The GATE receiver - A full-scale galileo/GPS monitor receiver

For the purpose of pre Galileo system verification and testing, the Galileo Test Environment (GATE) is setup in the German Alps to reproduce a realistic test bed for the Galileo satellite navigation system. In fact, a complete miniature navigation system is built up consisting of a control, ground and pseudo-space segment. For system monitoring and testing a receiver is required, which is capable of processing all signals specified in the Galileo system specification. To prove interoperability and for reference purposes the receiver will also process Galileo and GPS signals on L1 in a common processing chain. This paper describes a modular receiver design, developed for the use as a user receiver as well as a system monitor receiver. Detailed results from performance tests will be presented. Up to three single band receivers with radio frequency front-end and base band processor occupy up to nine slots of the PXI framework to serve any of the Galileo radio frequency ban ds E5, E6 and L1. One base-band board and a front-end system consisting of two cPCI boards cover each frequency band. The front-end system consists of a digital signal conditioning board and an analog front-end board. As the base-band units are based on field programmable gate arrays (FPGA), the actual band specific functionality of the receiver is implemented in a HDL and uploaded to the system. This flexibility allows all base-band units to be designed identically. The three receiver front-ends similarly have an identical PCB-layout, which reduces costs. The digital signal conditioning boards are all identical. The analog front-end boards have identical PCB layout, but differ in the components fitted (filters, LO-frequencies). Receiving the whole E5 band (i.e. E5a and E5b) including the first side-lobe (71 MHz) through one front-end system is the single most challenging requirement on the front-end system. To fulfill the required amplitude and group delay flatness in the pass-band is very challen