基于NOMA的多用户波束导向OWC系统

Placement and Resource Allocation of Wireless-Powered Multiantenna UAV for Energy-Efficient Multiuser NOMA

This paper investigates a new downlink nonorthogonal multiple access (NOMA) system, where a multiantenna unmanned aerial vehicle (UAV) is powered by wireless power transfer (WPT) and serves as the base station for multiple pairs of ground users (GUs) running NOMA in each pair. An energy efficiency (EE) maximization problem is formulated to jointly optimize the WPT time and the placement for the UAV, and the allocation of the UAV's transmit power between different NOMA user pairs and within each pair. To efficiently solve this nonconvex problem, we decompose the problem into three subproblems u…

Low-Complexity Block Coordinate Descend Based Multiuser Detection for Uplink Grant-Free NOMA

Grant-free non-orthogonal multiple access (NOMA) scheme is considered as a promising candidate for the enabling of massive connectivity and reduced signalling overhead for Internet of Things (IoT) applications in massive machine-type communication (mMTC) networks. Exploiting the inherent nature of sporadic transmissions in the grant-free NOMA systems, compressed sensing based multiuser detection (CS-MUD) has been deemed as a powerful solution to user activity detection (UAD) and data detection (DD). In this paper, block coordinate descend (BCD) method is employed in CS-MUD to reduce the comput…

Queueing Theoretic Models for Multiuser MISO Content-Centric Networks with SDMA, NOMA, OMA and Rate-Splitting Downlink

Multiuser, Multiple Input, Single Output (MU-MISO) systems are proving to be indispensable in the next generation wireless networks such as 5G and 6G. The spatial diversity of MISO systems have been leveraged in physical layer designs in these wireless systems to improve the capacity. Several recent studies have utilised redundancies in the content request along with the spatial diversity of a MISO system to improve the capacity further. It is shown that Max-Min Fair (MMF) Beamforming schemes for MISO based on SDMA, NOMA, OMA and Rate-Splitting could be used to improve the content delivery rat…

多播光无线系统中非正交多址的随机线性网络编码

Random Linear Network Coding for Non-Orthogonal Multiple Access in Multicast Optical Wireless Systems

本研究将随机线性网络编码应用于NOMA光无线多播系统，通过固定功率分配管理干扰，提升高密度室内网络性能，优于传统方案。

非协调上行链路非正交多址中具备优化电平选择概率的随机功率传输

Randomized Power Transmission with Optimized Level Selection Probabilities in Uncoordinated Uplink NOMA

针对非协调上行NOMA系统，本文提出优化功率电平选择概率以最小化BLEP、BEP等指标，分别给出两用户碰撞下的二次规划解法与多用户碰撞下的迭代解法，适配任意多用户检测算法与功率电平集。

Optimizing Information Freshness via Multiuser Scheduling with Adaptive NOMA/OMA

This paper considers a wireless network with a base station (BS) conducting timely status updates to multiple clients via adaptive non-orthogonal multiple access (NOMA)/orthogonal multiple access (OMA). Specifically, the BS is able to adaptively switch between NOMA and OMA for the downlink transmission to optimize the information freshness of the network, characterized by the Age of Information (AoI) metric. If the BS chooses OMA, it can only serve one client within each time slot and should decide which client to serve; if the BS chooses NOMA, it can serve more than one client at the same tim…

关于非正交多址接入（NOMA）的检测最优性及精确误码率分析

On the Detection Optimality and Exact BER Analysis of NOMA

研究非正交多址接入（NOMA）检测最优性及误码率，推导最优逐用户最大后验（MAP）检测器，确定近用户检测器与传统SIC的关系及两者等效性，给出考虑SIC统计变化的精确平均BER分析，在中低信噪比下有BER增益。

