一种多通道声呐接收机设计与实现

介绍一种用于图像声呐的多通道接收机设计与实现方法，详细介绍该接收机的设计原则，阐述接收机的组成和各模块的设计原理，优化接收机的电路拓扑结构，降低接收机通道的本底噪声，提高各通道的相位一致性。通过对本底噪声、增益控制、幅度一致性和相位一致性等关键性能指标的测试和数据分析，给出实际测试结果，验证了该多通道接收机满足该种类声呐的实际使用需求。     

不断发展的现代电子战接收机

密集而复杂的现代战争信号环境对电子战接收机提出了更高的要求，侦察与反侦察，干扰与反干扰的斗争尖锐激烈，传统的接收正面临着严峻的挑战。为在现代战争的电子对抗中赢得先机和掌握主动，国内外都没有投入了大量精力对现有接收机进行改造和对新型接收进行研制，主要讨论了电子战中几种常见接收机：瞬时测频接收机，信道化接收机，压缩接收机及声接收机的性能特点，提术发展和性能改进情况，最后对数字接收机的发展现状做了介绍。     

一体化BDS/GPS卫星导航接收机设计与实现

提出了一种一体化 BDS/GPS 卫星导航接收机设计方法，利用 Ansoft HFSS 仿真设计软件进行了天线设计，使用低噪声放大器、声表面滤波器、卫导芯片等较少的器件完成了卫星导航接收机的设计。并对设计的卫星导航接收机进行生产、调试和测试，给出了测试结果。结果表明，该一体化卫星导航接收机可满足使用要求。     

模块化雷达接收机的微电子化

本文阐述了雷达接收机模块化的必要性及可行性；提出了模块化雷达接收机的实施方案；论述了微电子技术在实现雷达接收机模块化中所起的重要作用，并对微电子技术在模块化雷达接收机中的应用前景提出了一些看法。在比较了国内外模拟集成电路及ＭＭＩＣ、ＨＭＩＣ器件之后，对模块化雷达接收机所用器件的国产化提出了一些希望。最后，介绍了我所微电子化接收机系列的研制情况。     

一种MLS地面静态标校测角接收机的设计与实现

从嵌入式系统高性能、低功耗、低成本特点出发，结合嵌入式 MLS 测角接收机的设计理念，开展了基于 ARM 微处理器的 MLS 测角接收机研制，详细介绍了硬件电路设计、信号处理软件设计和交互界面设计。测试表明，研制的 MLS 测角接收机功能、性能满足设计要求。     

单比特数字接收机

介绍了单比特电子战数字接收机的基本原理，该接收机在简化DFT算法的同时采用低比特A／D变换，降低了宽带电子战接收机的实现难度，克服了由于超宽带高速采样带来的一系列问题。分析了加窗对单比特接收机的性能影响，并给出了一种基于DSP的实现方法，在此基础上建立了一个单比特电子战系统测试系统。利用该系统通过仿真试验，详细研究了单比特接收机的虚警概率、检测概率及双信号动态范围，并与DFT接收机进行了比较，并指出除了双信号动态范围较小外，单比特电子战接收机的性能基本相同。增加输入信号的比特数是提高单比特电子战接收机双信号动态范围的有效方法，当采用2比特量化时该动态范围可以增加5dB。最后分析了该接收机的应用前景。     

多相滤波宽带信道化数字接收机

宽带雷达电子战数字接收机是当前国内外研究的重点，信道化接收机能够处理同时到达的多个信号并有较高的截获概率。多相滤波信道化接收机运算量小且易于实现。为克服因D倍抽取而产生的多相滤波信道化数字接收机的接收盲区，引入了重叠一半的多相滤波信道化数字接收机。利用瞬时自相关接收机，可在消除信道化接收机虚假输出的同时提高信道化接收机的测频精度。文中给出了上述数字接收机的实现方法，并通过仿真实验证明了以上结论的有效性。     

