Interference-Aware Cascade Modulation for Advanced Duplex Systems in Beyond-5G

In this paper, we propose a new data transmission scheme called interference-aware cascade modulation (IA-CM) for advanced duplex (AD) in Beyond-5G cellular systems where downlink (DL) and uplink (UL) signals are transmitted and received simultaneously within a carrier bandwidth. In IA-CM, self-interference due to simultaneous operation of DL transmission and UL reception in a base station is handled by adapting the modulation and coding scheme (MCS) level of the UL data transmission according to the level of self-interference that has a gradual decaying profile in the frequency domain. Consequently, unlike conventional scheme where a single MCS level is used for UL data transmission throughout the assigned UL bandwidth, multiple MCS levels are used in IA-CM based UL data transmission. In the process, the base station evaluates signal-to-interference-plus-noise ratio (SINR) in frequency selective manner taking into account the interference leakage generated from non-linearity of DL transmission, coupling with UL, and self-interference cancellation capability. in Fig. 1, two-dimensional resource allocation The benefits of IA-CM are verified from evaluations and it is observed that IA-CM achieves a 30% throughput gain over the conventional scheme when AD is used.