R. Labdaoui, K. Ghanem, and F. Y. Ettoumi, “A Hybrid Spatial Adaptive Modulation and Frequency Stochastic Approach for MU-MIMO-OFDM Systems in the Context of Underlay Cognitive Radios”, Period. Polytech. Elec. Eng. Comp. Sci., vol. 67, no. 4, pp. 376–383, Jan. 2023.