This presentation will focus on the practical implementation of massive MIMO concept, covering both prototype system and efficient integrated solution. Firstly the Lund massive MIMO testbed, LuMaMi, will be introduced, which is based on software-defined radio (SDR) and field programmable gate array (FPGA) technologies. Real-life measurements, including both in-door and (mobile) out-door scenarios, will be presented. The second part will be a cross-layer optimization method to achieve energy efficient massive MIMO precoding and detection. Algorithm, architecture, and circuit level design considerations will be presented and chip measurement results will be shown.