利用FPGA晶片實現正交分頻多工調變以進行電力線通訊

Realization of Orthogonal Frequency-Division Multiplexing Modulation for Power Line Communication Using FPGA Chip

李子豪(Zi-Hao Lee)

指導教授 ： 洪穎怡

中原大學/工學院/電機工程研究所/碩士(2009年)

https://doi.org/10.6840/cycu200900401

摘要

在科技不斷進步之下，傳統家庭數位化的發展是必然的趨勢，然而，數位化家庭的佈線與架設裝置都需要消耗大量成本，不過在每個家庭中都有完善的電源設施，所以電力線可以說是一般家庭內之最佳傳輸媒介，用其進行資料傳輸、網際網路及遠端監控等工作。本文主要是利用FPGA晶片來實現正交分頻多工(OFDM)之調變以進行電力線傳輸，首先將輸入資料進行前向錯誤糾正技術(FEC)之編碼，將其結果進行正交分頻多工之調變後，以電力線為傳輸媒介來做資料傳輸，再將電力線上擷取到的資料以正交分頻多工做解調，最後再做錯誤更正碼之解碼以還原原始資料。
本文所使用的FPGA晶片為Altera公司所開發之Stratix系列實驗板，其中IFFT/FFT轉換是利用Altera公司所設計之IFFT/FFT MegaCore Function來實現。本文利用電力線作為傳輸通道時，探討調整正交分頻多工之設定，以得到較佳之結果。本文主要以改變電力線傳輸通道的多重路徑之問題作錯誤率之統計，分別為改變電力線長短與在不同位置上並聯電阻兩種方式作為測試，由測試結果可知電力線長度越長及並聯電阻值越小，其資料錯誤率就越高。而改變編碼方式、子載波數與資料傳輸次數的搭配，會使資料錯誤率降低至最小。

關鍵字

快速傅利葉轉換 ； 正交分頻多工之調變 ； FPGA晶片 ； 電力線傳輸

並列摘要

Because of the progress of science and technology, the digital improvement of traditional household is an inevitable trend. However, the wiring and device of the digital house require high cost. There is almost a perfect power facility in every household. Therefore, power line is the best transmission media applying to data communication, internet and monitoring in the remote side. This thesis mainly developed the Orthogonal Frequency Division Multiplexing Modulation (OFDM) by using Field Programmable Gate Array (FPGA) in order to accomplish power line communication. Firstly, the input data need to be encoded with Forward Error Correction (FEC) and then the results are sent to the OFDM modulation. Then the power line is used to deal with data communication which is prepared for decoding with OFDM. Finally, it has to do the decode of error code for the sake of returning original data.
In this thesis, an FPGA, which is an experiment board developed by Altera company, is used. The IFFT/FFT is conducted by IFFT/FFT MegaCore Function designed by Altera company. This thesis deals with the settings of the OFDM. This thesis mainly focuses on investigating multi-path problem of the power line communication channel in order to evaluate the accuracy. This can be achieved by varying the length of the changing power line and the parallel resistance in different positions. The results show that the data transmission error is high if the length of the power line is long and the value of the parallel resistance is small. Through changing the modulations, and sub-carriers and the data transmitted number, the data transmission error can be decreased in order to achieve the realization of power line communication tunnel with OFDM.

並列關鍵字

FPGA ； FFT ； Power Line Communication ； OFDM Modulation

參考文獻

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