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Performance Analysis of HSDPA Systems using Low-Density Parity-Check (LDPC)Coding as Compared to Turbo Coding

Authors: K. Anitha Sheela, J. Tarun Kumar

Abstract:

HSDPA is a new feature which is introduced in Release-5 specifications of the 3GPP WCDMA/UTRA standard to realize higher speed data rate together with lower round-trip times. Moreover, the HSDPA concept offers outstanding improvement of packet throughput and also significantly reduces the packet call transfer delay as compared to Release -99 DSCH. Till now the HSDPA system uses turbo coding which is the best coding technique to achieve the Shannon limit. However, the main drawbacks of turbo coding are high decoding complexity and high latency which makes it unsuitable for some applications like satellite communications, since the transmission distance itself introduces latency due to limited speed of light. Hence in this paper it is proposed to use LDPC coding in place of Turbo coding for HSDPA system which decreases the latency and decoding complexity. But LDPC coding increases the Encoding complexity. Though the complexity of transmitter increases at NodeB, the End user is at an advantage in terms of receiver complexity and Bit- error rate. In this paper LDPC Encoder is implemented using “sparse parity check matrix" H to generate a codeword at Encoder and “Belief Propagation algorithm "for LDPC decoding .Simulation results shows that in LDPC coding the BER suddenly drops as the number of iterations increase with a small increase in Eb/No. Which is not possible in Turbo coding. Also same BER was achieved using less number of iterations and hence the latency and receiver complexity has decreased for LDPC coding. HSDPA increases the downlink data rate within a cell to a theoretical maximum of 14Mbps, with 2Mbps on the uplink. The changes that HSDPA enables includes better quality, more reliable and more robust data services. In other words, while realistic data rates are only a few Mbps, the actual quality and number of users achieved will improve significantly.

Keywords: AMC, HSDPA, LDPC, WCDMA, 3GPP.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1059948

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References:


[1] T. Ojanpera and R.Prasad, "An overview of air interface multiple access for IMT- 2000/UMTS", IEEE Commun. Mag., vol. 36, pp. 82-95, Sept. 1998.
[2] Simon Binar., Tektronix Inc, ÔÇÿÔÇÿHSDPA and HSUPA Functional Testing--, Protocol Monitoring Division, Berlin, Germany, 2006.
[3] Niyato, D Hossain, E Wavegedara, K.C. Bhargava, "Radio Link Level Performance in Multi-Rate MIMO Wireless Networks: Analysis and Optimization", Wireless Comm. and Networking Conference, 2007.WCNC 2007. IEEE vol , Issue , 11-15 March 2007 ,pp294 - 298.
[4] Claude Berrou, Alain Glavieux, "Near Optimum Error Correcting Coding and Decoding: Turbo Codes", IEEE Transactions on Communication, Vol.44, No.10, October 1996.
[5] Che-Sheng Chiu and Chen-Chiu Lin, "Comparative downlink shared channel performance evaluation of WCDMA release 99 and HSDPA", IEEE International Conference; year 2004 , vol. 2 , pages 1165-1170.
[6] 3GPP TR 25.858 V1.0.0 (2001-12), Physical layer aspects of UTRA High Speed Downlink Packet Access, Release 5..Ratio Combining (MRC) which is an receiver diversity estimator.
[7] J. R. Fonollosa, M. Heikkil├ñ, X. Mestre, A. Pagès, A. Pollard, L.Schumacher, A. Wiesel and J. Ylitalo, "Adaptive Modulation Schemes for MIMO HSDPA," IST Mobile & Wireless Telecommunications Summit 2002, Thessaloniki, Greece, June 2002.
[8] B. Hassibi and Bertrand M. Hochwald. "High rate codes that are linear in space and time", IEEE Trans. Info.Theory, April 2001.
[9] Robert C, Qiu, Wenwu Zhu,a-Qin Zhang, "Third-Generation and Beyond (3.5G) Wireless Networks and Its Applications", IEEE International Symposium on Circuits and Systems (ISCS), Scottsdale, Arizona, May 26-29
[10] R. G. Gallager, " Low Density Parity-Check Codes". MIT Press, Cambridge, MA, 1963.
[11] Amin Shokrollahi, "LDPC Codes: An Introduction. Digital Fountain", Inc.39141 Civic Center Drive, Fremont, CA 94538MIT Press, Cambridge, MA, 1963.
[12] Thomas J. Richardson and R├╝diger L. Urbanke. "The Capacity of Low- Density Parity-Check Codes Under Message-Passing Decoding", IEEE Trans. Info.Theory, vol. 47, no. 2, Feb 2001.
[13] David J.C. Mackay, "Near Shannon Limit Performance Of Low Density Parity Check Codes", Cavendish Laboratory, Cambridge, UK. Published in Electronics letters, Jul 1996.
[14] Andrea Goldsmith, "WIRELESS COMMUNICATIONS", Cambridge University Press, 2005. pp. 229-243.