In recent years SCMA has been proposed as a strong candidate to perform as access technique for fifth-generation mobile communications systems; usually for the uplink, bit pairs are mapped directly to code words and MPA is used in the receiver. In this work, we proposed to encode three bits to increase the capacity of data transmission in the uplink using singular value decomposition of the initial mother constellation to generate the codewords. In the receiver, the detection and decoding of data is more complex than its predecessors with two bits, since the symbols in the IQ constellation are closer to each other, so a receiver based on neural networks is proposed to perform these tasks. The experimental performance of this proposal was evaluated by implementing a software defined radio platform. The results show that, even under unfavorable SNR conditions, it is possible to use 8-APSK as a modulation technique with low error rate in the detection and decoding of SCMA signals.

中文翻译：

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使用 SVD-SCMA 的 8-APSK 调制在上行链路中的应用

近年来，SCMA 被提议作为第五代移动通信系统接入技术的有力候选者；通常对于上行链路，位对直接映射到码字，并且在接收器中使用 MPA。在这项工作中，我们建议使用初始母星座的奇异值分解来编码三个比特以增加上行链路中的数据传输容量以生成码字。在接收器中，由于 IQ 星座中的符号彼此更接近，因此数据的检测和解码比其前辈更复杂，因此提出了基于神经网络的接收器来执行这些任务。该提案的实验性能是通过实施软件定义的无线电平台来评估的。结果表明，