The low-density parity-check (LDPC) code optimization for spatial modulation (SM) is studied using the extrinsic information transfer (EXIT) chart technique. First, for the maximum a posteriori probability (MAP) detector of the SM, its EXIT chart is characterized through Monte Carlo simulations. Then, the optimized degree distribution is acquired by matching the check node decoder curve to the combined detector and variable node decoder curve. Simulation results show that these optimized codes have performance gains from 0.3 to 1.3dB, compared with the regular code and the optimized code for the additive Gaussian white noise channel, in 4×4 and 16×16 multiple-antenna systems.

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Satellite ATM networks is a new-type broadband satellite communication networks and plays an important role in the global communication networks.However, a major problem encountered for using satellite links to transport ATM cells is the high biterror ratio of satellite links, which severely impact the application of ATM over satellite. Therefore, in order to achieve a fiber-like quality on the satellite links, forward-error-correction codes are important for ATM cells. Considering the error characteristic of satellite links and ATM cell format, a novel LDPC coding scheme that four standard ATM cells being encoded as a whole is presented, which can achieve good performance and do not require to modifying standard ATM protocol. This scheme also makes use of the unequal error protection property of irregular LDPC codes, suitable for stressing protection to ATM cell header. Experiments show that the scheme proposed can distinctly improve bit-error ratio of satellite links and achieve good coding gain.

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