Peak-to-average Power Ratio Values Research Articles

Evaluation of Joint Technique Iterative Clipping Filtering (ICF) and Neural Network Predistortion on SDR-based MIMO-OFDM System

Multiple-input, multiple-output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) is a communications technology that powers numerous modern communication systems, including 5G and WiFi-6. This technology is utilized in current communication systems due to its high performance and extensive channel capacity. MIMO-OFDM does have disadvantages, such as large Peak-to-Average Power Ratio (PAPR) values. If the signal is processed by a nonlinear Power Amplifier (PA) device, a high PAPR value signal can result in both in-band and out-of-band signal distortion. To combat high PAPR values, PAPR reduction strategies such as Iterative Clipping Filtering (ICF) are utilized. From this study, using ICF with iteration 2 and Clipping Ratios (CR) 3 and 4 can improve the system's minimum Bit Error Rate (BER) by about 22.8% and 91.1%, respectively. Choosing the correct CR will improve the system, but using the lower CR will make it worse than a system without ICF. This occurs in systems using ICF with iterations two and CR 2 and at the same SNR conditions as systems without ICF; using ICF with iterations two and CR 2 results in higher BER values. The use of Predistortion Neural Network (PDNN) can overcome this problem. By using PDNN, there is an improvement in the system where the minimum BER value can reach 0.1 × 10-5. The percentage decrease in BER from using PDNN for ICF with iterations two and CR 2, 3, and 4 is 99.88%, 99.86%, and 98.807%, respectively. Thus, the joint techniques of ICF and PDNN can significantly enhance the performance of MIMO-OFDM systems with nonlinear PA. Importantly, the experiment was conducted on an SDR device, ensuring the real-world applicability of the results.

Exploring and Analyzing a Hybrid PAPR Reduction Method for OFDM Optimization

Orthogonal Frequency Division Multiplexing (OFDM) is a effective modulation technique widely used in modern communication systems, including 5G and wireless networks because of its high spectral efficiency and robustness towards multipath fading. However, OFDM signals are characterized by a high Peak-to-Average Power Ratio (PAPR), which can severely impact the power efficiency and operational cost of these systems. This research investigates and analyse effectiveness of two conventional PAPR reduction methods that is Selective Mapping (SLM), and Partial Transmit Sequence (PTS) with incorporating their approach of PAPR reduction to develop a hybrid variant: SLM-PTS. This study utilized MATLAB simulations to implement and test each PAPR reduction technique on a standard OFDM system model. Parameters such as the number of subcarriers, oversampling factor, and modulation types were systematically varied to analyze the impact on PAPR, BER, and computational complexity. The effectiveness of each technique was measured using the Complementary Cumulative Distribution Function (CCDF) of PAPR values and BER performance under different channel conditions. Key findings reveal that hybrid techniques, particularly SLM & PTS, offer significant improvements in PAPR reduction compared to traditional methods alone, without a corresponding increase in BER or computational overhead. The research underscores the potential of hybrid PAPR reduction techniques to significantly enhance the efficiency and reliability of OFDM systems. These findings have important implications for the design and optimization of next-generation wireless communication systems, suggesting that hybrid approaches can provide a balanced solution to the longstanding issue of PAPR in OFDM transmissions. This study contributes valuable insights into the practical application of combined PAPR reduction strategies, offering a pathway toward more power-efficient and robust OFDM technologies. Keywords : OFDM, PAPR, CCDF, SLM and PTS

Dynamic thresholding logarithmic companding for PAPR reduction in MIMO-OFDM systems for 5G wireless communication

