Performance gain of full duplex over half duplex under bidirectional traffic asymmetry

Recent work has demonstrated the advantage of full-duplex (FD) network over half-duplex (HD) network in bidirectional sum rate under the assumption of full-buffer and symmetric uplink-downlink traffics. In this paper, we consider asymmetric bidirectional traffics, and study the performance gain of FD network over both the traditional time-division duplex (TDD) network with static time slot splitting for uplink and downlink and the dynamic TDD with adaptive time slot splitting according to bidirectional traffics requirements. We use the number of users supported by the networks as performance metric, which is defined as the minimum of the number of users supported in uplink and downlink given random data rate requirements of users. To maximize the number of supported users, bidirectional time slot splitting is optimized for dynamic TDD network, and bidirectional power control at both BSs and users is optimized in FD network. Numerical results show the evident gain of FD network over traditional TDD for different levels of traffic asymmetry, and the gain over dynamic TDD decreases with the increase of traffic asymmetry.