Joint frequency offset estimation and multiuser detection using genetic algorithm in MC-CDMA

In order to combat intercarrier interference (ICI) and multiple access interference (MAI) simultaneously to achieve reliable performance in multi-carrier code division multiple access (MC-CDMA) systems, the paper proposes a new scheme for joint frequency offset estimation and multiuser symbol detection. The new approach is based on the widespread maximum likelihood principle to carry out concurrently frequency offset estimation to alleviate the ICI and multiuser detection to mitigate the MAI. The joint decision statistic, however, is highly nonlinear and conventional linear schemes are not applicable. To reduce the computational complexity without an increase of additional mechanisms, we employ a genetic algorithm (GA) to solve the nonlinear optimization involved. Due to the robustness of the GA, the joint decision statistic can be efficiently solved and near optimum results can be obtained. Simulation results show that the proposed approach offers satisfactory performance in various scenarios.