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的接入技术的有力候选者。通常对于上行链路，比特对直接映射到码字，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生成码字，对三个比特进行编码，以增加上行链路中的数据传输容量。在接收器中，数据的检测和解码比其前辈的两位更复杂，因为IQ星座中的符号彼此更接近，因此提出了基于神经网络的接收器来执行这些任务。通过实施软件定义无线电平台来评估该提案的实验性能。结果表明，即使在不利的信噪比条件下，也可以使用8-APSK作为低误码率的调制技术来检测和解码SCM​​A信号。