Subband CMA Adaptive Arrays in Multipath Fading Environment

CMA (Constant Modulus Algorithm) adaptive arrays are considered a promising method in mobile communications to mitigate multipath fading and to suppress co-channel interference signals. However, since a CMA adaptive array assumes no a priori information of the desired signal, it is difficult to separate and combine the multipath rays of the desired signal. Therefore, when CMA is applied, the input signal power of the multipath rays cannot be efficiently utilized. Moreover, since suppressing the multipath rays requires many degrees of freedom (DOFs) of the array, the array system becomes complicated. In this paper we propose the subband CMA adaptive array which enhances the signal correlation between the multipath rays in each subband, as such the multipath fading effect can be greatly mitigated. By using this method, the multipath rays of the desired signal are equalized and combined, whereas an interference signal with multipath rays can be suppressed by using a single DOF. © 2000 Scripta Technica, Electron Comm Jpn Pt 1, 83(11): 43–54, 2000