Wavelet Packet Modulation Research Articles

Design of WPM System using QPSK Modulation for Different Wavelets

To achieve high-speed network is a challenging task. Wavelet packet Modulation (WPM) is the promising technology for high-speed data transfer between the nodes within the network. WPM comprises of multicarrier modulation technique that overcomes the disadvantages of OFDM for efficient data transfer between the nodes of the network. The selection of proper wavelets for the WPM system is also important to achieve efficient communication between the nodes. In this paper, WPM based system has been established by using Quadrature Phase shift Keying (QPSK) modulation. In order to get a reliable and an efficient data transfer between the nodes, different wavelets were experimented by making use of the system. Almost, similar kinds of performances are observed for the wavelets (Daubechies, Haar, Symlet and Coiflet) in the proposed WPM system for values of SNR in range 0 to 20 db. If the value of SNR goes beyond 20 db then measurable differences are notable for the same wavelets in the system. Under different channel conditions, the WPM system was tested to conclude the final wavelet and channel condition for better performance of the system.

BER Performance Investigation of WPM with Unknown CSI Using Time-Domain MMSE Equalization

Wavelet Packet Modulation (WPM) is an emerging Multi-Carrier Modulation (MCM) technique regarded as a potential alternative to widely used Orthogonal Frequency Division multiplexing (OFDM). OFDM uses Cyclic Prex (CP) and can rely on one-tap equalization. Since WPM has overlapping symbols in the time domain, equalization cannot depend on the use of CP. This paper considers time-domain Minimum Mean-Square Error (MMSE) equalization for WPM with unknown Channel State Information (CSI), where equalizer filter coefficients are computed using known training sequences. The infuence of the transmission overhead due to training sequences on the Bit Error Rate (BER) performance is investigated considering quasistatic time-varying Rayleigh fading channels. Numerical results from computer simulations show that, with moderate overhead due to training sequences, BER performances are comparable with the case of known CSI. Furthermore, WPM is compared to OFDM with one-tap equalization, and is shown to provide better BER performances as compared to OFDM. Finally, this paper demonstrates improvement in Peak-to-Average Power Ratio (PAPR) of the transmitted signal using subcarrier combining for WPM in heterogeneous communication environments, where low-rate and high-rate devices share the same transmission resources.

Design and Analysis of a Wavelet Packet Modulation Based Differential Chaos Shift Keying Communication System

In this paper, a new multicarrier based DCSK system that is combined a wavelet packet modulation (WPM) with differential chaos shift keying (DCSK) and named WPM–DCSK is proposed. WPM–DCSK system is an extension of orthogonal frequency division multiplexing OFDM–DCSK system that aims to replace the fast Fourier transform in OFDM system with wavelet packet transform and improves the spectral efficiency by removing the cyclic prefix and reduced the complexity by using real operation instead of complex operation. WPM–DCSK system has all the benefit of OFDM–DCSK and furthermore improves the limitations and drawbacks of it. The data rate improvement, the energy saving improvement and data-energy- to-bit-energy-ratio factors are derived and compared with DCSK and OFDM–DCSK systems. The validity of the derived analytic expression of the bit error rate of the proposed system is confirmed by the simulation under an additive white Gaussian noise channel.

Peak-to-average power ratio reduction in wavelet packet modulation Using Binary Phase Sequence.

<p class="1">A novel method of Peak–to-Average–Power-Ratio reduction is presented in this paper using WPT for multi carrier modulationand Riemann matrix for phase sequencing in SLM. Wavelet Packet Multicarrier Modulation(WPM) is a betteralternative to the existing multicarrier transmission system,OFDM system which suffers from high PAPR.Further reduction in Peak to Average Power Ratio (PAPR)is achieved by using Wavelet Packet Modulation(WPM) with SLM technique. Classical SLM uses random phases for phase rotations which suffers from the additional load of transmitting SI(side Information) to receiver. So to overcome a novel method is proposed here which uses the principle of varying the phases of the subcarrier data block to be transmitted ,using rows of the normalised Reimann matrix as phase sequence vectors for the Selected Mapping (SLM)Technique. The generated WPM frame with minimum PAPR is selected and transmitted .The proposed system achieves a significant improvement in PAPR reduction over the OFDM-classical SLM and WPM-classical SLM.</p>

Design and implementation of Haar wavelet packet modulation based differential chaos shift keying communication system using FPGA

