| Summary: | 碩士 === 國立臺南大學 === 電機工程學系碩博士班 === 105 === In this thesis, a new Index Modulation (IM) technique is proposed to reduce the Peak-to-Average Power Ratio (PAPR) in the Orthogonal Frequency Division Multiplexing (OFDM) system. The mathematical software MATLAB is used as a simulation tool. In the first part of this thesis，a brief description about OFDM is discussed and its ability to improve the spectral efficiency of communication system is demonstrated. However, the Multi-Carrier Modulation technique in the OFDM system suffers a high PAPR problem, which can cause signal distortion.
A detail derivation of the maximum PAPR in the OFDM system is obtained. In the plot of a Complementary Cumulative Distribution Function (CCDF), it gives a description about PAPR in communication system. The IM technique in OFDM system can reduce PAPR. With increasing subcarriers, IM implemented by the Combination Element Method (CEM) can choose a corresponding subcarrier and transmit signal. Several methods related to reducing PAPR are also presented and compared. The MATLAB code is developed to simulate the performance of the proposed IM in OFDM system. With the different input signals, different subcarriers are used to map and transmit signal. Compared with conventional OFDM, IM is verified to provide a lower and concentrated PAPR.
Finally, it shows that IM can still maintain a good performance in reducing high PAPR in the case of increasing subcarrier number.
|
|---|
