Peak-to-Average power ratio (PAPR) Research Papers (original) (raw)

2025

Publication in the conference proceedings of EUSIPCO, Rhodes, Greece, 1998

2025

An asymmetric Doherty Power Amplifier (ADPA) is introduced using a new output combining circuit for easy of implementation with a large matching tolerance. The proposed APDA has been implemented using GaN HEMT devices at 2.6 GHz for WiMAX signal with 5MHz bandwidth and 8.3 dB peak to average power ratio. This ADPA delivers a saturated output power of 51.7 dBm and a drain efficiency of 60.4% at an average output power of 43.6 dBm. After linearization using digital feedback predistortion technique, the ADPA satisfies the linearity specification with -51.98 dBc of adjacent channel leakage ratio at 10MHz offset. To the best of our knowledge, the drain efficiency of 60.4% is the highest efficiency at 2.6GHz frequency for a WiMAX signal with 8.3dB PAPR.

2025

Abstmct-A new Linearization method for the high power amplifier modulated by a high peak-t-average ratio signal is propwed. The amplifier consists of a high power amplifier with a predistorter, a peak power limiter, and cancellation loops similar to the feedfonvard amplifier. The linearization performance is enhanced by reducing the peak input power to the ampiifler using a rate limiter and the distortion from the limited signal is restored at the cancellation sub-path. Simulation and experimental results for the amplifier module with WCDMA signal show a significant improvement of ACLR.

2025

The linear and efficient power amplification can be achieved with LINC (linear amplification with nonlinear components) amplifiers because RF power amplifiers deal with constant envelope signals in LINC systems. To increase the average efficiency in some modulation schemes with high peak to average ratio, reactance termination in combining circuit is used. However, the shunt reactance termination degrades the linearity performance of LINC. This work shows the effect of efficiency optimization with reactance termination on ACLR(Adjacent Channel Leakage Ratio) of LINC amplifiers with WCDMA modulation systems using envelope simulation.

2025, IEEE Transactions on Microwave Theory and Techniques

2025

As an efficient wireless transmission technology, multi-carrier communication find its way in many applications. However, high peak to average power ratio (PAPR) of the signal degrades the system performance. Selected mapping is a distortion-less scheme that can reduce the PAPR dramatically without spectrum loss, while its realization requires solving an integer-programming problem (NP-hard problem). To remedy this, a novel multi-objective quantum inspired evolutionary based scheme is proposed in the paper. With objective fitness function characteristics ranking, angle increment updating and information sharing, the new scheme can dramatically reduce the search iterations. Simulation results show that proposed evolutionary scheme can achieve a significant improvement with a low complexity. INDEX TERMS Physical layer techniques, evolutionary algorithm, peak to average power ratio, wireless communication. As a reliable transmission technology, multi-carrier communication has been widely used in a number of wireless standard systems [1], [2], including the IEEE 802.11 a/g/n standard, the terrestrial digital TV system DVB-T, the mobile broadband 3GPP Long Term Evolution (LTE), the wireless MAN IEEE 802.16 WiMAX (Worldwide Interoperability for Microwave Access), Ultra Wideband (UWB) and the mobile broadband wireless access (MBWA, IEEE 802.20). However, high peak-to-average power ratio (PAPR) in multi-carrier modulation (MCM) signal transmission requires that digital analog convert have long word length. If not, quantization noise might be generate, which, in turn, degrades the bit error rate performance. There have been lots of researches on reducing the PAPR performance (e.g., , [4] with the references therein), including signal distortion [5]-[7] tone injection [8]-[10], tone reservation [11], [12], and probabilistic schemes [13]-[17]. Among these schemes, selected mapping (SLM) [13]-[16] is a distortion-less scheme that can reduce the PAPR dramatically without signal and spectrum loss. It divides the input data The associate editor coordinating the review of this manuscript and approving it for publication was Jie Tang .

