Adaptive recursive algorithm for complementary subspace-based blindmultiuser detection

摘要

A novel blind adaptive multiuser detection scheme, the linearndecorrelating detector (LDD), based on a concept of the complementarynsubspace is proposed. Under this scheme, the information bits can benestimated from the received signal with the prior knowledge of thendesired user's signature waveform and its timing. The technique has twonkey elements: a geometric notion of the LDD and the subspace-basednconcept to estimate the orthogonal complement of the interfering space.nIt is then shown that the LDD can be formulated in terms of theninterference space constructed from the received signal, and the desirednuser's signature waveform. The interference space components can benadaptively estimated using the modified power-based methods with onlynO((K-1) N) flops of computation at each iteration, where N is thenprocessing gain, and K is the number of active users in the channel. Thennovel blind adaptive detector offers lower computational complexity. Thenproposed blind multiuser detection offers the optimal near-farnresistance, low computational complexity, and resistance against thenorthogonality error of the estimated interference space