| Summary: | 碩士 === 元智大學 === 通訊工程學系 === 100 === In this thesis, we proposed a reduced-complexity cyclic Viterbi detectors in receiver design for Single Carrier Block Transmission system (SCBT).Especially,we focus on of TD-LTE uplink Single-Carrier Localized Frequency Division Multiple Access(SC-FDMA) system. Viterbi algorithm is a well known fast-computation scheme to implement the Maximum Likelihood Sequence Estimate (MLSE),and is often used for channel decoding , equalization, and consider to be optimal receiver design. Based on the equivalent cyclic inter-symbol interference cyclic ISI model, we develop an algorithm, named the cyclic Viterbi algorithm. The major difference between it and the traditional “linear” Viterbi algorithm is that the final state in the cyclic viterbi trellis path searching is constrained to be the same as the initial state. In so doing, the cyclic Vitebi algorithm can attain significantly superior performance to that of the other linear equalizers. However, the SC-LFDMA systems, the computational complexity of cyclic Viterbi algorithm increase exponentially with the lengthed equivalent channel length. Therefore, decision feedback operation to cyclic the cyclic viterbi receiver, In order to reduce the partial channel length and the number of states involved in the cyclic-Viterbi trellis searching. Moreover, in the new receiver we designed a frequency domain all-pass filter (FD-APF) to solve the performance degradation problem when the channel is non-minimum phase. Finally, simulation results that reduced-complexity cyclic Viterbi receiver with decision feedback and FD-APF is truly successful in reducing the while achieving a performance closed to the optimal cyclic Viterbi receiver.
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