Multipath Characterization and Mitigation Using Modernized Signals

Numerous techniques have been proposed for minimizing the multipath error in GPS receivers. Performance of various techniques under different conditions - particularly for new modernized GPS (and Galileo) signals can be estimated using high-fidelity simulation of GPS receivers, GPS signals and in conjunction with appropriate simulation of multi-path environment. The multipath environment is complex and demands thorough consideration of reflection, scattering and differentiation processes. CRS has developed unique capability in terms of simulation of complex GPS systems, GPS receivers and environments. We describe a plan to utilize these tools and adapt them for simulation of several representative multipath mitigation techniques. The techniques include conventional receivers, strobe correlators, MEDLL and MMT. We also propose to investigate new techniques using adaptation of STAP, RAKE and Kalman filter techniques. The GPS receiver architectures (for M-code, L2/L5, Galileo) will be modified to incorporate the multipath mitigation techniques and during Phase I, we shall provide thorough simulation of different multipath-causing environments in these architectures. Selected simulated systems will be implemented for real-time prototyping of multipath mitigation and multipath characterization system during Phase II.