Schulist, Matthias; Hoidis, Jochen; Garavaglia, Andrea (QUALCOMM CDMA Technologies GmbH, Nordostpark 89, 90411 Nuremberg, Germany)
The recent progress of commercial HSPA+ (Evolved High Speed Packet Access) systems and the large availability of sophisticated User Equipment (UE) make Mobile Broadband Internet Access already a worldwide reality today. In this paper we focus on HSPA+ MIMO (Multiple Input Multiple Output) as one of the key performance drivers, providing currently data rates up to 28 Mbps. After describing the basic principles of MIMO techniques, we explore the standardized solution for HSPA+ as introduced in Release 7. Real world performance of trial and commercial networks as observed in Qualcomm measurement campaigns are shown and explained in detail for various test environments, where MIMO systems are deployed. Both single user stationary and mobility test results are discussed in detail. Some special interest is put on promising MIMO indoor solutions and their performance, as enabler of high speed, high capacity wireless systems. Latency performance measurements complement these interesting investigations. We conclude the paper with an outlook into the next steps of the 3G WCDMA technology and the further MIMO evolution.