التفاصيل البيبلوغرافية
العنوان: |
應用於高階正交振幅調變纜線通信之整合載波回復與快速多階模數盲蔽式等化器設計與FPGA實作 ; Design and FPGA Implementation of Joint Carrier Recovery and Fast MLMA Blind Equalizer for High-order QAM Cable Communications |
المؤلفون: |
陳蠡, Li, Chen |
المساهمون: |
范志鵬, 中興大學, 黃穎聰, 王欣平 |
بيانات النشر: |
電機工程學系所 |
سنة النشر: |
2012 |
المجموعة: |
National Chung Hsing University Institutional Repository - NCHUIR / 國立中興大學 |
مصطلحات موضوعية: |
Blind Equalizer, 盲蔽式等化器, Modulus, Carrier Frequency Offset, 模數, 載波頻率偏移 |
الوصف: |
本篇論文中提出了一種使用具有快速收斂特性的多階模數演算法(Multi Level Modulus Algorithm,MLMA),並應用在擁有兩級反饋式等化器(FBE,Feed-Back Equalizer)與收斂偵測器的盲蔽式等化器上,此演算法可應用於64/256/1024正交振幅調變(Quadrature Amplitude Modulation,QAM),其中藉由模數的同心圓模切割可以有效的提高錯誤係數更新的準確率,並且由兩級反饋式等化器的架構來達到降低位元錯誤率(Bit Error Rate,BER)的功能,再由收斂偵測器來切換多階模數演算法的工作模式來增快等化器收斂的速度。 收斂偵測器工作在獲取模式(Acquisition Mode)時,載波回復器(Carrier Recovery,CR)將會採用較大的更新係數來快速並且大幅度的追蹤載波頻率偏移(Carrier Frequency Offset,CFO),而當目前追蹤的頻率接近實際偏移頻率之後將會切換至追蹤模式(Tracking Mode),並改用較小的更新係數來緩慢並且小幅度的追蹤載波頻率偏移,如此一來就可以實現快速偵測載波頻率偏移並且幫助等化器快速收斂的目的。 在等化器架構方面,為了降低位元錯誤率,故採用了兩級反饋式等化器的架構,藉由第一級反饋式等化器來提高星座點收斂的正確性,而第二級反饋式等化器則可以更進一步的提高星座點的收斂準確率,使得星座點收斂的位置更靠近原始的星座點,連帶使得位元錯誤率也隨之降低。 我們不僅完成了軟體平台(Matlab)上浮點數與定點數的模擬,也更進一步的將模擬的結果實作為硬體。在硬體實作中選定了1024正交振幅調變等化器來作為實作的對象,並藉由FPGA的模擬平台(SMIMS)來驗證軟體模擬結果的正確性。 ; In this thesis, we propose an Multi-Level Modulus Algorithm(MLMA) that has fast convergence features and can be applied to the blind equalizer. We also use two-level feedback equalizers(FBE)and a convergence detector in the receiver design. This proposed MLMA algorithm can be used for 64/256/1024 Quadrature Amplitude Modulation(QAM)systems, and it seperated a single-region modulus to concentric circles of modulus, and then this work will raise updated precisions of error coefficients. The proposed two-level FBE architecture can reduce bit error rate (BER) further, and the convergence detector can switch working modes to increase the convergence speed of equalizations. When the convergence detector works in the acquisition mode, the carrier recovery loop will choose bigger updated coefficients to track a large carrier frequency offset(CFO). When the acquisition frequency offset is close to the correct carrier frequency offset, the working mode of the convergence detector will be changed to the tracking mode, and updated coefficients will be replaced with smaller updated coefficients for tracking CFO accurately. By this scheme, we can achieve a fast CFO detection and a fast convergence of equalization. In the equalizer architecture design, we use two-level FBE ... |
نوع الوثيقة: |
thesis |
اللغة: |
English |
Relation: |
http://www.airitilibrary.com/Publication/alDetailedMesh1?DocID=U0005-3105201111233500; U0005-3105201111233500; http://hdl.handle.net/11455/7317 |
الاتاحة: |
http://hdl.handle.net/11455/7317 |
Rights: |
none |
رقم الانضمام: |
edsbas.A0327726 |
قاعدة البيانات: |
BASE |