{"title":"Discrete Polyphase Matched Filtering-based Soft Timing Estimation for Mobile Wireless Systems","authors":"Thomas O. Olwal, Michael A. van Wyk, Barend J. van Wyk","volume":28,"journal":"International Journal of Electronics and Communication Engineering","pagesStart":1016,"pagesEnd":1024,"ISSN":"1307-6892","URL":"https:\/\/publications.waset.org\/pdf\/3493","abstract":"
In this paper we present a soft timing phase estimation (STPE) method for wireless mobile receivers operating in low signal to noise ratios (SNRs). Discrete Polyphase Matched (DPM) filters, a Log-maximum a posterior probability (MAP) and\/or a Soft-output Viterbi algorithm (SOVA) are combined to derive a new timing recovery (TR) scheme. We apply this scheme to wireless cellular communication system model that comprises of a raised cosine filter (RCF), a bit-interleaved turbo-coded multi-level modulation (BITMM) scheme and the channel is assumed to be memory-less. Furthermore, no clock signals are transmitted to the receiver contrary to the classical data aided (DA) models. This new model ensures that both the bandwidth and power of the communication system is conserved. However, the computational complexity of ideal turbo synchronization is increased by 50%. Several simulation tests on bit error rate (BER) and block error rate (BLER) versus low SNR reveal that the proposed iterative soft timing recovery (ISTR) scheme outperforms the conventional schemes.<\/p>\r\n","references":"[1] A. Shanmugam and A. R. Abdul Rajak, \"Optimal design of forward\r\nerror correcting codes for wireless communication\",\r\nwww.academicjournal.com, vol. 14, 2005.\r\n[2] CISCO, \"Cisco mobile exchange solution guide: Overview of GSM,\r\nGPRS, and UMTS\", www.cisco.com , 2002.\r\n[3] M. Sellathurai and S. Haykin, \"Turbo-Blast for wireless\r\ncommunications: theory and experiments,\" IEEE Trans. Sig. Proc..,\r\nvol. 50, no. 10, pp. 2538-2546, 2002\r\n[4] C. Herzet, V. Ramon, L. Vandendorpe, \"Iterative soft-decision directed\r\ntiming estimation for turbo receivers,\" IEEE 9th Symposium on\r\nCommun., and Vehicular Technology, pp. 97-101, 2003\r\n[5] N. Noels, V. Lottici, A. Dejonghe, H. Steendam, M. Moeneclaey, M.\r\nLuise, L. Vandendorpe, \"A theoretical framework for soft-informationbased\r\nsynchronization in iterative(turbo) receivers,\" EURASIP J.\r\nWireless Commun., and Network., vol. 2, pp. 177-129, 2005.\r\n[6] K. H. Mueller and M. Muller, \"Timing recovery in digital synchronous\r\ndata receivers,\" IEEE Trans. Commun., vol. Com-24, pp. 516-532, 1976.\r\n[7] J. G. Proakis and M. Salehi, Communication systems engineering. New\r\nJersey: Prentice Hall, 2002.\r\n[8] J. R. Barry, A. Kavcic, S. W. McLaughlin, A. Nayak, and W. Zeng,\r\n\"Iterative timing recovery,\" IEEE Signal Processing Mag., vol. 2, pp.\r\n89-102, 2004.\r\n[9] P. Kovintavewat, J. R. Barry, M. F. Erden, and E. M. Kurtas,\r\n\"Robustness of per-survivor iterative timing recovery in perpendicular\r\nrecording channels,\" IEEE Trans. Magnetics, vol. 10, pp. 807-808,\r\n2005.\r\n[10] B. Mielczarek, Turbo codes and channel estimation in wireless systems,\r\nPhD Thesis, Signals and Systems, Chalmers University of Technology,\r\nGoteborg, 2002.\r\n[11] J. M. Walsh, C. R. Johnson, and P. A. Regalia, \"Joint synchronization\r\nand decoding exploiting the turbo principle,\" in Proc. Conf. Inform.