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在雷达宽带接收系统中,数字中频接收采样率的选择要受限于射频系统的整体设计架构,信号处理系统需要的基带信号数据率可能无法通过对采样信号进行整数抽取获得。针对宽带系统采样率高、数字下变频采用并行多相滤波算法结构、基带信号由多个并行支路组成的特点,以及FPGA处理速率的限制,宽带信号分数抽取运算通常只能采用并行多相方式实现。在宽带数字下变频并行多路基带信号的基础上,通过并行多相内插滤波和并行多相抽取滤波算法,不需要提高FPGA的处理时钟,实现对大带宽信号的分数抽取运算。 相似文献
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提出了一种可变分数延时宽带数字滤波器的优化设计方法,该方法首先采用内插的方法提高采样率,降低信号的归一化带,再采用Farrow结构来实现分数延时,通过抽取,恢复信号的初始采样率.其实现形式采用基于多相滤波的级联结构,使得内插和抽取相互抵消,降低滤波器的阶数,提高运算效率.采用基于FPGA的并行分布式算法,设计利用了器件的结构特点以及与器件特性独立的2种方法,在时域实现了高速、高阶的宽带分数延时滤波器,并在Altera Stratix FPGA上进行了仿真验证,最高工作频率分别为184 MHz和119 MHz. 相似文献
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在多速率信号处理中,常采用多相滤波结构以有效地降低系统的运算量,提高系统信号处理的实时性。如果采用内插系统的多相滤波结构,在实现过程中受系统时钟频率的约束,将无法实现采样率超过时钟频率的高速率信号的传输。提出了一种基于多相滤波结构的新型高速信号处理算法,对高速信号进行多级多相滤波,从而将信号进行多相分解,采用多通道传输;利用多路低采样率信号得到高采样率的输出信号,并在接收端进行信号合成。具有运算量小、消耗资源少、便于实现等优点,并通过公式推导及仿真结果验证了其正确性,解决了高速率信号受系统时钟频率限制难以实现的问题。 相似文献
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正交插值可以由低通滤波法和多相滤波法来实现,文中从实现方式、采样率、滤波器方面进行了比较,使用matlab对两种方法进行了仿真分析,并在分析的基础上分别使用Xilinx公司的Virtex4 FPGA实现了两种结构.通过比较得出,多相滤波法相对于低通滤波法有很多优点:结构简单、资源占用少且易于实现. 相似文献
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为了解决现有的合成孔径雷达SAR回波信号采集存储系统不能同时满足高采样率、高采样精度、高存储速度、大存储容量、脱机运行的问题.该文提出了一种基于FPGA和DSP的SAR回波信号的采集与存储系统.该系统采用专用于数据硬盘存储的DSP功能模块SMT387和Virtex 4系列的 FPGA 器件XC4VFX12设计.Virtex 4系列FPGA主要控制采集存储系统的总体时序,采集回波信号的有效部分存入SATA硬盘,SMT387主要运用纽曼-皮尔逊准则的滑窗检测算法检测回波信号的具体位置,并计算出各种位置信息的具体参数,再将这些参数传到FPGA,控制系统的总体时序.该系统采样率达170百万次/秒,能够对正交两路信号同时采集,能够脱机、长时间存储120MB、16位的高速数据. 相似文献
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基于FPGA的直流相位跟踪检测系统设计 总被引:1,自引:0,他引:1
提出了一种基于FPGA实现的直流相位跟踪检测系统,分析了系统输出信号与输入信号保持同步的实现原理,并建立了基于FPGA的设计模型,进行了硬件仿真,确定了系统的采样率,最后通过实验验证了此FPGA系统可实现相位实时检测,误差为0.2%,证明了此系统可满足干涉式光纤电压传感器对相位检测的性能要求. 相似文献
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本文提出了一种对跳频信号进行解跳的方法。其基本思想是利用数字变频将跳频信号不同频率的各个跳段信号变频到统一载频上,使其转变为定频信号。文中着重论述了变频方案和内部参数的设计,并通过具体的例子说明了本方法基于HSP50214B的实现。 相似文献
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本文提出了一种高速实时信号多相位分解滤波方法,讨论了多相位分解滤波的基本原理、设计及FPGA实现,给出了多相位分解滤波算法的实现方案。在现有FPGA器件上实现了多相位分解滤波算法,可满足信号实时处理需求。 相似文献
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Yonah Z.O. El-Serafi A.M. Krause A.E. 《Industrial Electronics, IEEE Transactions on》1990,37(6):576-581
A feasibility study on the use of a digital computer as a variable-amplitude variable-frequency oscillator which generates two-phase sinusoidal excitation control signals for a dual-excited synchronous generator is described. The oscillator uses two input signals. One input signal is used to control the frequency of the oscillator outputs, and the other is used to control their amplitudes. By a single variable, the software can be configured to vary the oscillator frequency range and to greatly reduce (almost eliminate) the harmonic distortion of the output signals. The harmonic distortion is constant and independent of the output frequency for each possible oscillator frequency range. The software-based oscillator design is flexible and can be used to generate different types of multiphase signal waveforms 相似文献