单天线功率约束下的MISO NOMA下行波束赋形优化

MISO NOMA Downlink Beamforming Optimization with Per-Antenna Power Constraints

考虑多输入单输出（MISO）系统中非正交多址接入（NOMA）传输的多用户下行波束成形优化问题。总发射功率最小化的问题，制定了每天线功率约束和服务质量（QoS）约束下的NOMA原则。该问题是一个非凸二次约束二次规划问题，传统的半定规划松弛方法是不紧的。为了解决非凸NOMA波束形成问题，我们为每个信号干扰噪声比（SINR）约束构造了一个二阶锥近似，并形成了一个迭代算法，在该算法中求解了一系列二阶锥规划（SOCP）。SOCP序列的最优值是非增的，它收敛到一个局部最优值。然而，我们广泛的模拟结果表明，局部最优值或多或少是好的全局最优值。特别是，我们表明，SDP松弛是紧的两个用户的情况下，如果一个SINR的约束是严格的（非约束）在最优。详细的仿真结果表明，通过所提出的近似算法的性能增益的NOMA下行链路波束成形与每个天线的功率约束。

NOMA-ISAC: Performance Analysis and Rate Region Characterization

This paper analyzes the performance of a multiuser integrated sensing and communications (ISAC) system, where nonorthogonal multiple access (NOMA) is exploited to mitigate inter-user interference. Closed-form expressions are derived to evaluate the outage probability, ergodic communication rate, and sensing rate. Furthermore, asymptotic analyses are carried out to unveil diversity orders and high signal-to-noise ratio (SNR) slopes of the considered NOMA-ISAC system. As the further advance, the achievable sensing-communication rate region of ISAC is characterized. It is proved that ISAC system …

多介质波导下Pinching Antenna辅助NOMA系统的和速率最大化

Sum-Rate Maximization for Pinching Antenna-assisted NOMA Systems with Multiple Dielectric Waveguides

针对多介质波导PA辅助MISO-NOMA系统，本文提出频率相关功率衰减模型，通过交替优化算法联合优化预编码与PA位置以最大化和速率，性能显著优于传统及忽略衰减的简易PA系统，高载波下增益更突出。

非正交多址可见光通信系统中用于提升频谱效率的概率星座整形

Probabilistic Constellation Shaping for Enhancing Spectral Efficiency in NOMA VLC Systems

本文针对LED调制带宽受限问题，提出自适应编码概率整形的NOMA方案，通过交替优化编码速率、星座间隔和概率质量函数，显著提升多用户VLC系统的频谱效率并逼近容量。

On the Effective Rate of NOMA in Underlay Spectrum Sharing

In this paper, we present the delay-constrained performance analysis of a multi-antenna-assisted multiuser non-orthogonal multiple access (NOMA) based spectrum sharing system over Rayleigh fading channels. We derive analytical expressions for the sum effective rate (ER) for the downlink NOMA system under a peak interference constraint. In particular, we show the effect of the availability of different levels of channel state information (instantaneous and statistical) on the system performance. We also show the effect of different parameters of interest, including the peak tolerable interferen…

Rate-Splitting Multiple Access for Downlink Multiuser MIMO: Precoder Optimization and PHY-Layer Design

Rate-Splitting Multiple Access (RSMA) has recently appeared as a powerful and robust multiple access and interference management strategy for downlink Multi-user (MU) multi-antenna communications. In this work, we study the precoder design problem for RSMA scheme in downlink MU systems with both perfect and imperfect Channel State Information at the Transmitter (CSIT) and assess the role and benefits of transmitting multiple common streams. Unlike existing works which have considered single-antenna receivers (Multiple-Input Single-Output--MISO), we propose and extend the RSMA framework for mul…

多用户STAR-RIS辅助的MISO速率分割下行链路中的安全SWIPT

Secure SWIPT in the Multiuser STAR-RIS Aided MISO Rate Splitting Downlink

本文提出一种基于STAR-RIS辅助的安全SWIPT下行RSMA系统，通过顺序参数凸近似的两步迭代算法优化预编码和STAR-RIS配置，最大化最坏情况总保密速率，显著提升了保密传输速率和频谱效率，且性能优于OMA和NOMA。