2025, Zenodo (CERN European Organization for Nuclear Research)

The OFDM is one of the proven multicarrier modulation techniques, which provides high spectral efficiency, low implementation complexity, less vulnerability to echoes and non-linear distortion. Apart from the above advantages presently this technique is used by almost all wireless standards and above. The one major shortcoming in the implementation of this system is the high PAPR (peak-to-average power ratio) of this system. In this paper, Irregular Low-Density-Parity Check encoder is used effectively to reduce PAPR problem& improves BER. Low Density Parity Check codes (LDPC) are promising techniques to reduce the peak-to-average power ratio (PAPR) for orthogonal frequency division multiplexing (OFDM). Almost all peak-to-average power ratio reducing techniques are degrading the BER performance. The result shows that proposed system with LDPC code improves performance of BER than without LDPC coding. The performance of system is simulated by MATLAB software.

2025

Abtract Multiple-Input Multiple-Output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) is an attractive method which has gained significant interests as a promising candidate for the 4th Generation wireless communication. However, one of the main disadvantages of MIMO-OFDM is its high peak to average power ratio (PAPR). In this paper, Partial Transmit Sequences (PTS) method introduced in the MIMO-OFDM system is presented with various simulation results to verify its effectiveness. Results shows that PTS technique improves the performance of the MIMO-OFDM system, moreover, it can be shown that with increasing the value of the number of non overlapping sub-blocks, the PAPR performance becomes better. Different kinds of PTS schemes are also plotted. The Pseudo-random seems leading the better performance.

2025

We propose and experimentally demonstrate a fiber-wireless transmission system for optimized delivery of 60-GHz radio frequency (RF) signals through picocell mobile backhaul connections. We identify advantages of 60-GHz links for utilization in short-range mobile backhaul through feasibility analysis and comparison with an alternative E-band (60-90 GHz) technology. The 60-GHz fiber-wireless-fiber setup is then introduced: two spans of up to 20 km of optical fiber are deployed and bridged by up to 4 m of wireless distance. The 60-GHz radio-over-fiber technology is utilized in the first span of fiber transmission. The system is simplified and tailored for delivery of on-off keying data signals by employing a single module for lightwave generation and modulation combined with a simplified RF downconversion technique by envelope detection. Data signals of 1.25 Gb/s are transmitted, and a bit-error-rate performance below the 7% overhead forward-errorcorrection limit is achieved for a range of potential fiber deployment scenarios. A spurious free dynamic range of 73 dB-Hz 2=3 is attained for a frequency-doubling photonic RF upconversion technique. The power budget margin that is required to extend the wireless transmission distance from 4 m to a few hundred meters has been taken into account in the setup design, and the techniques to extend the wireless distance are analyzed.

2025, IEEE Access

Wireless communication systems are being considered for medical applications to facilitate the doctors' operation and the quality of the medical procedures. A demonstrative example of this is the catheterization laboratory (CathLab), where it is desirable to replace the existent wired connections by wireless alternatives. However, there are some challenging requirements that need to be fulfilled by the wireless link, especially for intra-vascular ultra-sound (IVUS) systems, since the images acquired by the catheter should be transmitted with very high data rate and low latency, together with the highest possible amplification efficiency, to increase the battery life. The communication requirements can be achieved with latest the Wi-Fi standard IEEE 802.11ax (Wi-Fi 6). However, since Wi-Fi is based on orthogonal frequency division multiplexing (OFDM) waveforms, the transmitted signals present high envelope fluctuations, leading to amplification difficulties due to the nonlinear distortion effects and low energy efficiency. In this paper, we present an innovative amplification scheme named quantized digital amplification (QDA). It is shown that the QDA allows a quasi-linear amplification of IEEE 802.11ax signals while maintaining a very high energy efficiency. To demonstrate this, a QDA prototype and a set of performance results, regarding both the linearity of the transmitted signals and the energy efficiency, are presented. INDEX TERMS CathLab, Wi-Fi, orthogonal frequency division multiplexing, peak-to-average power ratio, power amplification.

2025, HAL (Le Centre pour la Communication Scientifique Directe)

2025, International journal of engineering research and technology

OFDM is multi-carriercommunication technique which is used in bothwired and wireless communication. OFDM is thetime domain signal which is a sum of severalsinusoids and these sinusoids makes Peak to AveragePower Ratio (PAPR). This paper represents anoverview of reduction of PAPR using all proposedtechniques. According with performance oraccording with application we can use appropriatetechnique.

