Prefix-Free Code Distribution Matching for Probabilistic Constellation Shaping
Prefix-Free Code Distribution Matching for Probabilistic Constellation Shaping
复制标题
用于概率星座整形的无前缀代码分布匹配
DOI：
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发表时间：
2018
影响因子：
8.3
通讯作者：
Junho Cho
中科院分区：
文献类型：
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作者：
Junho Cho
在本文中，我们构造的变长无前缀码是最佳的（或接近最佳）的意义上说，没有（或很少）其他代码相同的基数可以实现一个较小的预期能量每个代码符号相同的分辨率。在每个码本4096个码字或更低的严格约束下，所构造的码在具有精细粒度的宽范围的分辨率上产生在无约束理论下限的十分之几dB内的每个码符号的能量。我们还提出了一种帧的方法，允许可变长度的代码被发送使用一个固定长度的帧。使用模拟和分析研究了成帧引起的惩罚，表明每个码符号的能量保持在0.3 dB的无约束的理论限制的一些测试代码具有大的帧长度。当所提出的方法被用来实现概率星座成形在加性白色高斯噪声信道中的通信，仿真结果表明，在0.21 dB和0.98 dB之间的成形增益实现相对于均匀的4，8，16，和32进制正交幅度调制。
In this paper, we construct variable-length prefix-free codes that are optimal (or near-optimal) in the sense that no (or few) other codes of the same cardinality can achieve a smaller expected energy per code symbol for the same resolution rate. Under stringent constraints of 4096 codewords or below per codebook, the constructed codes yield an energy per code symbol within a few tenths of a dB of the unconstrained theoretic lower bound, across a wide range of resolution rates with fine granularity. We also propose a framing method that allows variable-length codes to be transmitted using a fixed-length frame. The penalty caused by framing is studied using simulations and analysis, showing that the energy per code symbol is kept within 0.3 dB of the unconstrained theoretic limit for some tested codes with a large frame length. When the proposed method is used to implement probabilistic constellation shaping for communications in the additive white Gaussian noise channel, simulations show that between 0.21 dB and 0.98 dB of shaping gains are achieved relative to uniform 4-, 8-, 16-, and 32-ary quadrature amplitude modulation.