Reference no: EM132872441
KD7064 Optical Communication System - Northumbria University
Assignment task (100 marks)
In this assignment you will investigate a hybrid optical fibre and visible light communications system for use in indoor environment by means of numerical simulation.
As part of the last few meter access network, optical fibres are brought to homes and office from the hub to deliver high-speed internet services. The optical fibre link span from the hub to the office is 1 km, and the fibre used is a multimode step-index. At the office the optical signal from the fibre is converted back into the electrical signal using the optical receiver (Rx) which is then applied to the router and control unit. The output of the control unit is connected to the LEDs via an Ethernet cable, which delivers both power for illumination and data communications.
An office will have multiple working spaces, each working space is 2 m x 2 m (L x W) and it is illuminated by a single LED-based light position at the on ceiling pointing downwards to the centre of the working space, see Fig. 1. The height of the office is 4 m.
The full system specifications are:
You need to develop a simulation in MATLAB to design the system based on the following tasks:
Task 1: Design the optical fibre section
i. Determine the delay spread within the fibre considering the shortest and longest path lengths.
ii. Carry out full link power budget analysis considering all the key system parameters, and therefore determine the required optical transmit power. The link margin should be 4 dB.
iii. Obtain the full bandwidth budget analysis for the link from the backbone to output of the optical Rx.
iv. Discuss what light source would be best for this link and explain why.
Task 2: Design a single LED-based VLC system
The lighting engineer wants to optimise the LED usage by fitting a lens for each LED to ensure that the coverage of the beam is just covering every corner of a working space (to avoid the light spreading to the adjacent working space), i.e. the power received at one of the working space corners is 6 dB less than the power at the centre. In addition, this strategy will help to minimise the transmit power for each LED.
i. Using MATLAB tool to plot the received power (or illumination) profile on the working space floor when m = 1 and m = 5.
ii. Furthermore, determine the optimum Lambertian order m of the LED to achieve the condition that the engineer wants.
Task 3: Design a multiple-LED-based VLC system
The engineer uses 4 LEDs now in each cell to enhance the brightness of the cell as well as flatten the illumination level in each cell.
Determine the optimum position of 4 LEDs on the ceiling to achieve the most "flatten" received power (or illumination) profile on the working space floor.
In each case, you need to show the calculation, the used equation/formulas with explanation, the codes (with comments in detail), and the plotted results (if applicable).
Attachment:- Optical Communication System.rar