Study And Implementation Of Variable Rate Transmission In High Speed Packet Radio Network

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.