Multilayer spatial multiplexing in next-generation WiMAX

We propose in this paper as a possible candidate for next-generation WiMAX a multilayer spatial multiplexing scheme, which is flexible and conceptually simple. Every layer is a QPSK symbol stream, weighted by a coefficient, and superimposed on the other layers. A method to optimize the coefficients is described in details. At the receiver, an iterative (turbo-like) structure gives very good performance at an affordable complexity, as it is shown by simulation results, in a realistic and WiMAX-complying scenario.