Nearest neighbor bit assisted decision scheme for ISI mitigation in optical camera communications

Area of Science:

• Optical Camera Communication (OCC)
• Digital Signal Processing

Background:

• High transmission rates in OCC systems cause inter-symbol interference (ISI) due to reduced pixels per bit (PPB).
• Conventional thresholding schemes struggle with ISI, leading to indistinguishable gray scale values for data bits 0 and 1, and poor bit decision accuracy.

Purpose of the Study:

• To propose and experimentally demonstrate a novel signal decision scheme for OCC systems to mitigate ISI.
• To improve the bit error rate (BER) performance in OCC systems suffering from severe ISI.

Main Methods:

• Development and experimental validation of the Nearest Neighbor Bit Assisted Decision (NNBAD) scheme.
• Utilizing the nearest neighbor bit to assist in the bit decision process for pixels affected by ISI.

Main Results:

• The NNBAD scheme demonstrates significant robustness against ISI, outperforming conventional thresholding.
• Experimental results show a remarkable improvement in bit error rate (BER) performance.
• Achieved a throughput of 8.2 kbps with on-off keying (OOK) modulation under 600 lx illuminance.

Conclusions:

• The NNBAD scheme is an efficient solution for improving signal decision accuracy in OCC systems with severe ISI.
• This method enables higher transmission rates by effectively managing ISI.
• The proposed scheme offers a practical approach for enhancing OCC system performance.