Joint Power and Resource Block Allocation for Mixed-Numerology-Based 5G Downlink Under Imperfect CSI

Fifth-generation (5G) of wireless networks are expected to accommodate different services
with contrasting quality of service (QoS) requirements within a common physical infrastructure in an
efficient way. In this article, we address the radio access network (RAN) slicing problem and focus
on the three 5G primary services, namely, enhanced mobile broadband (eMBB), ultra-reliable and lowlatency
communications (URLLC) and massive machine-type communications (mMTC). In particular, we
formulate the joint allocation of power and resource blocks to the heterogeneous users in the downlink
targeting the transmit power minimization and by considering mixed numerology-based frame structures.
Most importantly, the proposed scheme does not only consider the heterogeneous QoS requirements of
each service, but also the queue status of each user during the scheduling of resource blocks. In addition,
imperfect Channel State Information (CSI) is considered by including an outage probabilistic constraint into
the formulation. The resulting non-convex problem is converted to a more tractable problem by exploiting
Big-M formulation, probabilistic to non-probabilistic transformation, binary relaxation and successive
convex approximation (SCA). The proposed solution is evaluated for different mixed-numerology resource
grids within the context of strict slice-isolation and slice-aware radio resource management schemes via
extensive numerical simulations.