多载波扩频NOMA水声通信串行干扰消除算法

非正交多址接入(NOMA)技术可以有效提高多载波扩频多用户下行水声通信的系统容量,针对非正交多址水声通信系统多用户检测过程中由多用户干扰导致的误码传播问题,提出一种适用于非正交多址水声通信的判决反馈串行干扰消除算法。算法利用重构的近端用户信号对输入信号进行修正,提高远端用户信号重建精度,减少串行干扰消除过程中的误码传播,提高系统解调性能。仿真和湖试数据处理结果表明,判决反馈串行干扰消除算法的远端、近端用户误码率均优于传统算法,能够有效抑制误码传播,提高通信质量。     

5G非正交多址技术关键问题研究

非正交多址接入(NOMA)技术是5G通信的关键技术之一。该技术采用功率域复用的方式增加用户接入数,具有较高的频谱效率和可靠性,应用前景广泛。因此,研究5G非正交多址接入技术具有相当重要的意义。尤其是对其关键问题,如用户间的资源分配和多址干扰的消除等方面的问题,更值得深入研究。分别对这两个关键问题,就国内外目前的研究进展进行了详尽的分析和探讨。从实际多用户小区的资源分配、单一的串行干扰消除技术出发,总结了目前研究中所存在的问题,并提出相关解决方案,为更好地发挥NOMA技术的性能优势、抑制多用户共享资源带来的多址干扰问题提供参考。随着研究的深入,资源分配和干扰消除两大关键问题必将得到完善的解决,非正交多址技术也会在5G通信领域中得到广泛的应用。     

多用户场景下SWIPT-NOMA网络中的保密能量效率优化

在采用非正交多址接入技术的无线携能通信网络中,窃听者的存在和不同用户配对方式将影响网络的保密能量效率.为寻求保密能量效率最大化支配下的网络资源配置方案,提出了一种改进的群智能搜索算法用于解决此非凸优化问题.改进的群智能搜索算法采用共生生物搜索技术,增强了对可行域的局部搜索能力.仿真结果表明,不同的用户配对方式在单时隙或多时隙场景下具有相异特征,改进后的群智能搜索算法比其他基线算法具有更佳的网络性能,为多输入多输出非正交多址接入无线携能通信网络中通信安全及能量效率的研究提供了依据.     

一种新的FrDMA-B3G移动通信系统方案

移动通信的快速发展不断带来新的需求特点和技术挑战.如何为未来多种业务提供QoS保证的接入服务,是未来移动通信需要迫切解决的问题.同时相对于不断增加的接入需求,可用无线资源的稀缺性要求未来移动通信能取得更高的频谱效率.据此,该文提出一种新的帧分多址(Frame Division Multiple Access, FrDMA)-B3G通信系统接入方案,且该方案的物理层采用OFDM调制技术和多种自适应调制编码模式,能取得较高的频谱效率.通过采用CDMA扩频技术取得多种接入速率,满足不同业务的接入需求.系统仿真显示该方案能较好地满足未来B3G通信系统的诸多需求.     

基于禁忌搜索和Q-learning的CR-NOMA系统的功率分配算法

针对下一代移动通信对于高速率和大规模连接的需求,对认知无线电(CR)-非正交多址接入(NOMA)混合系统中通过优化功率分配来提升次用户总传输速率进行研究,提出一种基于禁忌搜索和Q-learning的功率分配(PATSQ)算法.首先,认知基站在系统环境中观测并学习用户的功率分配,次用户采用NOMA方式接入授权信道.其次,...     

基于NOMA的D2D用户和蜂窝用户通信方案

LTE网络采用非正交多址来增强网络容量,采用D2D来提高频谱效率;让D2D用户使用非正交多址技术共享蜂窝用户的频谱资源可以缓解当下频谱资源短缺的问题,但也会在D2D用户和蜂窝用户之间引入干扰。提出了一种基于非正交多址技术（Non-orthogonal Multiple Access,NOMA）的D2D用户和蜂窝用户的共享研究方案,对于蜂窝用户和D2D用户之间的干扰采用SIC技术消除。该方案不仅通过调整用户的传输功率来优化系统的吞吐量,而且提高了边缘用户的性能。仿真结果表明,基于NOMA的D2D用户和蜂窝用户之间的通信方案在性能上优于传统的蜂窝资源分配方案和干扰控制方案。     

