基于串口通信的电脑遥控系统设计

基于硬件解码的遥控接收器需要与发射器配套,使用中受限,为此设计了一种基于串口通信的电脑遥控系统。从设计方案、设计原理、软件设计与系统特点、系统的新颖性、实用性及应用前景几方面进行了探讨。该系统采用单片机解码,配合上位机控制软件,使系统在适应性、实用性、经济性、可靠性、稳定性及控制的多样性上均具有优势。实验表明,该设计适用于智能家电、工业过程及互联网设备控制,已应用于共享实验设备的控制平台上。     

A modified hidden Markov model

This paper considers two discrete time, finite state processes X$X$ and Y$Y$. In the usual hidden Markov model X$X$ modulates the values of Y$Y$. However, the values of Y$Y$ are then i.i.d. given X$X$. In this paper a new model is considered where the Markov chain X$X$ modulates the transition probabilities of the second, observed chain Y$Y$. This more realistically can represent problems arising in DNA sequencing. Algorithms for all related filters, smoothers and parameter estimations are derived. Versions of the Viterbi algorithms are obtained.     

H.264视频解码的OpenMP并行优化

随着H.264视频格式得到广泛应用,对H.264解码的效率要求越来越高,对JM15.1模型中的H.264解码过程进行了分析.采用共享存储编程的工业标准OpenMP对解码过程进行了并行区的设置.设置私有变量防止数据竞争和调整了负载.解码效率提高了10%左右.     

多标准视频解码可重构分像素插值结构设计

在各类高清视频解码过程中,分像素插值是计算最为密集的处理环节之一.针对已有分像素插值结构在兼顾性能与灵活性方面所存在的不足,提出一种适用于多标准视频解码处理的可重构分像素插值结构设计.通过分析不同标准的插值计算模式之间的共性与差异,提出一种新型可重构并串混合滤波结构,其中的数据传输通路、输入/输出数据模式以及滤波计算单元均可进行动态配置,能够支持包括VC-1,H.264/263,AVS和MPEG-1/2/4在内的多种视频标准.实验结果表明,该设计能够完成多标准实时HDTV 1080 p(1920x1088@30 fps)视频解码;同已有工作相比,该设计在同等硅片资源下能够支持更多高清视频编解码标准.该设计目前已实际应用在一款多媒体SoC芯片中.     

AVR单片机捕获中断实现红外线解码

AVR单片机是Atmel公司推出的一个单片机系列。由于该系列单片机的集成度高，因此，其软／硬件设计都变得更加简洁。文中介绍通过AVR单片机的捕获中断来实现红外线通讯解码的一种方法。     

Channel coding for satellite mobile channels

The deployment of channel coding and interleaving to enhance the bit-error performance of a satellite mobile radio channel is addressed for speech and data transmissions. Different convolutional codes (CC) using Viterbi decoding with soft decision are examined with inter-block interleaving. Reed-Solomon (RS) codes with Berlekamp-Massey hard decision decoding or soft decision trellis decoding combined with block interleaving are also investigated. A concatenated arrangement employing RS and CC coding as the outer and inner coders, respectively, is used for transmissions via minimum shift keying (MSK) over Gaussian and Rayleigh fading channels. For an interblock interleaving period of 2880 bits, a concatenated arrangement of an RS(48,36). over the Galois field GF(256) and punctured PCC(3,1,7) yielding an overall coding rate of 1/2, provides a coding gain of 42dB for a BER of 10^?6, and an uncorrectable error detection probability of 1–10^?9.     

Is reading important in reading-readiness programs? A randomized field trial with teachers as program implementers.

The purpose of the present study was to examine the effectiveness and feasibility of phonological awareness training, with and without a beginning decoding component. 33 teachers in 8 urban schools were assigned randomly within their schools to 3 groups: control, phonological awareness training, and phonological awareness training with beginning decoding instruction and practice. Following training, teachers in the 2 treatment groups conducted the treatments for about 20 wks. In each teacher's class, pre- and posttreatment data were collected on 12–14 children (N?=?404); 312 children were tested again the following fall. At the end of kindergarten, the 2 treatment groups performed comparably and outperformed controls on the phonological awareness measures. On alphabetic (reading and spelling) tasks, however, the group participating in phonological awareness training with beginning decoding instruction did better than the other 2 groups. In the fall of the next year, many of these between-group differences remained but were less impressive. Implications are discussed for bridging research and practice. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

用软件实现回溯方式的维特比译码

本文在分析维特比译码原理的基础上，提出了用软件编程实现回溯方式的维特比译码的设计和处理技巧。     

一种改进的TPC混合译码算法

为简化Turbo乘积码(Turbo Product Code,TPC)译码处理过程,缩短接收机译码时延,针对航天测控领域应用广泛的子码为扩展汉明码的TPC码,提出一种改进的混合译码算法。改进算法以传统混合译码算法为基础,把SISO和HIHO两种译码器相结合,优化软输入输出(Soft In Soft Out,SISO)中的外信息计算方式,纠正硬输入输出(Hard In Hard Out,HIHO)中的特殊错误图样,并引入切换门限完成SISO到HIHO的自适应切换,实现了基于码字可靠性的智能译码。仿真表明,对于TPC码(64,57)2,误码率为10-5时,改进算法在不减弱译码性能的前提下,复杂度仅为原算法的1/2。改进算法的提出及应用,将有利于航天测控设备小型化和国产化。