Instruction Set Extensions for Matrix Decompositions on Software Defined Radio Architectures

Emerging wireless applications consistently demand higher data rates. Unfortunately, it is challenging to achieve high data rates within the limited amount of available frequency spectrum. Hence, enhanced spectral efficiency and link reliability within the available frequency spectrum are of the utmost importance in current and next generation wireless protocols. To attain high spectral efficiency and link reliability, wireless protocols employ increasingly complex 2-dimensional techniques that involve computationally-intensive matrix operations. Multiple-Input Multiple-Output (MIMO) communication is an example of a promising technique employed by wireless protocols to deliver higher data rates at the cost of increased algorithmic complexity. Application Specific Integrated Circuits (ASICs) have traditionally been used to implement compute-intensive wireless protocols. The wireless industry has been gradually moving towards an alternative programmable platform called Software Defined Radio (SDR) due to its significant benefits, such as reduced development costs, and accelerated time-to-market. The computationally-intensive matrix operations used in current and next generation wireless protocols are extremely expensive to implement in SDR platforms with conventional Digital Signal Processor (DSP) instruction sets. Hence there is a need for novel instructions, hardware designs and algorithm enhancements to enable higher spectral efficiency on SDR platforms. In this paper, we propose Single Instruction Multiple Data (SIMD) CoOrdinate Rotation DIgital Computer (CORDIC) instruction set extensions with CORDIC hardware support to speedup computationally-intensive matrix decomposition algorithms. The CORDIC instruction set extensions have been implemented on the Sandbridge Sandblaster SB3000 SDR platform and evaluated on conventional algorithms used for decomposing a closed loop 4-by-4 Worldwide Interoperability for Microwave Access (WiMAX) MIMO channel into independent Single-Input Single-Output (SISO) channels. Our experimental results on the closed-loop MIMO channel decomposition using CORDIC instructions demonstrate more than 6x speedup over a Sandblaster baseline implementation that uses state-of-the-art SIMD DSP instructions. The CORDIC instructions also provide similar numerical accuracy when compared to the baseline implementation. The techniques we propose in this paper are also applicable to other SDR and embedded processor architectures.     

下一代无线终端的体系结构

中国已经成为移动终端的最大市场,但还有相当多的人没有选择无线服务,因此预期市场会继续增长.市场的增长会有两种推动力:首先,很大一部分尤其是农村用户将从开发低成本手机中获益.这些入门级的手机主要用来通话,虽然功能有限,但是会使更多的人从移动电话中得到好处.实际上,在一些有线通信服务受限制的地区,很多潜在的用户会选择移动服务来代替有线服务.另外,一旦3G许可证发放给运营商,在这些新的高速率网络中就会出现新的服务,驱使现有的移动用户来升级他们的手机以便利用这些新的服务.     

基于软件无线电的数字通信信号产生技术

数字通信信号的产生主要是基带信号对载波进行调制,本文是通过软件无线电的思想来完成对基带信号可选择式的调制.本文设计中将2ASK、2FSK、2PSK三种调制方式集中于同一硬件平台之中,可以根据不同的要求采用不同的调制方式,改变了以往单一的调制方式,具有更大的灵活性.     

软件无线电技术

本简单介绍了软件无线电技术的产生原因及其优越性，分析了制约软件无线电技术发展的几个因素，同时介绍了软件无线电技术在第三代移动通信中的应用，最后的指出软件无线电技术的美好前途。     

软件无线电体系结构研究

软件无线电设备是未来十年电信产业朝着基于IP的网络、在一个混合层次结构的自组网络环境下提供全球无缝无线接入的关键。主要介绍了软件无线电的体系结构、微处理器的选择和软件结构。     

在SDR中利用软件无线电技术

尽管SDR概念已经在军用领域使用多年,但直到近期,成本敏感产品如汽车收音机和手机的设计者才得以认真考虑基于SDR的解决方案.摩尔定律和相应的利用数百万晶体管来制造高计算密集性信号处理芯片的能力是一项重大进展.NXP半导体的工程师已经创造了一种高度灵活的SDR概念,其中信号处理模块成为可以在不同标准之间共享的功能.本文中的汽车无线电接收机解决方案采用NXP及其合作伙伴拥有的嵌入式数字信号处理内核尖端技术,可立即适应目前在汽车中使用的一系列无线电标准,甚至可以利用软件来适应新的标准.     