In order to advance 5G wireless communication technology, this paper presents a novel method for lowering the Peak-to-Average Power Ratio (PAPR) in Multiple-Input Multiple-Output Orthogonal Frequency-Division Multiplexing (MIMO-OFDM) systems. It is called the Dynamic Thresholding-based μ-law (DT-μ-law) logarithmic companding technique, and it greatly improves the performance of the system by effectively broadcasting data streams on a single frequency across multiple channels. This technique's ability lies in compressing the amplitude of the transmitting signal beyond a specific threshold value before the parallel-to-serial conversion block in the MIMO-OFDM system. It employs the direct insertion of an offset value into the guard bits, rather than using a step function for the amplitude reduction process, which can reduce additional system complexity and data loss during signal expansion at the receiver end. This technique is more adequately suited for dynamic data rate shifting and interference within a limited threshold value. The dynamic thresholding value (α) is determined by calculating the median and standard deviation of the μ-law companding. This ensures the effective compression of higher amplitude signals at the transmitter, using μ-law log companding. To streamline the decompanding process at the receiver, an offset is introduced, facilitating a smoother transition and reducing complexity. The results demonstrate that the proposed DT- μ-law companding technique significantly improves PAPR reduction while maintaining low Bit Error Rates (BER) and high average spectral power efficiency. This efficiency is optimal when the μ value is maintained within the range of 4–4.5. Furthermore, it was observed that an increase in the μ value corresponds to a decrease in both PAPR value and BER. Specifically, at a signal-to-noise ratio of 15.2 dB, the BER stabilizes at 10−1. Compared to existing methods like the Max-Min Decomp-SLM approach, this technique offers lower Signal-to-Noise Ratio (SNR) values, thereby enhancing spectral efficiency and maximizing data capacity.

Low PAPR Filtered OFDM using Modified Selective Mapping

Wireless Communication has been witnessing generational change in the span of eight to ten years since it came in existence. From generation 1G to 3G and from 4G to 5G the telecommunication world has seen significant improvements along with enhanced performance with every passing year. The objective of research is to comprehensive study of Filtered Orthogonal Frequency Division Multiplexing (F-OFDM) as a promising waveform option for fifth-generation (5G) communications, distinguished by its capacity to suppress out-of-band emission (OOBE) and accommodate asynchronous transmission. Though there are many advantages but the challenge of a high peak-to-average power ratio (PAPR) among new waveform candidates can’t be ignored. To address this problem, the selective mapping technique is used as a key method to alleviate the elevated PAPR trend within multicarrier systems. This research put emphasis on applying selective mapping technique to overcome the high PAPR values in an F-OFDM system with different windowed filters such as kaiser, Nuttles blackman harris and Root raised cousine followed by a proposed Modified Selective mapping technique for further improved performance in terms of PAPR for the Filtered OFDM for different window functions in comparison with the conventional OFDM system, SLM F-OFDM system. Furthermore, PAPR performance is evaluated for all the three-system using the different window techniques analyzed for both systems, both with and without the SLM technique and Modified SLM technique to mitigate the PAPR disadvantage of the Filtered OFDM system. Simulation results underscore that F-OFDM enhanced by SLM and MSLM outperforms OFDM across PAPR.

A mathematical analysis of the PAPR in the NOMA waveform using SLM algorithm for 64-QAM

In Non-Orthogonal Multiple Access (NOMA) technology, a paradigm shift in wireless communication is observed, as it allows numerous users to simultaneously transmit data over the same spectral resources in a non-orthogonal manner. Despite the advancements it brings to the table, NOMA is faced with a notable technical obstacle, that being the elevated Peak-to-Average Power Ratio (PAPR). Elevated PAPR levels can lead to less efficient use of power and a deterioration in the fidelity of the signal. We proposed a Selective Mapping (SLM) as a powerful solution to address this issue. SLM is a PAPR reduction technique that applies controlled phase rotations to the symbols of different users before transmission, aiming to minimize the PAPR of the combined signal. In the context of NOMA, the application of SLM offers several notable advantages. SLM modifies the Power Spectrum Density (PSD), leading to a more uniform and spectrally efficient power distribution over the frequency spectrum. This enhancement in spectral efficiency concurrently lowers the risk of disrupting nearby frequency channels. Moreover, SLM exerts a favorable influence on the Bit Error Rate (BER) in NOMA systems, which contributes to improved transmission accuracy. Utilizing SLM to achieve lower PAPR values significantly diminishes the probability of symbol errors, thus enhancing the dependability. Additionally, it has been observed that the method in question delivers an improvement in PAPR, BER, and PSD with gains of 2.2 dB, 4 dB, and -620 respectively, in comparison to traditional SLM techniques.