\r\nSciences and Systems, 2004\r\n[12] D. Tabak and B. C. Kuo, Optimal control by mathematical\r\nprogramming. New Jersey: Prentice Hall, 1971.\r\n[13] H. Meyr, M. Moeneclaey, and S. Fechtel, Digital communication\r\nreceivers: Synchronization, channel estimation, and signal processing.\r\nNew York: John Wiley and sons, 1998.\r\n[14] A. Nayak, J. Barry and S. McLaughlin, \"Joint Timing Recovery and\r\nTurbo Equalization for Coded Partial Response Channels,\" IEEE Trans.\r\nMagnetics, vol. 38, no.5, pp. 2295-2297, Sept 2002.\r\n[15] F. J. Harris and M. Rice, \"Multirate digital filters for symbol timing\r\nsynchronization in software defined radios,\" IEEE journal on selected\r\nareas in commun., vol. 19, no. 12, pp. 2346-2357, 2001.\r\n[16] F. J. Harris, Multirate signal processing for communication systems.\r\nNew Jersey: Prentice Hall, 2004.\r\n[17] N. Noels, C. Herzet, A. Dejonghe, et al., \"Turbo synchronization: an\r\nEM interpretation,\" In Proc. IEEE international Conference on\r\nCommunications (ICC \u00d4\u00c7\u00ff03), Anchorage, Alaska, USA, May 2003.\r\n[18] N. Noels, H. Wymeerisch, H. Steendam and M. Moeneclay, \"The true\r\nCramer-Rao bound for timing recovery from a bandlimited linearly\r\nmodulated waveform with unknown carrier phase and frequency,\" IEEE\r\nTrans. Commun., vol. 52, no. 3, pp. 473-483, March 2004.\r\n[19] R. Koetter, A.C. Singer and M. Tuchler, \"Turbo equalization,\" IEEE\r\nSignal Processing Magazine, vol. 21, no. 1, pp. 67-80, January 2004.\r\n[20] J. Hagenauer and P. Hoher, \"A Viterbi algorithm with soft-decision\r\noutputs and its applications,\" IEEE Trans. Commun., vol. 47, pp. 1680-\r\n1686, 1989.\r\n[21] N. Metropolis and S. Ulam, \"The Monte Carlo method,\" American\r\nStatistic Association Journal, vol. 44, pp. 335-341, 1949.\r\n[22] T. O. Olwal, M. A. van Wyk, D. Chatelain, M. Odhiambo and B. J. van\r\nWyk, \"Low variance timing recovery in turbo receivers,\" In Proc. IEEE\r\n13th International Conference on Telecommunication (ICT \u00d4\u00c7\u00ff06),\r\nFunchal, Portugal, May 2006.\r\n[23] T. O. Olwal, M. A. van Wyk, D. Chatelain, M. Odhiambo and B.J. van\r\nWyk, \"Cramer-Rao bound on timing recovery for GSM receivers,\" In\r\nProc. IEEE ICTe Africa2006, Nairobi, Kenya, May 2006.\r\n[24] T. O. Olwal, M. A. van Wyk, B. J. van Wyk, M. Odhiambo and D.\r\nChatelain, \"Improved timing recovery in wireless mobile receivers\"\r\nAfrican Journal of Science and Technology (AJST), vol. 8, no. 1, pp. 71-\r\n86, 2007.\r\n[25] A. Dejonghe, X. Jaspar, X. Wautelet and L. Vandendorpe, \"Assessing\r\nthe performance of turbo-equalised bit-interleaved turbo-coded\r\nmodulation,\" In Proc. Symposium on Commun. Vehicular Tech., Ghent\r\n(Belgium), 2004.\r\n[26] N. Noels, H. Steendam and M. Moeneclay, \"On the Cramer-Rao lower\r\nBound and the performance of synchronizers for (turbo) encoded\r\nsystems,\" In Proc. 5th IEEE Workshop Sig. Proc. Advances in Wirel.\r\nCommun., Lisbon, Portugal, July 11-14, 2004.\r\n[27] P. Robertson, P. Hoeher and E. Villebrun, \"Optimal and Sub-optimal\r\nmaximum a posterior algorithms suitable for turbo decoding,\" In\r\nEuropean Trans. On Telecomm. vol. 8, no. March\/ April, pp. 119-125,\r\n1997.","publisher":"World Academy of Science, Engineering and Technology","index":"Open Science Index 28, 2009"}