适用于软件无线电的下载技术探讨

软件无线电设备具有很大灵活性，它的功能主要由软件进行定义和配置，因而修改其软件就能对设备功能进行升级甚至重新定义。在无线网络环境中，无线电软件下载能够动态士也要新设备软件，然而它本身是一个非常复杂的过程。本文对这个问题展开了讨论，包括无线电软件下载的定义、范畴、分类方法以及具体的下载步骤；同时，也详细地论述了重配置管理以及安全性下载两个关键问题。     

A Low-Power Multithreaded Processor for Software Defined Radio

Embedded digital signal processors for software defined radio have stringent design constraints including high computational bandwidth, low power consumption, and low interrupt latency. Furthermore, due to rapidly evolving communication standards with increasing code complexity, these processors must be compiler-friendly, so that code for them can quickly be developed in a high-level language. In this paper, we present the design of the Sandblaster Processor, a low-power multithreaded digital signal processor for software defined radio. The processor uses a unique combination of token triggered threading, powerful compound instructions, and SIMD vector operations to provide real-time baseband processing capabilities with very low power consumption. We describe the processor’s architecture and microarchitecture, along with various techniques for achieving high performance and low power dissipation. We also describe the processor’s programming environment and the SB3010 platform, a complete system-on-chip solution for software defined radio. Using a super-computer class vectorizing compiler, the SB3010 achieves real-time performance in software on a variety of communication protocols including 802.11b, GPS, AM/FM radio, Bluetooth, GPRS, and WCDMA. In addition to providing a programmable platform for SDR, the processor also provides efficient support for a wide variety of digital signal processing and multimedia applications. Michael Schulte received a B.S. degree in Electrical Engineering from the University of Wisconsin-Madison in 1991, and M.S. and Ph.D. degrees in Electrical Engineering from the University of Texas at Austin in 1992 and 1996, respectively. From 1996 to 2002, he was an assistant and associate professor at Lehigh University, where he directed the Computer Architecture and Arithmetic Research Laboratory. He is currently an assistant professor at the University of Wisconsin-Madison, where he leads the Madison Embedded Systems and Architectures Group. His research interests include high-performance embedded processors, computer architecture, domain-specific systems, computer arithmetic, and wireless systems. He is a senior member of the IEEE and the IEEE Computer Society, and an associate editor for the IEEE Transactions on Computers and the Journal of VLSI Signal Processing. John Glossner is CTO & Executive Vice President at Sandbridge Technologies. Prior to co-founding Sandbridge, John managed the Advanced DSP Technology group, Broadband Transmission Systems group, and was Access Aggregation Business Development manager at IBM’s T.J. Watson Research Center. Prior to IBM, John managed the software effort in Lucent/Motorola’s Starcore DSP design center. John received a Ph.D. in Computer Architecture from TU Delft in the Netherlands for his work on a Multithreaded Java processor with DSP capability. He also received an M.S. degree in Engineering Management and an M.S.E.E. from NTU. John also holds a B.S.E.E. degree from Penn State. John has more than 60 publications and 12 issued patents. Dr. Sanjay Jinturkar is the Director of Software at Sandbridge and manages the systems software and communications software groups. Previously, he managed the software tools group at StarCore. He has a Ph.D in Computer Science from University of Virginia and holds 20 publications and 4 patents. Mayan Moudgill obtained a Ph.D. in Computer Science from Cornell University in 1994, after which he joined IBM at the Thomas J. Watson Research Center. He worked on a variety of computer architecture and compiler related projects, including the VLIW research compiler, Linux ports for the 40x series embedded processors and simulators for the Power 4. In 2001, he co-founded Sandbridge Technologies, a start-up that is developing digital signal processors targeted at 3G wireless phones. Suman Mamidi is a graduate student in the Department of Electrical and Computer Engineering at the University of Wisconsin-Madison. He received his M.S. degree from the University of Wisconsin-Madison in December, 2003 and is currently working towards his PhD. His research interests include low-power processors, hardware accelerators, multithreaded processors, reconfigurable hardware, and embedded systems. Stamatis Vassiliadis was born in Manolates, Samos, Greece, in 1951. He is currently a Chair Professor in the Electrical Engineering, Mathematics, and Computer Science (EEMCS) department of Delft University of Technology (TU Delft), The Netherlands. He previously served in the Electrical and Computer Engineering faculties of Cornell University, Ithaca, NY and the State University of New York (S.U.N.Y.), Binghamton, NY. For a decade, he worked with IBM, where he was involved in a number of advanced research and development projects. He received numerous awards for his work, including 24 publication awards, 15 invention awards, and an outstanding innovation award for engineering/scientific hardware design. His 73 USA patents rank him as the top all time IBM inventor. Dr. Vassiliadis is an ACM fellow, an IEEE fellow and a member of the Royal Netherlands Academy of Arts and Sciences (KNAW).     

