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Mutual interference is a crucial issue for the visible light communication (VLC) systems to be addressed, including both co-channel interference (CCI) and inter-carrier interference (ICI). In this paper, to solve the CCI problem, a novel optical attocell network is introduced, which can be regarded as a hybrid network based on both single frequency network and multi-frequency network. Meanwhile, to eliminate the ICI, a pre-distorted enhanced asymmetrically clipped DC biased optical orthogonal frequency division multiplexing (PEADO-OFDM) approach is designed. In addition, the corresponding properties of PEADO-OFDM are analyzed, and different modulation schemes are employed for downlink and uplink in the same ADO-OFDM modulation framework to reduce the complexity of user processing. Simulation results indicate that the proposed PEADO-OFDM scheme outperforms the conventional ADO-OFDM approach in terms of bit error rate, while the processing latency and computational complexity are greatly reduced at the receiver.

In this paper, an adaptive modulation scheme for visible light communication (VLC) system based on partially pre-distorted layered asymmetrically clipped optical orthogonal frequency division multiplexing (LACO-OFDM) is proposed. The clipping noise that falls on the higher layers in the conventional LACO-OFDM results in inter layer interference, which can be eliminated by the operation of pre-distortion at the expense of extra power consumption. The proposed partially pre-distorted scheme makes a tradeoff between error propagation and power cost to suit different transmission environments. The probability distribution functions of the conventional and pre-distorted LACO-OFDM schemes are analyzed and compared and the layers that should be pre-distorted in the proposed scheme is decided adaptively by maximizing the achievable rate. The computational complexity of the proposed scheme is also investigated, which is acceptable compared with the previous schemes. Simulation results show that the proposed scheme has a superior bit error rate performance compared with the conventional and pre-distorted LACO-OFDM schemes.

Mutual interference is a crucial issue for the visible light communication (VLC) systems to be addressed, including both co-channel interference (CCI) and inter-carrier interference (ICI). In this paper, to solve the CCI problem, a novel optical attocell network is introduced, which can be regarded as a hybrid network based on both single frequency network and multi-frequency network. Meanwhile, to eliminate the ICI, a pre-distorted enhanced asymmetrically clipped DC biased optical orthogonal frequency division multiplexing (PEADO-OFDM) approach is designed. In addition, the corresponding properties of PEADO-OFDM are analyzed, and different modulation schemes are employed for downlink and uplink in the same ADO-OFDM modulation framework to reduce the complexity of user processing. Simulation results indicate that the proposed PEADO-OFDM scheme outperforms the conventional ADO-OFDM approach in terms of bit error rate, while the processing latency and computational complexity are greatly reduced at the receiver. [ABSTRACT FROM AUTHOR]

In this paper, we propose and experimentally demonstrate an optical self-interference cancellation (OSIC) system with baseband predistortion for wideband over-the-air in-band full-duplex (IBFD) communication. The key factors of OSIC bandwidth limitation are analyzed, and the solution toward it is proposed for the first time. Experimental results show that, by traditional OSIC under over-the-air condition, only narrow even zero band is with enough cancellation depth to satisfy IBFD. But with our proposed baseband predistortion scheme, deep OSIC depth is achieved over the whole 1 GHz/5 GHz baseband within the total 7–25 GHz available band of horn antennas. The employment of baseband predistortion obviously broadens the cancellation bandwidth of an EML-based OSIC system. The largest OSIC bandwidth for over-the-air IBFD communication is demonstrated so far.

In this paper, an adaptive modulation scheme for visible light communication (VLC) system based on partially pre-distorted layered asymmetrically clipped optical orthogonal frequency division multiplexing (LACO-OFDM) is proposed. The clipping noise that falls on the higher layers in the conventional LACO-OFDM results in inter layer interference, which can be eliminated by the operation of pre-distortion at the expense of extra power consumption. The proposed partially pre-distorted scheme makes a tradeoff between error propagation and power cost to suit different transmission environments. The probability distribution functions of the conventional and pre-distorted LACO-OFDM schemes are analyzed and compared and the layers that should be pre-distorted in the proposed scheme is decided adaptively by maximizing the achievable rate. The computational complexity of the proposed scheme is also investigated, which is acceptable compared with the previous schemes. Simulation results show that the proposed scheme has a superior bit error rate performance compared with the conventional and pre-distorted LACO-OFDM schemes. [ABSTRACT FROM AUTHOR]