Design of a Capacity-Approaching Chaos-Based Multiaccess Transmission System
Design of a Capacity-Approaching Chaos-Based Multiaccess Transmission System
复制标题
基于混沌的容量逼近多址传输系统设计
DOI：
10.1109/tvt.2017.2723608
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发表时间：
2017-12-01
影响因子：
6.8
通讯作者：
Chen, Guanrong
中科院分区：
文献类型：
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作者：
Chen, Pingping;Fang, Yi;Chen, Guanrong
作为基于沃尔什码的多址差分混沌移位键控（DCSK-WC）的增强版本，差分DCSK-WC（DDCSK-WC）具有更好的误码性能和更强的针对多径衰落信道中符号间干扰的鲁棒性。本文将Bahl–Cocke–Jelinek–Raviv (BCJR)解码算法应用于DDCSK-WC的检测，形成DDCSK-WC-BCJR。理论分析和仿真结果表明，BCJR 检测器相对于传统的广义最大似然检测器实现了显着的性能增益，同时保持硬件复杂性几乎不变。为了进一步提高性能，DDCSK-WC-BCJR系统中加入了基于原图的低密度奇偶校验信道码，构建了串行级联编码方案。然而，加性高斯白噪声 (AWGN) 信道中的容量逼近原写码在多径衰落信道上的 DDCSK-WC-BCJR 系统中表现不佳。为了解决这个问题，在修改后的外在信息传输分析的帮助下设计了一种新的原型代码。所提议的代码的解码阈值与系统容量限制的差距在 1.0 dB 以内。此外，原型编码DDCSK-WC-BCJR架构在实际UWB信道上的性能优势得到了体现。更重要的是，所提出的方案不需要像未编码DCSK方案那样的信道状态信息，这使得它对于低成本和低复杂度的无线通信应用非常有前途。
As an enhanced version of Walsh-code-based multiaccess differential chaos shift keying (DCSK-WC), the differentially DCSK-WC (DDCSK-WC) benefits from better error performance and stronger robustness against inter-symbol interference in multipath fading channels. In this paper, the Bahl–Cocke–Jelinek–Raviv (BCJR) decoding algorithm is applied in the detection of DDCSK-WC to form DDCSK-WC-BCJR. Theoretical analyses and simulation results demonstrate that the BCJR detector achieves a significant performance gain with respect to the conventional generalized-maximum-likelihood detector, while retaining the hardware complexity almost unchanged. To further improve the performance, protograph-based low-density-parity-check channel codes are incorporated into the DDCSK-WC-BCJR system so as to construct a serial concatenated coding scheme. However, the capacity-approaching protograph code in additive white Gaussian noise (AWGN) channels performs poorly in the DDCSK-WC-BCJR system over multipath fading channels. To tackle this problem, a new protograph code is designed with the help of a modified extrinsic information transfer analysis. The proposed code has decoding thresholds gap within 1.0 dB way from to the system capacity limits. Besides, the performance superiority of the protograph-coded DDCSK-WC-BCJR architecture is illustrated over a practical UWB channel. More importantly, the proposed scheme does not require channel state information as in uncoded-DCSK schemes, which makes it extremely promising for low-cost and low-complexity wireless communication applications.