Concerning with the direct sequence ( ds ) cdma system , this thesis focuses on several issues related to orthogonal spreading sequences and amc , including correlation properties of orthogonal variable - length spreading sequences and their effects on ds cdma system performance , performance of multicarrier ( mc ) ds cdma system with generalized orthogonal ( go ) sequences , adaptive modulation with throughput maximization , performance of adaptive turbo - qam coded modulation in generalized fading channel and performance of amc in wcdma high speed downlink packet access ( hsdpa ) 针对直接序列码分多址( dscdma )系统，本文主要研究了正交扩频序列和自适应调制编码若干问题，包括正交变长扩频序列的相关性及其对dscdma系统性能的影响、采用广义正交( go )序列的多载波直接序列码分多址( mcdscdma )系统性能、吞吐量最大化自适应调制、自适应turbo - qam编码调制在广义衰落信道中的性能，以及wcdma下行分组接入( hsdpa )中自适应调制与编码性能五个方面。
