An Approach of Branch Multithreading Switch Mechanism

Branch misprediction is a considerable drawback to processor performance. The capacity of mulfithreading technology that can hide latency among threads brings up new opportunities to diminish the effect of misprediction. Since previous multithrending approaches either bring up additional pipeline lost or lack flexibility to implement. In this paper, an approach is proposed, which exploits instruction extension and instruction prefetch mechanism together with a parallel decoder. Not only the impact of misprediction delay is diminished, but also no accessional waste is caused by the thread switch mechanism. Experiment shows that IPC is improved by 10.2%-25% compared with Gshare branch prediction method for the most of the benchmarks.     

一种基于虚拟NAND闪存接口的条码解码芯片及设备的设计方案

针对条码解码芯片的实际推广应用,本文介绍了一种基于虚拟NAND闪存的接口模块设计,并根据条码解码芯片及其接口性能指标,给出了几种应用方案。     

一种从数模混合信号中提取数字信号的时域算法

介绍了一种基于信号幅度特征的时域提取算法,可以准确地从数模混合信号中提取数字信号.此算法的实现简单,不需要太高的处理速度就可实现实时处理,可应用在数模混合信道的数字解码器中,实现数模混合信道的数字通信.     

基于Xvid视频流的在线考试监控系统的研究

保证在线考试的公平和公正,是推广和实施在线考试的一个重要任务,由于Xvid是免费且开源的编解码器,易于使用,算法高效,可以很好地承担在线考试系统监控视频流的传输任务。结合实例,设计并实现了基于Xvid视频流的在线考试监控系统。     

维特比译码的仿真与实现

维特比译码算法是一种最大似然序列检测的方法,首先分析仿真了在不同判决方式和回溯深度下的维特比译码的性能,得出结论:在无线高斯信道中,维特比译码采用3比特软判决及回溯深度为48的时候,系统能达到最佳的效果;利用上述结论使用Q1900芯片实现了维特比译码。     

新的时变信道下空时分组编码多用户系统解码器设计

该文提出了两种新的适用于时变信道下空时分组编码多用户系统的解码器设计方案。空时分组编码多用户系统下,传统的迫零(Zero Forcing, ZF)和最小均方误差(Minimum Mean Squared Error, MMSE)解码器设计均假定信道准静态衰落。信道时变时,这些传统解码器在解码某用户信号时引入符号间干扰(Inter-Symbol Interference, ISI),且这种干扰随信道时变增大而增加。基于此,该文设计了两种新的解码器,该解码器可显著降低信道时变的影响。仿真结果表明,随信噪比(Signal-to-Noise Ratio, SNR)增加,两种传统解码器均出现误码率性能平层,而新解码器获得了显著的性能改善。     

Low complexity concatenated coding schemes for digital satellite communications

A study of reduced complexity concatenated coding schemes, for commercial digital satellite systems with low-cost earth terminals, is reported. The study explored trade-offs between coding gain, overall rate and decoder complexity, and compared concatenated schemes with single codes. It concentrated on short block and constraint length inner codes, with soft decision decoding, concatenated with a range of Reed-Solomon outer codes. The dimension of the inner code was matched to the outer code symbol size, and appropriate interleaving between the inner and outer codes was used. Very useful coding gains were achieved with relatively high-rate, low-complexity schemes. For example, concatenating the soft decision decoded (9,8) single parity check inner code with the CCSDS recommended standard Reed-Solomon outer code gives a coding gain of 4.8dB at a bit error probability of 10^?5, with an overall rate of 0-78.     

基于MPEG-2视频基本流解码的容错方法研究

MPEG-2是一个被广泛应用的多媒体压缩标准,它所包含的系统、视频和音频部分均描述了压缩数据流的数据结构和严格的语法。以MPEG-2基本视频流为对象,分析了数字视频流中可能出现的错误及其解码后的症状,并提出了相对应的解决方法,最后用实验验证了一个实用方案的可行性。     

用于HDTV的Reed—Solomon译码器的设计

文章使用Berlekamp迭代算法,设计了一种（204,188）RS译码器电路。该译码器采用流水线结构,并在某些关键环节进行了优化,具有较高的添吐率,适合在高清晰度数字彩电（HDTV）中使用。     

一种PCM遥测同步解调器的设计

本文设计了一种用于PCM遥测的同步解调器 ,提出了针对瞬态过程PCM遥测解调数据的采集策略 ,利用缓冲PAM从连续不断的PCM码流中捕捉到瞬态过程。并用FPGA技术实现码同步器和帧同步器 ,使整个遥测解调器在单板PC插卡上实现并具有较低的成本 ,该方案用于 4MHz码速率的数据解调。用Labwindows/CVI编制了虚拟仪器面板 ,完成对硬件的控制和瞬态多路解调数据的曲线显示、处理和存储等功能