An Enhanced Partial Transmit Sequence Based on Combining Hadamard Matrix and Partitioning Schemes in OFDM Systems

The partial transmit sequence (PTS) considered as one of the efficient approaches to restrain the high peak to average-power ratio (PAPR) in orthogonal frequency division multiplexing (OFDM) frameworks. PTS relied on partitioning the input data block and rotate them with a set of the phase vectors. In this study, a novel technique is suggested to improve the PAPR reduction performance in the PTS technique by combining Hadamard matrix and the popular kinds of the partitioning schemes interleaving scheme (IL-PTS), adjacent scheme (Ad-PTS), and pseudo-random scheme (PR-PTS). The new approach employed Hadamard matrix to change some of the subcarrier phases of the partitioning scheme in the frequency-domain. The simulation results demonstrated that the new method improved the PAPR diminishment performance better than that of the PR-PTS and Ad-PTS. However, the proposed method achieved the same PAPR performance compared with the IL-PTS scheme

A New Subblock Segmentation Scheme in Partial Transmit Sequence for Reducing PAPR Value in OFDM Systems

Partial transmit sequence (PTS) is considered an efficient algorithm to alleviate the high peak-to-average power ratio (PAPR) in orthogonal frequency division multiplexing (OFDM) systems. The PTS technique is depended on the partitioning the input data sequence into the several subblocks, and then weighting these subblocks with a group of the phase factors. There are three common types of partitioning schemes: interleaving scheme (IL-PTS), adjacent scheme (Ad-PTS), and pseudo-random scheme (PR-PTS). The three conventional partitioning schemes have various performances of the PAPR value and the computational complexity pattern which are considered the main problems of the OFDM system. In this paper, the three ordinary partition schemes are analyzed and discussed depending on the capability of reducing the PAPR value and the computational complexity. Furthermore, new partitioning scheme is introduced in order to improve the PAPR reduction performance. The simulation results indicated that the PR-PTS scheme could achieve the superiority in PAPR mitigation compared with the rest of the schemes at the expense of increasing the computational complexity. Furthermore, the new segmentation scheme improved the PAPR reduction performance better than that the Ad-PTS and IL-PTS schemes

Zero-Padding techniques in OFDM systems

Although the OFDM system has been gaining importance in recent years, the high peak to average power ratio is considered the main limitation of the system. The oversampling operation in the frequency-domain plays an essential role in the PAPR calculations precisely. The main purpose of the paper to draw attention to zero-padding methods which are used to oversampled baseband OFDM signals. Moreover, to study the influence of the zero-padding methods on the accuracy of the PAPR calculations, and the spectral spreading of the OFDM signals. Simulation results show that the zero-padding method which inserts the zeros at the center of the baseband OFDM signal is better than the other zero-padding methods in terms of both accuracy PAPR calculations and spectral distributio

Symmetrical couple f-shaped notches with high rejection c-band of uwb patch antenna

The ultra-wideband (UWB) antenna is developed to cover a broad bandwidth. ‎The UWB radio systems are interfered ‎by the ‎same ‎spectrum ‎that shared with the local bands. In this paper, two F-shaped slots on a hexagonal patch UWB antenna are demonstrated ‎‎ to realize a high band rejection. The symmetrical couple F-slots is ‎notched on the hexagonal UWB ‎ ‎patch antenna to avoid the interference ‎and ‎‎enhance the notching results at C-band. The demonstrated ‎antenna employs a coplanar waveguide ‎(CPW) technique to meet a fractional bandwidth of 126%. The proposed method validates ‎several ‎‎reconfigurations of the F-slot location on the demonstrated design. Six steps ‎parametric study are considered to test the slots location. The results of the proposed antenna with slots are introduced based on analytical, simulation, and ‎measurement. The total design size ‎‎28 mm × 43 mm × 1.6 ‎mm is simulated by ‎using CST Microwave Studio. The two F-slots are achieved the antenna gain of -6 dB, ‎return loss of -1.2 ‎dB, and ‎VSWR of 15.2 at the rejected band of 4 GHz. The ‎measurement results are compared with the simulation results between the three ‎prototypes. The current ‎distribution on the design is discussed at 2.88 GHz and 4 GHz frequencies. The radiation patterns illustrate ‎omnidirectional of H-plane and bidirectional of E-plane. This paper validates the slots locations to enhance the notches performance and reduce the interference

A New Partitioning Scheme for PTS Technique to Improve the PAPR Performance in OFDM Systems

A high peak-to-average-power ratio (PAPR) is the primary drawback faced by the orthogonal frequency division multiplexing (OFDM) systems in the practical applications. Meanwhile, Partial Transmit Sequence (PTS) is regarded as one of the efficient PAPR reduction techniques in OFDM systems. PTS technique depends on partitioning the input data into the several subblocks in the frequency-domain and weighting these subblocks by a set of phase factors in the time-domain. As the result, there are three common types of subblocks partitioning schemes have been adopted in the PTS technique, interleaving scheme, adjacent scheme, and pseudo-random scheme. Each one of the conventional partitioning schemes has PAPR reduction performance and a computational complexity level different from others. In this paper, a new subblock partitioning scheme named terminals exchanging segmentation (TE-PTS) scheme has been proposed to improve the PAPR performance in PTS technique better than that of the interleaving scheme. The simulation results and the numerical calculations indicate that the PAPR reduction capacity of the proposed scheme is superior to that of interleaving scheme without increasing the computational complexity

