Developing energy-efficient MIMO radios

Shifting spatial signal processing in multiantenna systems from the digital base band to the RF front-end allows the development of energy efficient (green) MIMO radios. An integrated transceiver using RF-MIMO is designed in 0.25 mum SiGe technology together with a four-element antenna array. Low correlation between the antennas was achieved by using different diversity techniques and by optimizing the array configuration. Moreover, a base band processor with new MIMO algorithms and an 802.11 MAC processor were developed as a system-on-a-chip (SoC) design. The superior performance of the developed MIMO algorithms was demonstrated by Monte Carlo simulations. The size of the complete system was designed for a PCM-CIA card form factor. This allows enhancing 802.11a WLAN with MIMO features and still guaranteeing backward compatibility of the transceiver to the adopted 802.11 standard.