Rotating clustering with simulated annealing user scheduling for coordinated heterogeneous MIMO cellular networks

Rotating cluster mechanism for coordinated heterogeneous MIMO cellular networks

“…We are interested to know whether the results in [19,20] can be generalized into other types of network layouts and/or larger sets of possible cluster patterns, and how the rotating cluster patterns can be modified for those other layouts. This generalization aspect is quite important; cluster rotation would not be nearly so useful, if it only worked for a certain type of network layout.…”

“…Thus, the cluster-edge effect is averaged out and diminished over time since users, who are periodically located either near the border or the center of the clusters as the cluster borders change with each pattern, each receive data primarily during their most favorable pattern(s). In [19], we proposed a method of cluster rotation for the downlink of a multicell MU-MIMO HetNet, and its performance was compared with static clustering using both maximum throughput (MT) and PF scheduling metrics. A simulated annealing user scheduling algorithm and successive zero-forcing dirty paper coding (SZF-DPC) [31] precoding were used in the system.…”

“…It was shown in [35] that this method achieves performance close to that of an exhaustive search with much lower complexity, making its continued use in this context reasonable. The SAS algorithm in [19] was memoryless, while in [20], we added memory to the algorithm to further improve its performance. We have made additional refinements to the SAS algorithm in [35]; it is that version (adapted for weighted sum rates) that we use in this work.…”

“…To keep the same general methodology as in [19], we continue to use SZF-DPC precoding, which partially nulls the interference between users [31]. Since reduced-complexity user scheduling is necessary in practical systems with a large number of users, we use our previously proposed simulated annealing user scheduling (SAS) method [35].…”

“…The macro BSs in [19,20] were each equipped with one out of six sets (per site) of antenna arrays, with each set covering a cell; the hexagonal-shaped macro site coverage area thus was divided into six cells 1 . We are interested to know whether the results in [19,20] can be generalized into other types of network layouts and/or larger sets of possible cluster patterns, and how the rotating cluster patterns can be modified for those other layouts.…”