一种高效的LFM信号参数估计方法及性能分析

该文从最大似然估计出发,得出了一种LFM信号参数估计方法,并采用一阶扰动模型分析其统计性能.该方法涵盖经典的多项相位变换法,将最大似然估计的多维搜索转化为一维搜索,但性能较多项相位变换法更优,低信噪比时仍可接近Cramer-Rao界.另外,结合基于傅里叶系数内插的快速高精度测频算法,该方法运算量与多项相位变换法相当,便于实现.仿真验证了其有效性及性能分析.     

有效估计塔康测距信号多径时延的方法

该文利用塔康测距信号收发已知且能量集中的特点,在原有的频谱相除方法的基础上,提出采用功率谱密度函数并引入补偿因子进行频谱相除的方法,对接收信号中多径时延进行估计。该方法首先利用功率谱密度函数与本地参考信号的频谱相除,并通过补偿因子使带外噪声的能量不会因相除而得到很大加强;再利用反傅里叶变换从接收信号中恢复有用信号的波形;最后利用恢复的波形对多径时延进行估计。计算机仿真验证了算法的有效性。     

稳健估计的自适应信号处理方法

本文把应用数学学科研究的热门方法之一“稳健估计”应用于自适应信号处理系统中，理论分析和计算机模拟结果都证明ＲＥ方法在实际应用中，基本保持了最小二乘估计的优点。     

一种有效的MIMO OFDM信道估计方法

传统的MIMO OFDM信道估计方法总是假设信道在由若干OFDM符号组成的每一帧的传输过程中保持不变,但这个假设在快变信道的条件下就不成立了.本文提出了一种适合快变信道的有效的估计方法.该方法通过在每个OFDM符号中设置若干训练子载波来跟踪快变的信道.首先讨论了在每个OFDM符号中所需的训练子载波的数目及其相应的位置,给出了在多发射天线多接收天线条件下的训练子载波的正交结构,然后在估计出训练子载波处的信道频率响应后.提出了一种不同于根据邻近训练子载波进行线性插值的以获得用于传输数据的子载波的信道频率响应的方法.仿真结果表明了我们所提出的方法的有效性.     

CABAC熵编码机制下有效的变换域码率估计技术

 CABAC是H.264/AVC视频压缩标准中采用的一种熵编码机制,结合RDO模式选择技术,可以降低20％的码率.在RDO模式选择过程中,需要对编码块的每一种候选模式进行熵编码以获得编码位数,这在很大程度上增加了视频编码的计算复杂度.为了避免复杂的Lagrange耗费计算,本文第一次提出了一种CABAC熵编码机制下的变换域码率估计方法,基于量化变换系数和运动向量差对熵编码位数进行估计.在此基础上,本文将码率估计技术应用在RDO模式选择中,提出了基于码率估计的快速模式选择算法,减少了模式选择的计算时间.模拟结果显示,本文提出的CABAC熵编码机制下的变换域码率估计技术在对编码性能影响不大的情况下,减少了模式选择中51％的率失真耗费计算时间,采用全搜索运动估计算法时,节省33％的总编码时间.     

Statistical Performance Analysis and Estimation for Parallel Multimedia Processing

When parallelizing complex multimedia processing on multiple processors, the stochastic timing behavior should be carefully studied. Although there are already many papers on the performance analysis of stochastic parallel system, they are not targeted on multimedia processing. In this paper, first we study H.264/AVC encoder (running on x86) and QSDPCM encoder (running on TI TMS32C62) to characterize important aspects of the stochastic timing behavior in complex multimedia processing applications. It is shown that the variation and correlation are indeed very significant. In order to make systematic analysis feasible, we apply Stochastic Timed Marked Graph (STMG) as a formal model to capture essential timing related behaviors of parallel multimedia processing systems. Then, we show how the local timing variations and correlations interact and propagate to the global timing behavior; from this we conclude general parallelization guidelines. Furthermore, we develop an analytical performance estimation technique to derive the probability distribution of timing behavior for parallel multimedia processing systems that have correlated stochastic timing behaviors inside. The estimation technique is based on principal component analysis and approximations.     

Statistical Signal Processing and the Motor Cortex

Over the past few decades, developments in technology have significantly improved the ability to measure activity in the brain. This has spurred a great deal of research into brain function and its relation to external stimuli, and has important implications in medicine and other fields. As a result of improved understanding of brain function, it is now possible to build devices that provide direct interfaces between the brain and the external world. We describe some of the current understanding of function of the motor cortex region. We then discuss a typical likelihood-based state-space model and filtering based approach to address the problems associated with building a motor cortical-controlled cursor or robotic prosthetic device. As a variation on previous work using this approach, we introduce the idea of using Markov chain Monte Carlo methods for parameter estimation in this context. By doing this instead of performing maximum likelihood estimation, it is possible to expand the range of possible models that can be explored, at a cost in terms of computational load. We demonstrate results obtained applying this methodology to experimental data gathered from a monkey.     