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Multiphase clock generators are conventionally implemented with a feedback loop. This paper presents a non-feedback approach to generate multiphase clocks. A simple architecture of direct phase interpolation is proposed, in which the edges of two phase-adjacent signals are used to control the discharge (or charge) of two capacitors respectively, producing time-overlapped slopes. A resistor chain connected to the two capacitors is used to interpolate a number of new slopes in between. The generated phase resolution depends on the number and ratios of resistors thus is not limited by an inverter delay. Based on this architecture, a multiphase clock generator is developed. In addition, a phase error averaging circuit is used to correct interphase errors. The multiphase clock generator has been fabricated in a 0.35 m, 3.3 V CMOS process. The measured performance shows it can produce 8 evenly spaced clock signals in one input clock period and work in an input clock range from 300 MHz to 600 MHz. The measured maximum jitter performance is rms 6.8 ps and peak-to-peak 47 ps, respectively. 相似文献
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Haruyama Shinichiro Morelos-Zaragoza Robert Sanada Yukitoshi 《Wireless Personal Communications》2002,23(1):67-76
In this paper, a new software defined radio platform with direct conversionisintroduced.The platform is named SOPRANO, which stands for Software Programmableand Hardware Reconfigurable Architecture for Network.Main features of SOPRANO include a high-level design methodologyfor digital circuits, direct conversion based on six-port technology, andnovel digital signal processingalgorithms for multi-band and multi-mode operation.The first prototype of the SOPRANO platform has been built and was ableto receive M-ary PSK (Phase Shift Keying)and QAM (Quadrature Amplitude Modulation) signals,with two different carrier frequencies at 2.45 GHz and 5.25 GHz,by changing signal-processing software. 相似文献
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This paper describes the design and experimental verification of a current-mode multiphase sinusoidal oscillator (MSO) employing current differencing units. The oscillator, composed of n 1st-order all-pass sections, generates harmonic current signals with 2n equidistant phase shifts, where n ≥ 2. Compared with conventional MSOs, this circuit is characterized by an extremely simple circuitry and a minimum number of passive and active components. The oscillation condition and the frequency of oscillation are orthogonally controlled. The proposed circuit is suitable for IC fabrication. Experimental verification on an erlier manufactured chip together with a detailed analysis of real influences are included in the paper. 相似文献
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Muhammad Taher Abuelma’atti Muhammad Ali Al-Qahtani 《Analog Integrated Circuits and Signal Processing》1998,16(1):29-34
A multiphase active-R sinusoidal oscillator circuit is presented.The oscillator can produce M signals (M being even or odd) equally spaced inphase. The circuit has low component count, uses grounded resistors andenjoys low active and passive sensitivities. The feasibility of convertingthe circuit into a voltage controlled multiphase oscillator is studied.Simulation results are included. 相似文献
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双/多基地综合脉冲孔径地波雷达在发射站为多载频信号同时辐射,在接收站综合形成发射方向图之前需要对各发射信号分量进行分离.尽管采用数字混频和低通滤波器组可以对各发射分量进行分离,但运算量太大,难以实时实现.为此提出采用多相滤波器组信道化接收技术,设计该雷达的多相滤波器组信道化接收机.这种多相滤波器组信道化接收机与低通滤波器组信道化接收相比,运算量减少N2倍(N为信道数).最后给出了该雷达试验系统的实测数据处理结果,验证了这种多相滤波器组信道化接收技术在该雷达信号处理中的有效性. 相似文献
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In this paper multiphase oscillators built using fractional-order allpass filters are presented. We examine the theory behind
their operation and demonstrate their usefulness in the design of both multiphase and quadrature oscillators. Case design
examples are given for various scenarios, while PSPICE and experimental results verify their operation 相似文献