A critical review of MIMO OTA test concepts — Lessons learned from actual measurements

Multiple Input — Multiple Output (MIMO) Over-The-Air (OTA) performance testing of User Equipment (UE) has become an important issue in connection with the roll-out of Long Term Evolution (LTE). Its purpose is to assure that UE will provide satisfactory user experience and will not compromise network efficiency. Intended to become part of a commercial certification process, low complexity, high reproducibility and a coherent interpretation of results are mandatory. This contribution attempts a critical review of some of the essential concepts underlying proposals for MIMO OTA testing which have been made and are under discussion in 3GPP RAN4, CTIA and COST2100 SWG2.2.