Today we want fast ways of communication; research on even more faster alternatives is going. In present time, 4th generation wireless communication standards is among one of such technologies. The building block of this technology is MIMO-OFDM system. But one of the drawbacks associated with OFDM is high PAPR. In this paper, we propose a new nonlinear companding algorithm that transforms the MIMO OFDM signals into the desirable statistics form defined by a linear piecewise function. By introducing the variable slopes and an inflexion point in the target probability density function, more flexibility in the companding form and an effective trade-off between the PAPR and bit error rate performances can be achieved. The presented theoretical analyses are well verified via computer simulations.