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Histogram compensation to improve blind modulation detection in adaptive OFDM
(2009-12-01)
Lakanchanh, Donekeo
;
Yoshizawa, Shingo
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Noppanakeepong, Suthichai
;
Miyanaga, Yoshikazu
This paper proposes a blind modulation detection technique for adaptive orthogonal frequency division multiplexing (Adaptive OFDM) communications. Adaptive modulations are applied to improve communication performance in OFDM over complicated multi-path fading channels. This paper proposes a new method which reduces detection errors in blind modulation and improves communication throughput in adaptive OFDM systems. The new proposed is based on statistical methods using a combination of distance histogram and phase histogram methods. It can improve communication performance and increases a data rate by not sending side information about modulation modes. The proposed method has showed better blind detection performance at lower SNR regions than the previous method. ©2009 IEEE.
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New papr reduction in ofdm systems by hybrid algorithm of pts and appr methods
(2009-12-01)
Pradabpet, C.
;
Yoshizawa, S.
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Miyanaga, Y.
;
Dejhan, K.
In this paper, we propose a new peak to average power ratio (PAPR) reduction technique by a hybrid algorithm based on a partial transmit sequence (PTS) and adaptive peak power reduction (APPR) methods. This technique is used in a system based on orthogonal frequency division multiplexing (OFDM OFDM has orthogonally modulated sub-carriers which unexpectedly give large PAPR and tends to reduce the power efficiency of a RF amplifier. To reduce PAPR, the sequence of input data is rearranged by PTS for the reduction of PAPR and then fed to APPR process in the proposed system. The APPR method controls the peak level of the modulation signal by an adaptive algorithm. It reduces modulation signals over a predefined range. A proposed reduction method consists of these two methods and realizes both advantages at the same time. In simulation results, the proposed method shows the improvement on PAPR, PSD, and also the high performance on bit error rate of an OFDM system.
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A new weighting factor with concurrent PAPR reduction algorithm for STBC MIMO-OFDM
(2009-12-01)
Mata, Tanairat
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Boonsrimuang, Pornpawit
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Boonsrimuang, Pisit
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Kobayashi, Hideo
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. ©2009 IEEE.
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New PAPR reduction in an OFDM system using hybrid of PTS-CAPPR methods with GA coded side information technique
(2009-01-01)
Pradabpet, Chusit
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Yoshizawa, Shingo
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Miyanaga, Yoshikazu
;
Dejhan, Kobchai
In this paper, we propose a new PAPR reduction by using the hybrid of partial transmit sequences (PTS) and cascade adaptive peak power reduction (CAPPR) methods with side information (SI) technique coded by genetic algorithm (GA). These methods are used in an Orthogonal Frequency Division Multiplexing (OFDM) system. The OFDM employs orthogonal sub-carriers for data modulation. These sub-carriers unexpectedly present a large peak to average power ratio (PAPR) in some cases. A proposed reduction method realizes both the advantages of PTS and CAPPR at the same time. In order to obtain the optimum condition on PTS for PAPR reduction, a quite large calculation cost is demanded and thus it is impossible to obtain the optimum PTS in a short time. In the proposed method, by using the pseudo-optimum condition based on a GA coded SI technique, the total calculation cost becomes drastically reduced. In simulation results, the proposed method shows the improvement on PAPR and also reveals the high performance on bit error rate (BER) of an OFDM system. Copyright © 2009 The Institute of Electronics, Information and Communication Engineers.
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A new PAPR reduction in OFDM systems using PTS combined with APPR for TWTA nonlinear HPA
(2008-01-01)
Pradabpet, Chusit
;
Dejhan, Kobchai
In this paper, we propose a new Peak-to-Average Power Ratio (PAPR) reduction technique using a partial transmit sequence (PTS) combined with adaptive peak power reduction (APPR) methods. This technique is used in a system based on Orthogonal Frequency Division Multiplexing (OFDM). In order to reduce PAPR, the sequence of input data is rearranged by the PTS for the reduction of PAPR and then fed to the APPR process in the proposed system. The APPR method controls the peak level of the modulation signal by an adaptive algorithm. The proposed method shows the improvement on PAPR, on the power spectrum density (PSD) and on the high performance on bit error rate (BER) of an OFDM system.
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Proposal of simple PAPR reduction method for OFDM signal by using dummy sub-carriers
(2008-01-01)
Boonsrimuang, Pisit
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Mori, Kazuo
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Paungma, Tawil
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Kobayashi, Hideo
One of the disadvantages of using OFDM is the larger peak to averaged power ratio (PAPR) in its time domain signal as compared with the conventional single carrier modulation method. The larger PAPR signal would course the fatal degradation of bit error rate (BER) performance due to the inter-modulation noise occurring in the non-linear amplifier. To overcome this problem, this paper proposes a simple PAPR reduction method by using dummy sub-carriers, which can achieve the better PAPR performance with less computational complexity than the conventional method. This paper presents various computer simulation results to verify the effectiveness of proposed method as comparing with the conventional method in the non-linear channel. Copyright © 2008 The Institute of Electronics, Information and Communication Engineers.
