Low-complexity architecture of CFO and IQI compensation in MIMO-OFDM systems

This paper presents a low-complexity architecture compensating for carrier frequency offset (CFO) and IQ imbalance circuits in MIMO-OFDM receiver systems. A coordinate rotation digital computer based sinusoid iteration generator is also developed for CFO estimation and correction in wireless communication receivers. Besides the main effect from the multi-path, some non-ideal effects from imperfect hardware design should also be considered such as the IQ imbalance from direct conversion in RF front-end. The improved low-complexity compensation algorithm is adopted to implement MIMO-OFDM receivers. The integrated CFO and IQ compensation circuits reduce 34% of area by using hardware sharing.