Wireless Light Fidelity Channel Capacity Improvement Using Sparse Sampled Non-Orthogonal Frequency Shift Keying

A new technique, which can increase the wireless light fidelity channel capacity based on the white light emitting diode, is proposed. It is implemented by using the non-orthogonal frequency shift keying and the sparse carrier sampling at the same time. The proposed method is verified by using the 1-meter wireless visible light communication link with the 30-MHz frequency response. The maximum power penalty due to the sparse carrier sampling is 6 dB at the compression ratio of 62.5 %. The bit error rate of $9.5\times 10^{-4}$ is measured at the frequency spacing of 0.1 MHz (1% of 10-MHz RF carrier). The wireless channel capacity of 130 Mb/s, which corresponds to 13 times of on-off keying-non-return to zero signal (10Mb/s), is obtained at the compression ratio of 70 % using the proposed technique. We also confirm that the 16-NoFSK signal with the 26-dB input signal to noise ratio can be recovered even at the compression ratio of 75 % when the received optical power is more than -6 dBm.