Pornpawit Boonsrimuang

Improved PTS Method with New Weighting Factor Technique for OFDM Signal

Partial Transmit Sequence (PTS) method is a well - known method which can reduce the peak-to-average ratio (PAPR) for an OFDM signal. A major drawback of PTS method is its higher computation complexity due to the necessity of larger number of inverse fast Fourier transforms (IFFT). The PTS method with low computation complexity, called decomposition PTS sub-blocking was proposed [1] which employs the radix-*- inverse fast Fourier transform (IFFT) for the signals at the middle stages of an TV-point radix-*- IFFT and decimation in frequency (DIF) domain. This method (DIF-IFFT) can reduce the computation complexity relatively while providing PAPR reduction similar to other PTS techniques. On the other hand, PTS method can improve PAPR reduction performance very well as increasing a number of weighting factors and clusters. However, the size of side information proportionally increases as increasing the number of weighting factors or/and clutters, which are required to inform the side information to the receiver for recovering the original data. In this paper, we propose the new weighting factor technique in conjunction with D-PTS sub-blocking technique which can improve both the PAPR performance and computation complexity without any increasing of side information.

Improved PTS method with new weighting factor technique for FBMC-OQAM systems

Filter bank multi-carrier (FBMC) with offset quadrature amplitude modulation (OQAM) has been regarded as one of the candidates for next generation broadband wireless communication systems. Similar to OFDM systems, one of the major drawbacks in FBMC-OQAM systems is high peak-to-average power ratio (PAPR). To overcome this problem, Partial Transmit Sequence (PTS) method is a well — known method which can reduce the peak-to-average ratio (PAPR) for a multicarrier modulation signal. The PTS method can improve PAPR reduction performance very well as increasing the number of predetermined discrete phase factors and number of clusters. However, the side information is proportioned increasing as increased number of predetermined discrete phase factors or/and clutters that it is required to inform to the receiver for recovering the original data. In this paper, we propose the new discrete phase factor pattern which can improved the PAPR reduction performance better than conventional PTS method. This paper presents various computer simulation results to verify the effectiveness of proposed method.

A new weighting factor with concurrent PAPR reduction algorithm for STBC MIMO-OFDM

Partial Transmit Sequences (PTS) method seems to be attractive for the reduction of Peak to Average Power Ratio (PAPR) in the Orthogonal Frequency Division Multiplexing (OFDM) system, since it can obtain better PAPR property by modifying OFDM signals without any degradation of BER performance. Meanwhile it also shows the potential capability to be utilized in MIMO-OFDM system with a concurrent PAPR reduction algorithm based on the property of orthogonal Space-Time Block Coded (STBC)[1]. On the other hand, the PTS method can improve the PAPR reduction performance very well as increasing the number of weighting factors and clusters. However, the size of side information proportionally increases as increasing the number of weighting factors or/and clutters, which are required to the receiver for recovering the original data. In this paper, we propose a new determination method for the weighting factor of PTS in conjunction with the concurrent [2] algorithm for the STBC MIMO-OFDM systems, which can improve the PAPR performance, computation complexity without any increasing of side information, and improve the BER (Bit Error Rate) performance.

A low-complexity PS based radix IFFT method for PAPR reduction in OFDM systems

We have proposed one of the distortion-less PAPR reduction methods which employs the Permutation Sequence (PS) in the frequency domain with embedded side information. However, the proposed PS method has high computation complexity. To improve the computation complexity for the previous proposed PS method, this paper proposes a low-complexity PS method which can keep the better peak-to-average power ratio (PAPR). In the proposed PS method, the signals at the middle stages of an N-point radix IFFT using decimation in frequency (DIF) is considered for PS processing. This paper shows that the proposed method has a lower multiplicative complexity than conventional PS method with keeping the PAPR reduction performance. The proposed method is called PS based radix IFFT, where DIF-IFFT is assigned through different stages of the IFFT transform. This proposed method can reduce the multiplicative complexity relatively with keeping the similar PAPR reduction to other methods such as C-PTS and C-PS. The proposed method also can reduce the side information as compared with the C-PTS. This paper presents the various computer simulation results to verify the effectiveness of proposed method.

Peak-to-average power ratio reduction method for OFDM signal by using permutation sequences

Many PAPR reduction techniques for OFDM signal have been proposed up to today, which can be classified into two major methods as the distortion and distortion-less methods. The most of distortion-less methods show better PAPR performance without degradation of BER performance. This paper proposes a novel distortion-less PAPR reduction method which employs the permutation sequence in the frequency domain with embedded side information. The feature of proposed method is to achieve the better PAPR performance with very few side information for the correct demodulation of data information at the receiver. This paper presents various computer simulation results to verify the effectiveness of proposed method as comparing with the conventional OFDM method in the non-linear channel.

Proposal of D-PTS method with non-uniform weighting factor for PAPR reduction in OFDM systems

Partial Transmit Sequence (PTS) method is a well - known method which can reduce the peak-to-average ratio (PAPR) for an OFDM signal. A major drawback of PTS method is its higher computation complexity due to the necessity of larger number of inverse fast Fourier transforms (IFFT). The PTS method with low computation complexity, called decomposition PTS (D-PTS) sub-blocking was proposed [1] which employs the radix-r IFFT for the signals at the middle stages of an N-point radix-r IFFT and decimation in frequency (DIF) domain. This method can reduce the computation complexity relatively while providing PAPR reduction similar to other PTS techniques. On the other hand, PTS method can improve PAPR reduction performance very well as increasing a number of weighting factors and clusters. However, the size of side information proportionally increases as increasing the number of weighting factors or/and clusters, which are required to inform the side information to the receiver for recovering the original data. In this paper, we propose the non-uniform weighting factor technique in conjunction with D-PTS sub-blocking technique which can improve both the PAPR performance and computation complexity without any increasing of side information.

A new weighting factor of PTS OFDM with low complexity for PAPR reduction

A major drawback of Partial Transmit Sequence (PTS) method is its higher computation complexity due to the necessity of larger number of inverse fast Fourier transforms (IFFT). The PTS method with low computation complexity, called decomposition PTS sub-blocking was proposed [1] which employs the radix-r inverse fast Fourier transform (IFFT) for the signals at the middle stages of an N-point radix-r IFFT and decimation in frequency (DIF) domain. This method (DIF-IFFT) can reduce the computation complexity relatively while providing PAPR reduction similar to other PTS techniques. On the other hand, PTS method can improve PAPR reduction performance very well as increasing a number of weighting factors and clusters. However, the size of side information proportionally increases as increasing the number of weighting factors or/and clutters, which are required to inform the side information to the receiver for recovering the original data. In this paper, we propose the new weighting factor technique in conjunction with D-PTS sub-blocking technique which can improve both the PAPR performance and computation complexity without any increasing of side information.