软件无线电中的调制方式识别

本文研究了一种应用于软件无线电系统中的数字信号调制方式的自动识别算法,特别适用于可以用正交解调的调制方式的识别,在解调的同时识别调制方式的方法.还给出了计算机的仿真,结果表明效果良好.     

A Wideband RF Frontend Architecture for Software Defined Radio

This paper presents an RF front-end architecture for wideband software defined radio to function in 400 MHz to 3.5 GHz frequency range. The frequency range covers almost all the existing standards (like GSM, UMYS, CDMA, WiFi etc.) as well as future standards (like WiMax which is still to be deployed). Although the 400 MHz–3.5 GHz band is taken, the architecture allows designers to design the front-end for any range of frequencies. In wideband front-ends, devices with high linearity are used to lower the level of intermodulation products. There are different front-end architectures available for catering to wideband operation. However, some of these, particularly the wideband ones suffer with intermodulation problem. This paper presents a partitioning mechanism that uses multiple medium bands to limit the intermodulation problem. The proposed frequency-partitioning scheme makes it possible to suppress intermodulation products further for front-end using devices of given linearity. Thus this helps in achieving better performance along with relaxing the linearity requirement of devices.     

基于软件无线电的WCDMA仿真平台

本文介绍了一种关于3G的仿真平台的研究、开发和验证。结合软件无线电思想,参照3GPP协议,在COSSAP软件包中搭建起一个具有通用结构的、基于第三代WCDMA、FDD方式的下行链路物理层的仿真平台,并进行了Turbo编译码、RAKE接收机等3G关键技术的研究和单路数据业务、单路话音业务及多业务复用时系统性能的仿真验证。仿真结果与相关文献拟合得较好,结果证明可以把它作为进一步研究软件无线电中关键技术的基础平台。     

Filter Bank Channelizers for Multi-Standard Software Defined Radio Receivers

The ability to support multiple channels of different communication standards, in the available bandwidth, is of importance in modern software defined radio (SDR) receivers. An SDR receiver typically employs a channelizer to extract multiple narrowband channels from the received wideband signal using digital filter banks. Since the filter bank channelizer is placed immediately after the analog-to-digital converter (ADC), it must operate at the highest sampling rate in the digital front-end of the receiver. Therefore, computationally efficient low complexity architectures are required for the implementation of the channelizer. The compatibility of the filter bank with different communication standards requires dynamic reconfigurability. The design and realization of dynamically reconfigurable, low complexity filter banks for SDR receivers is a challenging task. This paper reviews some of the existing digital filter bank designs and investigates the potential of these filter banks for channelization in multi-standard SDR receivers. We also review two low complexity, reconfigurable filter bank architectures for SDR channelizers based respectively on the frequency response masking technique and a novel coefficient decimation technique, proposed by us recently. These filter bank architectures outperform existing ones in terms of both dynamic reconfigurability and complexity.     