Improved Algorithm of Partial Transmit Sequence Based on Discrete Particle Swarm Optimization

Orthogonal frequency division multiplexing (OFDM) in 5G has many advantages; however, one of the disadvantages is that the superposition of a large number of subcarriers leads to a high peak-to-average power ratio (PAPR) of the transmit signal. A high PAPR results in high-power amplifier distortion and performance degradation. The partial transmit sequence (PTS) algorithm is commonly used for PAPR reduction. It enumerates all combinations of phase factors, weighs the signal using each phase factor combination, and finds the set of phase factors that minimizes the PAPR value of the OFDM signal. The advantage of the PTS is that it determines the optimal solution through enumeration; however, its major drawback is the higher complexity caused by the use of enumeration. Some studies have introduced the discrete particle swarm optimization (DPSO) algorithm instead of enumeration to determine the optimal solution of the PTS algorithm. As an excellent optimization method, the DPSO algorithm represents each individual as a solution during the optimization. Through iterative updates of the initial population, individuals in the population continuously move closer to the optimal solution. This approach significantly reduces complexity compared with the exhaustive enumeration used in the traditional PTS algorithm. However, the disadvantage of the general DPSO algorithm is that it can result in premature and early convergence, which leads to degradation of the PAPR reduction performance. In this study, we propose an improved method based on the general DPSO-based PTS algorithm, and the improved algorithm MDPSO-PTS adopts dynamic time-varying learning factors, which can find the optimal combination of phase factors more efficiently. The MDPSO-PTS algorithm expands the search space when seeking the optimal combination of phase factors. This avoids the drawback of premature convergence commonly observed in general DPSO-PTS algorithms, preventing early consideration of local optima as global optima. A comparative simulation of the improved MDPSO-PTS algorithm with the general DPSO-PTS algorithm shows that the improved algorithm has stronger PAPR reduction, whereas the complexity remains basically unchanged. A comparative simulation with the traditional PTS algorithm shows a significant reduction in complexity, with only a slight, acceptable loss of reduction performance.

Papr reduction of FBMC-OQAM signals using Phase Search-PTS and modified discrete fourier transform spreading

In this research, a novel peak-to-average power ratio (PAPR) reduction technique for filter bank multicarrier (FBMC) modulation systems is presented. With multicarrier systems like FBMC, the strategy focuses on the survival of the fittest principle to suit the value of PAPR. The Filter Bank Multicarrier with Offset Quadrature Amplitude Modulation (FBMC-OQAM) has recently captured the attention of numerous academics due to its minimal adjacent channel leakage ratio (CLR). Unfortunately, the issue of increased PAPR measurement has a negative impact on the effectiveness of the FBMC system's energy measurement. In this study, the Phase search-based Partial Transmit Sequence (PS-PTS) approach and Modified Discrete Fourier Transform Spreading (MDFT) are developed for the PAPR reduction of the FBMC-OQAM signals. The increased PAPR measurement is reduced using the PTS and MDFT with osprey optimization method, which may result in a PAPR reduction of roughly 5.1 dB as comparable to the conventional approach.

SIMULASI SKEMA UNIVERSAL FILTERED MULTI-CARRIER (UFMC) PADA SISTEM KOMUNIKASI DIGITAL

Universal Filtered Multi-Carrier (UFMC) is a multi-carrier modulation scheme that is an alternative to the Orthogonal Frequency Division Multiplexing (OFDM) scheme currently used in 4G communication systems and wireless local area networks (WLAN). The weakness of OFDM lies in the high peak-to-average power ratio (PAPR) value and out-of-band (OOB) emission which can cause interference between carriers. UFMC is one of the schemes used to overcome the weaknesses of OFDM. This research aims to study the performance of UFMC for data transmission on AWGN channel with 256-QAM, 1024-QAM, and 4096-QAM modulation. In addition, 256-point, 512-point, and 1024-point FFTs were also used to see the effect on the achievable bit error rate (BER) and PAPR value. The simulation results show that for all simulated FFT sizes and QAM values, 256-QAM produces the lowest BER value. Using a 1024-point FFT, a BER of 10-3 can be achieved with an SNR of 20 dB. The lowest PAPR value obtained in the simulation is 7.1891 dB.

