Joint user scheduling and power optimization in full-duplex cells with successive interference cancellation

Abstract

This paper considers a cellular system with a fullduplex base station and half-duplex users. The base station can activate one user in uplink or downlink (half-duplex mode), or two different users one in each direction simultaneously (full-duplex mode). Simultaneous transmissions in uplink and downlink causes self-interference at the base station and uplinkto-downlink interference at the downlink user. Although uplinkto-downlink interference is typically treated as noise, it is shown that successive interference decoding and cancellation (SIC mode) can lead to significant improvement in network utility, especially when user distribution is concentrated around a few hotspots. The proposed temporal fair user scheduling algorithm and corresponding power optimization utilizes fullduplex and SIC modes as well as half-duplex transmissions based on their impact on network utility. Simulation results reveal that the proposed strategy can achieve up to 95% average cell throughput improvement in typical indoor scenarios with respect to a conventional network in which the base station is half-duplex.

Max-Min Fairness User Scheduling and Power Allocation in Full-Duplex OFDMA Systems

“…However, different from [19] but following a similar idea in [20], we assume that the TDA of the UEs are undetermined and optimize the uplink/downlink TDA, UP and power allocation jointly. In contrast to most of the existing works and our previous work [1] but sharing the same idea as [16], we formulate the joint design problem as a two-time-scale MMF rate maximization problem. In particular, by considering the fact that the TDA and the UP solutions should not change as frequently as the fast fading of the wireless channels, in the formulated two-time-scale problem, the TDA and the UP variables are optimized to maximize a long-term MMF rate averaged over fast fading channels, while power allocation is performed for maximizing the MMF rate during each coherence interval.…”

“…This is because if the CCI between an uplink UE and a downlink UE is strong, then it is undesirable to group them together as a downlink/uplink pair. Following this idea, references [15], [16] studied joint beamforming/power control and uplink/downlink UE selection algorithms for maximizing the network throughput. This paper considers a FD multi-user orthogonal frequency division multiple access (OFDMA) system, where different channels (i.e., resource blocks (RBs)) may be occupied by different UEs, and one RB can at most serve one uplink UE and one downlink UE simultaneously due to the FD capability.…”

Opportunistic Temporal Fair Mode Selection and User Scheduling for Full-duplex Systems

“…We do not provide the details due to the lack of space and refer the reader to [15]. According to [15], this heuristic scheduler requires i w UL,i + j w DL, j ≤ 1, since it uses an underlying HD scheduler. Consequently, there is a set of feasible temporal demands in S ∞ (V) characterized in Section III-A, which are not achievable by this heuristic method whereas according to Theorem 3, the optimal TBS provided in Section IV can achieve any choice of temporal demands belonging to S ∞ (V).…”

“…The parameter c is the step-size. Lines (8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23) verify that the temporal demand constraints and dual feasibility conditions are satisfied. The computational complexity of the algorithm is proportional to the number of virtual users which is O(n 2 ).…”

“…Furthermore, scheduling under long-term temporal fairness in FD systems is considered in [15], where a heuristic scheduler is provided by modifying an optimal temporal fair HD scheduler.…”