Adaptive gain and delay mismatch cancellation for LINC transmitter
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Linear amplification with Nonlinear Component (LINC) transmitter architecture is an efficient solution for high efficiency amplification of signals. Nonetheless, this solution suffers both from gain impairment and delay mismatch between the two signal paths. Indeed, a mismatch in propagation time between the paths degrades the quality of the transmit signal but also disrupts the convergence of the gain correction algorithm resulting in a degradation of its performance. In this paper, we present an adaptive algorithm based on a gradient descent formulation for the identification and correction of these delays. We also demonstrate its effectiveness when applied prior to the gain adjustment procedure. The identification approach is preferred here, to ensure monitoring facilities.
KeywordsRadio transmitters Power amplifiers Adaptive signal processing Delay filters Delay estimation Nonlinear distortion
The authors would like to thank Prof P. Gamand and S. Kowlgi Srinivasan for their contributions for this paper.
- 1.Berland, C., Bercher, J.-F., & Venard, O. (2008). Digital signal processing techniques to compensate for RF imperfections in advanced transmitter architectures, EuWiT 2008. European Conference on Wireless Technology, pp. 41–44.Google Scholar
- 5.Chandrasekaran, R., Gandhi, R., Kolanek, J. C., Shynk, J. J., & Thomas, A. L. (2001). Adaptive algorithms for calibrating a LINC amplifier, RAWCON 2001. IEEE Radio and Wireless Conference, 241–244.Google Scholar
- 9.GPP ETSI TS 125 101 V7.6.0 (2006-12). Universal Mobile Telecommunications System (UMTS); User Equipment (UE) radio transmission and reception (FDD)Google Scholar
- 11.Farrow, C. W. (1988). A continuous variable digital delay element. Proc. IEEE Int. Symp. Circuits Systems, 2641–2645.Google Scholar