Design and implementation of Haar wavelet packet modulation based differential chaos shift keying communication system using FPGA

Peak-to-Average Power Ratio Reduction in Lifting Based Wavelet Packet Modulation Systems Using Differential Evolution Algorithm

Integer wavelet transform (IWT) is an alternative to fast Fourier transform (FFT) in orthogonal frequency division multiplexing (OFDM) systems. It serves implementation flexibility and performance improvement by diminishing high side lobes, sensitivity to time and frequency synchronization. However, high PAPR of the transmitted signals is also a significant problem for IWT as in FFT based OFDM. One of the methods used for reducing the peak-to-average power ratio (PAPR) is partial transmit sequences (PTS) and this method requires an exhaustive search to obtain optimum reduction. This study examines the PAPR reduction potential of differential evolution algorithm based PTS scheme in lifting based wavelet packet modulation (LBWPM) system. The simulation results indicate that remarkable PAPR reduction performance with a low computational load for LBWPM system can be achieved using the proposed differential evolution based PTS scheme.

PAPR reduction using genetic algorithm in lifting-based wavelet packet modulation systems

Wavelet packet modulation (WPM) is a potential candidate in wireless communication systems by virtue of its exibility and modular implementation capability. However, WPM suffers from high peak-to-average power ratio (PAPR), which results in signal distortion when a high-power amplier is employed at the transmitter. The partial transmit sequence (PTS) is an attractive PAPR reduction method, but its computational complexity is high. In this paper, we propose a PTS based on the genetic algorithm (GA) scheme (GA-PTS) to reduce the computational complexity of the PTS in the lifting-based WPM (LBWPM) systems. Simulation results show that the proposed GA-PTS scheme provides signicant improvement in PAPR reduction while maintaining a low computational load. The cumulative distribution function performance of the LBWPM system is better than the performance of the classical WPM.

A Novel Transceiver Architecture Based on Wavelet Packet Modulation for UWB-IR WSN Applications

In last few years, several recent developments concern a new proposed techniques of communication for WSN (Wireless Sensors Network) using a complex methods and technics. This network is considered a future platform for many applications like: medical, agriculture, industrial, monitoring and others. The challenge of this work consists in proposing a new design of transceiver for WSN based on IDWPT (Inverse Discrete Wavelet Packet Transform) in emitter and DWPT (Discrete Wavelet Packet Transform) in receiver for mono and multi users using AWGN Channel. We will propose in this paper, a new concept of impulse radio communication for multiband orthogonal communication for UWB (Ultra-wideband) applications. The main objective of this work is to present a new form of pulse communication adapted to low through-put short-range applications and is scalable according to the type of use but also the number of sensors.

PAPR Reduction Schemes for Lifting Scheme based Orthogonal Wavelet Packet Multiplexing System

Lifting scheme based orthogonal wavelet packet multiplexing (LOWPM) system can increase computation ef- ficiency and save storage space, but as a new multicarrier modulation system, it also has the problem of high peak to aver- age power ratio (PAPR). In order to reduce computational complexity and improve the effect of PAPR suppression for Partial Transmit Sequence (PTS) technology, PAPR reduction schemes based on the technology of pruning wavelet packet modulation and the improved threshold search for PTS are put forward in the paper, through proper pruning of the full-tree structure of wavelet packet modulation in the PTS to reduce the number of nodes in the system, and finally im- prove the effect of PAPR reduction, on the other hand through improving threshold search to increase processing effi- cience. Simulation results show that the proposed algorithm compared with the original algorithm has corresponding per- formance improvement, and on the condition that not to affect the original bit error rate of system, can better reduce PAPR, while decrease the computational complexity.

A Proposed Turbo Coded Wavelet Packet Modulation based MC-CDMA

A turbo coded Discrete Wavelet Packet Transform DWPT based Multicarrier CDMA system has been proposed to enhance the bit error rate and complexity of the conventional MC-CDMA which based on Fast Fourier Transform FFT over different channel models. The decoding algorithm used maxlog-MAP algorithm. The computer simulation tests show that the BER of the coded DWPT based MC-CDMA has been improved by 4 dB compared with the coded FFT based MCCDMA over Additive White Gaussian Noise AWGN and 4.5 dB over the multipath fading channel at of BER=10.