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New PAPR reduction in OFDM system using hybrid of PTS-APPR methods with coded side information technique
(2008-01-01)
Pradabpet, Chusit
;
Yoshizawa, Shingo
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Miyanaga, Yoshikazu
;
Dejhantt, Kobchai
SUMMARY In this paper, we propose a new PAPR reduction by using the hybrid of a partial transmit sequences (PTS) and an adaptive peak power reduction (APPR) methods with coded side information (SI) technique. These methods are used in an Orthogonal Frequency Divi cion Multiplexing (OFDM) system. The OFDM employs orthogonal sub-carriers for data modulation. These sub-carriers unexpectedly present a large Peak to Average Power Ratio (PAPR) in some cases. In order to reduce PAPR, the sequence of input data is rearranged by PTS. The APPR method is also used to controls the peak level of modulation signals by an adaptive algorithm. A proposed reduction method consists of these two methods and realizes both advantages at the same time. In order to make the optimum condition on PTS for PAPR reduction, a quite large calculation cost must be demanded and thus it is impossible to obtain the optimum PTS. In the proposed method, by using the pseudo-optimum condition with a coded SI technique, the total calculation cost becomes drastically reduced. In simulation results, the proposed method shows the improvement on PAPR and also reveals the high performance on bit error rate (BER) of an OFDM system. Copyright © 2008 The Institute of Electronics.
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A new PAPR reduction in OFDM-WLAN systems by hybrid algorithm of PTS and APPR methods
(2007-12-01)
Pradabpet, C.
;
Yoshizawa, S.
;
Miyanaga, Y.
;
Dejhan, K.
In this paper, we propose a new PAPR reduction technique by a hybrid algorithm based on a partial transmit sequence (PTS) and adaptive peak power reduction (APPR) methods. This technique is used in a system based on Orthogonal Frequency Division Multiplexing (OFDM). OFDM has many orthogonally modulated subcarriers which unexpectedly give a large peak to average power ratio (PAPR) and tends to reduce the power efficiency of a RF amplifier. A sequence of input data is rearranged by PTS for the reduction of PAPR and then fed to APPR process in the proposed system. The APPR method controls the peak level of the modulation signal by an adaptive algorithm. It reduces modulation signals over a predefined range. A proposed reduction method consists of these two methods and realizes both advantages at the same time. In simulation results, the proposed method shows the improvement on PAPR and also the high performance on bit error rate performance of an OFDM system. ©2007 IEEE.
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PAPR reduction in OFDM systems by hybrid algorithm based on the PTS and APPR methods
(2007-12-01)
Pradabpet, Chusit
;
Miyanaga, Yoshikazu
;
Dejhan, Kobchai
In this report, we propose a new PAPR reduction technique by a hybrid algorithm based on a partial transmit sequence (PTS) and adaptive peak power reduction (APPR) method. This technique is used in a system based on Orthogonal Frequency Division Multiplexing (OFDM). OFDM has many orthogonally modulated subcarriers which unexpectedly give a large peak to average power ratio (PAPR) and tends to reduce the power efficiency of a RF amplifier. The input data using the PTS method, a sequence of input data is rearranged for the reduction of PAPR and fed to APPR process. The APPR method controls the peak level of the modulation signal based on an adaptive algorithm which reduces modulation signals over a predefined range. A proposed reduction method consists of these two methods and realizes bolt advantages at the same time. As simulation results, the proposed method shows the improvement on PAPR and also the bit error rate performance of an OFDM system.
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PAPR reduction of OFDM signal by use of DSI method with time-frequency domain swapping algorithm
(2007-01-01)
Boonsrimuang, Pisit
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Naito, Katsuhiro
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Mori, Kazuo
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Paungma, Tawil
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Kobayashi, Hideo
The main disadvantage of orthogonal frequency division multiplexing (OFDM) is the high time domain PAPR. The larger PAPR signal would fatally degrade BER performance in non-linear channels. This paper proposes an improved DSI method, which can achieve better PAPR and BER performances in the non-linear channel with less computation complexity than the conventional DSI method. The feature of proposed method is to employ the time-frequency domain swapping algorithm in the determination of frequency data for dummy sub-carriers. This paper presents various computer simulation results to verify the effectiveness of proposed DSI method. Copyright © 2007 The Institute of Electronics, Information and Communication Engineers.

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