LiNEV: Visible Light Networking for Connected Vehicles

DC-biased optical orthogonal frequency division multiplexing (DCO-OFDM) has been introduced to visible light networking framework for connected vehicles (LiNEV) systems as a modulation and multiplexing scheme. This is to overcome the light-emitting diode (LED) bandwidth limitation, as well as to reduce the inter-symbol interference caused by the multipath road fading. Due to the implementation of the inverse fast Fourier transform, DC-OFDM suffers from its large peak-to-average power ratio (PAPR), which degrades the performance in LiNEV systems, as the LEDs used in the vehicles’ headlights have a limited optical power-current linear range. To tackle this issue, discrete Fourier transform spread-optical pulse amplitude modulation (DFTS-OPAM) has been proposed as an alternative modulation scheme for LiNEV systems instead of DCO-OFDM. In this paper, we investigate the system performance of both schemes considering the light-emitting diode linear dynamic range and LED 3 dB modulation bandwidth limitations. The simulation results indicate that DCO-OFDM has a 9 dB higher PAPR value compared with DFTS-OPAM. Additionally, it is demonstrated that DCO-OFDM requires an LED with a linear range that is twice the one required by DFTS-OPAM for the same high quadrature amplitude modulation (QAM) order. Furthermore, the findings illustrate that when the signal bandwidth of both schemes significantly exceeds the LED modulation bandwidth, DCO-OFDM outperforms DFTS-OPAM, as it requires a lower signal-to-noise ratio at a high QAM order.

Low-PAPR OFDM Waveform Design for Radar and Communication Systems

In this correspondence we address the problem of designing OFDM waveforms with low peak-to-average power ratio (PAPR) for joint radar and communication (JRC) applications. The design problem is formulated as the minimization of PAPR with the constraint that the integrated periodic autocorrelation sidelobe level is zero. We propose an iterative algorithm based on the majorization-minimization (MM) technique to solve this design problem. The proposed algorithm yields OFDM waveforms with PAPR values close to one. The algorithm can also be used to design waveforms with spectral nulls. In extensive numerical simulations we compare the performance of our algorithm with that of a recently proposed benchmark.

Deep Unfolding Network for PAPR Reduction in Multicarrier OFDM Systems

In this letter, we propose a Deep Unfolding Network called PR-DUN to reduce the peak-to-average power ratio (PAPR), which is a thorny problem in Orthogonal Frequency-Division Multiplexing (OFDM) systems. The proposed multi-layer model is constructed by unrolling an iterative algorithm resulting in layers with trainable parameters, which are optimized to minimize a loss function related to the PAPR value. The deep unfolding model uses the backpropagation algorithm to transfer gradients backwards to adjust parameters. Furthermore, the proposed scheme can accommodate any transmit power constraint, and therefore can control the power increase caused by the auxiliary signal. Simulation results show that the proposed PR-DUN model achieves a larger PAPR reduction and a smaller bit error rate while being less computationally intensive than related solutions.

Trade-offs in the performance of a Free Space Optical communication system employing DCO-OFDM transmission with a PAPR-dependent DC-bias

Free Space Optical (FSO) communication technology has gained popularity because of its high bandwidth, which supports high-speed data transmission. Despite its merits over Radio Frequency technology, the FSO system performance is restricted by the combined impact of beam divergence, beam scintillation, and beam-wander effects triggered by atmospheric turbulence. A Gamma–Gamma probability density function (PDF) channel model is employed to model the irradiance fluctuations due to turbulence. In this paper, we evaluate the performance metrics of a FSO link employing the Direct Current-biased Optical Orthogonal Frequency Division Multiplexing (DCO-OFDM) modulation technique for different turbulent conditions. In our paper, we determine the DC-bias, which is proportional to peak-to-average-power ratio (PAPR) and a preclipping factor of nclip (<1) in order to reduce the transmitted optical power of the DCO-OFDM signal. We evaluate the average bit error rate (BER) and outage probability of the FSO link by considering the impact of system design parameters related to the OFDM signal, laser beam, and atmospheric turbulence on the received signal. Numerical simulation results show that, depending on the chosen values of PAPR and preclipping, an FSO link can experience either a power saving or a power penalty, for meeting the BER requirement. It is further demonstrated that trade-offs in performance at various levels exist between data transmission rate (QAM size), system power efficiency (preclipping), signal-PAPR and link-span to ensure target signal quality (BER and Outage). Under turbulence, the link with a longer span not only incurs a power penalty but also suffers from a reduced operating range by 3–4 dB.

