Performance Improvement of Digital Radio Mondiale System Using Non Uniform Constellations

The challenge in the designing of wireless communication system is to get close to the Shannon limit. In this paper, Non Uniform Constellations (NUCs) have been proposed as an alternative to uniform Quadrature Amplitude Modulation (QAM) in Digital Radio Mondiale (DRM) system based on Low Density Parity Check (LDPC). Indeed LDPC has been previously proposed in substitution of convolutionnal code and highlighted a better performance. Also 2D-NUCs performance have been previously highlighted in many broadcasting systems. These constellations shaping is jointly proposed with LDPC as an alternative to QAM + convolutional code in order to increase DRM system capacity. The simulation results show that DRM system based on LDPC/ NUCs outperforms the legacy system 1 dB, 1.18 dB and 1.25 dB SNR gain at a Bit Error Rate (BER) of 10
⁻³
respectively for code rates 1/2, 3/5 and 2/3.