Consiglio Nazionale delle Ricerche

Tipo di prodottoRapporto di ricerca (Research report)
TitoloWideband Compensation of I/Q Imbalance Distorsion in Virtual Instrumentation Up-Converters.
Anno di pubblicazione2010
  • Elettronico
  • Cartaceo
Autore/iV. Rampa, A. Giudici
Affiliazioni autoriDipartimento di Elettronica e Informazione, Politecnico di Milano; Istituto di Elettronica e di Ingegneria dell'Informazione e delle Telecomunicazioni
Autori CNR e affiliazioni
  • inglese
SintesiPurpose of this report is to describe a compensation scheme that is able to identify the model of the in-phase/quadrature (I/Q) distortion that can be experienced in general purpose RF upconverters that are usually found in virtual instruments. In addition, this report presents the algorithm that exploits this model to efficiently remove I/Q imbalance effects. Real-world upconverters that integrate Digital-to-Analog Converters (DAC), I/Q mixers, analog Base-band and RF filters, usually introduce a wideband I/Q mismatch that strongly reduces instrument performances. The proposed compensation strategy can increase EVM (Error Vector Magnitude) figures virtually eliminating Image Rejection Ratio effects with a simple asynchromous hardware architecture. While some I/Q compensation methods are already available from literature, they need synchronous RF measurement and compensation architectures that are complex, costly and difficult to arrange. Moreover, the parameteric approach followed in this paper, allows to better understand the I/Q inbalance problem and to propose design techniques that can alleviate this problem earlier during the design stage. The proposed system modeling scheme applies to a generic upconverter device, independently of the modulation standard, so it can be easily adapted, modified or simplified, to accommodate specific hardware systems and wireless standards. The novelties introduced in this report are the accurate system modeling and the incoherent measurement architecture needed to estimate the model parameters. The most important advantage of the proposed scheme relies on the measurement and estimation architecture, which doesn't require a fully coherent downconversion chain to recover the I/Q samples, but only power measurements, thus making time, frequency and phase synchronization unnecessary even in the case of strongly frequency-dependent I/Q imbalance. The proposed compensation scheme may be also implemented in I/Q downconverters but, in this case, the architectural advantage is not so evident for their synchronous detecting scheme. Finally, some experimental results are presented to show up the capabilities of the proposed compensation architecture.
Lingua sintesieng
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Pagine da-
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Pagine totali66
Numero volume della serie/collana-
Parole chiaveI/Q imbalance compensation, I/Q mixer
Link (URL, URI)-
Titolo parallelo-
ID report/working paper-
Note/Altre informazioniInternal Report N. IEIIT-CNR-100129-MI (29th January 2010)
Strutture CNR
  • IEIIT — Istituto di elettronica e di ingegneria dell'informazione e delle telecomunicazioni
Moduli CNR
    Progetti Europei-

      Dati storici
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      Area disciplinareComputer Science & Engineering
      Area valutazione CIVRIngegneria industriale e informatica
      Descrizione sintetica del prodotto