2025, IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY,

The capacity of fading channels under peak and average
power constraints in the low-SNR regime is investigated.
We show that the capacity scales essentially as C ≈ A SNR \int_{1-1/A}^{1}F^{-1}(t)dt, where A is the peak-to-average power ratio
(PAPR), and F (·) is the cumulative distribution function of the
fading channel. We also prove that an ON–OFF power scheme is
sufficient to asymptotically achieve the capacity. Furthermore, by
considering the variable PAPR scenario, we generalize the scalability
of the capacity and derive the asymptotic expression for the
capacity in the low-SNR regime.

2025, IJSEE

In recent years, the increase in electricity consumption in the household sector and the increase in the purchase price of electricity have led to the creation of an energy management system in smart homes. The smart home energy management system schedules the equipment for the next 24 hours. This paper examines a smart home that incorporates new technologies like interruptible loads, electric vehicles, energy storage systems, renewable energy sources, and smart devices. In this paper, the smart home energy management system, knowing its consumption needs and the current price of electricity in the electricity market, provides the power it requires by purchasing from the power grid or using the production power of renewable energy resources. Additionally, the smart home energy management system can sell its excess production power to the grid in a few hours. This paper aims to reduce the operating costs of a smart home during the day, and it has done so in several different scenarios. The effect of charging and discharging electric vehicle, energy storage system, and renewable energy resources in reducing costs has been investigated in these scenarios. The effectiveness of the proposed plan is checked in a typical house during 24 hours. With the implementation of smart home energy management programs, the operating cost decreased from 2.575 to 0.492 during 24 hours. Also, by checking the performance of the equipment at the time of planning, the efficiency of the model is proven.

2025, Journal of King Saud University - Engineering Sciences

2025, 2010 International Conference on Intelligent and Advanced Systems

2025, IAENG International Journal of Computer Science

AbstractThis paper presents a novel precoding based hybrid multi-carrier/single-carrier (MC/SC) uplink radio access system for layered orthogonal frequency division multiple access (Layered-OFDMA) of long-term-evolution advanced... more

2025, WSEAS TRANSACTIONS on COMMUNICATIONS archive

In OFDM systems, the problems associated with a high ratio of peak-to-average power still exist. A search for a simple and practical method to reduce the ratio continues. In this paper, a robust sub-optimal tone reservation method based on iterative re-weighted least-squares minimization of infinity norm is proposed. The method is simple and has a fast quadratic convergence and per iteration complexity lower than that of the FFT, where and are, respectively, the number of reserved subcarriers, and nonzero elements in the desired peak-reducing signal. In addition, the method does not experience peak re-growth problems and achieves high PAPR reductions of 3.9 dB and 5.6 dB for 1.6% and 5% reserved subcarriers respectively. For 20% reserved subcarriers, the method reaches 7.4 dB PAPR reductions. These reductions are at a small cost of 0.6 dB increase in the average transmitted power. The PAPR reductions from the proposed method compare well with the highly slow and complex optimal tone...

2025, Microelectronics Journal

Power efficiency is an important criterion for modern communications systems. It is well known that due to its high Peak-to-Average Power Ratio (PAPR) the Orthogonal Frequency Division Multiplexing (OFDM) modulation scheme presents serious power efficiency problems related to the High Power Amplifier (HPA) of the transmitter that are critical in satellite systems like Digital Video Broadcasting Satellite to Handheld (DVB-SH). In order to improve the power efficiency we propose to apply to DVB-SH the Active Constellation Extension (ACE) algorithm as a PAPR reduction method. Additionally we also present a new ACE optimization criterion: the reduction of the cubic metric (CM). The minimization of both metrics provides an important improvement of the out of band distortion and the Output Back Off (OBO) of the amplifiers, and consequently an increase of the HPA power efficiency.

2025, International Journal of Experimental Research and Review

A low-power strategy that can manage analogue, digital, and RF functionalities on a similar chip is crucial for wireless systems. Various difficulties restrict the widespread adoption of CMOS power amplifiers despite the fact that they provide highly integrated, low-cost wireless communication. Some of the main issues with CMOS power amplifiers include non-linearity, low breakdown voltage, a lack of high-voltage capacitors, and incorrect RF models. The RF signal is amplified without distortions using a linear power amplifier (LPA), which is less effective whenever driven by constant voltage. In order to significantly enhance the effectiveness of the power amplifiers, three frequently utilised techniques—Doherty, envelope elimination and restoration (EER), and envelope tracking (ET) techniques are reviewed in this work. Results point towards ET approach as the one that is ideally suited for future mobile communication systems. The essential component of ET systems, the envelope tracking power source, is what determines how effectively the system functions. It also lists the benefits of FinFET technology over CMOS and looks at three well-liked techniques for increasing power amplifier efficiency. Considering the advent of mobile communications systems, the frequency band and peak-to-average power ratio (PAPR) are quickly growing, posing significant design issues. FinFET as an alternative may considerably reduce the chip area.

