軟體定義無線電系統中數位中頻可程式化降頻器設計

Development of Digital IF Programmable Downconverter for Software Defined Radio Transceiver

巫昆霖(Kun-Lin Wu)

指導教授 ： 鄭獻勳 ； 繆紹綱

中原大學/工學院/電子工程研究所/碩士(2001年)

https://doi.org/10.6840/cycu200100454

摘要

國際通訊聯盟(ITU)所制定之IMT-2000系統目標在於建立一個可全球漫遊、跨系統、跨網路的無縫隙之第三代行動通訊標準，並須提供與現有第二代行動通訊系統相容的需求。然而不同系統間的架構存在編/解碼、解/調變、頻寬和資料傳輸速率等差異，因此第三代行動通信系統的設備需具有相容性(Compatibility)、使用彈性(Flexibility)、可重構性(Reconfigurability)和可升級性(Upgradability)的多功能需求。
　　本論文首先介紹軟體定義無線電系統，在考量現有硬體技術之限制，找出一可實現之軟體定義無線電收發機架構，再說明本論文所設計適用於軟體定義無線電收發機之數位中頻接收機，並利用串聯積分梳狀濾波器(cascaded integrator-comb; CIC)作抽選(decimation)濾波器，並加上串聯積分梳狀濾波器之補償濾波器完成數位中頻可程式化降頻器之設計。基於FPGA硬體實現的考量，將原先浮點(Floating-point)運算架構之系統以定點(Fixed-point)運算的設計來取代，評估所需運算、可能之字元長度(word length)及數位電路之複雜度，找出其最佳化之架構。最後透過MAX + PLUSⅡ完成可程式化降頻器之可共用元件電路閘層(Gate-level)的設計。
　　本論文將有助於建立更彈性化、模組化且多重標準(Multi-standard)的軟體定義無線電通訊系統。

關鍵字

串聯積分梳狀濾波器 ； 數位中頻接收機 ； 軟體定義無線電

並列摘要

The objective of the IMT-2000 system drawn up by ITU is to establish a seamless third generation mobile communication standard with the function of global roaming across any systems and networks. It also provides the compatibility with the second mobile communication systems. However, the transmission schemes, such as coding/decoding, modulation/demodulation, signal bandwidth and data transmission rates, among mobile communication systems are different. Therefore, the 3G mobile communication systems should be compatible, flexible, reconfigurable and upgradable to various mobile communication systems.
The thesis first introduces the software defined radio system, explores the practical structure of software defined radio transceiver under the limitation of existing hardware techniques and reveals the digital IF receiver technique used in this thesis. Then, we will use cascaded integrator-comb filter for decimation and its compensative filter to design the digital IF programmable downconverter. For the FPGA hardware implementation, we will replace the original floating-point operation system with the fixed-point operation. The required sampling rate, arithmetic operation, effective word length, and the complexity of digital circuits will be evaluated and optimized. Finally, we will accomplish the common component gate-level design of the programmable downconverter with MAX+PLUS II and download the programs to the ALTERA FLEX serial chips.
This thesis is very helpful to build flexible, multi-standard software defined radio communication systems.

並列關鍵字

cascaded integrator-comb filter ； digital IF receiver ； Software defined radio

參考文獻

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[7] K. Rissanen, “Technical challenges in software radio”, First European Workshop on Software Radio, Brussels, May. 1997.

[8] Noblet, C.; Aghvami, A.H., “Assessing the over-the-air software download for reconfigurable terminal”, IEE Personal Communications in the 21st Century (II), pp. 611-616, 1998.