A reduced PAPR hybrid OFDM visible light communication system

Abstract

Orthogonal frequency division multiplexing (OFDM) is used by visible light communication (VLC) systems. Its main goal is to lessen inter-symbol interference's negative impacts. As a result, a lot of bandwidth and a high data rate are transmitted. Using OFDM-based VLC systems, nonetheless, have a high peak-to-average power ratio (PAPR). This research presents a new VLC system for indoor applications that reduces the PAPR while maintaining an acceptable bit error rate (BER). To achieve this, a hybrid pre-coding technique-based PAPR reduction solution is proposed; Vander-monde like matrix (VLM) combined with Gaussian matrix (GM). This technique takes advantage of both VLM and GM as a two stages for the signal to simultaneously reduce the PAPR and save the BER from damage. According to the results, the proposed solution (VLM in conjunction with GM) lowers the PAPR to 9.5 dB. Our system performs better when compared to other systems like discrete cosine transform (DCT), GM, VLM, DCT&GM, and original OFDM by 27%, 25%, 11%, 20%, and 34%, respectively.

Optical-OFDM VLC System: Peak-to-Average Power Ratio Enhancement and Performance Evaluation

“…To the best of the authors' knowledge, we can categorize the PAPR mitigation approaches for MCM techniques as adding signal techniques (AST), multiple signal representation (MSR) techniques, and coding techniques (CT)/precoding techniques (PCT) [49].…”

“…The VLM methodology achieves this power redistribution by utilizing signal processing algorithms, including precoding matrices of dimensions N × N. This matrix is applied before the IFFT stage to alter the transmitted signal before sending it through the LED. These techniques carefully manipulate the signal characteristics to reduce PAPR and optimize power distribution [49].…”

Experimental Demonstration of a Visible Light Communications System Based on Binary Frequency-Shift Keying Modulation: A New Step toward Improved Noise Resilience

“…Here [44], the authors propose a DC optical OFDM pulse-position modulation which is evaluated against a DC optical OFDM pulse-width modulation (PWM), showing lower SNR requirements. Acknowledging the benefits of OFDM, and also the fact that its use can generate high peak-to-average power ratio (PAPR), the authors of [45] propose and evaluate a PAPR reducing algorithm based on a Vandermonde-like matrix combined with a Gaussian matrix, providing a 11-34% PAPR reduction with respect to other methods. The authors of [46] focus on the use of the VLC technology in an industrial IoT scenario.…”

“…Again, DC OFDM is considered as a suitable modulation technique. It should be emphasized that [44][45][46], as well as most of the works that are focused on different types of modulation evaluation are based on simulations, whereas the VLC channel model provided in [47] remains the basis for most of today's channel models. Different from FSK-based modulation such as OFDM, the work focused on phase-shift keying (PSK) modulation is rather limited, with only few such papers being available [48,49].…”

A DCT/DST Based Fast OFDM Method in IM/DD Systems

“…For instance, the article [20] proposes a hybrid PAPR reduction system for DCO-OFDM, which involves the application of DCT pre-coding, followed by multiplication of the IFFT output with a Gaussian matrix to reduce PAPR. This combined method achieves a modest PAPR improvement of approximately 1 dB without compromising BER performance when compared to the DCT pre-coded method.…”