数字视频处理中的块匹配运动估计技术

阐述了用于运动图像位移估计的块匹配技术,通过计算机模拟对各种算法性能进行了分析比较,提出了块匹配运动跟踪和补偿算法的改进方法.     

多率信号处理中的重采样技术

本文从基本原理、实现电路两个方面对多率信号处理中的重采样技术进行了详细分析 ,既分析了固定变换率重采样电路 ,又分析了自适应重采样电路。由于实现重采样技术的关键是求模运算的实现 ,所以文中对如何用累加器实现求模运算也进行了详细分析。     

Efficient Neuromorphic Signal Processing with Resonator Neurons

Journal of Signal Processing Systems - The biologically inspired spiking neurons used in neuromorphic computing are nonlinear filters with dynamic state variables, which is distinct from the...     

Signal Processing Techniques for 5G: An Overview

This paper gives an outline of the algorithms and implementation of the main signal processing techniques being developed for 5G wireless communication. The first part contains a review and comparison of six orthogonal and non-orthogonal waveform-generation and modulation schemes: generalized frequency-division multiplexing(GFDM), filter-bank multicarrier(FBMC), universal filtered multicarrier(UFMC), bi-orthogonal frequency-division multiplexing(BFDM), sparse-code multiple-access(SCMA), and non-orthogonal multiple access(NOMA). The second part discusses spatial signal processing algorithms and implementations for massive multiple-input multiple-output(massive-MIMO), 3D beamforming and diversity, and orbital angular momentum(OAM) based multiplexing. The last part gives an overview of signal processing aspects of other emerging techniques in 5G, such as millimeter-wave,cloud radio access networks, full duplex mode, and digital radio-frequency processing.     

视频信号处理SoC中异步时钟处理技术

为了解决视频信号处理SoC中处理器与众多接口驱动处于异步多时钟域可能产生的亚稳态问题,分析了亚稳态产生的原因,研究了格雷码、同步器、FIFO技术,结合VLIW视频信号处理SoC的结构,设计了FIFO和帧缓存存储模块,实验结果表明提出的方案可保证SoC中处理器和接口驱动间稳定的数据通信.而不会发生亚稳态现象.     

跳频信号功率谱密度估计

通过对跳频信号功率谱密度分析,指出经典周期图方法的不足,经过分析改进,得出跳频信号功率谱密度估计合适的方法和参数.仿真结果表明,改进方法具有良好的可行性功率谱估计性能.     

An NMOS Microprocessor for Analog Signal Processing

A special purpose microprocessor for real time processing of analog signals is described. Design and implementation of architecture allowing a user programmable and erasable read only memory (EPROM), a 25 bit digital processor and a 9 bit analog acquisition system on the same substrate is discussed. The relationship between the device's resources and specific signal processing building blocks is discussed.     

一种适用于微弱信号盲提取的白化方法

独立分量分析(ICA)算法是解决盲信号分离(BSS)问题的最有效方法之一.ICA中,对观测信号预白化处理的作用至关重要.通常采用主分量分析(PCA)来进行预白化处理.实际中,在利用广播、电视等作为照射源的被动雷达系统中,观测信号通常被强噪声和干扰严重污染,这很大程度上降低了BSS方法的性能.然而,传统的BSS方法中没有...     

雷达侦察抗反射信号处理技术

针对多路径反射引起的信号处理增批,提出了一种改进算法。该算法利用直射信号和反射信号脉冲序列的完整性和出现概率的不同,能有效区分反射信号和不同方位的同型雷达信号,在消除反射信号的同时,避免了对不同方位同型雷达的漏警。     

一种有效的基于Chirplet自适应信号分解算法

基于线性调频小波(chirplet)的自适应信号分解法,将待分析的线性调频(Chirp)信号分解成为一组chirplet基函数的线性叠加,能够更清楚地表述Chirp信号的时频特征.其中关键的问题,是如何自适应地估计与信号最匹配的chirplet,这将影响到自适应分解的效果.目前,还没有一种有效chirplet估计算法.本文提出了一种新的chirplet估计算法,该法充分利用了chirplet的特点,具有较高的参数估计精度.仿真数据的实验结果证明了该方法的有效性.