Figure 3: Convergence of the DCOA for setup 3a (JP-SU) under the per-antenna power constraint with 1 0 l o g 1 0 𝑃 = 2 . 5  dB. Duality gap and four antenna powers, as functions of the iteration number. The 4 different colors in the two lower sub-plots correspond to the 4 transmit antennas.