Block-Diagonalization Precoding in a Multiuser Multicell MIMO System: Competition and Coordination

Interference Mitigation and Sum Rate Optimization for MIMO Downlink Small Cells

“…The basic idea to tackle d.c. optimization is to convexify f (Q Q Q) to obtain the convex objective function. We can approximate the nonconvex part of the objective function by using its convex majorant [25], [30], [31]. Given Q Q Q (κ) at the κ-th iteration, one has…”

“…It is well-known that convex optimization problem can be efficiently solved by available convex programming solvers. As a result, to obtain the optimal solution to the d.c. programming (28), we solve a sequence of the convex optimization problem (31). In summary, the iterative procedure to solve problem (23) is described in Algorithm 2 where is an acceptable accuracy.…”

Performance evaluation and enhancement of massive MIMO communication systems

“…On the other hand, we study the performance of precoding schemes for multiple-antenna users. In this case, block diagonalization (BD), regularized BD (RBD) precoding schemes and their modified implementations (such as generalized ZF channel inversion and generalized MMSE channel inversion) can be applied [14][15][16][17]. However, the RBD precoding scheme has higher computational complexity than that of the BD precoding scheme (BD-PS) and its rate performance approaches to that of the BD-PS at high signal-to-noise ratio (SNR) region [15].…”

“…While the performance of the conventional MIMO systems with BD-PS has been well studied in the literature [14][15][16][17][79][80][81], there are only few works which investigate the performance of massive MIMO with BD-PS. Specifically, the rate performance of each single user has been studied in [45] with perfect CSI when N is large.…”

“…Given the strategies (i.e., tilt angles and power allocations) from other BSs reflected by the ICI, each BS selfishly adjusts its strategy to maximize the sum rate for its connected users. The multicell system is said to be in competition since all BSs are competing with each other to obtain their own optimal strategies in a noncooperative game [121][122][123][124]. A distributed algorithm is presented to compute the equilibrium state of the game.…”