A New Partitioning Scheme for PTS Technique to Improve the PAPR Performance in OFDM Systems

A high peak-to-average-power ratio (PAPR) is the primary drawback faced by the orthogonal frequency division multiplexing (OFDM) systems in the practical applications. Meanwhile, Partial Transmit Sequence (PTS) is regarded as one of the efficient PAPR reduction techniques in OFDM systems. PTS technique depends on partitioning the input data into the several subblocks in the frequency-domain and weighting these subblocks by a set of phase factors in the time-domain. As the result, there are three common types of subblocks partitioning schemes have been adopted in the PTS technique, interleaving scheme, adjacent scheme, and pseudo-random scheme. Each one of the conventional partitioning schemes has PAPR reduction performance and a computational complexity level different from others. In this paper, a new subblock partitioning scheme named terminals exchanging segmentation (TE-PTS) scheme has been proposed to improve the PAPR performance in PTS technique better than that of the interleaving scheme. The simulation results and the numerical calculations indicate that the PAPR reduction capacity of the proposed scheme is superior to that of interleaving scheme without increasing the computational complexity

A New Partitioning Scheme for PTS Technique to Improve the PAPR Performance in OFDM Systems

A high peak-to-average-power ratio (PAPR) is the primary drawback faced by the orthogonal frequency division multiplexing (OFDM) systems in the practical applications. Meanwhile, Partial Transmit Sequence (PTS) is regarded as one of the efficient PAPR reduction techniques in OFDM systems. PTS technique depends on partitioning the input data into the several subblocks in the frequency-domain and weighting these subblocks by a set of phase factors in the time-domain. As the result, there are three common types of subblocks partitioning schemes have been adopted in the PTS technique, interleaving scheme, adjacent scheme, and pseudo-random scheme. Each one of the conventional partitioning schemes has PAPR reduction performance and a computational complexity level different from others. In this paper, a new subblock partitioning scheme named terminals exchanging segmentation (TE-PTS) scheme has been proposed to improve the PAPR performance in PTS technique better than that of the interleaving scheme. The simulation results and the numerical calculations indicate that the PAPR reduction capacity of the proposed scheme is superior to that of interleaving scheme without increasing the computational complexity

New low‐complexity segmentation scheme for the partial transmit sequence technique for reducing the high PAPR value in OFDM systems

Orthogonal frequency division multiplexing (OFDM) has been the overwhelmingly prevalent choice for high‐data‐rate systems due to its superior advantages compared with other modulation techniques. In contrast, a high peak‐to‐average‐power ratio (PAPR) is considered the fundamental obstacle in OFDM systems since it drives the system to suffer from in‐band distortion and out‐of‐band radiation. The partial transmit sequence (PTS) technique is viewed as one of several strategies that have been suggested to diminish the high PAPR trend. The PTS relies upon dividing an input data sequence into a number of subblocks. Hence, three common types of the subblock segmentation methods have been adopted—interleaving (IL‐PTS), adjacent (Ad‐PTS), and pseudorandom (PR‐PTS). In this study, a new type of subblock division scheme is proposed to improve the PAPR reduction capacity with a low computational complexity. The results indicate that the proposed scheme can enhance the PAPR reduction performance better than the IL‐PTS and Ad‐PTS schemes. Additionally, the computational complexity of the proposed scheme is lower than that of the PR‐PTS and Ad‐PTS schemes

A Review of Optimization Algorithms in Solving Hydro Generation Scheduling Problems

The optimal generation scheduling (OGS) of hydropower units holds an important position in electric power systems, which is significantly investigated as a research issue. Hydropower has a slight social and ecological effect when compared with other types of sustainable power source. The target of long-, mid-, and short-term hydro scheduling (LMSTHS) problems is to optimize the power generation schedule of the accessible hydropower units, which generate maximum energy by utilizing the available potential during a specific period. Numerous traditional optimization procedures are first presented for making a solution to the LMSTHS problem. Lately, various optimization approaches, which have been assigned as a procedure based on experiences, have been executed to get the optimal solution of the generation scheduling of hydro systems. This article offers a complete survey of the implementation of various methods to get the OGS of hydro systems by examining the executed methods from various perspectives. Optimal solutions obtained by a collection of meta-heuristic optimization methods for various experience cases are established, and the presented methods are compared according to the case study, limitation of parameters, optimization techniques, and consideration of the main goal. Previous studies are mostly focused on hydro scheduling that is based on a reservoir of hydropower plants. Future study aspects are also considered, which are presented as the key issue surrounding the LMSTHS problem