查询词典 codes

Since the 2-D perfect difference codes have a MUI cancellation property and cross-correlation much lower than that of conventional 2-D spectral/spatial codes, such as Maximal-area matrices codes, the proposed system can completely eliminate the MUI and effectively suppress the PIIN.

由於二维完美相差码系具有一多使用者干扰相消特性，并且其交叉相关系数系远小於传统之二维频谱/空间码，如最大面积矩阵码maximal-area matrices codes， i.e。

The topics covered include the basic concepts of information theory--entropy, mutual information, channel capacity, information rate, Shannon's noiseless coding theorem and Shannon's fundamental coding theorem; modeling of information sources--zero-memory and Markov models; modeling of information channels--BSC and BEC channels, additivity of information and cascaded channels; construction of compact source codes--Kraft inequality, compact codes, Huffman and LZW compression codes; and analysis and design of error-control channel codes--Hamming distance, binary linear codes and the parity-check matrix, Hamming codes, checksum codes, cyclic codes and the generator polynomial and CRC codes.

课程的内容包括：信息论的基本概念（熵、交互信息、信道容量、信息率、 Shannon无噪声编码定理和Shannon基本编码定理）、信源模型（无记忆模型和Markov模型）、信息信道模型（BSC 和 BEC模型、信息的可加性和级联信道），紧致信源编码设计（Kraft不等式，紧致编码，Huffman 和LZW压缩编码）以及差错控制信道码的设计与分析（海明距离，二元线性码，奇偶校验矩阵，海明码，校验和，循环码，生成多项式和CRC码）。

The soft information from demodulator has been investigated in detail and has been applied to the turbo-codes.

因此本论文尤其详细研究了如何从调制器中得到正确的软信息，进而在Turbo-codes中如何使用这些软信息。

Some common used channel codes are introduced, and emphasis is placed on linear block codes, cyclic codes, BCH codes, RS codes, convolutional codes and the promising turbo codes, which is planned to be implemented in the third locomotive communication systems. Their performance is analysed and compared. And some method to reduce errancy is submitted, also the interleaved technique is introduced.

文章介绍了几种常用的信道编译码方案，如线性分组码，循环码，BCH码，RS码，卷积码等，分析和比较了它们的性能，并对第三代移动通信系统的选用码Turbo码作了简要介绍，对提高纠错性能提出了若干改进方案，同时介绍了交织技术减少差错的作用。

At last, By using the factorization properties of cyclotomic polynmials on finite fields and the construction characteristic of cyclic codes, we present the relation of the period distribution of cyclic codes and the period distribution of their dual codes, establish the explicit formula for the number of the codewords without inner-period of the cyclic codes and their dual codes, find the method for computing the dimension and the period distribution of narrow-sense primitive BCH codes,and study the inverse question of period distribution of cyclic codes.

最后，利用有限域上分圆多项式的分解特性和循环码的构造特点，揭示了循环码的周期分布与其对偶码周期分布之间的内在联系，确定了一般循环码及其对偶码内无内周期码字的精确计数公式，决定了狭义本原BCH码的维数与周期分布，讨论了循环码周期分布的反问题。

In this paper we have studied the performance of punctured turbo-codes with short interleaver in AWGN channel.

主要的贡献有：为实际应用Turbo-codes，需进一步提高码速率，往往采用在原有的编码基础上进行删除。

The general decoding method for Turbo codes provided by the invention adopts enhanced Max-Log-MAP algorithm, makes use of Max-Sum semiring property in the generalized distribution law and combines and simplifies measure and calculation of forward and backward status of traditional binary Turbo codes, which means combining grid graph of traditional binary Turbo codes in nature to ensure that the status measure and calculation of the traditional binary Turbo codes have the same calculation expression way with that of the duobinary Turbo codes so that a general decoding device can both decode the traditional binary Turbo codes and duobinary Turbo codes.

本发明提出的Turbo码通用译码方法采用增强型Max-Log-MAP算法，利用广义分配率中的Max-Sum半环性质，对传统二进制Turbo码的前向和后向状态度量计算进行合并简化，从本质上也就是对传统二进制Turbo码的网格图进行合并，使得传统二进制Turbo码的状态度量具有和双二进制Turbo码一样的计算表达方式，从而使得通用译码装置对于传统二进制Turbo码和双二进制Turbo码都可实现。

Secret Codes is a simple program which is able to store all your secret codes in the phone memory cyphering with one password.

Secret Codes是一个简单的应用程序，用它可以把你所有的密码存至你的手机存储里，然后将其统设为一个密码进行封存。

Reliable multicast solutions based on this technology include data carousels based on multiple transmissions, block encoding based on Reed-Solomon codes, and digital fountains based on fountain codes .

基于该技术的可靠组播解决方案主要包括：基于重复传输的数据轮播解决方案，基于RS码(reed-solomon codes)的分块编码解决方案，以及基于喷泉码的数字喷泉解决方案。

Imbursed by the sub-item"Research on System Framework of Joint Source-Channel Coding under Wireless Circumstance"of national high-tech research and development plan(863 plan)"Digital Audio, Video Encoding, Transmission, Testing and Applying Model"(No.2002AA119010), and the great item"Research of Future Communication System Fundamental Theory and Technology (No.60496315)", the dissertation studies several key techniques of Low-Density Parity-Check Codes that were considered much in error correction codes field.

本文正是在国家高技术研究发展计划(863计划)&数字音视频编码、传输、测试与应用示范&(No.2002AA119010)的子课题&基于无线环境的联合信源信道系统框架研究&、国家自然科学基金重大项目&未来移动通信系统基础理论与技术研究(No.60496315)&等研究项目的资助下，对近年来在纠错码领域表现抢眼的低密度校验码(Low-Density Parity-Check Codes，LDPC)的若干关键技术展开了研究。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。