This paper focus on the principles of the outer code and implementation in asic ( application specific integrated circuits ) of dvb - c ( digital vision broadcasting - cable ) channel receiver 本文着重于有线视频广播系统( dvb - c )传输系统中外码原理及其在专用集成电路芯片( asic )上的实现。
In the proposed scheme , the outer code comprising several block codes for error detection in parallel , and the inner code employing a recursive systematic convolutional ( rsc ) code for error correction , are linked by an interleaver 本文所讨论的体制中，串行级连码的外码由多个分组检错子码构成，内码是一个系统递归卷积码。
If a retransmission is needed , additional redundant bits for error correcting are sent . concatenation of an inner code and an outer code may provide a high coding gain and the capacity of a long code to correct errors 级联码是将两个或多个单码级联，在不增加译码复杂度的情况下，可以得到高的编码增益，达到与长码相同的纠错能力。
The subimage of the lowest frequency ( ll4 ) is carried out lossless compressed coding ; 2 the subimages on diagonal direction of the highest frequency ( hhl ) is abandoned and is not carried out coding , because it is of great probability for zero , and it little affects visual 其主要包括对最低频子带单独进行无损压缩编码，对最高频对角线方向子带舍去不编码。对其余各子带根据视觉特点的不同，分别分配不同的比特数并按其进行零树量化，最后再游程编码。
Compared with other space - time coding technologies , it can obtain well performance without perfect channel state information ( csi ) . in this dissertation , we look forward to improve the performance of the differential space - time system by concatenating it with an outer code and using iterative soft - decision decoding algorithm 差分空时码是一种适合未来3g 4g快变衰落信道的空时编码技术，与一般的空时码不同的是，它的译码不需要信道状态信息，但仍能保持良好的译码性能。
The main contributions of this paper are proposing the algorithm and implementation on asic of outer code in dvb - c system , especially for the design and implementation of rs decoder ip which can be implied in three hdtv channel decoder standards , also discuss the asic design skills focused on synthesis - oriented design and dft ( design for test ) 本文的主要贡献在与提出了dvb - c系统外码编解码的具体算法，并给出了具体的asic实现；提出了一种应用于hdtv信道解码的rs译码ip核的设计和实现以及验证策略；结合实际经验讨论了面向综合和测试的asic设计技巧。
