Classical and modern receiver architectures

This article is a review of several classical and modern wireless receiver architectures used in wideband wireless communication systems. The emphasis is on configurations suitable for integration on a single silicon chip. A full understanding of the design trade-offs discussed in this article is necessary for the proper introduction of a new modulation scheme presented in the article by Mirabbasi and Martin (2000) entitled, "Hierarchical QAM: a spectrally efficient DC-free modulation scheme".     

GPS接收器入门

GPS系统是由美国国防部设计和资助的精巧卫星导航系统,包含了24能持续发送地理位置海拔高度和时间信号的卫星,这些卫星平均分布运行在六个轨道上。一般来说,在地面上的GPS接收器能接收5～12个卫星信号,而为了获得地面上的定位坐标,至少需要4个卫星信号,三个用来确定GPS接收器的纬度、经度和海拔高度,第四个则提供同步校正时间。     

Link budget analysis for multistandard receiver architectures

As devices shrink, creating integrated circuits (ICs) that work with the required accuracy becomes more difficult due to issues related to device physics. Receivers are part of an area referred to as "mixed-signal design," meaning that both analog and digital circuitry will be on the same IC. This too presents many challenging issues, as the analog circuitry is highly sensitive to disruptions caused by the noisy digital circuitry. Therefore, accurate modeling and simulation is crucial in the design of wireless receivers to ensure the best possible operation of the fabricated IC. Through simulation and modeling a designer can determine if receiver architecture will meet the required specifications and pinpoint the possible problems before valuable time is spent developing the actual circuit. This article will present design issues for multistandard wireless receivers to give the reader an understanding of the challenges involved in link-budget analysis. TITAN (Toolbox for Integrated Transceiver Analysis), a link-budget analysis tool developed at The Ohio State University Analog VLSI Laboratory, will be presented as an example of a tool for receiver simulation. To determine design performance, various requirements must be translated to model parameters. Among the requirements for receivers are noise floor (NF), second- and third-order distortion (IP2 and IP3, respectively), reciprocal mixing, and phase noise. TITAN offers a graphical interface and encapsulated models to the designer, eliminating the possibility of formula corruption. The interface provides a more intuitive and sophisticated way of setting up the simulation and provides the designer with more readable results. Additionally, a blocking profile component allows the architecture to be tested across multiple standards.     

GPS接收机射频IC

本文简单介绍ＧＰＳ射频前端ＩＣ ＭＡＸ２７４０的典型应用。     

便携式GPS接收机设计

提出一种基于EM411GPS接收模块和PIC18F2520单片机的手持式GPS接收机设计方案。该方案具有电路简单、成本低、灵敏度高等优点,并可将接收的数据以FAT文件格式保存到SD卡中,通过SD卡将GPS数据导入电子地图,便于野外作业和户外运动使用。     

便携式GPS接收机设计

提出一种基于EM411 GPS接收模块和PIC18F2520单片机的手持式GPS接收机设计方案.该方案具有电路简单、成本低、灵敏度高等优点,并可将接收的数据以FAT文件格式保存到SD卡中,通过SD卡将GPS数据导入电子地图,便于野外作业和户外运动使用.     

GPS接收机模拟软件开发

随着科技的发展,GPS在越来越多的工程和科学领域得到应用,有关GPS的教学也逐渐引起重视。介绍了用于教学的GPS接收机模拟软件开发。该软件有助于课堂教学和课后学生练习GPS接收机的操作使用。软件采用VC++编程方法实现,接收机各功能的实现基本上采用事件响应函数的形式。运行结果表明,所有GPS定时校频接收机软件前面板模拟结果都与被模拟界面的画面及功能一致,完成GPS接收机的模拟。文中的软件开发方法可为其他教学模拟软件的开发提供参考。     

A multipath mitigation discriminator for GPS receiver

A novel technique for mitigating the multipath-induced code delay estimation error in Global Positioning System (GPS) is proposed. In contrast to conventional methods that aim to eliminate multipath signals, the proposed method exploits them to enhance the direct signal without affecting the accuracy of GPS code delay estimates. To achieve this, coherent accumulation of the received GPS signals is first done by transforming the received data into frequency domain and the parameters of multipath signals are then estimated by sparse reconstruction algorithm. Subsequently, a modified local reference signal is employed in delay lock loop (DLL) of the GPS receiver, which mitigates the pseudo-range estimation error and increases the correlation value of direct GPS signal. Simulation results demonstrate the performance and robustness of the proposed method.     