A kind of PAPR reduction method based on pruning WPM and PTS technology

Wavelet packet multicarrier system gains widespread concern because of its better resistance performance to Inter-Symbol Interference (ISI) and Inter-Carrier Interference (ICI), as well as the higher spectrum efficiency. However, multicarrier system has a high Peak to Average Power Ratio (PAPR), which will lead to many problems such as lower system performance. In order to solve the problem, a kind of PAPR reduction method based on pruning Wavelet Packet Modulation (WPM) and Partial Transmit Sequences (PTS) technology is proposed in this paper, through proper pruning of the full-tree structure of wavelet packet modulation in the PTS technology to reduce the number of nodes in the system, and finally improve the reduction effect of PAPR. Simulation results show that when Complementary Cumulative Distribution Function (CCDF) is 10−3, PTS based on pruning WPM compared with PTS technique and pruning technique has improved about 1 dB and 1.5 dB, which will not affect the system’s Bit Error Rate (BER) performance in the wavelet packet multicarrier system.

필터 설계 기법을 통한 WPM의 PAPR 감소에 관한 연구

WPM(Wavelet Packet Modulation) is multicarrier system which is suitable for high speed transmission. The main advantage of using the WPM system is the fact that the flexible system effectively can be realized by the combination of filter coefficient. On the other hand, the major problem of multicarrier system is known to be the high PAPR. In this paper we propose WPM system that has a minimum PAPR by using filter coefficient adjustment method. We first derive the filter coefficient equation and then select the coefficient that has a minimum PAPR. we conduct WPM system by using a selected coefficient and we demonstrate the system performance by using computer simulation.

Peak-to-Average Power Ratio Reduction using Artificial Bee Colony Algorithm in Wavelet Packet Modulation

Peak-to-Average Power Ratio Reduction using Artificial Bee Colony Algorithm in Wavelet Packet Modulation

Performance Evaluation of Complex Wavelet Packet Modulation (CWPM) System over Multipath Rayleigh Fading Channel

In this paper a novel multicarrier modulation system called Complex Wavelet Packet Modulation (CWPM) has been proposed. It is based on using the Complex Wavelet Transform (CWT) together with the Wavelet Packet Modulation (WPM). The proposed system has been tested for communication over flat and frequency selective Rayleigh fading channels and its performance has been compared with some other multicarrier systems. The simulation results show that the performance of the proposed CWPM system has the best performance in all types of channel considered as compared with OFDM, Slantlet based OFDM, FRAT based OFDM and WPM systems. Furthermore, the proposed scheme has less PAPR as compared with the traditional WPM multicarrier system.

Study: The Performance FFT and Wavelet Packet of OFDM Systems from through Demonstrated Numerical Examples

A major goal of the next-generation wireless communication systems is the development of a reliable highspeed wireless communication system that supports high user mobility. Multi-Carrier Modulation (MCM) technique is an attractive approach for high-speed digital radio communication systems in order to achieve a high spectral efficiency and to combat the frequency selectivity of the channel. Orthogonal frequency division multiplexing (OFDM) is a kind of MCM techniques. As proven by the success of OFDM, multicarrier modulation has been recognized as an efficient solution for wireless communications. Waveform bases other than sine functions could similarly be used for multicarrier systems in order to provide an alternative to OFDM. Wavelet Packet Modulation (WPM) was proposed as one of the multicarrier transmission methods like OFDM. Since it is a multicarrier transmission method. In this paper, we study the performance of FFT-OFDM and wavelet Packet (WP)- OFDM from through demonstrated numerical examples, and evaluation of FFT-OFDM and DWPT-OFDM in AWGN channel , Flat fading channel and Selective Fading Channel.

An Investigation on the Sensitivity of Wavelet Packet Modulation to Time Synchronization Error

Wavelet Packet based Multi-Carrier Modulation (WPMCM) offers an alternative to the well-established OFDM as an efficient multicarrier modulation technique. It has the advantage of being a generic transmission scheme whose actual characteristics can be widely customized to fulfill several requirements and constraints of advanced communication systems. In the last decades wavelets have been favorably applied in signal and image processing fields but only recently have they attracted the attention of the telecommunication community. A lot of research questions remain to be addressed before the novel WPMCM can be used in practice. One of the major concerns is the performance of WPMCM transceivers under time synchronization errors. This is important because WPMCM symbols overlap in the time domain. In this paper, we analyze the interference in WPMCM transmission caused by the time synchronization errors. The expressions for Inter Carrier Interference (ICI) and Inter Symbol Interference (ISI) in WPMCM transmission are derived and then through simulation studies, the ability of wavelet-based systems to cope with time synchronization errors is evaluated.

