Performance Comparison of Different Types of Receivers in Indoor MIMO-VLC Systems

In this paper, we compare the performance of non-imaging receiver (NImR), imaging receiver (ImR) and imaging angle diversity receiver (ImADR) in an indoor multiple-input multiple-output visible light communication (MIMO-VLC) system, in terms of area spectral efficiency (ASE). Analytical ASE expressions of MIMO-VLC systems using different types of receivers are derived and our analysis show that the MIMO-VLC system using an ImR or an ImADR achieves significantly improved ASE performance compared with the system using a NImR. Introduction As a promising alternative and complementary technology to RF technology, white light-emitting diodes (LEDs) enabled visible light communication (VLC) has attracted great interest for providing high-speed and electromagnetic interference-free wireless communication in indoor environments [1]. In order to provide sufficient illumination, multiple LEDs are commonly mounted in the ceiling. By leveraging the existing LED lighting fixtures, it is very natural to employ multiple-input multiple-output (MIMO) transmission to increase the capacity of VLC systems [2,3]. Three types of receivers can be applied in indoor MIMO-VLC systems, including non-imaging receiver (NImR), imaging receiver (ImR) and imaging angle diversity receiver (ImADR) [2-4]. So far, a few comparisons between NImR and ImR in indoor MIMO-VLC systems have been reported in the literature [2,5]. However, the comparisons are performed in terms of bit error rate (BER) for a specific link. Considering that a MIMO-VLC system always covers a certain area in an indoor environment, it is necessary and of great significance to investigate the system performance over its coverage. The area spectral efficiency (ASE), which was previously proposed for cellular mobile radio system as a suitable measure of spectral efficiency over a certain area [6], can be an effective performance metric for comparing different receivers in indoor MIMO-VLC systems. In this paper, we compare the ASE performance of NImR, ImR and ImADR in an indoor 4×4 MIMO-VLC system. Analytical ASE expressions of an indoor MIMO-VLC system using NImR, ImR, and ImADR are derived. The obtained analytical results show that the ASE performance of the 4×4 MIMO-VLC system can be significantly enhanced when an ImR or an ImADR is used instead of a NImR. The impact of different spacings between two adjacent LEDs and the number of active users on the ASE performance of the system in a 5m×5m×3m room is also analyzed. 341 Advances in Computer Science Research (ACRS), volume 54 International Conference on Computer Networks and Communication Technology (CNCT2016)