Conference Papers

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Author: search.filters.author.Priyatamkumar

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    Design and implementation of M-BCJR algorithm based turbo equalizer
    (Institute of Electrical and Electronics Engineers Inc., 2004) Priyatamkumar; Banakar, Dr.R.M.; Shankaranand, S.
    Turbo equalizers have been shown to be successful in mitigating the effects of inter-symbol interference introduced by partial response modems and by dispersive channels for code rates of R >1/2. We analyze the performance of iterative equalization and decoding (IED) using an M-BCJR equalizer. We use bit error rate (BER), frame error rate simulations and extrinsic information transfer (EXIT) charts to study and compare the performances of M-BCJR and BCJR equalizers on precoded and non-precoded channels. Using EXIT charts, the achievable channel capacities with IED using the BCJR, M-BCJR and MMSE LE equalizers are also compared. We predict the BER performance of IED using the M-BCJR equalizer from EXIT charts and explain the discrepancy between the observed and predicted performances by showing that the extrinsic outputs of the M-BCJR algorithm are not true logarithmiclikelihood ratios (LLR's). We show that the true LLR's can be estimated if the conditional distributions of the extrinsic outputs are known and finally we design a practical estimator for computing the true LLR's from the extrinsic outputs of the M-BCJR equalizer. © 2004 IEEE.
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    Parameters influencing air interference in 4G WCDMA mobiles
    (2006) Priyatamkumar; Banakar, Dr.R.M.; Shankaranand, Dr.B.
    Air interference, high usability and global coverage are some of the research challenges associated with 4G mobile systems. In this paper we analyze the parameters influencing air interface in 4G WCDMA systems at the physical layer and Link layer. A system model is proposed to increase the coverage range without increasing the transmitter power but by enhancing the SNR at the receiver end. ©2006 IEEE.