Hard Handover Optimization for Co-Channel WCDMA Heterogeneous Networks

Abstract

This research investigates a handover problem occurringwith current power control mechanisms in co-channel WCDMAheterogeneous networks. The problem is associated to themismatch between the required uplink transmit power when auser is communicating to a small cell and an underlyingmicrocellular base-station. As a result, there is a need forsignificant increases of users' transmit power when handing offfrom small cell to the macrocell tier. This sudden increase of thetransmit power results in increased uplink interference andmajor SIR drops for existing small cell users. This researchintroduces a realistic and efficient solution to adapt the transmitpower of the small cell users during the handover regime toprevent such SINR drops. Simulation results confirm significantperformance improvement when using the proposed scheme.