In-Band Full-Duplex-Applicable Area Expansion by Inter-User Interference Reduction Using Successive Interference Cancellation

Inter-User Interference Cancellation Scheme for 5G-Based Dynamic Full-Duplex Cellular System

“…Conversely, IUI occurs at the UE receiving the DL signal (DL-UE), where the UL signal transmitted by the UE transmitting the UL signal (UL-UE) degrades the reception quality of the DL signal. Various studies have proposed IUI reduction techniques at the physical (PHY) layer [15]- [20] and methods for avoiding IUI at the media access control (MAC) layer [21]- [24]. In the PHY layer, examples of IUI suppression involve beamforming [15], nulling signal generation and forwarding at the BS [16], [17], polarization state utilization [18], and successive interference cancellation (SIC) [19], [20].…”

“…Various studies have proposed IUI reduction techniques at the physical (PHY) layer [15]- [20] and methods for avoiding IUI at the media access control (MAC) layer [21]- [24]. In the PHY layer, examples of IUI suppression involve beamforming [15], nulling signal generation and forwarding at the BS [16], [17], polarization state utilization [18], and successive interference cancellation (SIC) [19], [20]. In contrast, IUI avoidance is achieved at the MAC layer by judiciously determining DL-UE and UL-UE pairs that are less susceptible to IUI based on collected IUI information.…”

“…A dynamic full-duplex cellular (DDC) system can operate in an environment where some UEs have no function for IBFD operation and represents a pragmatic and incremental approach to FDC implementation employing the MAC layer method [20]- [22]. The DDC system operates based on the conventional HD system and activates IBFD when conventional communication in an HD system experiences less degradation owing to IBFD, enabling adaptive IBFD within a reasonable situation.…”

“…This scenario is more likely to occur in smaller cell sizes owing to shorter distances between UEs and amplified IUI effects. Therefore, a PHYlayer IUI cancellation (IUIC) scheme employing SIC has been proposed for DDC systems [20], increasing the IBFDapplicability ratio. The method can reduce IUI by digital signal processing of UE even if the number of BS and UE antennas is small.…”

Throughput Enhancement of Dynamic Full-Duplex Cellular System by Distributing Base Station Reception Function

“…One of the factors limiting the improvement of spectral efficiency in DDC systems is the inter-user interference (IUI) caused by the UL-UE (UL communication-allocating UE) to the DL-UE (DL communication-allocating UE) when IBFD is applied. The impact of the IUI can be mitigated by appropriately selecting the pair of UEs to be assigned communication, and the IUI reduction method using successive interference cancellation has also been proposed [27]. The dominant factor limiting the improvement of the spectral efficiency in DDC systems is the residual component of the aforementioned SI, which cannot be fully suppressed by the SI canceller.…”