Frequency offset estimation in OFDM systems in presence of IQ imbalance
ICCS '02 Proceedings of the The 8th International Conference on Communication Systems - Volume 01
Efficient compensation of RF impairments for OFDM systems
WCNC'09 Proceedings of the 2009 IEEE conference on Wireless Communications & Networking Conference
IQ-Imbalance Compensation for OFDM in the Presence of IBI and Carrier-Frequency Offset
IEEE Transactions on Signal Processing
MIMO OFDM Receivers for Systems With IQ Imbalances
IEEE Transactions on Signal Processing
Frequency offset and I/Q imbalance compensation for direct-conversion receivers
IEEE Transactions on Wireless Communications
Low-Complexity EM-based Joint Acquisition of the Carrier Frequency Offset and IQ Imbalance
IEEE Transactions on Wireless Communications
Proper complex random processes with applications to information theory
IEEE Transactions on Information Theory
Influence of RF oscillators on an OFDM signal
IEEE Transactions on Consumer Electronics
Multicarrier modulation for data transmission: an idea whose time has come
IEEE Communications Magazine
| Hi-index | 0.08 |
Multi-input multi-output (MIMO) systems are often realized with low cost front-end architectures, e.g. the so-called direct conversion (or zero IF) architectures. However, such systems are very sensitive to imperfections in the analog front-end resulting in radio frequency (RF) impairments such as in-phase/quadrature-phase (IQ) imbalance and carrier frequency offset (CFO). These RF impairments can result in a severe performance degradation. In this paper we propose RF impairment compensation techniques for orthogonal frequency division multiplexing (OFDM) based MIMO systems. We consider a digital compensation scheme for joint transmitter/receiver frequency selective IQ imbalance, CFO and channel distortion. We also show that in the case where there is no transmitter IQ imbalance, the receiver IQ imbalance compensation can be de-coupled from the channel equalization resulting in a compensation in two stages. The two-stage scheme results in an overall lower computational requirement. The various compensation schemes are demonstrated to provide a performance close to the ideal case without RF impairments.