Maximal-Minimum hybrid approach with decomposed SLM technique for 5G UFMC system PAPR reduction

The Universal Filtered Multi-carrier (UFMC) system's low latency, minimal out-of-band, and low frequency offset support high spectral efficiency and impact 5 G cellular networks. Due to its high peak-to-average power ratio (PAPR), the system's performance is severely degraded. This paper proposes a hybrid Maximal-Minimum approach with decomposed selective mapping to minimize PAPR constraints for 5 G UFMC systems. The complex signal is decomposed into real and imaginary branches, allowing the inverse fast Fourier transform (IFFT) operation. In each branch, different phase vectors are mixed with real and imaginary terms. The FIR response is based on individually optimized PAPR values, which are then copied for transmission. Simulations showed that the proposed method reduced PAPR by optimizing the weighting factor within the Out of Band (OoB) range. It is superior in Bit Error rate (BER)-wise, reduction as compared with selective mapping (SLM) and decomposed-UFMC-SLM.

Experimental Demonstration of Constant-Envelope OFDM to Reduce Intermodulation Impairments and Increase Robustness Against Fiber Nonlinearities

Direct detection optical orthogonal frequency division multiplexing (DDO-OFDM) systems have been proposed as a well-suited solution for cost-sensitive applications, but also for metro/regional optical links. In this article, we experimentally demonstrate tolerance enhancements of constant-envelope OFDM (CE-OFDM) signals towards Mach–Zehnder modulator (MZM) intermodulation impairments and fiber nonlinear Kerr effects. The additional tolerance is achieved by the reduced peak-to-average power ratio (PAPR) of CE-OFDM signals, unlike conventional OFDM signals that inherently possess high PAPR values and therefore, are prone to distortions induced by the above-mentioned impairments. The experiments show that the transmission of CE-OFDM signals with PAPR <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$=3$</tex-math></inline-formula> dB over 1000 km of dispersion-uncompensated standard single-mode fiber (SSMF) is successfully accomplished. The proper choice of the MZM bias point, as well as the electrical phase modulation index, provides link length enlargements at the same bit error rate. An enlargement around 320 km of SSMF was achieved with an optical launch power of 10 dBm and with a guard-band of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\approx 16\%$</tex-math></inline-formula> of the signal bandwidth when compared to conventional DDO-OFDM systems.

Hybrid clipping and companding techniques based peak to average power ratio reduction in orthogonal frequency division multiplexing based differential chaos shift keying system

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.

Performance improvement on spectral efficiency and peak to avearge power reduction for 5G system

&lt;span&gt;Filter bank multicarrier with offset quadrature amplitude modulation (FMBC/OQAM) system which can offer higher data rate 1 Gbps and improved bandwidth efficiency because of not require of cyclic prefix (CP) to avoid interference from the adjacent channels compared to fourth generation (4G) orthogonal frequency division multiplexing (OFDM) and other wireless systems. Because of these advantages FBMC/OQAM are used in fifth generation (5G) technology. In this FBMC/OQAM system, bandwidth capacity will be further increased by using multiple input multiple output (MIMO) channel. But in our proposed scheme we can use hyper–MIMO channel, in which at base station (BS) more number of transmitting antennas are used that for the improve the spectral efficiency performance better than traditional MIMO channel. But the most important drawback of hyper MIMO FBMC/OQAM is the higher peak to average-power ratio (PAPR) that degrade overall system performance in 5G. In 4G technology, to reduce PAPR a number of techniques are used. In our proposed system we can use mu-law non-linear companding technique and precoding discrete cosine transform (DCT) to reduce PAPR value for multicarrier modulation system compare to other systems.&lt;/span&gt;

