摘要：探讨了基于turbo原理进行迭代检测的编码连续相位调制(CPM)系统在瑞利衰落信道下的性能.根据CPM的分解模型,把CPM分解为连续相位编码(CPE)与无记忆调制(MM)的组合,基于CPE的记忆特性和递归特性,结合外部的卷积码及交织器,建立了串行级联turbo CPM系统模型.针对短帧系统在迭代检测过程中存在的正反馈现象,设计了衰落信道下基于加权外信息交换的turbo CPM系统接收机,有效改善了系统收敛性.探讨了不同系统参数对系统性能的影响.仿真结果表明所设计系统在衰落信道下具有优异的功率与带宽性能.

摘要：针对航天测控通信系统中微弱信号处理的实际应用需求,研究了turbo译码算法在星载平台上的低复杂度实现技术。基于折线近似的Log_MAP算法,提出了一种新的基于FPGA的译码器实现方案,一方面简化了迭代译码过程中分支度量的计算存储方法,有效减少了存储容量及算法复杂度;另一方面采用半并行化及流水的数据处理方式,提高了译码处理速度。利用CCSDS标准建议的交织器和生成矩阵进行了仿真和实测,结果表明相较于其它结构,采用本文设计方案实现的turbo译码器在Slice资源没有增加的条件下存储复杂度降低了29.6%,且在输出误码率<10-6时编码增益达到了9.9dB,保持了良好的译码性能。本文译码器已成功应用于某航天型号工程。

摘要：Coding techniques have always been a major area of scientific interest. Due to this interest, many coding schemes were invented. Eventually, their implementation in various systems contributed in the evolvement of Wireless Communications. A breakthrough was definitely turbo coding. Particularly, the concept of joining two or more convolutional encoders in parallel (PCCC) or in serial (SCCC), along with the iterative decoding technique, literally raised the expectations of the anticipated BER performance. In fact, Concatenated Convolutional Codes clearly outperform convolutional codes. Moreover, various systems, either under development or either for future use, will have high standards. The previous systems should present exceptional tolerance of noise effects and consequently a low overall number of received errors. For this purpose a new PCCC design was developed. The system’s performance analysis, using an AWGN channel, showed better results for various iterations compared to other schemes such as typical PCCC, SCCC and finally a Convolutional encoder with a Viterbi decoder.

摘要：Puncturing is the predominant strategy to construct high code rate turbo codes. Puncturing tables are crucial to the performance of punctured turbo codes(PTC). This paper developed a new searching algorithm of optimal puncturing tables based on average distance spectrum(ADS) criterion. Consequently, some optimal puncturing tables were presented as the searching results. Finally, it presented the performance comparison among some optimal and bad puncturing tables by simulation.

摘要：This paper extends the work on cross-layer design which combines adaptive modulation and coding at the physical layer and hybrid automatic repeat request protocol at the data link layer. By contrast with previous works on this topic, the present development and the performance analysis as well, is based on rate compatible punctured turbo codes. Rate compatibility provides incremental redundancy in transmission of parity bits for error correction at the data link layer. turbo coding and iterative decoding gives lower packet error rate values in low signal-to-noise ratio regions of the adaptive modulation and coding (AMC) schemes. Thus, the applied cross-layer design results in AMC schemes can achieve better spectral efficiency than convolutional one while it retains the QoS requirements at the application layer. Numerical results in terms of spectral efficiency for both turbo and convolutional rate compatible punctured codes are presented. For a more comprehensive presentation, the performance of rate compatible LDPC is contrasted with turbo case as well as the performance complexity is discussed for each of the above codes.

摘要：电磁兼容性在数控电气控制系统中起着重要作用。根据开放式数控系统的控制特点,以"PC+turbo PMAC"为硬件平台,分别从turbo PMAC电源电磁兼容设计、I/O信号电磁兼容设计、光栅编码信号的抗干扰三个方面入手,介绍构建开放式数控系统的电磁兼容设计方法。通过以上电磁兼容设计,使得基于turbo PMAC的混联机床开放式数控系统控制可靠,运行良好。

摘要：1 显示模块的查找方法 在使用debug·com程序之前,应将turbo C2.0V的主文件TC·EXE换名,如TC。用debug·com的R命令查看TC·EXE的长度,其高位在BX中,低位在CX中。TC·EXE的长度为47171H bytes(即291185 bytes)。

摘要：本文详细介绍了在ＩＢＭＰＣ机及其兼容机上开发研制的ＩＥＥＥ４８８接口控制卡的ＧＰＩＢ操作语句。着重讲述了ＧＰＩＢ操作语句的设计及其在Ｃ语言下的应用，文中介绍了十几条常用的主要接口操作语句，并给出了控制ＦＬＵＫＥ８８４０表的实例。

摘要：随着计算机应用的普及,人机界面性能已成为一个计算机系统成败的主要因素之一。形象化的屏幕显示,引人入胜的菜单系统,是任何一个实用程序首要考虑的问题。我们利用 turbo Pascal 开发的菜单程序,实现了多级下拉式驱动,其结构与 turbo Pascal自身的菜单结构十分相似。本文将对它作出一些关键性的描述,以和全国同行们共同磋商。

摘要：表是Prolog的基本数据结构,为了掌握表处理,必须熟悉递归技术,表处理和递归构成了Prolog程序设计的重要内容.本文集中讨论了各种类型的表处理谓词,读者可直接调用它们,也可以仿照它们写出自己所需要的表处理谓词.