CHAPTER Power Allocation Games and Learning in MIMO Multiuser Channels 8.1 INTRODUCTION 8 This chapter is written in the same spirit as with the preceding one. One of the main objectives is always to illustrate notions such as the Nash equilibrium (NE), to show how NE existence and uniqueness theorems can be applied, and to show how the NE can be determined. The main technical differences with respect to the preceding chapter are: · other utility functions are considered for the transmitters (which are always the players); namely, transmission rates (Shannon rates in all sections and goodputs in Section 8.7); the strategy of a transmitter consists of choosing a power allocation policy ·