Prediction of performance of the DVB-SH system relying on Mutual Information
Prediction of performance of the DVB-SH system relying on Mutual Information
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基于互信息的 DVB-SH 系统性能预测
DOI：
10.1109/asms-spsc.2010.5586893
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
J. Lacan
中科院分区：
文献类型：
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作者：
W. Chauvet;Caroline Amiot;J. Lacan
DVB-SH（数字视频广播-卫星处理）是一种专门用于结合卫星和地面部分的混合广播系统的广播标准。在卫星部分，提出了基于卷积交织器的专用交错和时间切片机制，以减轻陆地移动卫星（LMS）信道的影响。根据该交织器的参数，该机制能够及时地将持续时间从100毫秒分割到大约30秒的码字。这种机制显著提高了代码的错误恢复性能，但在文献中，没有在系统级别对这种改进进行准确的评估。本文的目的是提出一种兼容快速仿真的预测方法，以包错误率（Packet Error Rate， PER）来定量评估系统性能。主要的困难是评估一个码字的解码概率提交到几个级别的衰减。我们提出的方法是使用发射端编码位与接收符号之间的互信息（MI）作为度量。结果表明，与基于信噪比和误码率（BER）的其他两种方法相比，通过平均码字上的MI并使用解码性能函数g使PER=g（MI）在高斯信道上确定，我们可以显着提高预测精度。我们在三个人工信道上评估了这些方法，其中每个码字以三到四个不同的衰减水平传输。基于信噪比的预测误差。基于输入ber的方法从0.5到1.7 dB（响应频率）不等。从0.7到1.2 dB)，而不是基于mi的方法在三种情况下达到0.1 dB的精度。然后，我们在具有各种DVB-SH交织器的真实LMS信道上对该方法进行了评估，结果表明该方法也可以高精度地预测瞬时PER。
DVB-SH (Digital Video Broadcasting- Satellite Handled) is a broadcasting standard dedicated to hybrid broadcasting systems combining a satellite and a terrestrial part. On the satellite part, dedicated interleaving and time slicing mechanisms are proposed to mitigate the effects of Land Mobile Satellite (LMS) channel, based on a convolutional interleaver. Depending on the parameters of this interleaver, this mechanism enables to split in time a codeword on duration from 100 ms to about 30s. This mechanism significantly improves the error recovery performance of the code but in literature, exact evaluation at system level of this improvement is missing. The objective of this paper is to propose a prediction method compatible with fast simulations, to quantitatively evaluate the system performance in terms of Packet Error Rate (PER). The main difficulty is to evaluate the decoding probability of a codeword submitted to several levels of attenuation. The method we propose consists in using as metric the Mutual Information (MI) between coded bit at the emitter side and the received symbol. It is shown that, by averaging the MI over the codeword and by using the decoding performance function g such that PER=g(MI) determined on the Gaussian channel, we can significantly improve the precision of the prediction compared to the two other methods based on SNR and Bit Error Rate (BER). We evaluated these methods on three artificial channels where each codeword is transmitted with three or four different levels of attenuations. The prediction error of the SNR-based (resp. the input BER-based) method varies from 0.5 to 1.7 dB (resp. from 0.7 to 1.2 dB) instead of the MI-based method achieves a precision in the order of 0.1 dB in the three cases. We then evaluate this method on real LMS channels with various DVB-SH interleavers and show that the instantaneous PER can also be predicted with high accuracy.