Interference Mitigation Using Angular Diversity Receiver With Efficient Channel Estimation in MIMO VLC

Abstract

Visible Light Communication (VLC) is a promising solution to meet the ever increasing demand for indoor data connectivity with high bit rates. VLC uses the license-free bands and provides high-speed connections unlike RF wireless communication. However; indoor VLC suffers from performance degradation due to either co-channel interference (CCI) or inter-symbol interference (ISI). In this paper, an interference management scheme is proposed for VLC Multi-Input Multi-Output (MIMO) based systems. The scheme reduces the number of interfered signals by using a constrained field-of-view angular diversity receiver CFOV-ADR and then uses least-square (LS) channel estimation with maximum-likelihood (ML) equalizer to resolve the interfered signals. The proposed interference mitigation scheme using constrained-FOV-ADR with channel estimation IM-CFOV-CE enables frequency reuse of one. The bit-error-rate (BER) is calculated at various room positions with different receiver's heights and rotation angles. The performance evaluation results reveal that the proposed system can achieve a higher number of downlink channels and superior BER performance than that of without CCI management. Also, the proposed scheme has been compared with Time Division Multiple Access (TDMA) technique, and achieves enhanced performance at all positions and orientations of the ADR. INDEX TERMS Angular diversity receiver (ADR), co-channel interference (CCI), interference mitigation, visible light communication (VLC).

Lights and Shadows: A Comprehensive Survey on Cooperative and Precoding Schemes to Overcome LOS Blockage and Interference in Indoor VLC

“…As demonstrated in [ 76 ], the use of ADRs improves the performance in terms of sum-rate and BER in MIMO systems. In this sense, the concepts of ADR and vROA photodetector provide a new degree of freedom in the design and the signal processing algorithms [ 29 , 79 , 80 , 81 ]. Notice that ADRs improve the visibility of the users in VLC systems and, combined with novel transmission schemes, may be an effective approach for overcoming the LoS-link blocking effects, even without much signal processing.…”

Signal to interference plus noise ratio improvement of a multi‐cell indoor visible light communication system through optimal parameter selection complying lighting constraints

“…Recently, a novel channel estimation approach is reported based on Bayesian CS algorithm 32 . Highly uncorrelated VLC‐MIMO (multiple‐input multiple‐output) channel matrices have been achieved by using different angular diversity receiving techniques where several photodiodes (PDs) are used as front‐end of the receiver 33‐35 . At the expense of receiver complexity and cost, this technique can eradicate CCI from the neighboring AP and reduce ISI caused by multipath reflection.…”

A STUDY OF THE INFLUENCE OF 650 nm LASER INTERFERENCE ON VISIBLE LASER LIGHT COMMUNICATION SYSTEM

“…The Visible Laser Light Communication System performs wireless communication, transferring data anywhere freely using a laser beam. This system is effective because it does not overcrowd the spectrum and is not regulated by the Government [1], [2], [3], [4], no electromagnetic radiation [5], [6], good security [5], low cost [6], and high signal power [7]. This system belongs to the visible light category which works in the 350nm to 750nm spectrum [1], [2], [5], [8], [9].…”

“…This system is effective because it does not overcrowd the spectrum and is not regulated by the Government [1], [2], [3], [4], no electromagnetic radiation [5], [6], good security [5], low cost [6], and high signal power [7]. This system belongs to the visible light category which works in the 350nm to 750nm spectrum [1], [2], [5], [8], [9]. As with radio communications, this system has no overhead of processing different regulatory rules and is quite fast.…”

“…The system is secure because intercepting transmission interrupts uses low power, communicating at 1.25 Gbps up to a distance of 6 Km. However, they need a Line of sight [1], [4], [10], [11] where the sender's receiver pair can't be mobile. Communication is successful when the path is set accurately, and the transmitting receiving antenna is tilted properly.…”