面向认知无线电的数字信号处理器体系结构技术研究

发布时间：2018-09-11 09:04

【摘要】：计算机和微电子技术的高速发展，促进了通信技术的快速革新。当前广泛使用的无线通信技术在人们的工作和生活中扮演着越来越重要的角色。与此同时，随着人们对于高速多媒体无线通信网络需求的不断增长，使得无线通信对无线电频谱资源需求与当前频谱固定分配策略下频谱利用率低下的矛盾变得越来越突出。认知无线电是一种具有频谱感知和智能决策能力的软件无线电，不仅能够提高无线电频谱资源的利用率，还将进一步提高通信系统的智能水平。认知无线电处理器在软件无线电处理器的需求之上，增加了频谱感知、可重构计算和智能决策等更多的功能和更高的计算性能需求。因此，对面向认知无线电的数字信号处理器体系结构进行深入研究具有十分重要的意义。本文在国家“863”高技术研究发展计划项目和多个国家自然科学基金项目的支持下，对认知无线电的频谱感知算法和体系结构、认知无线电可重构基带处理器体系结构以及自主认知无线电节点体系结构等方面展开了深入的分析研究，主要工作包括： 1、基于能量检测的认知无线电频谱盲感知算法和体系结构设计与实现。频谱盲感知对于认知无线电系统实现来说十分重要，为了加速能量检测计算和适应变化的检测精度需求，设计实现了一种具有动态可重构功能的流水线体系结构的FFT处理器，能够重构处理64到2048点的FFT计算，同时保持了良好的功耗和面积开销。提出了两阶段能量检测算法，基于这一算法和可重构FFT处理器设计实现了检测性能可调的能量检测器。 2、基于循环平稳特征检测算法的并行实时频谱感知协处理器体系结构设计与实现。循环平稳特征检测广泛应用于窄带信号到达角估计、信号识别以及雷达信号参数估计等领域，但是由于较高的计算复杂度一直限制其作为实时信号处理的工具。提出了一种计算高效的并行循环平稳特征检测算法，并在多核软件无线电处理器了进行了算法映射和实现验证，对于8MHz的32768次采样，频谱感知时间为78.8ms。基于并行循环平稳特征检测算法，设计实现了并行循环平稳特征检测器体系结构。能量检测器具有实现简单的优点，可以作为粗粒度频谱盲感知的手段，基于本文提出的可重构FFT处理器，设计实现了具有能量感知和循环平稳特征检测功能的可重构频谱感知协处理器，实现了频谱感知性能和功耗开销的平衡。 3、面向认知无线电的可重构基带处理器体系结构设计与实现。认知无线电可重构基带处理对数字信号处理器提出了新的挑战，提出了认知无线电基带系统模型，分析了以NC-OFDM为传输技术的基带处理计算特征。为了满足认知无线电对动态可重构的功能需求，提出了面向基带处理应用的可重构体系结构模型，设计实现了基于这一模型的可重构多处理器体系结构CORA，实验结果表明，这一体系结构设计能够满足基于NC-OFDM技术的认知无线电基带处理计算需求。 4、自主认知无线电概念模型、认知圈和自主认知无线电节点体系结构原型设计实现。为了实现从频谱感知认知无线电到理想认知无线电的演进，研究了自主系统设计原则并证明了理想认知无线电认知圈与自主系统设计原则的一致性，提出了自主认知无线电概念模型和自主认知无线电认知圈，给出了自主认知无线电概念模型相关部件的功能和详细定义。基于自主通信开源平台ACE Toolkit，，设计实现了自主认知无线电模拟环境。设计实现了MPSoC结构的自主认知无线电节点体系结构原型ACRA，将IEEE802.22协议规定的认知无线电功能定义映射到ACRA上的实验结果表明ACRA在频谱管理上的合理性以及频谱感知性能上的优势。综上所述，本文针对面向认知无线电的数字信号处理器体系结构技术进行了研究，提出了面向认知无线电的频谱感知协处理器，认知无线电基带处理模型和可重构基带处理器以及自主认知无线电节点体系结构模型和原型实现，对于推动认知无线电的相关研究和体系结构实现具有一定的意义和价值。
[Abstract]:The rapid development of computer and microelectronics technology has promoted the rapid innovation of communication technology. The widely used wireless communication technology is playing a more and more important role in people's work and life. At the same time, with the increasing demand for high-speed multimedia wireless communication network, wireless communication on radio. Cognitive radio is a kind of software radio with spectrum sensing and intelligent decision-making ability. It can not only improve the utilization of radio spectrum resources, but also further improve the intelligence level of communication system. Line processor adds more functions and higher computational performance requirements such as spectrum sensing, reconfigurable computing and intelligent decision-making to the needs of software radio processors. Therefore, it is of great significance to study the architecture of digital signal processor for cognitive radio in depth. With the support of the project of Technology Research and Development and several projects of National Natural Science Foundation of China, the spectrum sensing algorithm and architecture of cognitive radio, the reconfigurable baseband processor architecture of cognitive radio and the node architecture of autonomous cognitive radio are studied in depth.
1. Design and implementation of spectrum blind sensing algorithm and architecture for cognitive radio based on energy detection. Spectrum blind sensing is very important for the implementation of cognitive radio system. In order to accelerate the calculation of energy detection and adapt to the requirements of changing detection accuracy, a pipeline architecture with dynamic reconfigurable function is designed and implemented. The FFT processor can reconstruct the FFT computation between 64 and 2048 points, while maintaining good power consumption and area overhead. A two-stage energy detection algorithm is proposed. Based on this algorithm and reconfigurable FFT processor, an energy detector with adjustable detection performance is designed and implemented.