2024, GLOBECOM '03. IEEE Global Telecommunications Conference (IEEE Cat. No.03CH37489)

Efficient OFDM transmission has been limited by power amplifier (PA) non-linearity combined with OFDM's high peak-to-average power ratio (PAPR). In this paper, we show that minimizing the PAPR of an OFDM signal, subject to constraints on allowable constellation error and out-of-band noise, can be formulated as a convex optimization problem. The globally optimal solution can be calculated with low complexity using known algorithms. A system model is proposed for transmitting OFDM signals with maximum power-efficiency regardless of PA linearity. No change in receiver structure is required. Simulation results are presented for the 802.11a WLAN standard.

2024, European Journal of Advances in Engineering and Technology

Orthogonal Frequency Division Multiplexing (OFDM) is a gifted scheme to accomplish high data transmission for
high speed communication systems. Consequently, it is treated as a strong candidate for forthcoming wireless applications. Nevertheless, the foremost drawback of OFDM signal is high Peak to Average Power Ratio (PAPR), which
degrades the performance of the primary resources of the communication system. Selective Mapping (SLM) technique is the most familiar to condense the PAPR. However, conventional SLM technique requires many Inverse Fast
Fourier Transforms (IFFTs), which surges the computational complexity. Moreover, conventional SLM requires
side information, which raises the transmitting power as well as error rate. In this paper, we proposed a novel SLM
scheme using exhaustive search method to enhance the PAPR reduction performance, which requires only one IFFT
and no side information. In our work (8, 4) extended Hamming code is employed as single error correcting code.
The PAPR performance of the exhaustive search SLM and conventional SLM is compared for all possible combination of (8, 4) extended Hamming codes. Numerical results confirmation that the PAPR reduction performance of
exhaustive search SLM is superior to that of the conventional SLM.

2024, Physical Communication

2024

Classical linear amplifiers such as A, AB and B offer very good linearity suitable for RF power amplifiers. However, its inherent low efficiency limits its use especially in base-stations that manage tens or hundreds of Watts. The use of linearization techniques such as Envelope Elimination and Restoration (EER) allow an increase of efficiency keeping good linearity. This technique requires a very fast dc-dc power converter to provide variable voltage supply to the power amplifier. In this paper, several alternatives are analyzed to implement the envelope amplifier based on a cascade association of a switched dc-dc converter and a linear regulator. A simplified version of this approach is also suitable to operate with Envelope Tracking technique. I.

2024, Analysis of the opportunities for reduction of Intercarrier Interference in OFDM

In this article are described the possibilities of reduction Intercarrier Interference in OFDM. Also has made analysis of the populares methods-Frequency-domain equalization, Time-domain windowing, ICI Self-cancellation scheme, Partial... more

2024, International Journal of Computer Science and Network Security, VOL.24 No.9, September 2024

Precoding of the orthogonal frequency division multiplexing (OFDM) with Walsh Hadamard transform (WHT) is known in the literature. Instead of performing WHT precoding and inverse discrete Fourier transform separately, a product of two matrix can yield a new matrix that can be applied with lower complexity. This resultant transform, T-transform, results in T-OFDM. This paper extends the limited existing work on T-OFDM significantly by presenting detailed account of its computational complexity, a lower complexity receiver design, an expression for PAPR and its cumulative distribution function (cdf), sensitivity of T-OFDM to timing synchronization errors, and novel analytical expressions signal to noise ratio (SNR) for multiple equalization techniques. Simulation results are presented to show significant improvements in PAPR performance, as well improvement in bit error rate (BER) in Rayleigh fading channel. This paper is Part II of a three-paper series on alternative transforms and many of the concepts and result refer to and stem from results in generalized multicarrier communication (GMC) system presented in Part I of this series.