Hybrid-Domain Evaluation PTS with Adaptive Selection Methods for PAPR Reduction

The partial transmit sequence (PTS) technique is a fairly suitable scheme to mitigate the high peak-to-average power ratio (PAPR) problem inherent in 5G multicarrier systems, especially considering a high-order QAM modulation design. However, the high computational complexity level and the speed of the convergence for optimizing the phases of the transmitting signal restrict this technique in practical applications. In this paper, a low-complexity frequency-domain-evaluated PTS (F-PTS) based on a spacing multiobjective (SMO) processing algorithm is proposed to reduce the PAPR values. The PAPR performance are accurately predicted in terms of modifying relative dispersion in the frequency domain. As a result, the complexity of searching the optimal phase factors and IFFT computing is simplified. Moreover, a frequency-domain- and time-domain-evaluating PTS (FTD-PTS) is employed to search the optimal solution with a reasonable complexity. Simulation results verify that the operation rate of F-PTS is significantly improved after transferring the exhaustive search strategy of PTS into the SMO algorithm, and the F-PTS PAPR reduction performance is just 0.3 dB away from theoretical optimal performance. The FTD-PTS spends an acceptable operation rate to obtain optimal PAPR reduction performance, which subtracts 0.5 and 0.6 dB more than PSO-PTS and conventional PTS at CCDF=10−3, respectively.

Performance Analysis of FS-FBMC/OQAM System Using Turbo and LDPC Codes

Filter Bank Multicarrier (FBMC) with offset QAM (OQAM) is a possible waveform candidate for 5G and future wireless systems and standards. FBMC is realized using either polyphase network (PPN)-FFT or Frequency Spread (FS)-FBMC. In this paper, channel coding schemes such as turbo codes and low-density parity check (LDPC) codes were investigated in terms of their peak-to-average power ratio (PAPR) and bit-error-rate (BER) reduction performances for FS-FBMC/OQAM and Orthogonal Frequency Division Multiplexing (OFDM) systems in additive white Gaussian noise (AWGN) channel. Simulation results show that turbo coded and LDPC coded FS-FBMC/OQAM systems performed better than turbo coded and LDPC coded OFDM systems in terms of BER performance. Also, LDPC coded FS-FBMC/OQAM system because of its adequate BER performance, reasonable PAPR performance, and reduced computational complexity was found to be an appropriate choice among other systems for 5G and future wireless networks. It was also found that incorporating channel coding resulted in a very large coding gain with only a minor rise in the system's PAPR value.

Performance Analysis of PTS PAPR Reduction Method for NOMA Waveform

Cellular systems utilize single and multicarrier waveforms for high-speed data transmission. The Fifth-Generation (5G) system proposes several techniques based on multicarrier waveforms. However, the Peak to Average Power Ratio (PAPR) is one of the significant concerns in advanced waveforms as it degrades the framework's efficiency. Non Orthogonal Multiple Access (NOMA) can provide massive connectivity, which is the crucial requirement of the Internet of Things (IoT). The 3rd generation tested NOMA applications in downlink and uplink transmission. However, NOMA uplink transmission in the power domain has performance degradation and is not considered a possible technique in 3rd generation power projects (3GPP). Presently, NOMA is not just a concept but has been introduced as a standard method in various transmission schemes. NOMA suffers from a high peak to average power ratio (PAPR), which forces the power amplifier (PA) to shift into a nonlinear region. The high value of PAPR leads the power amplifier of the multicarrier technique into a nonlinear region. As the performance of the power amplifier degrades, the overall system performance goes down. In this work, we suggest different methods to overcome the issue of PAPR in multicarrier techniques such as Selective Mapping (SLM) and Partial Transmit Sequence (PTS). The simulation results reveal that the performance of the proposed PTS is better than that of the conventional SLM and PTS.

PAPR Reduction in DCO-OFDM Based WDM VLC

Visible light communication (VLC) can achieve high data rate transmission with multicarrier modulation techniques. The common variant is direct current (DC) optical orthogonal frequency division multiplexing (DCO-OFDM) which offers a spectral efficient modulation solution for VLC. However, similar to other multicarrier modulation schemes, DCO-OFDM suffers from a high peak-to-average power ratio (PAPR). In this paper, the efficacy of pilot-assisted (PA) PAPR reduction system in DCO-OFDM based VLC is demonstrated experimentally. Wavelength division multiplexing (WDM) is applied using three off-the-shelf light emitting diodes (LEDs). PA DCO-OFDM is compared to the conventional DCO-OFDM based on achievable data rate and bit error rate (BER). The available modulation bandwidth of each LED is utilised by adaptive bit and power loading in both systems. The proposed system reduces the high PAPR values of the system, hence, reduces the clipping noise and minimises the nonlinearity effect of each wavelength. Thus, the PA DCO-OFDM has achieved more than 7&#x0025; data rate higher than that of the conventional DCO-OFDM with no PAPR reduction.