Software Defined Radio Technology for Highly Reliable Wireless Communications

This paper introduces the concept of highly dependable wireless communications for wireless robotics based on software defined radio (SDR) technologies. The features and advantages of SDR technologies are initially explained, whereupon the research and development activities of KDDI R&D Laboratories are presented. Advanced applications of SDR for telerobotic control, which require highly reliable wireless communications and for multi-mode wireless sensor networks are proposed as potential markets for wireless robotics and machine to machine communication. Finally, the current status and research issues of SDR are summarized and this paper is concluded.     

软件无线电技术及其应用探讨

软件无线电的出现是无线电通信从模拟到数字、从固定到移动后,由硬件到软件的第三次变革,被认为是继模拟通信技术、数字通信技术之后的第三代无线通信技术。软件无线电以其极强的灵活性和开放性代表着无线通信系统的发展趋势。本文分别从软件无线电技术特点、关键技术、应用等方面分别进行了阐述。     

软件定义无线电的应用与发展

软件定义无线电作为一种无线通信技术,可应用于探测无线电信号质量和探索无线电信号等应用场景。本文首先介绍了无线电信号特征在信号源定位,无线电监测和信号源身份识别中的应用研究,进一步分析了软件无线电的系统架构对无线电信号高质量接收的影响,给出了软件无线电在教学上的应用实例,最后总结了软件无线电在技术应用,系统设计和工程实践中的发展现状,并给出了未来软件定义无线电的发展预测。     

Flow‐Based QoS Management Architectures for the Next Generation Network

At the extremes of the complexity‐performance plane, there are two exemplary QoS management architectures: Integrated Services (IntServ) and Differentiated Services (DiffServ). IntServ performs ideally but is not scalable. DiffServ is simple enough to be adopted in today's core networks, but without any performance guarantee. Many compromise solutions have been proposed. These schemes, called quasi‐stateful IntServ or stateful DiffServ, however, have not attracted much attention due to their inherently compromising natures. Two disruptive flow‐based architectures have been recently introduced: the flow‐aware network (FAN) and the flow‐state‐aware network (FSA). FAN's control is implicit without any signaling. FSA's control is even more sophisticated than that of IntServ. In this paper, we survey established QoS architectures, review disruptive architectures, discuss their rationales, and points out their disadvantages. A new QoS management architecture, flow‐aggregate‐based services (FAbS), is then proposed. The FAbS architecture has two novel building blocks: inter‐domain flow aggregation and endpoint implicit admission control.     

软件无线电数字下变频及抽取技术研究

数字采样及数字下变频技术是研究软件无线电接收机的重要内容之一.其中针对多种速率信号的采样,对可变的信号符号率与固定的系统采样率进行实时匹配问题,是研究多速率信号数字化所遇到的难点问题之一.文中通过抽取和内插技术的组合解决了这一问题.并在此基础上着重研究了高速抽取和内插的多项滤波结构,为数据率的快速匹配奠定了基础.     

软件无线电台的发展及应用

该文介绍了软件无线电(Software Defined Radio)的定义,给出了软件无线电台的模型和解决方案。结合联合战术电台系统(JTRS)对软件无线电台的要求,论述了发展SDR电台需要解决的技术难题,并给出了软件无线电台的实例。     

下一代光因特网体系结构的选择与比较

下一代光因特网(NGOI)体系结构的基本特征是两层(业务层和传送层)和三个平面(数据平面、控制平面、管理平面)。分析和归纳了四种主流的面向下一代光因特网体系结构模型。提出了一种基于通用多协议标记交换(GMPLS)技术和光电混合交换技术的集成光因特网模型,该模型与其它模型相比较,结合了光电两个领域的技术优势,具有网络综合性能高,容易实现,扩展性好等优点。     

信道化技术在软件无线电接收机中的应用

软件无线电是目前通信领域研究的热点，其关键技术之一的数字中频技术则是多速率信号处理理论的典型应用。介绍了一种基于多相滤波的数字信道化技术在软件无线电接收机中的应用，利用离散傅里叶变换(DFT)的成熟理论和多相滤波的灵活处理，在接收机的数字中频段提出了一种高效的处理结构，对其原理、性能和特点进行了深入地探讨和研究，较好地解决了当前无线通信中硬件速度和高速数据流不匹配的问题。计算机模拟结果证明了处理结构的可行性和有效性。