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Characterization and Optimization of LDPC Codes for the 2-User Gaussian Multiple Access Channel
EURASIP Journal on Wireless Communications and Networking volume 2007, Article number: 074890 (2007)
Abstract
We address the problem of designing good LDPC codes for the Gaussian multiple access channel (MAC). The framework we choose is to design multiuser LDPC codes with joint belief propagation decoding on the joint graph of the 2-user case. Our main result compared to existing work is to express analytically EXIT functions of the multiuser decoder with two different approximations of the density evolution. This allows us to propose a very simple linear programming optimization for the complicated problem of LDPC code design with joint multiuser decoding. The stability condition for our case is derived and used in the optimization constraints. The codes that we obtain for the 2-user case are quite good for various rates, especially if we consider the very simple optimization procedure.
References
Rimoldi B, Urbanke R: A rate-splitting approach to the Gaussian multiple-access channel. IEEE Transactions on Information Theory 1996,42(2):364-375. 10.1109/18.485709
Ahlswede R: Multi-way communication channels. Proceedings of the 2nd IEEE International Symposium on Information Theory (ISIT '71), 1971, Aremenian Prague, Czech Republic 23-52.
Liao H: Multiple access channels, Ph.D. thesis. University of Hawaii, Honolulu, Hawaii, USA; 1972.
Palanki R, Khandekar A, McEliece R: Graph based codes for synchronous multiple access channels. Proceedings of the 39th Annual Allerton Conference on Communication, Control, and Computing, October 2001, Monticello, Ill, USA
Amraoui A, Dusad S, Urbanke R: Achieving general points in the 2-user Gaussian MAC without time-sharing or rate-splitting by means of iterative coding. Proceedings of IEEE International Symposium on Information Theory (ISIT '02), June-July 2002, Lausanne, Switzerland 334.
De Baynast A, Declercq D: Gallager codes for multiple user applications. Proceedings of IEEE International Symposium on Information Theory (ISIT '02), June-July 2002, Lausanne, Switzerland 335.
Kschischang FR, Frey BJ, Loeliger H-A: Factor graphs and the sum-product algorithm. IEEE Transactions on Information Theory 2001,47(2):498-519. 10.1109/18.910572
Pearl J: Probabilistic Reasoning in Intelligent Systems: Networks of Plausible Inference. Morgan Kaufmann, San Mateo, Calif, USA; 1988.
Tanner RM: A recursive approach to low complexity codes. IEEE Transactions on Information Theory 1981,27(5):533-547. 10.1109/TIT.1981.1056404
Richardson TJ, Urbanke R: The capacity of low-density parity-check codes under message-passing decoding. IEEE Transactions on Information Theory 2001,47(2):599-618. 10.1109/18.910577
Ten Brink S: Designing iterative decoding schemes with the extrinsic information transfer chart. International Journal of Electronics and Communications 2000,54(6):389-398.
Roumy A, Guemghar S, Caire G, Verdú S: Design methods for irregular repeat-accumulate codes. IEEE Transactions on Information Theory 2004,50(8):1711-1727. 10.1109/TIT.2004.831778
Bennatan A, Burshtein D: On the application of LDPC codes to arbitrary discrete-memoryless channels. IEEE Transactions on Information Theory 2004,50(3):417-438. 10.1109/TIT.2004.824917
Wang C-C, Kulkarni SR, Poor HV: Density evolution for asymmetric memoryless channels. IEEE Transactions on Information Theory 2005,51(12):4216-4236. 10.1109/TIT.2005.858931
Chung S-Y, Richardson TJ, Urbanke R: Analysis of sum-product decoding of low-density parity-check codes using a Gaussian approximation. IEEE Transactions on Information Theory 2001,47(2):657-670. 10.1109/18.910580
Hu X-Y, Eleftheriou E, Arnold D-M: Progressive edge-growth tanner graphs. Proceedings of IEEE Global Telecommunications Conference (GLOBECOM '01), November 2001, San Antonio, Tex, USA 2: 995-1001.
Tian T, Jones C, Villasenor JD, Wesel RD: Construction of irregular LDPC codes with low error floors. Proceedings of IEEE International Conference on Communications (ICC '03), May 2003, Anchorage, Alaska, USA 5: 3125-3129.
Richardson TJ, Shokrollahi MA, Urbanke R: Design of capacity-approaching irregular low-density parity-check codes. IEEE Transactions on Information Theory 2001,47(2):619-637. 10.1109/18.910578
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Roumy, A., Declercq, D. Characterization and Optimization of LDPC Codes for the 2-User Gaussian Multiple Access Channel. J Wireless Com Network 2007, 074890 (2007). https://doi.org/10.1155/2007/74890
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DOI: https://doi.org/10.1155/2007/74890