In this paper, two recent global optimisation techniques: particle swarm optimisation and central force optimisation are considered for optimising the location of the diffusion spots, which are used as transmitters in an indoor optical wireless communications system. The diffusion spots are uniformly distributed along a circle on the ceiling of the communications environment. The location of the diffusion spots is optimised for maximising the signal-to-noise ratio and minimising the root-mean-square delay spread at the receivers in the presence of noise sources. A performance comparison between the central located position of the spots and the optimised positions for three different scenarios is considered to validate and show the strengths of the applied optimisation techniques in solving this sort of problems. The used techniques can provide the communication system with the ability to adapt to changes in the surrounding environment, which will benefit future switching towards real-time intelligent systems.