In this paper, we propose to increase the throughput of Multi-Carrier Code Division Multiple Access (MC-CDMA) systems using Non Orthogonal Multiple Access (NOMA). During the first slot, the base station harvests energy from Radio Frequency (RF) signals received from node A. The harvested energy is used to transmit data to users. The suggested system model uses K different spreading sequence with low intercorrelation. The base station combines the symbols of L NOMA users and transmit them over the same spreading code. The obtained chip sequence is transmitted over different subcarriers. Each user removes the guard interval then it performs a Discrete Fourier Transformation (DFT) to compute the soft output. The weak user uses the soft output of a given NOMA symbol to detect its own symbol. Strong users uses the soft output to detect the symbol of weak users as it is transmitted with a large power. Then, strong user performs Successive Interference Cancelation (SIC) to remove the signal of weak user and to detect its own symbol. We also optimize the powers dedicated to NOMA users and harvesting duration to maximize the total average throughput. When there are two (respectively three or four) users per spreading code, the total throughput of MC-CDMA using NOMA is twice (three times or four times) the throughput of conventional MC-CDMA systems.

在本文中，我们建议使用非正交多址（NOMA）来提高多载波码分多址（MC-CDMA）系统的吞吐量。在第一个时隙期间，基站从节点A接收到的射频 (RF) 信号中获取能量。收集到的能量用于向用户传输数据。建议的系统模型使用K个不同的低互相关的扩频序列。基站将L个NOMA用户的符号组合起来并通过相同的扩频码进行传输。获得的码片序列在不同的子载波上传输。每个用户删除保护间隔，然后执行离散傅里叶变换 (DFT) 来计算软输出。弱用户使用给定 NOMA 符号的软输出来检测自己的符号。当弱用户以大功率传输时，强用户使用软输出来检测弱用户的符号。然后，强用户执行连续干扰消除(SIC)以去除弱用户的信号并检测自己的符号。我们还优化了 NOMA 用户专用的能力和收获持续时间，以最大限度地提高总平均吞吐量。当每个扩频码有两个（分别是三个或四个）用户时，使用NOMA的MC-CDMA的总吞吐量是传统MC-CDMA系统吞吐量的两倍（三倍或四倍）。