Circularity-Based I/Q Imbalance Compensation in Wideband Direct-Conversion Receivers
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- 15 July 2008
- journal article
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Transactions on Vehicular Technology
- Vol. 57 (4), 2099-2113
- https://doi.org/10.1109/tvt.2007.909269
Abstract
Communication receivers that utilize I/Q downconversion are troubled by amplitude and phase mismatches between the analog I and Q branches. These mismatches are unavoidable in practice and reduce the obtainable image frequency attenuation to the 20-40-dB range in practical receivers. In wideband multichannel receivers, where the overall bandwidths are in the range of several megahertz and the incoming carriers located at each other's mirror frequencies have a high dynamic range, the image attenuation of the analog front-end (FE) alone is clearly insufficient. In this paper, two novel blind low-complexity I/Q imbalance compensation techniques are proposed and analyzed to digitally enhance the analog FE image attenuation in wideband direct-conversion receivers. The proposed algorithms are grounded on the concept of circular or proper complex random signals, and they are, by design, able to handle the often overlooked yet increasingly important case of frequency-dependent I/Q mismatches. The first technique is an iterative one, stemming from adaptive filtering principles, whereas the second one is a moment-estimation-based block method. The performance of the algorithms is evaluated through computer simulations, as well as real-world laboratory signal measurement examples in practical multicarrier receiver cases. Based on the obtained results, the proposed compensation techniques can provide very good compensation performance with low computational resources and are robust in the face of different imbalance levels and dynamics of the received signals, as well as many other crucial practical aspects such as the effects of the communications channel and carrier synchronization.Keywords
This publication has 31 references indexed in Scilit:
- Dirty RF: A New ParadigmInternational Journal of Wireless Information Networks, 2006
- Second-order analysis of improper complex random vectors and processesIEEE Transactions on Signal Processing, 2003
- Signal processing challenges for applying software radio principles in future wireless terminals: an overviewInternational Journal of Communication Systems, 2002
- Correction of frequency-dependent I/Q mismatches in quadrature receiversElectronics Letters, 2001
- A novel adaptive mismatch cancellation system for quadrature IF radio receiversIEEE Transactions on Circuits and Systems II: Analog and Digital Signal Processing, 1999
- Second-order statistics of complex signalsIEEE Transactions on Signal Processing, 1997
- Widely linear estimation with complex dataIEEE Transactions on Signal Processing, 1995
- Digital CommunicationPublished by Springer Nature ,1994
- On circularityIEEE Transactions on Signal Processing, 1994
- Proper complex random processes with applications to information theoryIEEE Transactions on Information Theory, 1993