Runtime Precoding: Enabling Multipoint Transmission in LTE-Advanced System-Level Simulations

Abstract

System-level simulations have become an indispensable tool for predicting the behavior of wireless cellular systems. As exact link-level modeling is unfeasible due to its huge complexity, mathematical abstraction is required to obtain equivalent results by less complexity. A particular problem in such approaches is the modeling of multiple coherent transmissions. Those arise in multiple-input-multipleoutput transmissions at every base station but nowadays so-called coordinated multipoint (CoMP) techniques have become very popular, allowing to allocate two or more spatially separated transmission points. Also, multimedia broadcast single frequency networks (MBSFNs) have been introduced recently in long-term evolution (LTE), which enables efficient broadcasting transmission suitable for spreading information that has a high user demand as well as simultaneously sending updates to a large number of devices. This paper introduces the concept of runtime-precoding, which allows to accurately abstract many coherent transmission schemes while keeping additional complexity at a minimum. We explain its implementation and advantages. For validation, we incorporate the runtime-precoding functionality into the Vienna LTE-A downlink systemlevel simulator, which is an open source tool, freely available under an academic noncommercial use license. We measure simulation run times and compare them against the legacy approach as well as link-level simulations. Furthermore, we present multiple application examples in the context of intrasite and intersite CoMP for train communications and MBSFN.INDEX TERMS Link abstraction, link quality model, runtime-precoding, 3GPP, LTE-A, Vienna LTE-A downlink system level simulator, MIESM, Vienna LTE-A downlink link level simulator, LTE transmission modes, coordinated multipoint, multimedia broadcast single frequency networks, high-user mobility.

3GPP 3D MIMO channel model: a holistic implementation guideline for open source simulation tools

“…9a, it is observed that the results scale approximately linear with the number K of UEs and with the simulation length N TTI . Such behavior was already observed in [22] together with a more detailed description of its origins. In this paper, our main interest is on the impact of the elevation direction and the application of the 3GPP 3D channel model for interfering channels on the simulation run time.…”

“…We now extend this approach by also taking into account the interfering links. We integrate our code into the Vienna LTEA Downlink System Level Simulator (current version v1.8r1375) [22]. The simulator is implemented in object-oriented MAT-LAB and is made openly available for download under an academic, non-commercial use license.…”

“…On link level, channel realizations are typically calculated per OFDM symbol and LTE-A subcarrier [21]. On system level, they are commonly generated per physical resource block (RB) and transmission time interval (TTI) [22].…”

“…6 and, thus, serves as a representative example. Its centerpiece is the link abstraction model that specifies the interaction between link-and system level simulations [1,22]. This structure is expected to persist in simulation tools for the fifth generation of mobile cellular networks (5G) [24].…”

Improved Capacity and Fairness of Massive Machine Type Communications in Millimetre Wave 5G Network

“…An algorithm was developed in Reference [8] in order to optimise the number of RRUs deployed in a network using game theory. Multipoint transmission coordination of distributed RRUs has been investigated in References [9,10]. While the first investigation on using remote antennas in the mmWave band was introduced in Reference [11], where the author has demonstrated the importance of remote antennas on minimising the shadow fading of wireless networks in the Local Multipoint Distribution Service (LMDS) band.…”