A New Selective Mapping Scheme for Visible Light Systems

Abstract

The huge bandwidth and immunity to electromagnetic interference make Visible Light Communication (VLC) systems as preferred technique for designing the physical layer of 5G applications. Unfortunately, the superimposition of multiple subcarriers in DC-biased Optical Orthogonal Frequency Division Multiplexing (DCO-OFDM) system leads to a high peak to average power ratio (PAPR). The well-accepted nondistorting PAPR reducing schemes like selective mapping (SLM) require an obligatory transmission of side information (SI) reducing the bandwidth efficiency of the system. To address these issues, a simple SI cancellation algorithm using pilots associated with channel estimation is proposed in this work. In short, the DCO-OFDM system is presented with a modified cluster architecture and each cluster is assigned with at least one pilot. Every cluster is restricted to have same phase and this idea provides the pilots to perform joint channel estimation and SI cancellation. The experimental results obtained by using Universal Software Radio Peripheral (USRP) as hardware and LabVIEW as software indicate a significant reduction in PAPR without effecting the real-time channel response. INDEX TERMS Visible light communication (VLC), DC biased optical orthogonal frequency division multiplexing (DCO-OFDM), selective mapping (SLM), and Universal software radio peripheral (USRP).

Low-Complexity Optical Transmitter Design for Future Generations

“…Figure 1 illustrates the outcomes of the PAPR CCDF simulation for the CSLM, as well as suggested candidates for the phase vector's size L = 2,4, and 8. It is well knowledge that the PAPR performance is better if the amount of the phase sequence vectors in the SLM scheme rises [20]. The PAPR reduction capability for the phase sequence vector of length 2 is much lower than that of the phase sequences of length 4 and 8.…”

“…In their model, the authors deployed a scaling factor α p that depends directly on the diode characteristics. A simple SI cancelling technique is developed by S.P.Valluri et al [20] wherein Pilots are incorporated into the action to execute SI cancellation and joint channel estimation. Top samples are detected and appended without utilising the SI in the approach used by Ganesh Miriyala et al [21].…”

Peak-to-Average Power Ratio reduction in Wavelet based OFDM using Modified Selective Mapping for Cognitive Radio Applications

“…In the above study, both conventional and modified SLM methods are compared, and simulation results claim superior performance of modified SLM compared to Conventional SLM techniques. The additional side information transmission requirement of SLM is addressed in a paper proposed by Valluri et al [14], in which a simple SI cancellation algorithm using channel estimation-related pilots is proposed. The author presented a revamped cluster architecture that ensures that each cluster has at least one pilot.…”

A new complexity reduction scheme in selective mapping‐based visible light communication direct current‐biased optical orthogonal frequency division multiplexing systems

“…Authors in Ref. [27] proposed a scenario where pilots are brought into the play for performing joint channel estimation and cancellation of SI. The computational complexity is reduced moderately with a bit compromising in PAPR reduction performance.…”