译码的

The main idea about it is that the messages passed on the bipartite graph of LDPC are based on the probability differences, and the renewal of both check nodes and message nodes is carried out on the special addition domain.

提出了一种新的基于差分的译码算法，其主要思想是：在LDPC码的二部图上所传递的消息是概率的差分值，而对于校验节点和消息节点的更新都是在特定的加法域中进行。

In part one (chapter 2-3), two new methods and systems of optical parallel logic operation are studied. Triple-in Double-out shadow-casting logic operation system is proposed and realized for the first time. Based on this, optical full adder and 3-bit decoder array logic have been obtained. It is the first time to use coding pattern and different reading-writing model to realize BSO-PROM optical parallel logic operation where the time-order operation is avoided, so that the computing speed of optical parallel logic gate which uses this kind of spatial light modulator is increased, and it is successfully used in optical symbolic substitution .

在第一部分，对两种新的并行光学布尔逻辑运算方法及系统进行了研究：首次提出并实现了三输入、双输出铸影光学逻辑运算系统及其由此得到的光学全加器，并提出一种以此为基础的3-比特译码器阵列逻辑，首次利用图形编码和不同的读写模式实现了无时序操作的BSO-PROM光并行逻辑运算，大大提高了这种空间光调制器用作光并行逻辑门的运算速度，使之成功地用于光学符号代换之中。

Finally it mathematically calculates the CRC at bit and byte level and deducts a 16-bit CRC. The calculation and deduction consolidate the CRC theory. Chapter three also introduces the modulation by two, CRC polynomial, reflection polynomial applied in noise environment and the relationship between reflection polynomial and general polynomial.

第三章首先阐述了循环冗余码与循环码的关系——循环冗余码是一种短循环码、循环冗余码具有所有循环码的很多性质；然后，简单介绍循环冗余码的编码、译码原理和实现；最后，从普通数学的角度，分别用按比特、按字节求解CRC，详细推导了校验码宽度为16的CRC的理论过程，进一步为循环冗余码的研究提供有力的理论基础。

At last, this article discusses the coding method of STBC and introduces a new imbed coding method and give a simple decoding method.

最后探讨了空时分组码的编码方法，具体给出了一种简单的四发射天线传输实矩阵的编码方法并提出了一种基于嵌入码的准正交空时分组码的设计方法，并给出了一种比较简单的空时分组码的译码方法。

Both LDPC codes and OFDM technology are studied in this paper. The working and the results obtained are summarized as follow:1. The definition of LDPC codes and its coding/decoding ideas are systematically summarized, a general algorithm of changing any parity-check matrix to lower triangular form, which is suitable for quick encoding, is given out, along with a girth checking algorithm. Absolutely random LDPC codes construction is improved, a new half random construction of LDPC codes with linear time coding and no 4-cycles is brought out.

系统地阐述了低密度校验码的定义及编译码原理，提出了一种将任何校验矩阵变换成适于快速编码的近似下三角形式的通用算法及一种围长检测算法，对完全随机的校验矩阵构造法进行了改进，提出了一类消除4环且可近似线性编码的校验矩阵半随机构造法，仿真表明，在高编码效率情况下，改进后的半随机构造法，其性能稍优于完全随机构造法，并可以线性时间编码，因此更适合实际应用。

Moreover, an improved upper bound on the average MAP decoding error probability of linear Slepian-Wolf systems for stationary memoryless sources is derived. Based on this improved bound, we analyze the performance of Slepian-Wolf systems based on LDPC codes and random permutations, and prove that under some conditions, all but diminishingly small proportion of LDPC encoders and permutations are good enough for the design of practical Slepian-Wolf systems when the coding length is very large.

然后，论文在相关平稳无记忆信源下推导出线性Slepian-Wolf系统平均MAP译码错误概率的一个改进上界，并在这一改进上界的基础上，分析了基于LDPC码和随机置换的Slepian-Wolf系统的性能，证明了在一定的条件下，当编码长度非常大时，几乎所有的LDPC编码器和置换对于实际Slepian-Wolf系统的设计都是足够好的。

The form and transmutation of inhabitation form can be simulated as a code coding/decoding process. In this way, the study on the symbolism and vicissitude of inhabitaticn form constructs microcosmical viewpoint, and the discussion in macrocosmic placing the form and transmutation of inhabitation form into the background of culture vicissitude is also carried out.

居住形态的形成和嬗变可以看作为一个符码的编码/译码过程，这样，对居住形态象征意义及其变迁的研究构成了一个微观维度的视角；同时，本文亦将居住形态的形成与嬗变置入文化变迁的大背景中，从宏观维度加以讨论。

Up to now, the performance analysis of noncoherent space-frequency coding whose receiver does not know the channel state information and the methods to reduce the encoding-decoding complexity have not been solved, and this has constituted a bottleneck of the research of noncoherent space-frequency coding.

非相干空频码具有接收端不需要知道信道信息的特点，而到目前为止，针对非相干空频码的性能分析和如何降低编译码复杂度的问题还没有得到很好的解决，这些问题已成为研究非相干空频码的瓶颈。

We will describe the use of a modified telephone coupler to allow students to access to caller ID signal and then discuss a number of the DSP methods and techniques that are required to successfully demodulate, decode, and display the caller ID information.

本文主要描述的是一种经过修改的电话耦合装置的用途，准许学生获得主叫的身份信息，还讨论利用DSP的技术成功的解调，译码并且显示主叫的信息。

Concatenated code is one of the most prospective method to solve this difficult problem.

级连码是目前知道的最有希望达到这一目标的手段之一，而研究其快速有效的译码方法是使其走向实用的最重要的课题。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。