Visible light communication (VLC) can provide short-range optical wireless communication, together with illumination using light-emitting diode (LED) lightings. Since conventional forward error correction (FEC) codes cannot provide two lighting related features, dimming support, and flicker mitigation, the existing coding schemes for reliable VLC usually rely on auxiliary coding techniques, which cause a complicated structure and a low transmission efficiency. In this paper, based on polar codes, an efficient and flicker-free FEC coding scheme for dimmable VLC is proposed to increase the transmission efficiency and simplify the coding structure. Taking advantage of polar codes’ recursive encoding structure, the proposed scheme can guarantee the equal probability and the short runs of 1 s and 0 s for arbitrary code rate without extra coding components. Numerical results show that the proposed scheme can have twice higher transmission efficiency than the existing schemes. Furthermore, at a dimming ratio of @math or @math , the coding gain of the proposed scheme is about 4.6 dB and 1.4 dB higher than that of the Reed–Solomon (RS) codes based scheme and the low-density parity check code based scheme, respectively.
@cite_7: In this letter, we propose an adaptive forward error correction scheme based on low-density parity-check (LDPC) codes to efficiently adjust dimming values in visible light communication (VLC) systems. The proposed code is a quasi-cyclic LDPC code, in which extension and puncturing methods are used to maintain dimming control. The significant advantages of the proposed method are due to the lower number of codes required to support codes with different coding rate and the relatively small performance degradation for dimming control. Simulation results show that our proposed method efficiently maintains the dimming control in VLC systems with LDPC codes.
@cite_21: In this letter, we propose a new forward error correction (FEC) coding method using a coset constructed from a bent function and a Reed-Muller (RM) code for providing accurate dimming control in on-off keying-based visible light communication (VLC) systems. By partitioning the coset made from bent function and the first-order RM codes, the new FEC scheme can be made to be suitable for dimming close to 0 or 100 . Therefore, it can contain minimal compensation symbols in supporting multiple dimming target values, which causes improved coding gain when the total amount of frame data is fixed. Simulation results for various dimming target values show that the proposed scheme leads to about 1-dB signal-to-noise ratio gain in 10-2 bit error rate compared with other three FEC codes.
@cite_1: Abstract In this paper, a novel error control scheme using Fountain codes is proposed in on–off keying (OOK) based visible light communications (VLC) systems. By using Fountain codes, feedback information is needed to be sent back to the transmitter only when transmitted messages are successfully recovered. Therefore improved transmission efficiency, reduced protocol complexity and relative little wireless link-layer delay are gained. By employing scrambling techniques and complementing symbols, the least complemented symbols are needed to support arbitrary dimming target values, and the value of entropy of encoded message are increased.
@cite_0: Run-length limited (RLL) codes are widely used in visible light communications to avoid long runs of 1s and 0s that potentially cause the flicker. This letter explores the serial concatenation of convolutional codes and Miller codes to simultaneously achieve forward error correction and RLL control. Miller codes with high bandwidth efficiency are much ignored in practice due to their disappointing power efficiency. The novelty of this letter is that we identity the merit of this previously unfavorable RLL code (i.e., trellis structure and soft decidability), exploit some important coding principles (i.e., interleaved serial concatenation and soft-iterative decoding), and assemble it to a powerful turbo structure that makes it outperform the existing favorable choices. A modified Bahl-Cocke-Jelinek-Raviv decoding algorithm is developed for the proposed concatenation. Analysis and simulations confirm that the new system is capable of solid RLL control and a superb performance better than the existing schemes.
@cite_2: 
@cite_5: In this letter, we propose a novel forward error correction (FEC) coding method using a modified Reed-Muller (RM) code for providing accurate dimming control in on-off keying (OOK) based visible light communication (VLC) systems. The proposed FEC scheme has a property that produces exactly same occurrence probability of 1's and 0's. Therefore, it can contain minimal compensation symbols in supporting multiple dimming target values. Moreover, VLC with our proposed scheme provides more coding gain than VLC scheme with the conventional FEC codes [the first-order RM and Reed-Solomon (RS) codes]. Simulation results for various dimming target values show that the proposed scheme leads to at least 2 dB or more signal-to-noise ratio (SNR) gain in 1 bit error rate (BER) than two FEC codes.
@cite_15: This letter presents an error correction scheme for dimmable visible light communication systems. To provide dimming control of on-off keying, the proposed coding scheme yields a codeword with the codeword weight adapted to the dimming requirement. It also allows an arbitrary value of the dimming requirement unlike existing coding schemes which have a limited support of this feature. To this end, turbo codes are employed together with puncturing and scrambling techniques to match the Hamming weight of codewords with the desired dimming rate. We demonstrate the decoding performance of the proposed coding scheme under iterative decoding and compare it with other existing error correction schemes. The simulation results prove that the proposed scheme has superior decoding performance, arbitrary dimming rate support, and diverse code rate options.
@cite_20: 
@cite_17: For visible light communications (VLCs), dimming support is desirable to provide variable levels of lighting brightness. When error correction coding schemes are used for VLC systems, different code rates should be employed according to target dimming levels. In this letter, we propose a coding scheme, which can provide a wide range of brightness and a simple encoding decoding structure for all different rates by using a rate-compatible punctured code. Puncturing patterns having the minimum bit error rate are provided by computer search. The results show that the VLC system with the proposed coding scheme can achieve optimum performances as well as a precise dimming support.
In IEEE VLC standard @cite_20 @cite_2 , either a Reed-Solomon (RS) code or a concatenated code composed of RS and convolutional codes (CC) is directly used as the error-correcting code (ECC) for short data frames. No modification of FEC codes is made in the scheme as it uses CSs for dimming function and RLL line codes for flicker mitigation. In recent years, several improved coding schemes have been proposed @cite_5 @cite_21 @cite_15 @cite_7 @cite_17 @cite_0 @cite_1 .