Enhanced Virtual Antenna Mapping (E-VAM)

Abstract

3GPP Release 7 introduced several new powerful features to the existing HSDPA (High Speed Downlink Packet Access) functionality including Single Input Multiple Output using 64 Quadrature Amplitude Modulation (SIMO 64 QAM) and Multiple Input Multiple Output (MIMO). Amongst these, first implementations of MIMO brought about inadvertent performance degradation in existing non MIMO devices and terminals in the field. The objective of this paper is to provide an insight into a solution initially sought to resolve this MIMO coexistence issue using already available Virtual Antenna Mapping (VAM) and its modification which resulted in a valuable optimisation technique in itself -"Enhanced VAM" -irrespective of MIMO deployment.