Macro-femto inter-cell interference mitigation for 3GPP LTE-A downlink

In LTE-A or Rel. 10+, heterogeneous network deployments are supported to improve the user experienced link performance. However, such deployments give rise to new interference problems. In this study, macro-femto-cell interference scenarios for LTE-A downlink are investigated. We focus on the critical interference scenario of colliding cell-specific reference signals (CRSs). As conventional receivers with channel estimation based on the interfered CRSs fail to work properly, we present advanced interference mitigation schemes for user equipment (UE), such as the received-power dependent interference cancellation (IC), decision-directed channel estimation and IC-assisted channel estimation. Numerical simulation results showed that the proposed schemes are able to significantly reduce the inter-cell interference so that high throughput can be ensured even under the harsh macro-femto interferences.