一种多级GPS抗干扰接收机设

针对空时联合处理在GPS抗干扰方面应用时其性能取决于天线阵元数,从而带来计算量和体积增大的问题,提出了一种多级抗干扰GPS接收机的设计方法,在与空时联合处理同样的抗干扰性能的情况下具有较小的复杂度。最后给出的仿真结果表明其在减少运算量、提高抗干扰性能方面有优势。     

A performance comparison of two p-i-n FET receiver circuit architectures

Two conceptually different p-i-n FET receiver circuit architectures are evaluated using a SPICE circuit simulation. The popular p-i-n FET transimpedance amplifier is compared to a new architecture that uses distributed gain and dual feedback. To highlight the importance of circuit architecture to receiver performance, identical device parameters are used in each circuit model. Frequency, phase, and pulse responses are computed and presented in graphical form. Results demonstrate that the popular receiver is adversely sensitive to FET transconductance variations and distorts the pulse reponse, whereas the distributed gain and dual feedback design is substantially independent of transistor parameters and free of pulse distortion.     

GPS接收机中数控振荡器电路的设计

提出了一种用于GPS接收机系统中数控振荡器模块的电路设计。通过Verilog HDL语言完成了NCO的设计,并利用Modelsim软件对其进行仿真。通过采集实时数据测试,验证了该模块可以完成中频载波信号和多普勒的剥离。最后针对数控振荡器的性能指标做了简单分析,对信噪比和杂散度等关键参数测试,使用MATLAB软件对其性能进行仿真,验证其满足接收机的要求。     

GPS接收机联合空时抗干扰方法

传统的阵列抗干扰技术应用于GPS接收机抗干扰前端的主要问题是自由度有限、对多径干扰处理困难，因而无法应付恶劣场景和主动干扰。采用本文新颖之处是采用联合空时处理技术，在不增加阵元的情况下，能使阵的自由度大大增加，从而使抗干扰能力有质的提高。本文研究GPS接收机干扰场景的联合空时处理方法，针对空时处理使计算量显著增加这一致命缺陷，讨论降秩算法的多级嵌套维纳滤波实现，仿真结果证实了算法的抗干扰能力。     

A performance comparison of two p-i-n FET receiver circuit architectures

Two conceptually different p-i-n FET receiver circuit architectures are evaluated using a SPICE circuit simulation. The popular p-i-n FET transimpedance amplifier is compared to a new architecture that uses distributed gain and dual feedback. To highlight the importance of circuit architecture to receiver performance, identical device parameters are used in each circuit model. Frequency, phase, and pulse responses are computed and presented in graphical form. Results demonstrate that the popular receiver is adversely sensitive to FET transconductance variations and distorts the pulse reponse, whereas the distributed gain and dual feedback design is substantially independent of transistor parameters and free of pulse distortion.     

优化的PFA算法在GPS软件接收机中的应用

根据GPS数据的特殊存储结构,提出了一种2bit量化的方式来表示导航数据以及本地载波,将基带混合过程演化为位运算过程,结果作为PFA算法的输入;将PFA算法中用到的部分旋转因子转换为16bit补码预存到数据表,使用时通过映射的方式得到全部旋转因子,因此PFA算法中所有的浮点运算都被转化为了整数运算方式,实验表明此方法大幅提升了PFA算法的效率,进而有效缩短了捕获时间。     

全球定位系统信号接收机射频模块的设计

主要以研究GPS接收机为目的,以Zarlink公司的GP2015型电路为核心进行GPS射频前端设计,其中主要包括二级滤波器和晶体振荡器等外围电路的设计,其关键是计算滤波网络参数以匹配带宽要求及整个电路的布局.对后端的相关和定位解算进行了相应的介绍,整个模块在GPS接收机中相对独立,可以作为独立的部分来设计.     

GPS软件接收机关键技术研究及实现

研究了GPS软件接收机的关键技术和具体实现。设计并实现了一种基于FFT的码相位并行的快速信号捕获方案：介绍了码跟踪环与载波跟踪环的算法流程并详细推导了伪距及精密伪距的计算过程,在建立载体运动模型的基础上运用卡尔曼滤波对定位结果滤波处理,提高了定位精度,减小了定位方差。通过实验,验证了文中软件接收机算法的可行性,接收机定位精度较高,定位均方差较小。     

Split-sum correlator simplifies range computations in GPS receiver

A novel correlator architecture for handling the satellite-to-receiver time skew in a Global Positioning System (GPS) receiver is presented. The correlator's signal integration and numerically-controlled oscillator updates are referenced to receiver time epochs rather than satellite epochs as in traditional architectures. To avoid straddling navigation data bits, the correlation is split into two parts. The technique was successfully implemented and integrated into a field programmable gate array-based multichannel software GPS receiver     

GPS软件接收机跟踪环路设计

GPS软件接收机跟踪环路的设计在环路参数与鉴相器选择上有很大空间。在分析GPS跟踪原理的基础上．对比码环与载波环不同鉴相器的性能,然后在不同环路参数下对跟踪效果进行了仿真比较,最后选择一组鉴相器并设计合适的环路参数,对实际采集的GPS中频信号进行跟踪,跟踪结果验证了设计环路的有效性。