Low-Complexity Multipath Mitigation Technique Based on Multi-Correlator Structures

Abstract

Multipath propagation is still a major source of error in global navigation satellite systems (GNSSs), especially in urban environments. Conventional GNSS receivers provide under such conditions only a degraded accuracy. At the same time, applying an effective but computationally complex multipath mitigation algorithm potentially exceeds cost or energy consumption requirements. Therefore, a low-complexity multipath mitigation technique is proposed in this paper. It relies on a multi-correlator structure with an Extended Kalman Filter (EKF) replacing the conventional delay locked loop (DLL) for the code tracking. Multipath resilience is achieved by incorporating the radio propagation channel between satellite and user in the measurement model, inherently accounting for reflected signal replicas. In order to reduce complexity, the effect of the number and distribution of the correlators used has been investigated. It turned out, that even with a very low number of correlators, a high multipath mitigation capability is maintained. The results have been validated with actual measurement data.