduce the satellite channel emulation at RF level in the Satcom lab. The transmission link will be influenced as in a real environment. In the case of the channel emulator developed in the geo satellite system, the channels refer to the links from a terrestrial station, via a transparent satellite and finally to another terrestrial station. As shown in the Figure 1, it is a typical satellite access scheme for the connections of forward and return link channels. Each link is equipped with a PC, a modem EL470, a dish antenna. The forward link and return link communicate with each other through a geo satellite.
In this project, we remove all the elements between the two modems in order to make the emulation with NI hardware and LabVIEW software. The emulator generates the signal to make the two modems believe that the bi-directional satellite Internet access still works.
In general, hardware-based satellite channel emulators are around 100k euros on the market thus it is such a high price for the common customers. Compared to a realistic environment, emulator is much less costly. In fact, it is possible that the total price of the instruments is around 5k euros with controllable features of emulations in the lab. Another motivation to carry out the emulation is related to the bandwidth, given that, the bandwidth for the common satellite emulations on the market is up to 600MHz while it is accessible to reproduce it with only 5MHz.
As far as satellite emulation is concerned, it is increasingly significant to use the FPGA (Field Programmable Gate array) as a resource of software-define radio system (SDR). This implementation technology provides important advantages with higher performances, such as higher design flexibility and lower cost per channel.