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一种降低OFDM信号PAPR的改进PTS方法 总被引:1,自引:0,他引:1
正交频分复用(OFDM)系统的一个主要缺点是信号的峰值功率与平均功率比(PAPR)很高。本文研究了利用信号扰码技术降低OFDM系统峰均比的一种典型算法:部分传输序列法(PTS),提出了一种将随机分割方法、交织分割方法与迭代移位搜索加权因子相结合的改进PTS算法。仿真结果表明,改进后的算法在改善PAPR性能和计算的复杂度之间取得了较好的折衷。 相似文献
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传统的降低OFDM信号峰均比值的部分传输序列(PTS)方法需计算全部相位旋转因子序列所对应的峰均比值,因而计算复杂度很大.该文分析了OFDM信号峰值出现的规律,提出了搜索合乎需求的相位旋转因子序列的一般性原则,并在此基础上提出了一种全新的降低PTS方法复杂度的方案.理论分析和仿真结果表明,该方法在大幅降低系统复杂度的同时,性能损失较少. 相似文献
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PTS与限幅结合降低OFDM峰均比的改进算法 总被引:2,自引:2,他引:0
提出了一种基于部分传输序列(PTS)算法和限幅算法相结合的改进算法来降低正交频分复用(OFDM)系统的峰均功率比(PAPR).该算法先利用PTS算法对OFDM信号进行处理从而选择出限幅噪声最小的一路OFDM信号,所得OFDM信号再利用限幅法进行处理.因此可有效改善OFDM信号经过限幅引起的限幅噪声,减小限幅对OFDM系统的影响.数据仿真验证了所提方法的有效性. 相似文献
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正交频分复用(OFDM)技术的一个主要缺点是有很高的峰均功率比(PAPR),目前已有许多用来降低OFDM信号峰均功率比的方法,部分传输序列(PTS)就是其中之一,此外,它还可以改善OFDM信号的峰均功率比的性能。本文对部分传输序列(PTS)的方法进行了描述,并且提出了一种减小复杂度的方法。 相似文献
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A partial transmit sequence technique with error correction capability and low computation
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Hsin‐Ying Liang Hung‐Chi Chu Chuan‐Bi Lin Kuang‐Hao Lin 《International Journal of Communication Systems》2014,27(12):4014-4027
Orthogonal frequency division multiplexing (OFDM) is a popular transmission technique in wireless communication. Although already widely addressed in many studies, OFDM still has flaws, one of which is the occurrence of high peak‐to‐average power ratio (PAPR) in the transmission signal. The partial transmit sequence (PTS) technique is one method adopted to reduce high PAPR in OFDM systems. However, as PTS utilizes phase factors to generate multiple candidate signals, large amounts of calculation and time are required to search the candidate signal with the minimal PAPR, which will then be adopted as the final transmission signal. This paper proposes a novel PAPR reduction method, which can be applied in OFDM systems with M‐ary phase‐shift keying modulation. It not only requires less computation but also possesses error correction capabilities. More precisely, the proposed method is to divide a block‐coded modulation code into the direct sum of a correcting subcode for encoding information bits and a scrambling subcode for generating phase factors. Our proposed method is a suboptimal technique with low computation, because it uses a genetic algorithm with a partheno‐crossover operator as the transmitted signal selection mechanism. Simulation results show our proposed method has better PAPR performance than the GA‐PTS scheme. Based on the simulation results in Figures 5 and 6, it is evident that our proposed method can be employed in any OFDM system by using M‐PSK modulation.Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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Sub-optimum PTS for PAPR reduction of OFDM signals 总被引:2,自引:0,他引:2
As an attractive technique for peak-to-average power ratio (PAPR) reduction, partial transmit sequences (PTS) provides good PAPR reduction performance for orthogonal frequency division multiplexing (OFDM) signals. However, optimum PTS (OPTS) requires an exhaustive search over all combinations of allowed phase factors, resulting in the high complexity. Proposed is a sub-optimum partial transmit sequences (sub-OPTS) for PAPR reduction of OFDM signals. In sub-OPTS, both the alternate optimisation and the linear property of inverse discrete Fourier transform are employed. Simulation results show that sub-OPTS can reduce the computational complexity dramatically and achieve almost the same PAPR reduction performance compared to OPTS. 相似文献
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部分传输序列(PTS)算法能够有效地降低OFDM通信系统的平均峰值功率比(PA-PR)。文中研究了哈达码矩阵及传统的μ率压缩算法,提出了一种新的能够有效的降低PAPR算法。提出的算法是基于传统的PTS算法,利用哈达码矩阵优化部分传输序列,结合μ率压缩算法进而降低OFDM系统的PAPR值。通过实验仿真证明,文中提出的算法能够降低OFDM系统的PAPR值,而且性能更加优越于单独的μ率压缩以及传统的PTS算法,具有良好的峰值平均功率比性能。 相似文献
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Byung Moo Lee Rui J. P. de Figueiredo Youngok Kim 《Wireless Personal Communications》2012,62(2):431-442
The high peak-to-average power ratio (PAPR) of time domain signals has been a major problem in orthogonal frequency division
multiplexing (OFDM) systems, and thus various PAPR reduction algorithms have been introduced. Partial transmit sequence (PTS)
is one of the most attractive solutions because of its good performance without distortion. However, it is considered as an
impractical solution for the realization of high-speed data transmission systems due to its high computational complexity.