2. Architecture design and implementation of parallel real-time spectrum sensing coprocessor based on cyclostationary feature detection algorithm. Cyclic stationary feature detection is widely used in narrowband signal DOA estimation, signal recognition and radar signal parameter estimation, but its high computational complexity has limited its application as real-time signal processing. A computationally efficient parallel cyclostationary feature detection algorithm is proposed. The algorithm is mapped and implemented on a multi-core software radio processor. For 32768 sampling times at 8 MHz, the spectrum sensing time is 78.8 Ms. Based on the parallel cyclostationary feature detection algorithm, the parallel cyclostationary feature detection is designed and implemented. Based on the reconfigurable FFT processor proposed in this paper, a reconfigurable spectrum sensing coprocessor with the functions of energy sensing and cyclostationary feature detection is designed and implemented, which realizes the balance of spectrum sensing performance and power consumption. Balance.
3. Architecture design and implementation of a reconfigurable baseband processor for cognitive radio. Reconfigurable baseband processing for cognitive radio poses a new challenge to digital signal processors. A cognitive radio baseband system model is proposed. The computational characteristics of baseband processing based on NC-OFDM transmission technology are analyzed. A reconfigurable architecture model for baseband processing applications is proposed, and a reconfigurable multiprocessor architecture CORA based on this model is designed and implemented. The experimental results show that the architecture design can meet the requirements of baseband processing computation in cognitive radio based on NC-OFDM technology.
4. The conceptual model of autonomous cognitive radio, the prototype design and implementation of cognitive circle and node architecture of autonomous cognitive radio. The conceptual model of autonomous cognitive radio (ACR) and the cognitive circle of autonomous cognitive radio (ACR) are proposed. The functions and detailed definitions of related components of the conceptual model of autonomous cognitive radio (ACR) are given. Based on ACE Toolkit, an autonomous cognitive radio simulation environment is designed and implemented. The point architecture prototype ACRA maps the cognitive radio function definition stipulated in IEEE 802.22 protocol onto ACRA. The experimental results show that ACRA is reasonable in spectrum management and has superiority in spectrum sensing performance.
In summary, this paper studies the architecture technology of digital signal processor for cognitive radio, proposes the spectrum sensing coprocessor for cognitive radio, the baseband processing model for cognitive radio, the reconfigurable baseband processor, and the architecture model and prototype implementation of autonomous cognitive radio nodes. The research and architecture implementation of mobile cognitive radio is of great significance and value.
【学位授予单位】：国防科学技术大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TN925;TP332

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