Low complexity LDPC coded IB-DFE for multilevel modulations and coded OFDM: comparison and complexity trade-offs

Research output: Chapter in Book/Report/Conference proceedingConference contribution

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In this paper, we propose IB-DFE receiver (Iterative Block Decision Feedback Equalization) with iterative SISO LDPC decoding (soft-input soft-output - Low Density Parity Code) suitable for SC-FDE (Single- Carrier with Frequency-Domain Equalization) with multilevel modulations. This scheme can be implemented in a simple way using an analytical characterization where the any multilevel constellation is represented as a sum of BPSK (Bi-Phase Shift Keying) sub-constellations. This decomposition also allows energy efficient amplification compatible with grossly nonlinear amplifiers where BPSK component is amplified independently. The proposed system is compared with LDPC-coded OFDM (Orthogonal Frequency Division Multiplexing) with similar complexity. It is shown that the proposed system allows significant improvements on error performance without significant increase on decoding process’ complexity. The simulation results show that the iterative equalization together with the iterative decoding of LDPC improves the performance significantly when compared with uncoded schemes, even for small block sizes. In addition, the proposed coded IB-DFE scheme outperforms coded OFDM and has similar performance to uncoded IB-DFE even for lower number of iterations in the iterative equalization process, which can contribute for reductions in the computational load at the receiver’s side.
Original languageUnknown
Title of host publicationTelecommunications and Multimedia (TEMU), International Conference on
Publication statusPublished - 1 Jan 2014
EventTEMU -
Duration: 1 Jan 2014 → …


Period1/01/14 → …

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