2024, Al-Qadisiyah Journal for Engineering Sciences (QJES) Scopus

Visible light communication (VLC) has gained attraction for its use in high-speed wireless connectivity leveraging LED lighting elements. Orthogonal Frequency Division Multiplexing (OFDM) is an attractive modulation scheme due to its spectral efficiency and resilience to multipath distortion. However, the nonlinear electro-optic transfer characteristics of optical components introduce signal clipping and quantization noise which corrupt OFDM signals. This paper provides an in-depth analysis of clipping and quantization noise to quantify the impact of LED nonlinearities on OFDM-based VLC system performance. Detailed mathematical models are derived for clipping distortions caused by LED optical power saturation and quantization errors from ADC/DAC finite precision in the modulator and driver circuitry. This analysis is quantified through simulations of the degradations in terms of error vector magnitude (EVM), signal-tonoise ratio (SNR) loss, and bit error rate (BER) under varying clipping ratios and quantization bit-depths. The 16-QAM OFDM transmission shows that the LED driver should possess at least 12 dB signal linear dynamic range and 3-bit quantization to restrict SNR penalty within 3 dB. Adaptive tone mapping and digital pre-distortion techniques are examined to compensate for intensity distortions enabling high-speed OFDM transmission over VLC links.

2024, International journal of Computer Networks & Communications

This paper is concerned with the performance improvement of PAPR reduction of orthogonal frequency division multiplexing (OFDM) signal using amplitude clipping & filtering based design. Note that OFDM is one of the well adept multi-carrier multiplexing transmission scheme which has been implemented in long term evolution (LTE) downlink. Nonetheless peak to average power ratio (PAPR) is the more rattling problem with OFDM, consequently in this paper a reduction procedure of the PAPR by using amplitude clipping and filtering is proposed. Here we used IIR bandpass elliptic filter after amplitude clipping to reduce the PAPR. The performance of the system in terms of bit error rate (BER) is also canvased as a new filter based clipping method. Our results show that the proposed methodology of clipping method with the IIR elliptic band pass filter significantly reduces the PAPR value.

2024, 2010 Twenty-Fifth Annual IEEE Applied Power Electronics Conference and Exposition (APEC)

Modern transmitters usually have to amplify and transmit complex communication signals with simultaneous envelope and phase modulation. Due to this property of the transmitted signal, linear power amplifiers (class A, B or AB) are usually employed as a solution for the power amplifier stage. These amplifiers have high linearity, but suffer from low efficiency when the transmitted signal has high peak-to-average power ratio. The Kahn envelope elimination and restoration (EER) technique is used to enhance efficiency of RF transmitters, by combining highly efficient, nonlinear RF amplifier (class D or E) with a highly efficient envelope amplifier in order to obtain linear and highly efficient RF amplifier. This paper presents solutions for the power supply that acts as the envelope amplifier and class E amplifier that is used as a nonlinear amplifier. The envelope amplifier is implemented as a multilevel converter in series with a linear regulator and can provide up to 100 W of peak power and reproduce sine wave of 2 MHz, while the implemented class E amplifier operates at 120 MHz with an efficiency near to 90%. The envelope amplifier and class E amplifier have been integrated in order to implement the Kahn's technique transmitter and series of experiments have been conducted in order to characterize the implemented transmitter. I.

2024, International Journal of Computer Network and Information Security (IJCNIS)

Wireless communication systems are becoming so promising day-by-day due to the mobility and the dynamicity of communication pattern. But, to fulfill the wide range of user’s demand it has become much important to use some techniques which would be most efficient in terms of bandwidth and speed. The multicarrier strategy, called as orthogonal frequency division multiplexing (OFDM) has outstanding features to fulfill these demands. Multipath fading, delay spread, frequency selective fading and inter channel interference all of these limitations of wireless communication compound it with the scarcity of bandwidth gave rise to OFDM. However, the high peak-to-average power ratio is a great problem or a barrier in OFDM which causes the signal being distorted with the insufficient power at the receiver. There are some specified techniques to minimize it. In this paper, we have used clipping and filtering methods to minimize the effect of peak-to-average power ratio.

