High accuracy multi-link synchronization in LTE: Applications in localization

High accuracy multi-link timing estimation in synchronization is urgently demanded for LTE-based positioning services. However, measuring timing from multiple links in LTE has inter-cell interference problem since the transmitters share the same frequency band. State-of-the-art interference cancellation approaches have the error propagation problem at cell edges, where two links have similar power level. This paper analyzes the performance change of timing estimation after interference cancellation, and proposes a maximum-likelihood (ML) estimator which jointly estimates the timing and power of multiple links, which is exploited in an innovative multi-link synchronization algorithm. The performance of the joint ML estimator is verified to outperform the independent estimator and the estimated timing is applied in positioning algorithm, which indicates accurate and robust performance in different geometric conditions.