| Summary: | 碩士 === 國立台灣工業技術學院 === 電子工程技術研究所 === 85 === AbstractIn this thesis, we propose a
feedback-detector receiver for theasynchronous code division
multiple access ( CDMA ) system tocancel multiple-access
interference (MAI) and near-far interference.The feedback-
detector receiver utilizes decision results of stronger users
to forming decisions of the weaker users. The design
criterion and technique we used are linear minimum mean
square error (LMMSE) and decision feedback method,
respectively. The concepts of the signal waveform vector
and the projection orthogonality principle are employed in
analysis. We also developa multi-user amplitude estimator
by using a sequential method ofmoment (MM) algorithm and
geometric projection orthogonalalityconcept. MUSIC (Multiple
Signal Classification) is employed todevelop Gaussian variance
estimator. The receiver performance is studied by using
simulationexperiment. The results show that the feedback-
detector receiver performs much batter, in term of the
bit-error rate, than conventional detector and decorrelating
detector, especially when in diverse channel conditions.
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