2024

In this paper BER performance of communication system with using different modulation techniques i.e. BPSK, QPSK and GMSK in Rayleigh Fading Channel is enhanced by using LPDC encoder. Low density parity check (LDPC) codes are one of the best error correcting codes in today's coding world and are known to approach the Shannon limit. As with all other channel coding schemes, LDPC codes add redundancy to the uncoded input data to make it more immune to channel impairments. The choice of digital modulation scheme will significantly affect the characteristics and performance and resulting physical realization of a communication system. In order to choose the most suitable modulation have several criteria such as power efficiency and bandwidth efficiency and bit error rate are used for evaluation. We have describes the new combined method that consists of a cooperative approach of several different algorithms for improve the performance of system i.e. reducing BER.

2024

Wireless Broadband services heavily rely on Orthogonal Frequency Division Multiplexing (OFDM) technique. OFDM has several advantages which makes it suitable for high speed data communications. One of the major drawback of OFDM is its high peak-toaverage power ratio (PAPR). There are several methods to overcome this drawback. Partial Transmit Sequence (PTS) is one of them. In this paper, a modified version of the iterative flipping algorithm has been proposed i.e. modified flipping PTS (M-PTS) , which reduces the performance gap between the iterative flipping algorithm (I-PTS) and the conventional PTS technique. In the proposed algorithm, performance analysis has been done with considering performance/ complexity trade-off.

2024, IEEE Transactions on Vehicular Technology

This paper presents an efficient technique for reducing the bit error rate (BER) of orthogonal frequency-division multiplexing (OFDM) signals transmitted over nonlinear solid-state power amplifiers (SSPAs). The proposed technique is based on predicting the distortion power that an SSPA would generate due to the nonlinear characteristics of such devices. Similar to the selective-mapping or partial-transmit-sequence (PTS) schemes, the predicted distortion is used to select a set of phases that minimize the actual SSPA distortion. Simulation results confirmed that the signal-to-noise ratio that is required to obtain a BER of ∼10 −4 using the proposed technique is less by about 8 dB when it is compared to the standard PTS utilizing 16 partitions. Moreover, complexity analysis demonstrated that the proposed system offers a significant complexity reduction of about 60% compared to state-of-the-art methods. Index Terms-Distortion-to-signal power ratio (DSR), intermodulation distortion (IMD), orthogonal frequency-division multiplexing (OFDM), partial transmit sequence (PTS), peak-to-average power ratio (PAPR), selective mapping (SLM), solid-state power amplifiers (SSPAs).

2024, AEU - International Journal of Electronics and Communications

In this paper the use of complementary Golay sequences (CGS) for peak-to-average power ratio (PAR) reduction and forward error correction (FEC) in an orthogonal frequency division multiplexing (OFDM)-based wireless local area network (WLAN) system is explored; performance is examined and complexity issues are analyzed. We study their PAR reduction performance depending on sequence lengths and we have found that, for the case that the number of sub-carriers differs from the sequence length, some interesting relationships can still be stated. Regarding their error correction capabilities, these sequences are investigated considering M-PSK constellations applied to the OFDM signal specified in IEEE 802.11a standard. Computational load for both Golay encoding and decoding processes is addressed and we provide an exhaustive analysis of their complexity. In order to overcome memory restrictions and speed up algorithmic operations, a novel algorithm for real-time generation of the Golay Base Sequences is proposed and evaluated giving as a conclusion that these sequences can be real-time generated with actual Digital Signal Processors (DSP). Our proposal lies on an efficient permutation algorithm that obtains the current permutation without the need for generating previous ones. Its complexity is calculated and turns out to be significantly low; the advantages are specially appreciated at the decoding stage. We also introduce a hybrid solution to get a trade-off between complexity and memory requirements. Moreover, the whole system is also implemented in a DSP to validate the proposal in a prototype, where its feasibility has been confirmed.