DME／P地面接收机的实现

主要介绍了精密测距系统地面接收机的组成及工作原理，详细分析了精密测距接收机采用的几种新技术：HAF检测技术、DAC检测技术、第一脉冲译码等技术的应用，为改善接收机的技术性能提供了可靠的科学依据。     

数字监测接收机的主要性能指标分析

结合数字监测接收机的基本工作原理，对接收机的主要指标进行分析，指出其与模拟接收机对应指标的差别，并给出了测试方法。     

短毫米波和亚毫米波接收机的发展现状

本文概述了短毫米和亚毫米波接收机的发展现状，介绍了接收机的重要组成部件：混频器、振荡器和放大器的发展水平以及毫米波单片集成电路的现状，给出了接收机的最新性能指标。     

Minimax Noncoherent Detection of BFSK Signals in Nonwhite Gaussian Noise

We derive an optimum receiver for noncoherent detection of binary frequency shift keyed (BFSK) signals in nonwhite Gaussian noise. It will be shown that the achieved symbol error rates are smaller when operating on a nonwhite Gaussian noise channel than on a white Gaussian noise channel. The well-known BFSK receiver designed for white noise proves to be a minimax receiver when used in nonwhite noise. We show that the symbol error probability of the minimax receiver does not depend on the noise characteristics.     

GMSK中频数字化非相干接收机的设计与实现

针对突发模式下的GMSK信号,设计并实现了一种非相干数字化接收机,并且提出了一种更容易硬件实现而且频谱更好的GMSK信号产生方式。该接收机为了降低系统的复杂度,接收机采用2bit差分的方式按样点先进行信号解调,然后利用提出的基于引导码的位定时算法,在8个符号之内实现了位定时的快速捕获。最后在FPGA上的实现证明了接收机的可行性和优越性。     

Symbol synchronization in convolutionally coded systems (Corresp.)

Alternate symbol inversion is sometimes applied to the output of convolutional encoders to guarantee sufficient richness of symbol transition for the receiver symbol synchronizer. A bound is given for the length of the transition-free symbol stream in such systems, and those convolutional codes are characterized in which arbitrarily long transition free runs occur.     

Bit error probability of a matched filter in a Rayleigh fadingmultipath channel in the presence of interpath and intersymbolinterference

The exact bit error probability of a matched filter receiver in a known discrete Rayleigh fading multipath channel is determined for a binary antipodal system. The matched filter receiver or the RAKE is one form of a diversity receiver. Traditionally, both the interpath interference (IPI) and the intersymbol interference (ISI) caused by the non-ideal autocorrelation function of the bit waveform are neglected in the analysis of the RAKE. Previously, the exact matched filter bounds; which include IPI, were derived. This bound gives the performance of the matched filter if only one symbol is transmitted. In our analysis, a symbol sequence is transmitted instead of only one symbol. Thus, our analysis includes both IPI and ISI as well as the correlation between the paths, The analysis permits direct comparisons between different kinds of bit waveforms     

Ultrafast Operation of Digital Coherent Receivers Using Their Time-Division Demultiplexing Function

The digital coherent receiver, which is a combination of a phase-diversity optical homodyne receiver and digital signal processing (DSP), can demodulate any multilevel coded optical signals without relying upon an optical phase-locked loop. However, the maximum symbol rate processed by such a receiver is limited by the speed of electric analog-to-digital converters and digital signal processors. Although real-time operation at 10 Gsymbol/s using an application-specific integrated circuit has recently been demonstrated, it is still difficult to increase the symbol rate beyond 40 Gsymbol/s. In order to cope with this difficulty, we propose a novel scheme, which employs a local oscillator (LO) pulsed at the subharmonic frequency of the symbol rate, enabling time-division demultiplexing of the signal at the digital coherent receiver. We demonstrate that the new type of digital coherent receiver operating at 10 Gsymbol/s can demodulate the aggregate symbol rate of 160 Gsymbol/s. From these results, we can expect ultrafast coherent optical fiber communication in the future.      

