The problem of waveform adaptation to maximize information rate in a multiple-in multiple-out cognitive radio (MIMO-CR) network is investigated from a non-cooperative game theoretic viewpoint.The existence and uniqueness of the Nash equilibrium under certain circumstances is proved and a decentralized iterative water-filling algorithm with punishing price

MIMO-CR IWFA

is proposed to solve the above problem

the pricing mechanism is used to satisfy the interference-temperature constraint while achieving the Nash equilibrium

the conditions for the convergence of MIMO-CR IWFA are also provided.Simulation results show our MIMO-CR IWFA can satisfy the interference-temperature constraint perfectly and is fast convergent;and though constrained by PU's interference-temperature

the performance of MIMO-CR IWFA can still approach the classical MIMO IWFA

which does not consider the interference-temperature constraint

with the increase of co-channel interference between MIMO-CRs.