2024, International Journal of Microwave and Wireless Technologies

ildu kim, junghwan moon, jungjoon kim, seunghoon jee, junghwan son and bumman kim This paper demonstrates a highly efficient 3-stage Doherty power amplifier (PA) employing an envelope tracking (ET) technique. The '3-stage' Doherty PA is the most efficient architecture for a high peak-to-average power ratio (PAPR) signal among the various Doherty PAs. However, because of the lower peaking biases than those of the 'N-way' Doherty PA, the proper load modulation is hard to be achieved. To get proper modulation, the peaking PAs' gate biases have been adaptively controlled using the ET technique, and the peak power and maximum efficiency characteristic along the backed-off output power region is successfully achieved. By ADS and Matlab simulations, the overall behavior of the 3-stage Doherty PA employing the ET technique has been fully analyzed. To maximize the overall efficiency of the proposed 3-stage Doherty PA, the unit PA has been designed using class F 21 PA. For verification, the amplifier is implemented using 5 W and 10 W PEP LDMOSFETs for the 802.16e mobile world interoperability for microwave access (WiMAX) at 1 GHz with a 8.5 dB PAPR. The measured drain efficiency of the proposed 3-stage Doherty PA is 55.5% at an average output power of 37 dBm, which is a 7.54 dB backed-off output power. The digital feedback predistortion (DFBPD) algorithm has been used to linearize the proposed PA considering the ET technique. After linearization, the 233.15 dB of relative constellation error (RCE) performance is achieved, satisfying the system specification. These results show that the 3-stage Doherty employing the ET technique and saturated PA is the most suitable PA for the highly efficient and linear transmitter.

2024, International Journal of Innovative Research in Technology

Over the past two decades, the rapid development of wireless communication technology has brought great convenience to people's lives and work. In the 21st century, wireless communication technologies, especially mobile communication technology, presents unprecedented development. The aim of next generation of mobile wireless communication system is to achieve ubiquitous, highquality, high-speed mobile multimedia transmission.

2024

2024, International Journal of Scientific & Technology Research

In the recent time, the speed in transmission of data over wireless communication channel is considered as the requirement in the communication world. This paper is focused on the transmission of images using Low-Density-Parity-Check (LDPC) coded Massive Multiple Input Multiple Output (MIMO) systems based on Orthogonal Frequency Division Multiplexing (OFDM) system over selective Rayleigh fading channel. The Quality objective measures and Bit Error Rate (BER) are used to examine the performance of the system. Simulation results prove that the proposed system enhances the performance of the recovered images. Also LDPC Coded Massive MIMO OFDM system gives an excellent BER performance.

2024, International Journal of Electrical and Computer Engineering (IJECE)

In this paper, a hybrid approach using clipping and companding techniques is introduced to reduce the peak to average power ratio (PAPR) of orthogonal frequency division multiplexing based differential chaos shift keying (OFDM-DCSK), which is the major drawback of the OFDM-DCSK. The hybrid function is processed at the end of the transmitter before transmitting the signal. However, there is no need for an inverse function at the receiver, which decreases the system complexity. Several techniques have been proposed in the literature for decreasing the PAPR value. Clipping and companding are active methods in terms of reducing the PAPR. Finally, the PAPR reduction and bit error rate (BER) performances are evaluated. The simulation results show that this technique gives better performance as compared with the clipping and companding techniques.

2024

The rapid increasing demand on high data rates in wireless communications systems has arisen in order to support broadband services. The 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) aims at very high peak data rates such as 1 Gbps in local areas and 100 Mbps in wide areas. LTE has adopted Orthogonal Frequency Division Multiple Access (OFDMA) as downlink and Single Carrier Frequency Division Multiple Access (SC-FDMA) as uplink for multiple access schemes. SC-FDMA has drawn great attention as an attractive alternative to OFDMA, especially in the uplink communications where lower peak-to-average power ratio (PAPR) greatly benefits the mobile terminal in terms of transmit power efficiency and reduced cost of the power amplifier. It has been adopted as the uplink multiple access scheme in 3GPP Long Term Evolution (LTE), or Evolved UTRA (E-UTRA). The SC-FDMA is almost similar to that of OFDMA systems in its complexity and it provides same throughput as that of OFDMA...

2024

The frequency spectrum has become scarce and an expensive resource limiting the bandwidth. The future systems need to be characterized by significantly enhanced spectral efficiency in order to increase link throughput and network capacity. In order to achieve high throughput and network capacity the best approach for real time application would be combining MIMO wireless technology with OFDM for next generation wireless local area networks. In the current paper a high level Matlab Simulink 4 x 4 spatially multiplexed MIMO OFDM transceiver encoded at ½ rate using 64 size FFT is designed and implemented.

