###### Abstract  
Visible light communication (VLC) is an emerging optical wireless technology capable of delivering high data rates for both indoor and outdoor environments. When combined with multiple-input, multiple-output (MIMO) systems, VLC demonstrates enhanced capacity, extended transmission range, and improved reliability. However, VLC systems are susceptible to ambient light interference, which can degrade performance. This paper investigates the performance of MIMO-VLC systems using three modulation techniques: non-return to zero (NRZ), return to zero (RZ), and quadrature phase shift keying (QPSK). The study evaluates the VLC systems in terms of bit error rate (BER), quality factor (Q-factor), and received power over varying link distances. The obtained results show that MIMO-based systems outperform single-input, single-output (SISO) systems in terms of transmission range, with MIMO achieving up to 1450 m using QPSK, compared to 1125 m for SISO. Under ambient light noise, MIMO-based systems experience a greater reduction in transmission distance (13.6%) compared to SISO (6.2%), but the overall performance gain of MIMO compensates for this degradation. Among the modulation schemes, NRZ and QPSK provide the best performance, showing greater resilience to ambient light interference. The findings confirm that MIMO-VLC systems, particularly with NRZ and QPSK, offer a robust solution for overcoming interference and maximizing transmission distance in real-world applications.  
wireless communication; VLC; MIMO; interference from ambient light; modulation techniques; data rate 2025  
26 March 2025  
16 June 2025  
23 June 2025  
26 June 2025  
26 March 2025  
16 June 2025  
23 June 2025  
26 June 2025  
###### Abstract  
Visible light communication (VLC) is an emerging optical wireless technology capable of delivering high data rates for both indoor and outdoor environments. When combined with multiple-input, multiple-output (MIMO) systems, VLC demonstrates enhanced capacity, extended transmission range, and improved reliability. However, VLC systems are susceptible to ambient light interference, which can degrade performance. This paper investigates the performance of MIMO-VLC systems using three modulation techniques: non-return to zero (NRZ), return to zero (RZ), and quadrature phase shift keying (QPSK). The study evaluates the VLC systems in terms of bit error rate (BER), quality factor (Q-factor), and received power over varying link distances. The obtained results show that MIMO-based systems outperform single-input, single-output (SISO) systems in terms of transmission range, with MIMO achieving up to 1450 m using QPSK, compared to 1125 m for SISO. Under ambient light noise, MIMO-based systems experience a greater reduction in transmission distance (13.6%) compared to SISO (6.2%), but the overall performance gain of MIMO compensates for this degradation. Among the modulation schemes, NRZ and QPSK provide the best performance, showing greater resilience to ambient light interference. The findings confirm that MIMO-VLC systems, particularly with NRZ and QPSK, offer a robust solution for overcoming interference and maximizing transmission distance in real-world applications.