Chusit Pradabpet

A new PAPR reduction in OFDM-WLAN systems by hybrid algorithm of PTS and APPR methods

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.

New PTS Method with Coded Side Information Technique for PAPR Reduction in OFDM Systems

In this paper, we propose a new PAPR reduction by using a partial transmit sequences (PTS) method with coded side information (SI) technique. 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. In order to reduce PAPR, the sequence of input data is partitioned into disjoint sub-block of PTS. If number of sub-block increases, high efficiency of PAPR reduction can be obtained. However, a quite large calculation cost must be demanded and thus it is impossible to obtain the optimum PTS. In the proposed method, we introduce a coded side information technique assuming the pseudo-optimum condition into the PTS. The total calculation cost becomes drastically reduced and side information bits for recovering original data in demodulation. In simulation results, the proposed method demonstrated the improvement of PAPR and bit error rate (BER) performance.

New PAPR Reduction in OFDM System Using Hybrid of PTS-APPR Methods with Coded Side Information Technique

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 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. 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.

Design and implementation of biquad digital filter

This paper presents a design and implementation of biquad digital filter based on poles-zeros placement on a unit circle of z-plane. The proposed digital filter can be given three frequency-responses as lowpass filter (LPF), highpass filter (HPF) and bandpass filter (BPF) at the same time. In the design process the Matlab program was used, for real world implementation by using TMS320C31 DSP board. The experimental results shown by the dynamic signal analyzer to indicate that the obtained frequency responses give the same results as design specifications.

Phase rotation optimization in hybrid of PTS-CAPPR method by GA for PAPR reduction in OFDM systems

In this paper, we propose a new PAPR reduction using the hybrid of a partial transmit sequences (PTS) and cascade adaptive peak power reduction (CAPPR) methods with 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 consists of these two methods and realizes both advantages at the same time. The proposed method when number of sub-block increases, PAPR is getting small. However, the calculation cost of its selection must be considerably large. We introduce GA method, the total calculation cost becomes drastically reduced. The parameter for simulation used standard WLAN in IEEE 802.11a system. 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.

A New PAPR Reduction Technique for OFDM-WLAN in 802.11a Systems

In this paper, we proposed a new PAPR reduction technique using selective mapping (SLM) cascade with 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 sub-carriers which unexpectedly produce high peak to average power ratio (PAPR). The high PAPR will occasionally reach the amplifier saturation region and therefore result in signal distortion, which causes bit error rate (BER) degradation. The proposed method, a sequence of input data is rearranged by SLM for the reduction of PAPR and then fed into the APPR process in the proposed system. The APPR method controls the peak levels of the modulation signal by an adaptive algorithm. It reduces modulation signals over a predefined range. The parameter for simulation used standard WLAN in IEEE 802.11a system. In simulation results, the proposed method shows the improvement on PAPR, power spectrum density (PSD) and high performance BER compared with conventional APPR.

PAPR reduction in OFDM systems using SLM cascade with APPR methods

In this paper, we proposed a new PAPR reduction technique using selective mapping (SLM) cascade with 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 produce a peak to average power ratio (PAPR) and tend to reduce the power efficiency of a RF amplifier. A sequence of input data is rearranged by SLM for the reduction of PAPR and then fed into the APPR process in the proposed system. The APPR method controls the peak levels of the modulation signal by an adaptive algorithm. It reduces modulation signals over a predefined range. In simulation results, the proposed method has shown better PAPR reduction compared to the SLM and the APPR.

The hybrid of PTS-CAPPR methods with MA for PAPR reduction in OFDM systems

The hybrid of partial transmit sequences (PTS) and cascade adaptive peak power reduction (CAPPR) methods have been used to reduce peak to average power ratio (PAPR) of orthogonal frequency division multiplexing(OFDM) system. When number of sub-block increases, PAPR is getting small. However, the calculation cost of its selection must be considerably large. W e introduce memetic algorithm(MA), the total calculation cost becomes drastically reduced. The parameter for simulation used standard WLAN in IEEE 802.11a system. In simulation results, the proposed method shows the improvement performance PAPR, bit error rate (BER) and power spectrum density (PSD) of an OFDM system.

New hybrid of PTS-CAPPR methods using GA for PAPR reduction in OFDM systems

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 coded side information (SI) technique design 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 consists of these two methods and realizes both advantages at the same time. In order to obtain 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 designed by GA, 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.

Variable to variable crossover in GA to solve PAPR reduction in OFDM systems

The hybrid of partial transmit sequences (PTS) and cascade adaptive peak power reduction (CAPPR) methods have been used to reduce peak to average power ratio (PAPR) of orthogonal frequency division multiplexing (OFDM) system. When number of sub-block increases, PAPR is getting small. However, the calculation cost of its selection must be considerably large. We introduce variable to variable crossover in GA, the total calculation cost becomes drastically reduced. The parameter for simulation used standard WLAN in IEEE 802.11a system. In simulation results, the proposed method shows the improvement performance PAPR and bit error rate (BER) of an OFDM system.