Filtered-OFDM for Visible Light Communications

In visible light communications (VLCs), adaptive Orthogonal Frequency Division Multiplexing (OFDM) systems can adjust the transmission parameters according to channel estimation results to improve the system performance. Filtered-OFDM (F-OFDM) is a new flexible and adaptive technology based on OFDM systems and can further improve the system performance. In F-OFDM scheme, the out-of-band emission of OFDM signal is greatly inhibited by using the filter and the guard interval of the two subbands is reduced to save the spectrum resources. In this paper, we creatively apply the F-OFDM technology to visible light OFDM systems and derive the specific signal expression. Simulation results show that as the number of quadrature amplitude modulation (QAM) increases, the bit error rate (BER) performance of the F-OFDM system gets worse. Compared with asymmetrically clipped optical OFDM (ACO-OFDM) and direct current biased OFDM (DCO-OFDM) in VLCs, F-OFDM has better BER performance in 4QAM, 16QAM, and 64QAM schemes.

[1]  Harald Haas,et al.  Visible light communication using OFDM , 2006, 2nd International Conference on Testbeds and Research Infrastructures for the Development of Networks and Communities, 2006. TRIDENTCOM 2006..

[2]  Yi Hong,et al.  Flip-OFDM for optical wireless communications , 2011, 2011 IEEE Information Theory Workshop.

[3]  Rafael Perez-Jimenez,et al.  Adaptive OFDM system for communications over the indoor wireless optical channel , 2006 .

[4]  Joseph M. Kahn,et al.  Multiple-Subcarrier Modulation for Nondirected Wireless Infrared Communication , 1994, IEEE J. Sel. Areas Commun..

[5]  S. Dimitrov,et al.  Signal Shaping and Modulation for Optical Wireless Communication , 2012, Journal of Lightwave Technology.

[6]  Ming Jia,et al.  Filtered OFDM: A new waveform for future wireless systems , 2015, 2015 IEEE 16th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC).

[7]  Jean Armstrong,et al.  Comparison of Asymmetrically Clipped Optical OFDM and DC-Biased Optical OFDM in AWGN , 2008, IEEE Communications Letters.

[8]  Xiqi Gao,et al.  Cellular architecture and key technologies for 5G wireless communication networks , 2014, IEEE Communications Magazine.

[9]  Harald Haas,et al.  Avoiding spectral efficiency loss in unipolar OFDM for optical wireless communication , 2014, 2014 IEEE International Conference on Communications (ICC).

[10]  J. Armstrong,et al.  Comparison of ACO-OFDM, DCO-OFDM and ADO-OFDM in IM/DD Systems , 2013, Journal of Lightwave Technology.

[11]  Rafael Perez-Jimenez,et al.  OFDM over indoor wireless optical channel , 2005 .

[12]  Xi Zhang,et al.  Filtered-OFDM - Enabler for Flexible Waveform in the 5th Generation Cellular Networks , 2014, 2015 IEEE Global Communications Conference (GLOBECOM).

[13]  Yejun He,et al.  A Filtered OFDM Using FIR Filter Based on Window Function Method , 2016, 2016 IEEE 83rd Vehicular Technology Conference (VTC Spring).

[14]  Harald Haas,et al.  Novel Unipolar Orthogonal Frequency Division Multiplexing (U-OFDM) for Optical Wireless , 2012, 2012 IEEE 75th Vehicular Technology Conference (VTC Spring).

[15]  Wen Tong,et al.  Enabling technologies for 5G air-interface with emphasis on spectral efficiency in the presence of very large number of links , 2015, 2015 21st Asia-Pacific Conference on Communications (APCC).

[16]  Harald Haas,et al.  OFDM Visible Light Wireless Communication Based on White LEDs , 2007, 2007 IEEE 65th Vehicular Technology Conference - VTC2007-Spring.

[17]  Ivan Andonovic,et al.  Modified asymmetrically-clipped optical orthogonal frequency-division multiplexing system performance , 2013, 2013 IEEE Photonics Conference.

[18]  Jean Armstrong,et al.  Power efficient optical OFDM , 2006 .