ORIGINAL RESEARCH

Open Access

Multispectral Optical camera communication links based on spectral signature multiplexing

  • Pages: 91-100
  • First Published: 08 June 2023
Multispectral Optical camera communication links based on spectral signature multiplexing

This paper focuses on using the multispectral cameras' features to take advantage of the light-emitting diode (LED) behaviour in a novel communication scheme based on spectral signature multiplexing. The thermally induced LED variations can be detected by the multispectral camera to obtain new communication channels from the same device.

Open Access

Enhanced secrecy outage probability for multiple-input single-output-VLC systems through optical beamforming and improved light emitting diodes deployment

  • Pages: 101-109
  • First Published: 21 April 2023
Enhanced secrecy outage probability for multiple-input single-output-VLC systems through optical beamforming and improved light emitting diodes deployment

The authors propose to arrange the light emitting diodes (LEDs) on the ceiling for an indoor visible light communication (VLC) system in order to minimise the {\it secrecy outage probability} (SOP) at the location of the legitimate user (LU). By deriving the secrecy capacity for a multiple-input single-output (MISO)-VLC system, we evaluate the SOP at the LU’s location which is used as the appropriate metric to determine the position of the LEDs on the ceiling.

Open Access

A unilateral 3D indoor positioning system employing optical camera communications

  • Pages: 110-119
  • First Published: 09 June 2023
A unilateral 3D indoor positioning system employing optical camera communications

This paper investigates the use of a visible light positioning system in an indoor environment to provide a three dimensional (3D) high-accuracy solution. The proposed system can retrieve the 3D coordinate of the Rx using a combination of the angle of arrival and received signal strength (RSS). We show that, the proposed method outperforms previously reported RSS under all circumstances and is immune to varying exposure times within the standard range of 250 μs to 4 ms. We experimentally demonstrate that the proposed algorithm can achieve a 3D root mean squared error of 7.56 cm.

Open Access

Carrier synchronisation in multiband carrierless amplitude and phase modulation for visible light communication-based IoT systems

  • Pages: 120-128
  • First Published: 02 June 2023
Carrier synchronisation in multiband carrierless amplitude and phase modulation for visible light communication-based IoT systems

The feasibility of a multi-user IoT communication system addressing the issue of carrier synchronisation is evaluated. A simulation model was built used to estimate the pull-in and lock ranges under different channel conditions showing that the system was able to synchronise under the presence of noise, but needs to be improved when adjacent bands are used.

Open Access

Performance analysis of uplink optical wireless communications in the presence of a simultaneously transmitting and reflecting reconfigurable intelligent surface

  • Pages: 129-138
  • First Published: 06 June 2023
Performance analysis of uplink optical wireless communications in the presence of a simultaneously transmitting and reflecting reconfigurable intelligent surface

For the first time we have used a brand-new technology which is named as STAR-RIS in an indoor optical wireless communication system to mainly improve not only the coverage of the system, but also improve performance of the sum- rate. Thus, two-user uplink scenario in presence of STAR-RIS is considered, and the achievable rates are derived for different operation modes of STAR-RIS. Finally the sum-rate is optimised over STAR parameters.

Open Access

Non-linear modelling and distortion compensation in optical Fast-orthogonal frequency division multiplexing systems

  • Pages: 139-148
  • First Published: 13 June 2023
Non-linear modelling and distortion compensation in optical Fast-orthogonal frequency division multiplexing systems

The accuracy of the generalised memory polynomial (GMP) for the non-linear modelling of optical Fast-OFDM links is studied. The GMP is used for performance investigations of a distortion compensation approach to IM/DD Fast-OFDM. Excellent BER improvements are achieved using the proposed compensation scheme, for up to 16PAM modulation and 256 Fast-OFDM subcarriers.

Open Access

Material characterisation for optical wireless communication combining measurement and Monte Carlo simulations

  • Pages: 149-161
  • First Published: 03 July 2023
Material characterisation for optical wireless communication combining measurement and Monte Carlo simulations

This paper proposes a method for optical characterisation of materials, which is a very important input for realistic channel simulation based on Ray-Tracing Monte-Carlo algorithms. This original approach consists first in carrying out some measurements of the optical power received after propagation in the environment containing the materials sought, using a simple and low-cost experimental setup. In a second step, this approach uses an optimization algorithm to estimate the optical characteristics of the materials.

Open Access

Frame recovery using multiple images in rolling shutter based systems

  • Pages: 162-174
  • First Published: 17 July 2023
Frame recovery using multiple images in rolling shutter based systems

An algorithm for decoding identifiers in rolling shutter based communication systems is proposed by the authors, based on reconstructing the original bitstream from multiple frames. The algorithm was validated by simulation for 6-bit, 8-bit and 10-bit codewords, showing an improvement in the recovery probability compared to a baseline algorithm. An experimental validation was also conducted for codewords with 6 bits.

Open Access

Electro-optical spiking neural networks using an enhanced optical axon with pulse amplitude modulation and automatic gain controller

  • Pages: 175-183
  • First Published: 18 August 2023
Electro-optical spiking neural networks using an enhanced optical axon with pulse amplitude modulation and automatic gain controller

The authors explore the possibility to implement NOMA with PAM in optical axons (OA) that interconnects electronic spiking neurons. This OA is improved by using at the receiver an amplifier with automatic gain that is adjusted based on a reference optical signal of different wavelength than the main beam. The results show that when the enhanced OA is used to multiplex the connections of the SNN with the sensors and actuators, the robotic hand is able to grasp an object despite relative motions of neurons.

Open Access

Performance evaluation technique for screen-to-camera-based optical camera communications

  • Pages: 184-193
  • First Published: 07 August 2023
Performance evaluation technique for screen-to-camera-based optical camera communications

The paper carries out an experimental investigation for data transmission in optical camera communication under different conditions.