Design and implementation of a cost-effective and adjustable pseudolite transmitter

Global navigation satellite systems have had great effect on our lives for its availabilities and conveniences; however there exist some weaknesses like dependence on geometric layout of satellites and attenuation of signals. These vulnerabilities restrict the applications, and then an auxiliary tool called pseudolite has been developed, so do the manufacturers like Locata Technology and Space Systems Finland Ltd, whose products have been tested and applied in industries. But these pseudolites are of high price or matched with specific receivers, which are unable to be applied on a large scale. Therefore, we design and implement a pseudolite transmitter which is programmable, compatible of universal GNSS receivers and inexpensive but effective with wide output frequency range including GPS, BDS, etc. This paper introduces the hardware structure of pseudolite transmitter in detail based on similar constitutions between pseudolite transmitters and GNSS satellites. At first, with the overall system architecture as a start, the principle, hardware design and functions of every module are introduced; some relevant tests especially power tuning are conducted respectively. Then measured by standard instruments and commercial GPS receiver, some results and technical parameters were derived. At last, some discussions and conclusions about the design are layout.