TSVD regularization in GPS multicorrelator multipath estimation

Multipath is one of the main error sources of the differential applications of global positioning systems (GPS). The maximum likelihood estimation of multipath is simplified using the idea of deploying estimation points. There is ill-conditioning in the simplified model, decreasing the numerical stability of the maximum likelihood estimation (MLE) in some conditions. The influence of ill-conditioning on MLE is analyzed, and truncated singular value decomposition (TSVD) regularization is proposed to overcome the ill-conditioning. Simulations show that under some noise level, TSVD estimation of multipath performs much better in than the MLE, demonstrating the validity of the method proposed in this paper.