In this paper, a novel PAPR reduction algorithm based on a tree-structured searching technique is proposed to reduce the PAPR
with low complexity. In the proposed scheme, the computational complexity of searching process is decreased by adjusting the
size of tree with two parameters, width and depth, while preserving good performance. The simulation results show that proposed
scheme provides similar performance with optimum case with remarkably reduced computational complexity. 相似文献
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Bhalchandra M. Hardas Sanjay B. Pokle 《Journal of Communications Technology and Electronics》2017,62(12):1388-1395
Orthogonal frequency division multiplexing (OFDM) a multicarrier system [1, 2] provides base for all advanced wireless communication system. The performance of OFDM is degraded by peak-to-averagepower ratio (PAPR). High PAPR requires high power amplifiers (HPAs). The nonlinearity of the HPA exhibits amplitude and section distortions, that cause loss of orthogonality among the subcarriers, and hence, intercarrier interference (ICI) is introduced inside the transmitted signal. Not only that, high PAPR put together lands up in in-band distortion and out-of-band radiation. Rather than using HPA’s, the only way to improve performance of OFDM system is to reduce PAPR. The PAPR reduction of OFDM system gives fair reduction in PAPR under partial transmits sequence (PTS) and DCT-SLM techniques. Here in this paper we proposed a combination of PTS and DCT-SLM and an algorithm to cut back the PAPR. This hybrid combined technique reduces PAPR effectively and minimizes the complexity of PTS technique. 相似文献
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Yuh-Ren Tsai Sin-Jhih Huang 《Communications Letters, IEEE》2008,12(1):20-22
Partial transmit sequence (PTS) is one of the effective and uncomplicated PAPR reduction methods for OFDM systems. The phase factors applied in the weighting sequences are assumed to be uniformly distributed within [0, 2pi). By carefully investigating the phase distribution of OFDM signals, we proposed a modified PTS scheme outperforming the conventional PTS scheme in PAPR reduction performance. The process of the proposed scheme is the same as the conventional PTS, except for applying the new non-uniform phase factors. The required side information is the same as the conventional PTS applying uniform phase factors. 相似文献
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This work presents a novel transform kernel scrambling (TKS) scheme for reducing the peak-to-average transmitter power ratio
(PAPR) for Orthogonal Frequency Division Multiplexing (OFDM) symbols. This scrambling scheme suppresses the peak envelope
power of OFDM signals due to de-correlation among the original QAM constellation in multiple OFDM symbols via transformation.
The performance of the reduction of PAPR for OFDM signals with various unitary transform kernels is also evaluated. Since
specific unitary transform kernels in TKS processing block is only used for scrambling, no side information is required. For
the ease of presentation, the system performance has been demonstrated by a computer simulation. Simulation results confirm
the superiority of the proposed scheme in the PAPR reduction. 相似文献
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高的峰值平均功率比(Peak-to-Average Power Ratio,PAPR)是光正交频分复用(Optical Orthogonal Frequency Division Multiplexing,O-OFDM)系统的一个主要缺点,选择性映射(Selective Mapping,SLM)法能有效降低高PAPR出现的概率,但它的计算复杂度较高.一些低复杂度的SLM方案能够有效地降低复杂度,但同时也降低了PAPR的抑制性能.为了平衡这两个因素,将低复杂度SLM方案与次优选择的思想相结合,文章提出了一种联合改进的PAPR抑制方案.在低复杂度方案中,通过将一个复频域信号分为两个实信号,再利用快速傅里叶变换(Fast Fourier Transform,FFT)的平移和反折性质将其重建成新的信号,以得到更多的备选信号,如此便能降低计算复杂度.然后,再结合次优选择的思想,选择PAPR最小的一路以得到最优的PAPR抑制性能.仿真结果验证了该方案的有效性. 相似文献
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In general, there has been a trade-off between performance of peak-to-average power ratio (PAPR) reduction and computational complexity in partial transmit sequence (PTS) orthogonal frequency division multiplexing (OFDM). In this paper, a novel subblock partition scheme (SPS) for PTS OFDM is proposed and analyzed. In this scheme, signals assigned randomly in partial subbands are duplicated and concatenated repetitively to generate each subblock. The proposed scheme, therefore, has a form of concatenation of pseudo-random and interleaved SPS. As results of simulations, the proposed scheme shows almost same PAPR reduction performance as compared to the conventional pseudo-random SPS which has been known to have the best performance. However, computational complexity can be reduced extensively. Hence, the proposed scheme may be considered to be more suitable than the conventional ones for application in high speed transmission systems such as digital terrestrial broadcasting 相似文献
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In recent time orthogonal frequency division multiplexing (OFDM) has proved its mettle as a preferred choice for high speed transmission in wireless applications due its efficient mechanism to combat the inter symbol interference. However sudden high peaks in OFDM signal envelope lead to high peak to average power ratio (PAPR). Enhanced values of PAPR result into complex RF amplifier circuit with reduced efficiency. There are various methods available for PAPR reduction, out of them partial transmit sequence (PTS) is most effective proven choice for PAPR reduction. However PTS technique requires cumbersome searching of all possible phase factors to find optimal phase factor which produces lowest PAPR, the information regarding optimal phase set used at the transmitter need to be sent to the receiver as side information (SI) for decoding purpose, however transmitting SI requires additional transmission bandwidth thus reducing overall bandwidth efficiency. To reduce the exhaustive searching genetic algorithm (GA) could be used with PTS leading to GA-PTS system. In this paper a GA-PTS system is proposed which uses novel octagonal geometry for constellation extension purpose. This scheme does not require transmission of any side information for decoding purpose at receiver and at the same time GA-PTS system reduces the required number of searches. Simulations are presented to show that proposed scheme provides similar PAPR performance as conventional PTS but without need of SI transmission at reduced number of searches. 相似文献