任意抽样网格上的多维FFT算法

任意抽样网络上的多维ＦＦＴ算法在卫星遥感遥测、电视图像信号处理、天线设计等方面有着广泛的应用,本文将一维混合基和二维矢量基ＦＦＴ的一种算法结构描述方法推广到任意抽样网格上的多维ＦＦＴ算法,简化了对这种算法的进一步研究和应用。     

DMT调制系统中一种新的信道冲激响应最优缩短算法

在离散多音调制（ＤＭＴ）系统中，每个符号块在进行传输前通常要加入循环前缀（ＣＰ），以保证子信道之间的相互独立性，消除符号块间的干扰。ＣＰ的长度等于有效信道冲激响应的记忆长度。较长的ＣＰ大大降低了ＤＭＴ调制系统的传信率。为了避免采用较长的ＣＰ，通常在接收端采用有限冲激响应滤波器（ＦＩＲ）缩短有效信道冲激响应的长度。文献［１］给出了计算最优缩短冲激响应滤波器（ＳＩＲＦ）抽头系数的算法，但该算法要求ＳＩＲＦ抽头的长度必须小于或等于目标冲激响应的记忆长度。本文改进了这种算法，使其可计算任意长度ＳＩＲＦ的抽头系数。     

HDTV RS码编译码器中的论文对偶基比特并行乘法器

重点介绍了一种适合ＨＤＴＶ的ＲＳ码编译码器乘法器：对偶基比特并行乘法器的算法和实现方案。根据有限域ＧＦ（ｐｍ）中的有关定义和定理导出了对偶基比特并行乘法器的算法；给出了详细的实现电路并举例说明了其应用；简要介绍了其在ＨＤＴＶ的ＲＳ码编译码器中的应用，并和“查表法”实现的乘法器作了比较。说明了对偶基比特并行乘法器在硬件规模上的优越性。     

F4m上厄米特自正交常循环码

有限域上常循环码具有丰富的代数结构,其编译码电路容易实现,因而在信息传输实践中具有重要的应用.该文研究了一类有限域上任意长度的厄米特自正交常循环码的结构,给出了此类有限域上厄米特自正交常循环码的生成多项式与存在条件,确立了此类有限域上厄米特自正交常循环码的计数公式,并且利用此类有限域上偶长度的厄米特自正交常循环码构造了最优的量子码.     

数字式语音录放集成电路TC8831F

数字式语音录放集成电路ＴＣ８８３１Ｆ靳张铝ＴＣ８８３１Ｆ是日本东芝公司生产的一种数字式语音录放集成电路，主要应用在语音处理方面。它将语音信号经模／数（Ａ／Ｄ）转换后存于半导体动态存储器（ＤＲＡＭ）中，需要放音时再从ＤＲＡＭ中取出，经数／模（Ｄ／Ａ）转...     

索尼公司开发新型5．6英寸多晶硅TFT－LCD模块

索尼公司开发新型５．６英寸多晶硅ＴＦＴ－ＬＣＤ模块日本索尼公司已开发成功内置驱动电路的新型５．６英寸多晶硅（Ｐ－Ｓｉ）彩色薄膜晶体管液晶显示（ＴＦＴ－ＬＣＤ）模块。与非晶硅（ａ－Ｓｉ）ＴＦＴ—ＬＣＤ模块相比，它有两个突出优点：其一是每个象素上的ＴＦＴ...     

基于DDS的DTMF软件合成器

介绍了一种基于ＤＤＳ的ＤＴＭＦ软件合成器之工作原理及其实现,分析了时钟相位噪声、杂散噪声、相位截断误差对输出滤形的影响。这种基于ＤＤＳ的ＤＴＭＦ软件合成器的输出频率步进均匀,频率分辨率高,可产生任意频偏的ＤＴＭＦ信号,适用于ＤＴＭＦ电路的计算机测控系统。     

应用FPGA技术实现FFT

介绍了应用ＦＰＧＡ技术实现ＦＦＴ的方法,它既有ＤＳＰ器件的灵活性,又有专用ＦＦＴ芯片的快速性,可以广泛地应用于信号处理的各个领域。     

语音信号的频域非线性波形编码

本文主要研究语音信号的分段离散Ｆｏｕｒｉｅｒ变换（ＤＦＴ）波形编码。提出新的信号分析工具——非线性ＤＦＴ，它不仅表征了时间序列的局部线性信息，而且也包含有时间序列的全局大范围的二阶（平方）非线性特征，因此它具有比线性ＤＦＴ更强的信号分析能力。利用该ＤＦＴ对一长分段（如，５１２或者１０２４个样点）语音信号进行波形编码，在获得较高的压缩比（压缩比为８或１６）的情况下，能很好地保持原语音信号波形的细节特征。     

分离M维DFT快速算法

本文提出了一种新的多维信号ＤＦＴ快速算法，该算法是将多维ＤＦＴ转变成多组一维奇频率ＤＦＴ进行运算，那么其运算量主要取决于一维奇频率ＦＦＴ算法，同时，这有很强的结构，可实现同址运算，文中例举了二维信号时，它与多项式算法的比较，结果是实数据时，两者相同，复数据时，本文算法比文献在加法运算量方面略优，文中还给出了三维四维的运算量。     

基于两族函数的低相关二元序列集构造

低相关序列集在码分多址(CDMA)扩频通信系统和密码系统中具有极其重要的作用,运用有限域上的函数族能有效地构造相关性较好的序列集.针对n≡2(mod 4)时,本文首次运用阶数为2ⁿ的有限域上的两个二次布尔函数族,构造了2^2n-2个低相关序列集;这里每个序列集包含2ⁿ+1条周期为2ⁿ-1的二元序列,其最大相关值为2^n/2+1+1.这将为通信系统和密码系统提供更多可供选择的序列集.     

