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Optimization of Quantization in Higher Order Modulations for LDPC-Coded Systems
Abstract:In this paper, we evaluate the choice of suitable quantization characteristics for both the decoder messages and the received samples in Low Density Parity Check (LDPC) coded systems using M-QAM (Quadrature Amplitude Modulation) schemes. The analysis involves the demapper block that provides initial likelihood values for the decoder, by relating its quantization strategy of the decoder. A mapping strategy refers to the grouping of bits within a codeword, where each m-bit group is used to select a 2m-ary signal in accordance with the signal labels. Further we evaluate the system with mapping strategies like Consecutive-Bit (CB) and Bit-Reliability (BR). A new demapper version, based on approximate expressions, is also presented to yield a low complexity hardware implementation.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1075222Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1597
 Digital Video Broadcasting (DVB); Second Generation Framing Structure,Channel Coding and Modulation Systems for roadcasting, Interactive Services, News Gathering and Other Broadband Satellite Applications, ETSI EN Std. 302 307 (v1.1.2), Jun. 2006, Rev. 1.1.1.
 J. Hagenauer, E. Offer, and L. Papke, "Iterative decoding of binary block and convolutional codes," IEEE Trans. Inform. Theory, vol. 42, no. 2, pp. 429-445, Mar. 1996.
 R. M. Tanner, A recursive approach to low complexity codes, IEEE Transactions on Information Theory, vol. 27, IEEE, 1981, pp. 533-547.
 John R. Barry, Low-density parity-check codes, Tech. report, Georgia Institute of Technology, 2001.
 R. Pyndiah, A. Picart, and A. Glavieux, "Performance of block turbo coded 16-QAM and 64-QAM modulations," in Proc. IEEE Global Telecommunications Conference (GLOBECOM-95), Singapore, Nov. 1995, vol. 2, pp. 1039-1043.
 F. Tosato and P. Bisaglia, "Simplified soft-output demapper for binary interleaved COFDM with application to HIPERLAN/2," in Proc. IEEE ICC 2002, New York, May 2002, vol. 2, pp. 664-668.
 D. Oh and K. K. Parhi, "Performance of quantized min-sum decoding algorithms for irregular LDPC codes," in Proc. IEEE ISCAS 2007, New Orleans, LA, May 2007, pp. 2758-2761.
 S. Papaharalabos, M. Papaleo, P. T. Mathiopoulos, M. Neri, A.Vanelli- Coralli, and G. E. Corazza, "DVB-S2 LDPC decoding using robust check node update approximations," IEEE Trans. Broadcast., vol.54,no. 1, pp. 120-126, Mar. 2008.