| Summary: | 碩士 === 中華大學 === 資訊工程學系碩士班 === 90 === Code-division multiple access (CDMA) techniques allow many users to transmit simultaneously in the same band without substantial interference by using approximately orthogonal spread-spectrum waveforms. In an OVSF-CDMA system, each user is assigned a single orthogonal variable-spreading-factor code; a higher data rate access is possible by using a lower spreading factor. In this thesis, we discuss the OVSF code management problem on Ad Hoc networks. To reduce call-blocking rate, we propose three different distributed schemes, which heavily exploit two techniques: code exchange and optimal code tree management. Simulation results demonstrate that our schemes, with the help of these techniques, dramatically reduce the call-blocking rate without suffering high overhead.
|
|---|
