HSDPA Performance with Dual Stream MIMO in a Combined Macro-Femto Cell Network

3rd Generation Partnership Project (3GPP) responsible of the standardization of 3G systems selected dual stream Transmit Antenna Array (D-TxAA) as the Multiple Input - Multiple Output (MIMO) scheme for High Speed Downlink Packet Access (HSDPA) in 3GPP specification Release 7. MIMO doubles the theoretical peak data rate of HSDPA from 14.4 Mbps to 28.8 Mbps. However, successful reception of dual stream MIMO transmissions requires good signal conditions. Very high signal to noise ratios can be achieved with the use of femto base stations in small isolated areas with insufficient or no macro cell coverage. This paper studies the effect of D-TxAA concept in a combined single frequency macro and femto cell scenario with Linear Minimum Mean Squared Error (LMMSE) chip-level equalizer receivers used at user entities (UE). The impact of receivers employing MIMO transmission mode is analyzed as a function of indoor user penetration using fully dynamic system level simulations.