论文标题
改进的基于EPA的接收器设计用于上行链路LDPC编码SCMA系统
An Improved EPA based Receiver Design for Uplink LDPC Coded SCMA System
论文作者
论文摘要
稀疏代码多重访问（SCMA）是有效启用未来机器类型通信（MTC）大规模连接性的新兴范式。在这封信中，我们构想了低密度奇偶校验检查（LDPC）编码的SCMA系统的上行链路传输。 LDPC-SCMA系统的传统接收器设计基于消息传递算法（MPA），用于多源检测，然后是单个LDPC解码，可能会遭受高复杂性和大解码延迟的缺点，尤其是当该系统具有较大的代码书大小和/或高超载因子时。为了解决这个问题，我们通过将期望传播算法（EPA）应用于联合检测和解码（JDD），介绍了一种新颖的接收器设计，该算法（JDD）涉及LDPC代码的汇总因子图和稀疏代码书。我们的数值结果表明，所提出的基于EPA的JDD接收器比常规涡轮接收器的优越性，其复杂性和更快的收敛速率都没有明显的错误率降级。
Sparse code multiple access (SCMA) is an emerging paradigm for efficient enabling of massive connectivity in future machine-type communications (MTC). In this letter, we conceive the uplink transmissions of the low-density parity check (LDPC) coded SCMA system. Traditional receiver design of LDPC-SCMA system, which is based on message passing algorithm (MPA) for multiuser detection followed by individual LDPC decoding, may suffer from the drawback of the high complexity and large decoding latency, especially when the system has large codebook size and/or high overloading factor. To address this problem, we introduce a novel receiver design by applying the expectation propagation algorithm (EPA) to the joint detection and decoding (JDD) involving an aggregated factor graph of LDPC code and sparse codebooks. Our numerical results demonstrate the superiority of the proposed EPA based JDD receiver over the conventional Turbo receiver in terms of both significantly lower complexity and faster convergence rate without noticeable error rate performance degradation.
