CRS interference cancellation algorithm for heterogeneous network

Abstract

Heterogeneous network is introduced to improve the network capacity in LTE Release 9 and system beyond. The potential traffic congestion due to increased users can be alleviated by the cooperation between macro-cell and pico-cell. However, the inter-cell interference caused by RF signal from macro-cell will reduce the performance severely. Enhanced inter-cell interference coordination is proposed in Rel. 10 to solve this problem using almost blank subframe (ABS). Yet, the cell specific reference signal in ABS can still cause interference to the data resource element (RE) from the pico-cell inevitably for non-colliding scenario. In this Letter, a novel interference cancellation (IC) algorithm is proposed to mitigate the interference. First, the timing and carrier frequency offset of interference signal is estimated and compensated. Second, the interfering channel response is estimated by utilising the channel statistics. Third, the interference signal is reconstructed based on the channel estimation and cancelled in the received signal in time domain. The experiment results show that the performance of proposed IC algorithm is robust.