Multiple Input Multiple Output (MIMO) was standardized by the 3GPP in 2008 in release R7. During the 2nd half of 2009, MIMO network and device equipment for HSPA and LTE were delivered to the market.
At that time, MIMO in HSPA networks wasn’t widely-deployed for a number of reasons: the relatively scarcity of compatible devices, the perceived cost to upgrade the base station hardware, and the impact the first implementations of MIMO (based on STTD) had on legacy HSDPA users.
Since then, through the significant progress at 3GPP level and in the ecosystem, combined with smart network based optimization techniques, MIMO HSPA has become a robust and affordable technology.
This paper is designed to provide a neutral and balanced view of MIMO technology and its role in the evolution of mobile networks, while exploring concerns raised by some industry players and telecoms operators about the use of MIMO with HSPA.