Bonfring International Journal of Research in Communication Engineering
Online ISSN: 2277-5080 | Print ISSN: 2250-110X | Frequency: 4 Issues/Year
Impact Factor: 0.528 | International Scientific Indexing(ISI) calculate based on International Citation Report(ICR)
Reduced State MAP Equalization and Decoding in Wireless Mobile Coded OFDM
M. Jini and R. Sabitha
Abstract:
Orthogonal frequency division multiplexing is used in high data rate applications such as digital video broadcasting, WLAN and WiMAX. But Performance of OFDM in wireless mobile environment degrades due to intercarrier interference which occurs due to multipath fading effect. This problem can be solved using an equalizer. In this paper a soft in soft out (SISO) Maximum a Posteriori Equalizer (MAP) is proposed. This equalizer makes use of BCJR algorithm. A trellis is constructed and bit log likelihood ratios (LLR) for received sequence are computed. A reduced state SISO MAP equalizer and two computationally efficient Linear Minimum Mean square Error based Equalization methods such as recursive q-tap SIC-LMMSE equalizer and recursive Sliding window SIC-LMMSE equalizer are also considered here. This method provides better bit error rate than previous methods and complexity is also lesser. RS-MAP equalizer and computationally efficient recursive LMMSE based equalizers are used that provides good performance and complexity trade-off. The performance of these different proposed equalizers has also been evaluated
Keywords: Interchannel interference, Turbo processing, Maximum a Posteriori Equalization, Maximum Likelihood Sequence Estimator
Volume: 2 | Issue: Special Issue on Communication Technology Interventions for Rural and Social Development
Pages: 06-09
Issue Date: February , 2012
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