电子质量
電子質量
전자질량
ELECTRONICS QUALITY
2012年
1期
24-27
,共4页
连续相位调制%基于环的串行级联连续相位调制%交织增益%自由距离%误码平层%收敛门限
連續相位調製%基于環的串行級聯連續相位調製%交織增益%自由距離%誤碼平層%收斂門限
련속상위조제%기우배적천행급련련속상위조제%교직증익%자유거리%오마평층%수렴문한
CPM (Continuous Phase Modutation)%SC-CPM with Ring CCs%interleaver gain%free distance%error floors%convergence thresholds
连续相位调制(CPM)技术是一类恒包络的数字调制技术,CPM信号的恒包络这一特性使它们对于非线性信道和衰落信道具有很强的抵抗性.特别适用于卫星通信和移动无线通信信道。与PSK调制方式相比,CPM调制系统不仅能够提供较高的频谱效率,而且具有一定的编码增益,这是因为接收器可以利用相位成型滤波器引入的记忆特性。CPM调制系统可以分解为一个连续相位编码器(CPE)和一个无记忆调制器(MM)的级联,因此出现了多种卷积码与CPM结合的调制方案,例如串行级联连续相位调制、基于环的串行级联连续相位调制、实用的连续相位调制、卷积编码器与扩展信道编码器的串行级联,等等。其中,基于环的串行级联连续相位调制具有很好的性能,在交织增益、自由距离、误码平层和收敛门限可能成为未来连续相位编码调制系统的发展方向。
連續相位調製(CPM)技術是一類恆包絡的數字調製技術,CPM信號的恆包絡這一特性使它們對于非線性信道和衰落信道具有很彊的牴抗性.特彆適用于衛星通信和移動無線通信信道。與PSK調製方式相比,CPM調製繫統不僅能夠提供較高的頻譜效率,而且具有一定的編碼增益,這是因為接收器可以利用相位成型濾波器引入的記憶特性。CPM調製繫統可以分解為一箇連續相位編碼器(CPE)和一箇無記憶調製器(MM)的級聯,因此齣現瞭多種捲積碼與CPM結閤的調製方案,例如串行級聯連續相位調製、基于環的串行級聯連續相位調製、實用的連續相位調製、捲積編碼器與擴展信道編碼器的串行級聯,等等。其中,基于環的串行級聯連續相位調製具有很好的性能,在交織增益、自由距離、誤碼平層和收斂門限可能成為未來連續相位編碼調製繫統的髮展方嚮。
련속상위조제(CPM)기술시일류항포락적수자조제기술,CPM신호적항포락저일특성사타문대우비선성신도화쇠락신도구유흔강적저항성.특별괄용우위성통신화이동무선통신신도。여PSK조제방식상비,CPM조제계통불부능구제공교고적빈보효솔,이차구유일정적편마증익,저시인위접수기가이이용상위성형려파기인입적기억특성。CPM조제계통가이분해위일개련속상위편마기(CPE)화일개무기억조제기(MM)적급련,인차출현료다충권적마여CPM결합적조제방안,례여천행급련련속상위조제、기우배적천행급련련속상위조제、실용적련속상위조제、권적편마기여확전신도편마기적천행급련,등등。기중,기우배적천행급련련속상위조제구유흔호적성능,재교직증익、자유거리、오마평층화수렴문한가능성위미래련속상위편마조제계통적발전방향。
Continuous Phase Modulation (CPM) schemes belong to a class of constant-envelope digital modulation schemes,the constant-envelope nature of the CPM signals makes them robust for the nonlinear and fading channels, and very useful for the satellite and the mobile radio channels.Comparing to PSK modulation,CPM modulation can not only provide spectral economy,but also exhibit a "coding gain",because the decoder can exploit the memory intro- duced by the phase-shaping filters.CPM can be decomposed into a Continuous Phase Encoder (CPE) followed by a Memoryless Modulator (MM),so many modulation schemes of combination of convolutionat encoder and CPM modu- lator have arised,such as SC-CPM,SC-CPM with Convolutional Codes over Rings,P-CPM and Concatenation of convolutional endocder and extended CE,etc.Among them, SC-CPM with Ring CCs schemes can offer good perfor- mance,if the interleaver gain,free distance,error floors and convergence thresholds can be investigated in depth,it maybe the development direction of the coded CPM shemes.