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Iterative Decoding Performance for Gray Coded QAM Signals with I/Q Phase Unbalance  

Kim Ki-Seol (한양대학교 전자통신컴퓨터공학과)
Park Sang-Kyu (한양대학교 전자통신컴퓨터공학부)
Publication Information
The Journal of Korean Institute of Communications and Information Sciences / v.31, no.6A, 2006 , pp. 611-616 More about this Journal
Abstract
In this paper, we propose a practical implementation method of a soft bit decision expression for an R-QAM (Gray coded Rectangular Quadrature Amplitude Modulation) signal based on the Max-Log-MAP algorithm. The parameters of the soft decision expression for the practical implementation can be obtained with simple arithmetic functions associated with some deterministic parameters such as a received value, distances between symbols, and the order of modulation on a signal space. Also, we analyze the performance of an iterative decoding scheme for the QAM signal with I/Q phase unbalance. The unbalance results from the non-ideal characteristic of components such as a phase shifter between in-phase and quadrature paths for quadrature modulator/demondulator.
Keywords
QAM; Max-Log-MAP; Iterative decoding; Phase unablance; Soft decoding;
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Times Cited By KSCI : 1  (Citation Analysis)
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