Per-path interference cancellation for multi-cell channel estimation in TD-SCDMA downlink system

The non-orthogonality among basic midamble sequences causes inter-cell interference to the channel estimation in TD-SCDMA downlink receiver at UEs. To mitigate this kind of interference, per-chip interference cancellation methods are conventionally adopted, which however suffer from high complexity. In this paper, the strategy of per-path interference cancellation is proposed in the scenario of downlink multi-cell channel estimation, which enjoys much lower complexity than per-chip ones. Two different iterative procedures, parallel interference cancellation (PIC) and successive interference cancellation (SIC), are adopted respectively. It is demonstrated by simulation results that the proposed algorithm has much higher estimation accuracy.