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卷积码和Turbo码在视频传输中的性能比较 总被引:3,自引:0,他引:3
提出改进的数字视频传输方案和移动信道模型,分析卷积码和Trubo码在不同调制方式的性能仿真结果,得出在AWGN和衰落信道上传输DVB信号时编码方案。 相似文献
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性能接近Turbo卷积码的Turbo三维乘积码 总被引:1,自引:1,他引:0
目前一般认为采用迭代译码的Turbo卷积码适合于低码率的情况。而Tur-bo分组码,尤其是Turbo乘积码,则较适合于高码率的应用。文中使用Pyndiah提出的方法研究了Turbo三维乘积码,用试探法对分组失代译码的参数进行了优化实验结果表明,在低码率应用时,例如码率为R=0.536的Turbo三维(32,26,4)^3乘积码的性能已与C.Berrou[1]的Turbo卷积码接近,它也应是低码率纠错应用中一个有竞争力的选择。 相似文献
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文中对现有的主要Turbo码,包括并行级联卷积Turbo码、串行级联卷积Turbo码、分组乘积Turbo码,对它们的译码算法、硬件产品和在无线通信系统中的应用进行分析和介绍。 相似文献
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Turbo码是在1993年的国际通信会议(ICC’93)上由法国学者C.Berrou等人率先提出的一种新型信道编码方案。Turbo码很好地应用了香农信道编码定理中的随机性编译码条件,从而获得了接近香农理论极限的译码性能。由于其很强的抗衰落、抗干扰能力,Turbo码在INMARSAT-phoneM4系统,CDMA多用户检测和第三代移动通信系统IMT-2000中得到了广泛的应用。但Turbo码也存在着 相似文献
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Turbo码以其优异的纠错性能被应用于多领域。为了提高DVB-S系统的性能,文中将Turbo码引入了DVB-S系统。利用仿真系统,引入Turbo码与传统的系统进行了性能比较。针对两种不同译码算法,给出了两种系统在不同信噪比下的误码率曲线。实验结果表明,引入Turbo码后系统的性能有明显的提高。 相似文献
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由于大气中的雷电脉冲噪声的严重影响,当传送可靠性要求极高的数据信息时,现行甚低频通信系统难以满足要求。为了有效克服大气噪声的影响,提高甚低频通信系统的可靠性,在考虑了便于系统升级改造等因素的基础上,提出了一种适用于甚低频数据通信传输的差错控制方案。该方案采用级联码和信道交织技术,级联码内码仍用原系统的BCH(Bose-Chaudhuri-Hocquenghem)码,外码选择RS(Reed-Solomon)码,内、外码之间插入了块交织形式的交织器。为了验证方案的纠错性能,给出了基于该方案的甚低频通信系统计算机仿真方案和仿真结果。结果表明,该方案在编码增益、正确解码概率等方面具有较大优势,在系统升级改造上有一定的实用意义。 相似文献
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Subhabrata Banerjee Sudipta Chattopadhyay 《International Journal of Communication Systems》2018,31(2)
Different forms of turbo codes (TCs) have already been used in the contemporary message transferring system for transmission of the protected information because of their astonishing bit error rate (BER) behavior. However, it suffers from poor “flattening effect” performance. To overcome this limitation, component encoders having higher memory elements or more number of component encoders may be considered. At the initial segment of this article, the proposal of binary 4‐dimensional turbo code (4D‐TC) with appropriate “generator polynomial” combination and suitable interleaver arrangement has been abridged in Third‐Generation Partnership Project standard. This is an amended form of 3‐dimensional turbo code where some part of the “parity bits” is re‐encoded by the third encoder, and rest part is re‐encoded by the fourth encoder consisting of single memory component. Afterwards, performance of the proposed structure has been assessed by varying block length, number of component encoders, puncturing rate, and channel condition. At the consequent segment, “constricted upper bound” on the BER performances of the 4D‐TC has been assessed by adopting an approach called simplified augmented state diagram. Moreover, an exhaustive analysis has been performed on the novel simplified augmented state diagram approach–based 4D‐TC by fluctuating several internal parameters of the code structure like generator polynomial combination, block length, puncturing rate, interleaver combination, and permeability rate. In this regard, the existing augmented state diagram approach has been considered for comparative analysis as well. 相似文献
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本文介绍了802.16a协议中的多进制卷积Turbo码编码原理以及基于比特判决的MAP算法,并提出了一种改进的交织方案以及仿真结果. 相似文献
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