论文标题
下行链路IoT网络中针对超低解码复杂性的低预测SCMA代码簿的设计
A Design of Low-Projection SCMA Codebooks for Ultra-Low Decoding Complexity in Downlink IoT Networks
论文作者
论文摘要
本文想象着一种新颖的稀疏代码多访问（SCMA）代码簿设计，该设计是由在下行链路互联网（IoT）网络中提供超低解码复杂性和良好错误性能的强烈需要的，其中提供了大量的低端和低站IoT Iot通信设备。通过专注于典型的里奇亚式褪色渠道，我们分析了叠加的SCMA代码字的成对概率，然后推断出设计指标以进行多维星座结构和稀疏代码书优化。为了显着降低解码复杂性，我们主张将多维星座元素投射到每个维度的几个重叠的复数，称为低投影（LP）中的关键思想。用于多阶段LP优化的新兴调制方案，称为金角度调制（GAM），其中所得的多维星座称为LP-GAM。我们的分析和仿真结果表明，提出的LP代码簿（LPCB）的优越性，包括一次性解码和出色的错误率性能。尤其是，与传统的代码簿相比，拟议的LPCB导致解码的复杂性降低至少$ 97 \％$，同时拥有大型欧几里得距离。提出的LPCB的一些示例可在\ url {https://github.com/ethanlq/scma-codebook}上找到。
This paper conceives a novel sparse code multiple access (SCMA) codebook design which is motivated by the strong need for providing ultra-low decoding complexity and good error performance in downlink Internet-of-things (IoT) networks, in which a massive number of low-end and low-cost IoT communication devices are served. By focusing on the typical Rician fading channels, we analyze the pair-wise probability of superimposed SCMA codewords and then deduce the design metrics for multi-dimensional constellation construction and sparse codebook optimization. For significant reduction of the decoding complexity, we advocate the key idea of projecting the multi-dimensional constellation elements to a few overlapped complex numbers in each dimension, called low projection (LP). An emerging modulation scheme, called golden angle modulation (GAM), is considered for multi-stage LP optimization, where the resultant multi-dimensional constellation is called LP-GAM. Our analysis and simulation results show the superiority of the proposed LP codebooks (LPCBs) including one-shot decoding convergence and excellent error rate performance. In particular, the proposed LPCBs lead to decoding complexity reduction by at least $97\%$ compared to that of the conventional codebooks, whilst owning large minimum Euclidean distance. Some examples of the proposed LPCBs are available at \url{https://github.com/ethanlq/SCMA-codebook}.
