IET COMMUNICATIONS, vol.12, no.10, pp.1155-1162, 2018 (Journal Indexed in SCI)
Article / Article
Title of Journal :
channel estimation, matrix inversion, OFDM modulation, search problems, mean square error methods, multi-access systems, pilot optimisation technique, OFDM-IDMA system, advanced pilot design procedure, HS algorithm, pilot positions, channel estimation performance, multicarrier transmission technologies, harmony search algorithm, pilot distribution pattern, mean square error, Gershgorin disc theorem, MSE calculation, least squares estimator, orthogonal frequency division multiplexing, pilot placement strategies, interleave division multiple access system, matrix inversion process, DIVISION MULTIPLE-ACCESS, CHANNEL ESTIMATION, OPTIMIZATION, ARRANGEMENT
The direct effect of the pilot positions to the channel estimation performance gives an opportunity for minimising the estimation errors in multicarrier transmission technologies. To this end, harmony search (HS) algorithm is proposed for optimising the pilot distribution pattern in order to increase the performance of least squares estimator employed in orthogonal frequency division multiplexing-interleave division multiple access (OFDM-IDMA) system. Besides, the upper bound of mean square error (MSE) utilised as the fitness function of HS algorithm is obtained by using Gershgorin disc theorem to get rid of matrix inversion process required in MSE calculation. In the simulations, the authors' proposed HS-based pilot optimisation technique proves to be an effective way of pilot design for OFDM-IDMA system by providing a clear performance superiority over the other considered pilot placement strategies.