基于非完美功率域非正交多址接入网络的上行链路低功耗研究

功率域非正交多址接入(PD-NOMA)技术可以有效提高无线网络频谱利用率,满足大规模节点接入及低时延等需求,但存在功耗大的缺点,在工业传感器网络中面临巨大挑战.对此,基于PD-NOMA的上行网络,接收机使用串行干扰抵消(SIC)迭代解码,在给定实时性需求下,通过用户调度和功率分配的联合优化,最小化网络的功耗.通过分析最...     

基于动态因子图更新率的SCMA检测算法

稀疏码分多址系统(sparse code multiple access,SCMA)作为一种码域的非正交多址技术,在相同时频资源条件下承载更多用户,能够满足5G通信的海量连接需求,但是接收端采用的消息传递算法(message passing algorithm,MPA)存在复杂度较高等问题.因此,该文提出了一种基于动态...     

多IRS辅助的NOMA URLLC系统性能优化

工业自动化等新型无线通信场景具有严格的低时延性和高可靠性需求，在网络中联合使用智能反射面(IRS)、非正交多址接入(NOMA)以及超可靠低时延通信(URLLC)技术能支持海量终端接入，并提供更低的通信时延、更高的可靠性，以及更高的吞吐量性能。考虑多IRS辅助的NOMA URLLC系统在多个用户被划分为多个簇的情况下，用户簇和IRS如何最佳配对和通信资源如何优化的问题，研究了联合优化用户发射功率分配、IRS反射波束成型以及用户簇IRS配对决策问题，最大化用户的吞吐量之和。为解决所考虑的非凸优化问题，提出一种基于交替迭代算法，通过巧妙地引入松弛变量，并采用半正定松弛方法，高效求解功率分配优化、IRS反射波束成型优化以及用户簇IRS配对决策优化三个子问题。仿真结果表明，所提算法能显著提高系统吞吐量，并且显示了用户簇IRS配对决策优化的必要性与有效性。     

基于FD-NOMA的无人机通信系统容量分析

为了提高无人机与地面用户的通信质量，提出了一种基于全双工和非正交多址接入技术的无人机通信系统模型，并分析了城市和郊区两种场景下该系统模型的遍历容量。首先，推导出两种场景下该系统模型的精确容量表达式；然后，通过引入Q函数和利用截断方法解决了式中指数积分函数的计算问题，得到了容量的近似闭式表达式，并在城市场景下，采用取系数因子的方法得到了更精确的容量近似闭式表达式；最后，仿真和数值结果表明，莱斯因子对系统容量存在一定影响，增加无人机数量或非正交多址接入功率向量都可以获得更好的容量性能。     

Hierarchy sustains partial cooperation and induces a Braess-like paradox in slotted aloha-based networks

This paper studies a hierarchical distributed choice of retransmission probabilities in slotted aloha. In particular, we consider a wireless system composed of one central receiver and several selfish mobile users communicating via the slotted aloha protocol. The set of mobile users is split into two classes: leaders and followers. We then study the induced non-cooperative hierarchical game based on the Stackelberg equilibrium concept. Using a 4D Markovian model, we compute the steady state of the system and derive the average throughput and the expected delay as well. We start by discussing the protocol design and propose a controlled slotted aloha using a virtual controller. The virtual controller can sustain partial cooperation among concurrent mobile users when accessing the channel by making the channel lossy. This leads us to identify a Braess-like paradox in which reducing capacity to the system may improve the performance of all mobile users. We then investigate the impact of hierarchy among mobile users in such a random access protocol and discuss how to distribute leader/follower roles. We show that the global performance of the system is improved compared to standard slotted aloha system. However, slight performances slow-down may be observed for the followers group when the total number of mobile users is relatively small.     

