【作者】 晏颖；

【导师】 李建东；

【作者基本信息】 西安电子科技大学 ， 通信与信息系统， 2002， 硕士

【摘要】 本文首先研究了多进制正交码扩频的原理及多进制正交码扩频信号的最佳接收机模型，讨论了CODIT工程中可变速率传输的概念和原理。其次，在导频信道辅助的多进制正交码扩频系统中提出了一种可变速率传输的方案：同步信道采用固定的速率，用64位的m序列扩频，传输同步和数据信道的速率信息。数据信道采用512Kbps、256Kbps、128Kbps和64Kbps四种传输速率，分别用Walsh序列进行16进制扩频。然后讨论了发射模块和接收模块的软硬件设计与实现，并对系统在多径衰落信道中的性能进行了研究。本文还提出了一种利用计算机增强性并口实现计算机与高速分组无线网Modem连接的方法。本文的最后讨论了系统中有待进一步解决的问题。更多还原

【Abstract】 In this thesis, the principle of M-ary orthogonal spread spectrum and the optimal receiver model of M-ary orthogonal spread spectrum signal are studied firstly. The concept and principle of variable rate transmission in CODIT is discussed. Secondly, a new scheme of variable rate transmission in a pilot channel aided M-ary orthogonal spread spectrum system is presented. Pilot channel spread by a 64-bit m-sequence carries the synchronization information and rate information of data channel. Data channel spread by 16-ary orthogonal code carries data with the rate of 512kbps, 256kbps, 128kbps and 64kbps. Thirdly, the design and implementation of hardware and software of variable rate transmission are given in detail. System performance in multi-path fading channel is also studied. Then a new design of linking the computer and HSPRN modem via Enhanced Parallel Port (EPP) is presented. Finally, the problems to be solved of the system are discussed.更多还原