Performance of polar codes with the construction using density evolution

Polar coding, proposed by Ar?kan, makes it possible to construct capacity-achieving codes for symmetric binaryinput discrete memoryless channels, with low encoding and decoding complexity. Complexity of the originally proposed code construction method, however, grows exponentially in the blocklength unless a channel is the binary erasure channel. Recently, the authors have proposed a new capacity-achieving code construction method with linear complexity in the blocklength for arbitrary symmetric binary-input memoryless channels. In this letter, we evaluate performance of polar codes designed with the new construction method, and compare it with that of the codes constructed with another heuristic method with linear complexity proposed by Ar?kan.     

Block-coded M-PSK modulation over GF(M)

Channel codes where the redundancy is obtained not from parity symbols, but from expanding the channel signal-set, are addressed. They were initially proposed by G. Ungerboeck (1982) using a convolutional code. Here, a block coding approach is given. Rate m/(m+1) coded 2^m+1-ary phase-shift keying (PSK) is considered. The expanded signal-set is given the structure of a finite field. The code is defined by a square nonsingular circulant generator matrix over the field. Binary data are mapped on a dataword, of the same length as the codewords, over an additive subgroup of the field. The codes using trellises are described, and then the Viterbi algorithm for decoding is applied. The asymptotic coding gain ranges from 1.8 to 6.0 dB for QPSK going from blocklength 3 to 12. For 8-PSK, the gain is from 0.7 to 3.0 dB with blocklength 4 to 8. With only four states in the trellis, codes of any length for QPSK and 8-PSK are constructed, each having an asymptotic coding gain of 3.0 dB. Simulation results are presented. It is found that the bit-error rate performance at moderate signal-to-noise ratios is sensitive to the number of nearest and next-nearest neighbors     

Computing the k-error joint linear complexity of binary periodic multisequences

Complexity measures for multisequences over finite fields, such as the joint linear complexity and the k-error joint linear complexity, play an important role in cryptology. In this paper we study a fast algorithm, presented by Venkateswarlu A, to computer the k-error joint linear complexity of a binary periodic multisequence. In this paper, the aim is mainly to complement the theoretical derivation and proof of the existing algorithm. Moreover, our algorithm reduces computation.     

Encoding and Progressive Transmission of Still Pictures in NTSC Composite Format Using Transform Domain Methods

Coding schemes suitable for progressive transmission of still pictures in NTSC composite format are studied. Transform coding methods based on the discrete cosine transform (DCT) and the WalshHadamard transform (WHT) are used. The transform coefficients are segmented into groups having similar properties. Variable blocklength to variable length codes are used to encode the quantized coefficients for each of the groups. Progressive transmission is achieved by sending the coefficients belonging to particular groups in successive passes over the image. Results are presented for coding the NTSC signal sampled at four times the color subcarrier frequency with an orthogonal structure, and at twice the subcarrier frequency with a hexagonal structure.     

面向智能网联汽车边缘网络的分布式端-边协同算法

车联网高级安全服务中,智能网联车辆配备了摄像头,可以拍摄周围的视频,用于安全、交通监控和监视等目的。车辆将获取的视频上传到边缘计算节点后,可以对视频进行分析和备份,以满足不同的安全驾驶需求。然而,车辆连续直接向边缘计算节点上传生成的视频内容会非常消耗带宽,并消耗大量的能量。基于该问题,提出一种面向智能网联汽车边缘网络的分布式端-边协同算法。针对车联网高可靠低时延内容传输的特点,引入有限块长度编码机制。同时,引入车辆视频信息源的压缩编码功率消耗,建立车辆能耗模型。根据车辆视频信息源的视频质量要求,通过调整视频编码码率、信息源传输速率,以及车辆多路径路由的决策,提出一种完全分布式的优化算法,以提高网络资源利用率,并保证单个车辆的能耗公平性。     

Identification via channels

The authors' main finding is that any object among doubly exponentially many objects can be identified in blocklength n with arbitrarily small error probability via a discrete memoryless channel (DMC), if randomization can be used for the encoding procedure. A novel doubly exponential coding theorem is presented which determines the optimal R, that is, the identification capacity of the DMC as a function of its transmission probability matrix. This identification capacity is a well-known quantity, namely, Shannon's transmission capacity for the DMC     

有限域上两类新的2-重量码的构造

有限域上二重量码的构造是图论、编码与密码中的重要研究课题.本文得到了有限域上两类新的2-重量码并且它们都是最优的,达到了Griesmer界.这些码由有限域的扩域上迹码的p元像定义,有阿贝尔码的代数结构,利用特征和和高斯和来计算了它们的重量分布.我们也计算了这些像码的对偶码的极小距离.最后对扩域上迹码的像在秘钥共享方案中的应用进行了刻画.     

几类指标为2的不可约拟循环码的重量分布

少重量线性码在认证码、结合方案以及秘密共享方案的构造中有着重要的应用。如何构造少重量线性码一直是编码理论研究的重要内容。该文通过选取特殊的定义集,构造了有限域上指标为2的不可约拟循环码,利用有限域上的高斯周期确定了几类指标为2的不可约拟循环码的重量分布,并且得到了几类2-重量线性码和3-重量线性码。结果表明,由该文构造的3类2-重量线性码中有两类是极大距离可分(MDS)码,另一类达到了Griesmer界。