OFDMA认知无线电网络中面向功率控制的频谱定价与分配

针对OFDMA认知无线电网络,提出一种基于Stackelberg博弈的频谱定价和分配模型.对于次基站控制次网络传输功率来保护主网络通信的场景,主基站可通过该模型获得最优的频谱定价方案.从功率控制的角度,重新设计次用户的效用函数,运用Stackelberg博弈对单个主基站和多个次用户在频谱租赁市场中的交易行为进行建模.通过逆向归纳法,求解市场均衡下的最优频谱定价,使得主基站在考虑主网络QoS降级的同时获得最大收益.此外,对于主基站只能获取本地信息的情形,提出了基于动态Stackelberg博弈的分布式频谱定价和分配模型.仿真实验表明,该模型能够在控制次网络传输功率的基础上,提供最优频谱定价和频谱分配方案.     

移动边缘计算中基于Stackelberg博弈的算力交易与定价

针对移动边缘计算中轻量级智能设备计算和存储能力有限等问题，提出一种基于Stackelberg博弈的计算卸载解决方案。首先，结合区块链技术构建基于云挖掘机制的算力交易模型——CPTP-BSG，允许移动智能设备（矿工）将密集且复杂的计算任务卸载到边缘服务器；其次，将矿工与边缘计算服务提供商（ESP）之间的算力交易建模为一个两阶段的Stackelberg博弈过程，并构建矿工与ESP的预期利润函数；然后，使用逆向归纳法分别在统一定价和歧视性定价策略下分析纳什均衡解的存在性和唯一性；最后，提出一种低梯度迭代算法来实现矿工和ESP的利润最大化。实验结果证明了所提算法的有效性，并且与统一定价相比，歧视性定价更符合矿工的个性化算力需求，能达到更高的算力需求总量和ESP利润。     

Performance analysis of LTE downlink system using relay-based selective transmission

As society continues to integrate information-based technologies into daily life, there is an increased need for small, powerful mobile phones. Recently, relaying technologies have been researched for standardization of the next generation of mobile communication systems, including third-Generation Partnership Project (3GPP) LTE-Advanced, IEEE 802.16j, and IEEE 802.16m. Especially, LTE-Advanced is an evolutionary version of IMT-2000 defined by the ITU. To satisfy these requirements, relaying technology is considered as a powerful candidate scheme with carrier aggregation, MIMO, and CoMP. Relaying technology has been introduced to guarantee high data rates to multiple users. It can also extend cell coverage or effectively increase the average throughput of the cell by installing relay nodes at cell edges or in shadow areas. Thus, in this paper, we propose a method for boosting reception performance using the downlink transmission method of the LTE system, which is the next-generation mobile communication technology standard currently underway in 3GPP. At the moment, orthogonal frequency division multiplexing (OFDM), which is suitable for high-speed data transmission and multipath, is commonly used in an LTE downlink system. However, the OFDM method has a disadvantage of displaying a relatively higher PAPR at the terminal since it basically uses a multi-carrier. To this end, single carrier division multiple access (SC-FDMA) is used in an LTE uplink system in order to compensate for this defect related to high PAPR of OFDM at such an important terminal where power efficiency is important. However, when the channels in the frequency domain deteriorate signals, SC-FDMA reveals a defect in that the impact of deteriorated parts spreads and causes performance degradation. To this end, we propose that a relay be installed between the station and terminal, the distance between BS and RS be set at 500 or 1,000 m, and orthogonal frequency division multiple access (OFDMA) and SC-FDMA be chosen as transmission methods of RS. This paper found SC-FDMA to be a better choice when RS is closer to BS, whereas OFDMA is a better choice when the distance between BS and RS is farther. The system’s reception performance improved when the transmission method fit the circumstances in the middle between BS and MS.     

移动边缘计算中基于Stackelberg博弈的算力交易与定价

针对移动边缘计算中轻量级智能设备计算和存储能力有限等问题,提出一种基于Stackelberg博弈的计算卸载解决方案。首先,结合区块链技术构建基于云挖掘机制的算力交易模型——CPTP-BSG,允许移动智能设备（矿工）将密集且复杂的计算任务卸载到边缘服务器;其次,将矿工与边缘计算服务提供商（ESP）之间的算力交易建模为一个两阶段的Stackelberg博弈过程,并构建矿工与ESP的预期利润函数;然后,使用逆向归纳法分别在统一定价和歧视性定价策略下分析纳什均衡解的存在性和唯一性;最后,提出一种低梯度迭代算法来实现矿工和ESP的利润最大化。实验结果证明了所提算法的有效性,并且与统一定价相比,歧视性定价更符合矿工的个性化算力需求,能达到更高的算力需求总量和ESP利润。     