Performance comparison of wavelet packet transform (WPT) and FFT-OFDM system based on QAM modulation parameters in fading channels

Orthogonal Frequency Division Multiplexing (OFDM) has been widely adopted in many applications due to its good spectral performance and low sensitivity to impulse noise and multipath channels. It has been widely adopted and standardized in many applications today. It is well known in OFDM that a cyclic prefix (CP) is appended to each symbol in order to mitigate the effect of Inter-Symbol-Interference (ISI). However, this reduces the spectral efficiency. A perfect reconstruction using wavelet packet transmultiplexer in OFDM transceiver counters the degrading effect of ISI, and also conserves bandwidth. In comparison to FFT-OFDM, Wavelet Packet Modulation (WPM) offers much lower side lobes in the transmitted signal, which reduces inter carrier interference (ICI) and narrowband interference (NBI). WPM improves spectral efficiency due to the exclusion of CP. Nevertheless, it requires an efficient equalization technique to counter the ISI and ICI. Wavelet based OFDM has been suggested to improve BER performance of transceiver in wireless communication. In this paper, a study of wavelet packet transform modulation WPT-OFDM scheme is conducted, and the performance comparison is made against the traditional FFT-OFDM over various fading channels. The analysis is done using various number of modulation QAM constellation points. Specifically, the analysis is on the effect of QAM constellation points in AWGN channel, flat fading channel and frequency selective fading channels. Simulation results using QAM Modulation points (8 to 64 Point), and the BER best performance of WPT- OFDM system is when the QAM Modulation parameter (QAM = 8) in all channels.

웨이블릿 패킷 다중반송파 변조 시스템의 협대역 간섭에 대한 성능

현재 많은 광대역 전송 시스템의 변복조 방식으로 직교 주파수 분할 다중화(orthogonal frequency division multiplexing: OFDM) 방식이 널리 사용되고 있다. OFDM 방식은 기저파형으로 서로 직교하는 정현파를 사용하는 직교 파형 변조의 하나이다. 이 논문에서는 기저파형으로 정현파 대신 웨이블릿 패킷을 사용하는 웨이블릿 패킷 변조에 대해 살펴보고자 한다. 웨이블릿 패킷은 시간-주파수 2차원 평면에서 서로 다른 모양을 가질 수 있기 때문에 채널환경에 따라 그에 적합한 파형을 쉽게 설계할 수 있다. 이 논문에서는 다중반송파 변조방식의 다른 형태로서 웨이블릿 패킷 변조의 특징에 대해 살펴보고, 협대역 간섭 환경에서 대역폭을 유연하게 조절함으로써 간섭의 영향을 감소시킬 수 있음을 보이고자 한다. These days, orthogonal frequency division multiplexing (OFDM) transmission method is widely used for broadband communication systems. The OFDM, which uses sine waves as orthogonal basis functions, is one of the orthogonal waveform modulation techniques. In this paper, we investigate a wavelet packet modulation method which uses wavelet packets instead of sine waves as the basis functions. The wavelet packets may have different patterns in two dimensional time-frequency domain, and we can design the packets appropriate for the channel environments with much flexibility. In this paper, we investigate the characteristics of the wavelet packet modulation as one of the multicarrier modulation methods, And we illustrate by simulations that narrowband interference can be reduced effectively by control the bandwidth of the wavelet packets.

Wavelet packet modulation for wireless communications

As proven by the success of OFDM, multicarrier modulation has been recognized as an efficient solution for wireless communications. Waveform bases other than sine functions could similarly be used ...

Wavelet packet modulation for wireless communications

As proven by the success of OFDM, multicarrier modulation has been recognized as an efficient solution for wireless communications. Waveform bases other than sine functions could similarly be used for multicarrier systems in order to provide an alternative to OFDM. In this paper, we study the performance of wavelet packet transform modulation (WPM) for transmission over wireless channels. This scheme is shown to be overall quite similar to OFDM but with some interesting additional features and improved characteristics. A detailed analysis of the system's implementation complexity as well as an evaluation of the influence of implementation-related impairments are also reported. Copyright © 2004 John Wiley & Sons, Ltd.