Subband Full Duplex (SBFD) is an innovative duplexing method for advanced 5G/6G cellular communication that enhances uplink coverage and minimizes communication latency compared to TDD. SBFD allows a base station to transmit and receive simultaneously in distinct downlink and uplink sub bands within the channel bandwidth of a TDD carrier. To maximize the advantages of SBFD communications, it's crucial to mitigate self-interference and cross-link interference between nodes. This paper initially discusses the enablers for interference mitigation in SBFD deployment, followed by an evaluation analysis and field measurement results of SBFD duplex technology for a 5G massive-MIMO macro network in the 5G band.

Time-division duplex (TDD) and frequency-division duplex (FDD) are mainly used in commercial new radio (NR) deployments, where the time- or frequency-domain resources are split between downlink (DL) and uplink (UL). Full duplex (FD) will enable 5G-advanced and 6G systems to go beyond TDD and FDD operation into a new duplexing mode that leverages the benefits of both TDD/FDD deployments. It achieves higher throughput and lower latency while enabling flexible UL/DL scheduling. However, there are several challenges that need to be overcome to enable FD operation in large-scale system deployment, including intranode and internode [user equipment (UE) and next-generation node B (5G base station)] interference along with intercarrier interference. In this article, we present solutions to mitigate self-interference (SI) and cross-link interference (CLI) in 5G-advanced/6G systems, provide system-level evaluations, and discuss the outcome of Third Generation Partnership Project (3GPP) study item on duplexing evolution. We introduce the concept of subband FD (SBFD) as an effective solution for a macro network to achieve the key features of FD, such as latency reduction and UL link budget improvement. Finally, we present the field test results for the performance of world-first SBFD prototype of high transmit power massive-multi-input-multioutput (MIMO) macro network.

We present our study results on the neural network based approaches to the transmitter/receiver design over nonlinear channel. In the first part, we discuss the transmitter design for the peak-to-average power (PAPR) reduction. The algorithm unrolling is applied to a well-known PAPR reduction algorithm. The learning-based approach achieves the performance on par with the classical approach, but at the smaller computational complexity. The second part discusses the joint transmitter/receiver design for the mitigation of the transmitter nonlinearity. It is shown that by combining the neural network with the unfolded algorithm for PAPR reduction at the transmitter and employing the receiver neural network, sizable gain is achieved when the emission criterion is relaxed.

In this paper, we discuss UE power saving (PS) techniques for eXtended Reality (XR) applications in 5G NR system. XR traffic is characterized by pseudo periodic packet arrival, high bit rate, and low latency requirement. It is challenging to support such traffic in a small device form factor with limited battery size, e.g., head-mounted display (HMD) or XR glasses. Therefore, it is desired for 5G NR to support effective UE PS techniques. We first discuss a few PS techniques defined in 5G NR specifications Release 15 and 16. Then, we introduce new PS techniques that are evaluated via system level simulations with the UE power consumption model defined in a 3GPP. Evaluation results show that UE power consumption can be substantially reduced by the new PS techniques, up to 40%.

We present system-level evaluation results to characterize the performance of eXtended Reality (XR) applications over a 5G NR system. A split-rendering framework is assumed, where the XR device uses 5G to offload computation associated with rendering and encoding of video frames to an edge server. The XR traffic model includes rendered video frames on the downlink and user pose and control updates on the uplink. We present results for both sub-6 GHz (FR1) and millimeter-wave (FR2) bands. Additionally, we also discuss potential enhancements to further improve user experience for XR applications over 5G.