Performance analysis of interference measurement methods for link adaptation in 5G New Radio

5G New Radio (NR) is coming faster than expected with early deployments which take place early 2019. It is more than a new mobile generation that offers higher data rates compared to previous generations, although it’s still the main driver. It will enable many new use cases and deployment scenarios that can be put into three main categories: enhanced mobile broad band (eMBB), ultra-reliable low latency communications (URLLC) and massive machine type communications (mMTC). 5G NR aims to further increase frequency resources utilization and efficiency. Cell edge users usually suffer from high levels of interference known as inter-cell interference. This phenomenon results in lower performance for the cell edge users and inefficient utilization of radio resources. Link adaptation techniques aim to increase cell edge performance by exploiting varying channel conditions and interference level at user equipment (UE). In this thesis channel state information (CSI) is studied as an essential part of link adaptation process. Channel quality indicator (CQI) is the main component of CSI reports from UE that gives recommendations about the next transmission modulation order and code rate. The accuracy of reported CQI depends on the accuracy of channel and interference measurements. In this thesis two different interference measurement methods based on two reference signals are studied: CSI interference measurement (CSI-IM) and non-zero power CSI reference signal (NZP CSI-RS). In this thesis performance with different configurable factors, different channel models and UE speeds are considered. Overall system overhead is also studied to give recommendation about the configuration of lower system overhead. Simulation results has shown that CSI-IM based interference measurement is more efficient compared to NZP CSI-RS method and operates well in different channel scenarios and different UE speed. While NZP CS-RS shows sensitivity to frequency selective channels and in higher user mobility cases. On the other hand, from overall system overhead perspective, CSI-IM based configuration is the best solution

Blind detection of interfering cell data channel power level in 3GPP LTE/LTE-Advanced downlink

Nowadays wireless cellular networks can be seen as ubiquitous systems used by a majority of the world's population and their usage continues to grow in the future. Continuously higher data rates and shorter latencies are required due to the introduction of new mobile devices and services. In addition, mobile networks are more and more used as a primary connectivity solution in several places. Thus, new technologies are required to improve the capacity and latency of mobile networks. Long Term Evolution (LTE) and LTE-Advanced are technologies standardized by Third Generation Partnership Project (3GPP) with the potential to fulfill these requirements for future mobile networks. LTE/LTE-Advanced cellular networks are usually interference limited, because neighbouring cells use the same frequency band for data transmission. Because of this, several users may experience high interference levels and thus cannot achieve high data rates without proper counteractions. Consequently, advanced techniques to control, suppress or cancel the interference are of interest to be studied for LTE and LTE-Advanced by 3GPP. Network Assisted Interference Cancellation and Suppression (NAICS) techniques are currently been studied by 3GPP. One of the recent studies on NAICS is so called blind detection of interfering cell parameters in a user equipment for advanced non-linear receivers. Such receivers have the capability to suppress or cancel interference significantly but they require the knowledge of specific parameters of the interfering cell to perform efficiently. These parameters have to be either signaled by the network or blindly detected from the received signal in user equipment. The topic of this thesis is to study the feasibility of blind detection of interfering cell's data channel power level, which is crucial knowledge to non-linear receivers. The study is performed at radio link level by using numerical simulations, in which the transmitter and receiver processing are modeled in detail. In addition, also the effects caused by the radio channel to the transmitted signals are modeled. The performance of one non-linear receiver, namely Symbol Level Interference Cancellation (SLIC) receiver, with blind detection is compared to the performance of SLIC receiver which has the knowledge of all required parameters. While Linear Minimum Mean Squared Error - Interference Rejection Combiner (LMMSE-IRC) receiver operates as the baseline. From the simulation results it can be seen that the blind detector performs well. Consequently this blind detector can be one noteworthy option to avoid signaling of interfering cell's data channel power level

D3.2 First performance results for multi -node/multi -antenna transmission technologies

This deliverable describes the current results of the multi-node/multi-antenna technologies investigated within METIS and analyses the interactions within and outside Work Package 3. Furthermore, it identifies the most promising technologies based on the current state of obtained results. This document provides a brief overview of the results in its first part. The second part, namely the Appendix, further details the results, describes the simulation alignment efforts conducted in the Work Package and the interaction of the Test Cases. The results described here show that the investigations conducted in Work Package 3 are maturing resulting in valuable innovative solutions for future 5G systems.Fantini. R.; Santos, A.; De Carvalho, E.; Rajatheva, N.; Popovski, P.; Baracca, P.; Aziz, D.... (2014). D3.2 First performance results for multi -node/multi -antenna transmission technologies. http://hdl.handle.net/10251/7675

D 3. 3 Final performance results and consolidated view on the most promising multi -node/multi -antenna transmission technologies

This document provides the most recent updates on the technical contributions and research challenges focused in WP3. Each Technology Component (TeC) has been evaluated under possible uniform assessment framework of WP3 which is based on the simulation guidelines of WP6. The performance assessment is supported by the simulation results which are in their mature and stable state. An update on the Most Promising Technology Approaches (MPTAs) and their associated TeCs is the main focus of this document. Based on the input of all the TeCs in WP3, a consolidated view of WP3 on the role of multinode/multi-antenna transmission technologies in 5G systems has also been provided. This consolidated view is further supported in this document by the presentation of the impact of MPTAs on METIS scenarios and the addressed METIS goals.Aziz, D.; Baracca, P.; De Carvalho, E.; Fantini, R.; Rajatheva, N.; Popovski, P.; Sørensen, JH.... (2015). D 3. 3 Final performance results and consolidated view on the most promising multi -node/multi -antenna transmission technologies. http://hdl.handle.net/10251/7675