摘要
阐述了将编码与调制相结合的网格编码调制与解调的基本原理 ,设计了一种四维 6 4 QAM网格编码调制电路 ,通过扩展信号集提供编码冗余度 ,并通过集分割增加信号点间的欧氏距离。为克服因信号集扩展而使信号点间距离减小所降低的功率利用率 ,采用四维网格编码的方法 ,以较低的编码冗余度实现约 4 d B的编码增益 ,克服了一般纠错编码在提高功率利用率时使频谱利用率下降的缺点。并用四进制差分编码与比特转换相结合克服了收端载波恢复的相位模糊问题 ,还提出了用 VLSI实现维特比译码的面积效率结构模型。
The fundamental theory of Trellis coded modulation which combinds encoding and decoding and demodulation is described. A 4D-64QAM trellis coded modulation circuit is also designed. We provide coding redundance by enlarging the signal set,and extend the distance between the signal points. In order to overcome the descending of utilizing rate of power which caused by the diminished distance between signals,We use four-dimentional trellis coding to achieve 4 dB coding gains with lower coding redundance.We overcome the disadvantage in some common coding and modulation system which reduces the utilizing rate of frequency spectrum when increasing the utilizing rate of power. And quaternary differential coding and bit conversion are combined to overcome the phase ambiguity problem for recovering carrier at the receiver. At the same time a class of area-efficient architectures for the VLSI implementation of Viterbi decoding are presented.
出处
《数据采集与处理》
CSCD
2002年第1期58-62,共5页
Journal of Data Acquisition and Processing