Bidirectional iterative ISI canceller for high-rate DSSS/CCK communications

This paper proposes a new RAKE receiver incorporated with a bidirectional iterative intersymbol interference (ISI) canceller in order to reinforce multipath robustness of high-rate direct-sequence spread-spectrum complementary code keying (DSSS/CCK) systems. The proposed RAKE receiver first combines multipath signal components through a channel matched filter (CMF) and removes postcursor-ISI by employing a codeword decision feedback equalizer (DFE). Then, a CCK codeword detector tentatively determines the current CCK codeword symbol and reuses it to subtract precursor-ISI from the previous symbol. Therefore, the ultimate symbol decision is made using the delayed signal with both postcursor-ISI and precursor-ISI cancelled. The detection performance can be more improved through an iterative refinement processing between the postcursor and the precursor components. Simulation results exhibit a significantly improved error rate performance of the proposed receiver compared with that of the legacy RAKE receiver employing only a postcursor DFE. The additional cost for realization of the proposed receiver is one symbol decision delay and reuse complexity of the DFE and the codeword detector.     

用于DVB-S信道芯片设计的符号检测

介绍了用于DVB-S信道接收芯片设计的符号检测系统,阐述了数据源的结构,数据同步、码流的实时分析、检测的过程和检测的方法.     

Adjacent-Channel and Quadrature-Channel Interference in Minimum Shift Keying

In this paper we present formulas for the computation of error probability in the presence of quadrature-channel or adjacentchannel interference in addition to intersymbol interference in a minimum shift keying system. The filters in the receiver and transmitter are arbitrary but with a finite number of poles. The effect of phase jitter in the main channel, phase and symbol timing misalignment in the interfering channels, and sampling time jitter is taken into account. The probability of error is averaged over the phase and symbol timing misalignment. Numerical results are presented for Butterworth filters in the receiver and transmitter with two, three, and four poles. Curves of error probability as a function of various variables (signal-to-noise ratio, bandwidth of receiver and transmitter filters, number of poles, channel frequency separation, phase jitter, sampling time, and symbol timing and phase misalignment) are presented. The method of this paper can readily be applied to other filters; hence, it can be used in the design and prediction of the performance of digital communication systems.     

On the performance of a rapid synchronization algorithm for IR‐UWB receivers

Because of the very low signal duty cycles, synchronization is the most critical issue in ultra wideband (UWB) impulse radio (IR) systems. Some effective synchronization schemes like a symbol‐differential (SD) IR‐UWB receiver have been proposed to synchronize received signals rapidly. Yet, SD IR‐UWB receiver is unsuitable for operation in multi‐user environment because of multiple access interference (MAI). By taking advantage of frame‐differential IR‐UWB receivers, we propose a parallel frame‐differential (PFD) IR‐UWB receiver to do so. Our proposed PFD IR‐UWB receiver manifests better immunity against message passing interface and MAI than the SD IR‐UWB. Based on this PFD IR‐UWB receiver, uncertain (search) regions are limited to one frame duration without any symbol‐level synchronization process. Performance of PFD and SD receivers are compared by computer simulations, showing that the proposed PFD receiver not only achieves significant bit error rate performance but also better and more robust results than the SD receiver in this literature. Copyright © 2012 John Wiley & Sons, Ltd.     

固定波形时间保护间隔OFDM系统循环卷积特性研究

针对固定波形时间保护间隔OFDM系统接收端OFDM信息符号和信道冲击响应之间不具有循环卷积特性的系统特点,本文提出一种简单有效的信号处理算法对该系统接收端OFDM信息符号和信道冲击响应之间的循环卷积特性进行恢复。理论分析和计算机仿真表明,该算法能够恢复接收端此循环卷积特性;在时延扩展和AWGN信道条件下,系统误符号性能受到的影响微弱。