减少OFDMç³»ç»Ÿçš„å³°å‡åŠŸçŽ‡æ¯”çš„ç ”ç©¶ - Wen Chen - 上海交通大学

上 海 交 通 大 学 博 士 学 位 论 文减 少 OFDM 系 统 的 峰 均 功 率 比 的 研 究to determine the optimal target clipping level, and analyse the complexityof the algorithm in detail. Simulation results demonstrate that our schemecan obtain better PAPR reduction regardless of the initial clipping level.3. A method based on hexagonal constellation is proposed to reduce PAPRand to eliminate increments in average transmitted power for OFDM signals.The parametric minimum cross entropy algorithm is used to solve thesignal’s optimal expression. In order to reduce the complexity, we proposean adaptive parametric minimum cross entropy algorithm to solve the signal’soptimal expression. Compared to the existing algorithms, simulationresults show that the two algorithms can obtain better PAPR reduction.4. We propose a new method to compute the continuous time PAPR forOFDM signals. Compared to the existing methods, the method overcomesthe drawback with larger computational load and improves computationalefficiency. Our method only needs to expand and simplify N −1 Chebyshevpolynomials of the first kind, and avoids the computation of the derivativeof Chebyshev polynomials of the first kind. We also use the algorithm forpolynomial real roots isolation to efficiently find the real roots of polynomial.KEY WORDS: OFDM,SLM,PTS,TR,TI,PAPR— iv —