Fixed-Complexity Tree Search Schemes for Detecting Generalized Spatially Modulated Signals: Algorithms and Hardware Architectures. - Tsung-Hsien Liu; Shih-Lun Wang; You-Jia Lin; Yin-Tsung Hwang; Chiao-En Chen; Yuan-Sun Chu (IEEE Trans. Circuits Syst. I Regul. Pap., 2021)