Hardware Implementation of Front End I/Q Imbalance Mitigation Techniques For High Data Rate OFDM

Abstract

Modern communication networks suffer from various imperfections that significantly degrade their performance. Transmitters (Tx) and receivers (Rx) employ local oscillators to up-and-down-convert the in-phase (I) and quadrature-phase (Q) signals to the carrier frequency and baseband. re¬spectively. However, due to the non-idealities of the local oscillators and mixers, there is an imbalance in the gain and phase of the up/down¬converted I/Q signals. This problem is quite prevalent in direct-conversion radio architecture where the image falls within the band of interest after down-conversion. A low-cost implementation of such physical layers is challenging be¬cause of impairments associated with the analog components therefore ef¬ficient digital hardware is needed to mitigate these effects. The effects of I/Q imbalance can be mitigated using signal process-ing techniques, instead of adding hardware components to the transceiver topology or making changes in the transceiver topology.