Spectral efficient and fair user pairing for full-duplex communication in cellular networks

Abstract

A promising new transmission mode in cellular networks is the three-node full-duplex mode, which involves a base station with full-duplex capability and two half-duplex user transmissions on the same frequency channel for uplink and downlink. The three-node full-duplex mode can increase spectral efficiency, especially in the low transmit power regime, without requiring full-duplex capability at user devices. However, when a large set of users is scheduled in this mode, self-interference at the base station and user-to-user interference can substantially hinder the potential gains of full-duplex communications. This paper investigates the problem of grouping users to pairs and assigning frequency channels to each pair in a spectral efficient and fair manner. Specifically, the joint problem of user uplink/downlink frequency channel pairing and power allocation is formulated as a mixed integer nonlinear problem that is solved by a novel joint fairness assignment maximization algorithm. Realistic system level simulations indicate that the spectral efficiency of the users having the lowest spectral efficiency is increased by the proposed algorithm, while a high ratio of connected users in different loads and self-interference levels is maintained.

On the spectral efficiency and fairness in full-duplex cellular networks

“…However, the authors do not provide power control and channel allocation schemes that are developed with such objectives in mind. In contrast, our previous work [9] formulated the maximization of the minimum spectral efficiency problem and proposed a max-min fair power control and channel allocation solution.…”

“…Therefore, in this work we aim to fill this research gap by proposing a multi-objective optimization problem to maximize simultaneously both the weighted sum spectral efficiency and the minimum spectral efficiency of all users. Such an optimization problem poses technical challenges that are markedly different from those investigated in our previous works [2], [9]. In particular, we develop an original and new solution approach based on the use of the scalarization technique to convert the multi-objective into a single-objective mixed integer nonlinear programming (MINLP) problem that considers jointly user pairing and UL/DL power control.…”

“…Another important objective is to improve the fairness and per-user quality of service (QoS) of FD cellular networks, as emphasized in [1], [2], [8], [9]. In our previous work, we proposed a weighted sum spectral efficiency maximization, where the weights represent path-loss compensation and are thus related to the rate distribution and fairness in the system [2].…”

Downlink Error Rates of Half-Duplex Users in Full-Duplex Networks Over a Laplacian Inter-User Interference Limited and EGK Fading

“…The authors in [11] mitigate the interuser interference via an optimal channel allocation and power control that maximizes the system performance. In addition, in [12], [13] the authors investigate the user scheduling and power allocation by maximizing the system sum rate. However, the algorithms in [8], [11]- [13] require the instantaneous mutual channel state information between UEs, which is hard to estimate and/or communicate.…”

“…In addition, in [12], [13] the authors investigate the user scheduling and power allocation by maximizing the system sum rate. However, the algorithms in [8], [11]- [13] require the instantaneous mutual channel state information between UEs, which is hard to estimate and/or communicate. A more practical way to mitigate the inter-user interference is to pair interfering users in the 3NT based on their statistical mutual channel conditions, which requires statistical studies for the inter-user interference problem.…”