The evolving 5G case study in United States unilateral spectrum planning and policy

This paper tracks increasingly aggressive initiatives by the United States government to reallocate spectrum on an expedited and unilateral basis well before conclusion of inter-governmental coordination. Rather than embrace the customary commitment to achieve consensus on global spectrum allocations at the International Telecommunication Union (“ITU”), the Federal Communications Commission (“FCC”) has auctioned off large blocks of frequencies for the next generation (“5G”) of wireless services.The FCC might have framed its first 5G auction, reassigning Ultra High Frequency (“UHF”) spectrum, as a one-time deviation from compliance with long standing, intergovernmental coordination procedures. These frequencies have ideal signal propagation characteristics and the Commission could use financial incentives—unavailable in most nations—to expedite “repacking” by incumbent broadcasters willing to move, share or abandon spectrum in exchange for ample financial compensation. However, the FCC has continued to auction off 5G spectrum on grounds that it must find ways to abate an acute shortage of wireless bandwidth and doing so will regain or maintain global leadership in wireless technologies. This paper offers a critical rebuke to unilateral spectrum management, because the short-term benefits expected by the U. S. government likely will be offset by countervailing harms to 5G manufacturers, carriers and consumers. The paper tracks fractious preparation for the ITU's 2019 World Radio Conference by the U.S. delegation and the mixed record achieved there. Additionally, the paper explains how injecting trade, industrial policy and national security issues at the ITU can trigger more delays and disputes, including possible retaliation by nations displeased with U.S. efforts to subvert traditional technology optimization goals.A worst case scenario has the ITU deadlocked and unable to reach closure on “mission critical” spectrum planning issues at World Radio Conferences, convened every four years. The paper concludes that costs and likely challenges to the efficacy and legitimacy of the ITU will reduce the benefits accruing from the FCC's unilateral, spectrum planning campaign.     

Fast and accurate yearly time series forecasting with forecast combinations

It has long been known that combination forecasting strategies produce superior out-of-sample forecasting performances. In the M4 forecasting competition, a very simple forecast combination strategy achieved third place on yearly time series. An analysis of the ensemble model and its component models suggests that the competitive accuracy comes from avoiding poor forecasts, rather than from beating the best individual models. Moreover, the simple ensemble model can be fitted very quickly, can easily scale horizontally with additional CPU cores or a cluster of computers, and can be implemented by users very quickly and easily. This approach might be of particular interest to users who need accurate yearly forecasts without being able to spend significant time, resources, or expertise on tuning models. Users of the R statistical programming language can access this modeling approach using the “forecastHybrid” package.     

基于软件无线电平台的1090ES扩容信号收发处理

随着空中交通的信息传输与新应用拓展需求不断增加，1090ES信号容量有限问题日益显现，对1090ES信号进行容量扩充是一种有效解决途径。针对一种基于脉内调相的1090ES信号扩容技术，给出了叠加调制的信号模型，研究了1090ES信号的解调解码算法；在GNU Radio+ USRP软件无线电平台上，实现了1090ES扩容信号的产生和接收处理，包括脉冲位置调制（Pulse Position Modulation，PPM）与8PSK叠加调制、低通滤波、报头检测、载波同步、PPM解码和相位解调等，并利用Matlab对实验的解码错误率和信号的频谱特性做了统计分析与仿真，结果表明了该扩容技术的可行性。     

一种嵌入式软件无线电频谱监测系统

为了降低研发成本，提高频谱系统的灵活性和缩短研制周期，提出了一种基于软件无线电的嵌入式频谱监测系统。首先研究了系统硬件平台组成和特点，在此基础上设计了一种灵活的软件定义系统架构；然后考虑到硬件平台自身性能的限制，重点研究了频率偏移校正、频谱扫描策略等关键技术，分别提出了基于GSM信号和温度传感器的频偏校正方法和基于相关性的扫频策略；最后通过具体实验，对系统性能进行验证与评估，结果表明所提出的频偏校正方法能够将绝对平均频偏控制在1.749×10-6以内，所设计的基于相关性的扫频策略对时变信号的频谱监测效果最好。     

基于图论的认知无线网络频谱动态分配

在认知无线电网络中，图论与量子遗传算法相结合的频谱分配策略能够提高频谱利用率，但存在早熟和收敛精度不够等缺点。为了解决该问题而实现算法的优化，对图着色理论的频谱分配模型进行数学建模，并针对该模型提出了改进的量子遗传算法。首先，通过使用小生境技术初始化种群，使种群分布更加广泛、算法的收敛度更高；其次，根据进化代数对量子旋转角进行实时动态调整，对染色体进行阈值变异，防止个体陷入早熟，跳出局部解；然后，对干扰约束条件进行重新设计，有效地避免盲目性，提高了网络的公平性和网络效益。仿真结果表明，所提算法有效地提高了频谱利用率，极大地增强了网络系统的性能。     

Platform selection by software developers: Theory and evidence

This paper analyzes platform selection (affiliation) by game developers in the Japanese home video game industry. We develop an elementary model of affiliation by software developers and propose the hypothesis that wider availability of game titles for a platform positively inclines game developers to affiliate with that platform when releasing new game titles. Then, using data for Japan, we estimate a multinomial logit model that includes both the attributes of game developers and the characteristics of platforms, and find evidence supporting this hypothesis. Overall, the findings suggest that game developers expect the indirect network effect to apply, and the prospect of future growth matters to them when deciding with which platform to affiliate.     

一种通用数字中频正交扩频调制器的实现

提出了一种适应于宽带扩频通信系统的数字中频调制的实现方案,它基于正交调制、DDS、数字上变频和数字内插等技术,采用通用硬件平台,可以生成多种中频调制信号,可广泛用于数字化扩频通信电台、宽带CDMA、软件无线电、遥控遥测等通信系统中。     

码分无线射频识别系统空中接口协议设计及性能分析

为进一步提高无线射频识别系统单个读写器识别电子标签的速率,设计了一种将码分与统计时分技术相结合的新型无线射频识别系统的空中接口协议,并分析了系统的抗噪声性能、识别速率等主要性能指标。仿真结果表明,新型无线射频识别系统在抗噪声性能和识别速率等方面均优于基于现有国际标准ISO/IEC 18000-6C的无线射频识别系统。     

Implementing product platforms in the global enterprise: Lessons from an LED industry leader

Product platforming—using technology subsystems or components that are shared within and across product lines—is a proven way to increase the effectiveness of innovation processes in established companies and startups alike. Yet, embracing the product platforming strategy turns out to be difficult in practice, particularly within the context of global, diversified companies. In this article, we examine the strategies and challenges of implementing product platforms across multiple business segments and multiple geographies. Using the experience of global LED industry leader Signify, we explore the challenges of global platforming and the technological, organizational, management process transformations needed for success. We also examine how platforming strategies change as manufacturers enter the world of connected things.