Exploiting scalar effects of MIMO detection in could base-station: Feasible scheme and universal significance

In this paper, the problem of exploiting potential benefit from centralized processing nature of cloud base-station is addressed. We propose to exploit one kind of benefit available in cloud base-station, called scale effects, for MIMO detection by employing the scale effects oriented MIMO detector (SEOD). From this study, it can be found that SEOD is a feasible scheme being able to exploit two types of scale effects. The first type, called scale effect on diversity order, denotes the feature that the worst-case complexity per user of MIMO detection could decrease as the number of users increases while bringing no loss of diversity order; the second one, called scale effect on detecting outage, is the feature that the probability of detecting outage owing to the run-time limit is equal to or is asymptotic to a monotonic decreasing function of the number of users when fixing the worst-case complexity per user for MIMO detection. By using the large deviation principle (LDP), this work presents the proof of the existence of scale effect on detecting outage in SEOD which has not been obtained in literatures. Provided SEOD as a representative case, we also state the universal significance of exploiting scale effects for cloud base-station.