2024

Orthogonal Frequency Division Multiplexing (OFDM) is a promising candidate supporting high data rates with reasonable complexity in wireless fading channels. However, a major disadvantage of OFDM is its large peak-to-average power ratio (PAPR), which significantly decreases the transmitter high power amplifier's efficiency. There are several techniques to reduce this PAPR. Almost, all of them, are either suited for specific application or works with small number of subcarriers. If these problems are overcome, then they, like PTS, usually need side-information to be transmitted along with the modified signal. A simple and efficient Hybrid OFDM Transceiver is suggested that effectively reduces PAPR. Also, system's BER is improved. Unlike PTS, no side-information for transmission is needed. Two modified algorithms for the proposed modulator are presented for which the PAPR reduction capability is either comparable or better as compared PTS.

2024, International Journal of Electrical and Computer Engineering (IJECE)

Multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) technological support for the simultaneous and frequent access by a large number of users to radio resources. For 5G cellular systems, this exhaust is not enough to provide physical layer services. An appropriate Peak-to-average power ratio (PAPR) minimization principle, which maximizes data capacity and channel utility, has been used to address this issue. In this paper, mainly focus on minimize the high PAPR of the candidate sequence of the OFDM sub-block using modified enhancement asymmetric arithmetic coding scheme (M-EAAC). According to this, circular shifting of the candidate sequence is established in the spatial circular shifting and temporal interleaving (SCS-TI) form to generated different set of conjugated phases which is multiplied with candidate sequence. Then, the transmitting antenna is identified the best lowest PAPR of the candidate sequence is chosen for entire OFDM data transmission. The simulation results conveys that the proposed SCS-TI method provide acceptable improvement in the PAPR reduction as compared with conventional selective mapping (SLM) and pseudo-random SLM (PR-SLM). Moreover, the complexity evaluation which ensure the proposed method provides better improvement at three important stages includes inverse fast Fourier transform (IFFT) operation, optimization process, and PAPR calculation at each candidate sequence.

2024, International Journal of Electronics

In this paper, a Novel Partial Transmit Sequence-based scheme is proposed, namely (N-PTS). The aim is to solve the major hindrance of high Peak to Average Power Ratio (PAPR); as well as to combat the overlapping structure issue affecting Filter Bank Multicarrier system based on the Offset Quadrature Amplitude Modulation (FBMC-OQAM). On that note, computational complexity is also reduced. The proposed scheme uses FBMC-OQAM signal in the frequency domain. To this end, the lowest PAPR value is calculated from data located in a Storage Device (SD). Accordingly, it is properly identified through its location referred to as 'Row' which consists of the Side Information (SI) to recover the original signal at the receiver. As a result, a substantial reduction in PAPR and computational complexity are achieved. Finally, it is found necessary to mention that SI is claimed not to require extra bits to be transmitted, using phase offset with Minimum Euclidian Distance (MED) criterion, while the Bit Error Rate (BER) performance remains very satisfactory.

2024, Expert Systems with Applications

In recent years, power grids have been evolving to decentralised production and control. Direct Load Control (DLC) methods are oriented to manage loads on the demand side. A DLC method based on Multi-Objective Particle Swarm Optimisation (MOPSO) algorithm is described. This method sets up the operation of the appliances when a power restriction must be accomplished. Since the method must operate in real-time, the calculations are distributed. The operation of appliances is obtained by dividing the power restriction among neighbourhoods and calculating multiple local optimisations.The method has been experimentally evaluated through simulations.

2024, Anais do 2002 International Telecommunications Symposium

In this contribution, we present a family of decoupled space-time (D-ST) equalizers for improved reception in the presence of co-channel interference (CCI) and inter-symbol interference (ISI) in mobile communication systems. Basically, a D-ST equalizer separates CCI and ISI suppression in two processing stages. In the first one, an adaptive array (AA) spatially cancels only the co-channel interferers, while in the second one an equalizer performs temporal ISI suppression. The main idea of D-ST equalization is to use all the degrees of freedom of the array to improve CCI reduction and to preserve all ISI structure of the desired signal to be better exploited by a temporal equalizer following the array. In order to accomplish this task, a canceling filter is employed to generate a filtered version of the training sequence used to cancel the user signal in array coefficient adjustment. Simulation results are presented to compare the performance of some D-ST equalizers to that of conventional spacetime structures in CCI/ISI-limited scenarios.