In the third part , a new adaptive trellis coded modulation ( atcm ) solution was presented . we analysis the best coding scheme in different channel modes , different snr and different demodulation solution 仿真结果表明,在解调观测长度相同的情况下,其性能和多码元差分解调方式大致相同,但大大简化了接收机结构。
Space - time block code use linear combination to combine the modulo of received signal vectors from different antenna to obtain the same performance as receive diversity . while the space - time trellis code directly combine the received 空时分组码通过线性组合,可以把多根天线上的接收信号矢量的模相加,得到与接收分集相同的效果。
The fourth part considered how to improve system performance by adopting transmission diversity in flat fading channels . in the traditional space - time trellis code design , the space diversity , time diversity and channel code are concerned together to get best space diversity , time diversity and code gain 传统的空时格码把空间分集、时间分集和前向纠错编码联合设计,以n摘要获得最大的空间分集、时间分集、信道编码的增益。
This chapter first introduces the principium of trellis coded vector quantization , then focuses on analyzing the algorithm of wavelet image classified weighted tcvq and its realization process , also gives tcvq application to wavelet image coding and its simulation results 首先分析了网格编码矢量量化的原理,在第三章矢量量化的基础上详细介绍了小波图像分类加权tcvq算法的原理和实现过程,并给出了tcvq在小波图像量化中的应用实例和仿真结果。
For its error correction performance extremely close to the shannon limit , from the beginning , turbo codes attracts the eyes of enormous professionals and researchers . in turn , it is called the greatest contribution after ungerboeck ' s trellis coded modulation ( tcm ) 因为它具有极其逼近香农极限的纠错性能,从一开始turbo码便吸引了通信领域无数专家学者的关注与研究,进而被誉为继ungerboeck提出格状编码调制( tcm )以来,信道编码领域最伟大的贡献。
Since the fundamental idea of tcq originates from trellis coded modulation , in order to comprehend tcq , it firstly introduces tcm . also , because viterbi decoding algorithm is the key of coding gain of tcm and tcq , it particularly introduces convolutional coding and viterbi decoding algorithm 由于tcq的基本思想源于tcm ,较好地掌握tcm的思想有助于深刻理解tcq ,所以首先介绍了网格编码调制;维特比算法是tcm和tcq提高编码增益的关键,文中对tcm和tcq都要用到的卷积编码和维特比译码也作了详细的介绍。
The technology of trellis coded modulation ( tcm ) and viterbi decoding which could achieve high transmitting rate at a low bit ' error rate are demonstrated in detail . and then the design and achievement of itu - t v . 32 modem that based on one - dimensional tcm are expatiated . the paper also discusses the multi - dimensional tcm the itu - t v . 34 modem that based on it and tcm ' s application in the carrier communication 文中深入研究了可保证一定误码率的情况下能实现较高传输速率的网格编码调制( tcm )技术和维特比译码技术,阐述了基于单维网格编码调制的itu - tv . 32modem的设计和实现,讨论了多维网格编码调制技术和基于其的itu - tv . 34modem ,并对网格编码调制在载波通信中的应用作了简单介绍。
Space - time codes can be divided into tree mainly parts : bell layered space - time architecture ( blast ) , space - time trellis codes ( sttc ) and space - time block codes ( stbc ) . in this paper , we mainly compare the performance of blast and stbc in many aspects , such as design criterion , transmission rate , diversity gain , diversity combining , bit error rate and channel capacity etc . in this paper , we first respectively analysed the instantaneous received symbol energy - to - noise ratio of v _ blast in the diversity combining methods of maximal ratio combining ( mrc ) , equal gain combing ( egc ) and selective combing ( sc ) Mimo技术核心是空时编码( stc ) 。空时编码主要分为三种:分层空时码( blast ) 、空时格码( sttc )和空时块码( stbc ) 。本文主要对分层空时码和空时块码这两种编码方式在设计准则、传输速率、分集增益、接收合并、比特差错率和信道容量等方面进行了较为详尽的研究。
Based on the analysis of image wavelet transformation and the space / frequency distributing characteristics of different subbands " coefficients , this dissertation fully exploits the following theories and methods : scalar quantization , vector quantization , trellis coded quantization , trellis coded vector quantization , vector classification , codebook expansion and weighted mean square error rule basing mankind visual characteristics , etc . from different angles of information amalgamation , it develops several innovative algorithms of image compression and coding , gives their realization schemes , and makes plentiful simulation tests 本文在分析了图像小波变换的原理和子带系数空间及频率分布特点的基础上,充分利用标量量化、矢量量化、网格编码量化、网格编码矢量量化、矢量分类、码书扩展和基于人眼视觉特性的加权均方误差准则等思想和方法,从信息融合的不同角度展开了对小波图像的压缩编码研究,同时也讨论了这些方法在静止图像量化中的具体应用。
The paper discusses the part of asic design of tcm ( trellis coded modulation ) in hdtv 8vsb terrestrial channel broadcasting receiver chip . in testing , the tcm can improve the signal - to - noise by 3 . 3db compared with uncoded 4 - vsb modulation , and with the 12 path intrasegment interleaving in tcm coding and viterbi decoding , system can control short burst noise error efficiently 在高清晰度电视信道接收芯片中内码是8 ? vsb的格状编码,在系统性能上使用tcm编码要比未编码有3 . 3db的编码增益,另外在格状编码中加入了12路的内交织,可有效的抑制短的突发噪声对接收端viterbi解码性能的影响。