Sum Rate and Reliability Analysis for Power-Domain Nonorthogonal Multiple Access (PD-NOMA)
Sum Rate and Reliability Analysis for Power-Domain Nonorthogonal Multiple Access (PD-NOMA)
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DOI：
10.1109/jiot.2021.3050990
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发表时间：
2021-01
影响因子：
10.6
通讯作者：
Taehyeun Park;Gilsoo Lee;W. Saad;M. Bennis
中科院分区：
文献类型：
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作者：
Taehyeun Park;Gilsoo Lee;W. Saad;M. Bennis
非正交多址（NOMA）被视为未来物联网（IoT）系统的重要技术。在上行链路功率域NOMA（PD-NOMA）中，分配IoT设备的上行链路发射功率对于最大化设备的总速率和可靠性两者是重要的。然而，当接收信号功率受到随机衰落信道的影响时，优化上行链路发射功率具有挑战性。因此，在这篇文章中，上行链路发射功率分配的问题是研究一个无线网络与PD-NOMA，服务于上行链路物联网服务。这被提出作为确定在基站（BS）处的目标接收信号功率的问题，使得用户的和速率的可靠性和上限被联合最大化，其中在BS处的接收信号功率由于Nakagami衰落信道而对于设备是未知的。为了找到使用PD-NOMA的设备的较低和较高的目标接收功率值的最优分配，根据目标接收功率值和功率差阈值导出和速率的可靠性和上界。对于Nakagami- $m$衰落信道的一种特殊情况，理论分析表明，当目标接收功率值最大时，该算法具有最高的可靠性和最大的和速率上界。对于一般的Nakagami- $m$衰落信道，仿真结果表明，有一个折衷之间的可靠性和速率上限，因此，分配较低和较高的目标接收功率值是必要的，以满足物联网设备的通信要求。此外，针对Nakagami- $m$衰落信道的特殊情况，仿真结果表明，所推导的最优发射功率达到了最优和速率上界和可靠性，并且两个设备的目标接收功率值必须最高，才能达到和速率上界和可靠性上界的最大值。此外，在仿真结果中，增加较低和较高的目标接收功率值增加了和速率和可靠性的上限。
Nonorthogonal multiple access (NOMA) is seen as an important technology for tomorrow’s Internet-of-Things (IoT) systems. In uplink power-domain NOMA (PD-NOMA), allocating the uplink transmit power of the IoT devices is important to maximize both the sum rate and the reliability of devices. However, it is challenging to optimize the uplink transmit power when the received signal power is affected by a random fading channel. Hence, in this article, the problem of uplink transmit power assignment is studied for a wireless network with PD-NOMA that serves uplink IoT services. This is posed as a problem of determining the target received signal power at the base station (BS) so that the reliability and upper bound of sum rate of the users are jointly maximized, where the received signal power at the BS is unknown to the devices due to Nakagami- $m$ fading channel. To find an optimal allocation of the lower and higher target received power values for the devices using PD-NOMA, the reliability and upper bound of sum rate are derived in terms of target received power values and power difference threshold. For a special case of Nakagami- $m$ fading channel, the theoretical analysis shows that the highest reliability and the highest upper bound of sum rate are achieved, when the target received power values are highest. For a general Nakagami- $m$ fading channel, simulation results show that there is a tradeoff between reliability and sum-rate upper bound and, thus, allocation of lower and higher target received power values is necessary to satisfy the communication requirements of IoT devices. Moreover, for a special case of Nakagami- $m$ fading channel, simulation results show that the derived optimal transmit power achieves the optimal sum-rate upper bound and reliability, and the target received power values of two devices must be highest for the maximum upper bound of sum rate and reliability. Furthermore, in simulation results, increasing the lower and higher target received power values increases both the upper bound of sum rate and reliability.