多对一供应链零售商驱动型收入共享契约下的生产决策

针对多对一供应链结构中零售商具有较强议价能力的特点,建立了零售商为主方、制造商为从方的Ｓｔａｃｋｅｌｂｅｒｇ主从对策模型;给出在零售商提供契约条款的对称博弈中,制造商生产产品策略存在唯一最优解的证明;分析了零售商契约参数变量的决策问题;讨论了收入共享契约下分散供应链同集中供应链决策的关系．通过仿真实验,分析验证了契约参数及产品的可替代性对供应链绩效的影响．     

Design of Embedded Filters for Inner‐Loop Power Control in Wireless CDMA Communication Systems

We study inner‐loop power control for mobile wireless communication systems using code division multiple access transmission. We focus on the uplink, i.e., on communication from the mobile‐ to the base‐station, and show how to minimise the variance of the signal‐to‐interference ratio (SIR) tracking error through incorporation of recursive filters. These filters complement existing power controllers and are designed by using a linear model which takes into account quantisation of the power control signal, dynamics of channel gains, interference from other users, target SIR, and SIR estimation errors. Simulation results indicate that significant performance gains can be obtained, even in situations where the models used for design are only an approximation. Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society     

Competitive scheduling for OFDMA systems with guaranteed transmission rate

Next-generation broadband wireless standards use orthogonal frequency division multiple access (OFDMA) as the preferred physical layer multiple access scheme, especially for the downlink. Due to limited resources available at the base station, multi-user resource allocation is crucial for delivering the applications with various quality-of-service (QoS) demands. We study the OFDMA resource allocation problem for the adaptive modulation and coding (AMC) mode of mobile WiMAX, in which resources in the form of allocation units (AU) are to be allocated and the channel knowledge of only some good sub-channels for the users is available to the scheduler. The objective is to maximize the sum-rate for all the users while maintaining guaranteed minimum and maximum traffic rates for certain users under a total transmission power constraint. Two novel factors, band selectivity factor (BSF) and competition factor (CF), are introduced. Based on the two factors, we propose a sub-optimal approach, rate-guaranteed competitive scheduling (RCS). It is suitable to be deployed in practical systems and exploits multi-user diversity with very low complexity. Simulation results show that RCS can achieve almost 75% of throughput of the optimal solution.     

A Stackelberg game-theoretic approach to optimal real-time pricing for the smart grid

This paper proposes a Stackelberg game approach to maximize the profit of the electricity retailer (utility company) and minimize the payment bills of its customers. The electricity retailer determines the retail price through the proposed smart energy pricing scheme to optimally adjust the real-time pricing with the aim to maximize its profit. The price information is sent to the customers through a smart meter. According to the announced price, the customers can automatically manage the energy use of appliances in the households by the proposed optimal electricity consumption scheduling system with the aim to minimize their electricity bills. We model the interactions between the retailer and its electricity customers as a 1-leader, N-follower Stackelberg game. At the leader’s side, i.e., for the retailer, we adopt genetic algorithms to maximize its profit while at the followers’ side, i.e., for customers, we develop an analytical solution to the linear programming problem to minimize their bills. Simulation results show that the proposed approach is beneficial for both the customers and the retailer.     

基于多跟随者Stackelberg博弈的流速控制算法

由于现实网络中,端系统的角色往往并不平等,存在某些端系统制定整个网络的流速控制策略,其他端系统只能跟随这些策略,不能简单地使用非合作博弈理论研究Internet中非合作端系统的贪婪行为。该文在讨论了一次博弈模型和流速控制博弈均衡的解析解的基础上,对多跟随者Stackelberg博弈模型的流速与拥塞控制行为进行了深入研究。提出了多跟随者Stackelberg博弈流速控制模型,论证了Stackelberg均衡的存在性,并推导出在Stackelberg均衡点上领导者和多跟随者流速率的解析解。最后,文章设计了一种基于多跟随者Stackelberg博弈的流速控制算法(FCSM),并讨论了FCSM算法执行的过程。