رسالة جامعية
Efficient Maximum Likelihood Multi-User Receiver Design with Channel Dependent Scheduling for SC-LFDMA System
| العنوان: | Efficient Maximum Likelihood Multi-User Receiver Design with Channel Dependent Scheduling for SC-LFDMA System |
|---|---|
| العنوان البديل: | SC-LFDMA系統之高效率最大似然多用戶接收機設計與通道相依排程 |
| المؤلفون: | Chuan-Shun Lin, 林傳舜 |
| مرشدي الرسالة: | Jeng-Kuang Hwang, 黃正光 |
| المجموعة: | National Digital Library of Theses and Dissertations in Taiwan |
| الوصف: | 101 In this thesis, we investigate three important topics related to 4G LTE uplink SC-FDMA system, including optimal receiver algorithm design, multiuser channel and carrier frequency offset (CFO) estimation, and channel dependent scheduling. First, based on the equivalent Cyclic-ISI channel model, the performance and complexity of a Cyclic Viterbi receiver with Decision Feedback and all-pass filter are discussed in terms of the feedback memory length to Cyclic Viterbi memory length. It is shown that the full-length Cyclic Viterbi receiver’s performance is equal to the optimal cyclic maximum likelihood sequence estimator (MLSE). To reduce the receiver complexity significantly, the feedback memory length can be increased. Furthermore, using repetition coding, a low-complexity receiver structure is proposed, which consists of a common reduced-state Cyclic Viterbi receiver cooperated with parallel decision feedback filters, since this parallel architecture effectively reduces the equivalent channel memory. Second, by exploiting the LTE CAZAC sounding reference signal, we devise a FFT-based low-complexity multiuser channel estimation (MUCE) algorithm. Then it is extended to the case with residual CFOs too, and a joint CFO-MUCE estimation scheme is proposed by using the Nelder-Mead simplex method to estimate CFOs first. Moreover, in the presence of sparse channel, we elaborate the MUCE to the Tap-Selective Maximum Likelihood (TS-ML) MUCE scheme, which uses MDL criterion to detect the number of significant channel taps and their positions, leading to improved estimation performance. Finally, we treat the channel dependent scheduling (CDS) issue by dividing the total subcarriers into several chunks to be allocated to multiple for SC-FDMA uplink users. Compared to the fixed-bandwidth CDS scheme, a variable-bandwidth CDS scheme is formulated and shown to provide higher overall system capacity by allowing different number of chunks to be allocated to different user. At last, to further increase the system throughput, adaptive modulation scheme is used to choose a suitable modulation under different SNRs. |
| Original Identifier: | 101YZU05650037 |
| نوع الوثيقة: | 學位論文 ; thesis |
| وصف الملف: | 89 |
| الإتاحة: | http://ndltd.ncl.edu.tw/handle/69546896979666269705Test |
| رقم الانضمام: | edsndl.TW.101YZU05650037 |
| قاعدة البيانات: | Networked Digital Library of Theses & Dissertations |
| الوصف غير متاح. |