5G Channel Simulation Platform

5G Channel Simulation Platform for the Next Generation of Mobile Networks and Innovative Technologies

Abstract

The exponential increase in mobile data traffic is considered to be a critical driver towards the new era, or 5G, of mobile wireless networks. 5G will require a paradigm shift that includes very high carrier frequency spectra with massive bandwidths, extreme base station densities, and unprecedented numbers of antennas to support the enormous increase in the volume of traffic. This paper discusses several design choices, features, and technical challenges that illustrate potential research topics and challenges for the future generation of mobile networks. This article does not provide a final solution but highlights the most promising lines of research from the recent literature in similar ways for the 5G project. The potential physical layer technologies that are considered for future wireless communications include spatial multiplexing using massive multi-user multiple-input multiple-output (MIMO) techniques with millimetre-waves (mm-waves) in small cell geometries. These technologies are discussed in detail, along with the areas for future research.

1 Introduction

There has been some debate in the improvement of the 3GPP TR 38.900 Release 14 channel model for over 6 GHz. The key problems studied in this thesis include interference cancellation in HetNet, impairments calibration for massive MIMO, channel state estimation for VLC, and low latency parallel Turbo decoding technique. Firstly, inter-cell interference in HetNet is studied and a cell specific reference signal (CRS) interference cancellation method is proposed to mitigate the performance degrade in enhanced inter-cell interference coordination (eICIC). This method takes carrier frequency offset (CFO) and timing offset (TO) of the user’s received signal into account. By reconstructing the interfering signal and cancelling it afterwards, the capacity of HetNet is enhanced. Secondly, for massive MIMO systems, the radio frequency (RF) impairments of the hardware will degrade the beamforming performance. When operated in time duplex division (TDD) mode, a massive MIMO system relies on the reciprocity of the channel which can be broken by the transmitter and receiver RF impairments. Impairments calibration has been studied and a closed-loop reciprocity calibration method is proposed in this thesis.

The global bandwidth shortage facing wireless carriers has motivated the exploration of the underutilised millimetre-wave (mm-wave) frequency spectrum for future broadband cellular communication networks. There is, however, little knowledge about cellular mm-wave propagation in densely populated indoor and outdoor environments

Obtaining this information is vital for the design and operation of future fifth-generation cellular networks that use the mm-wave spectrum.

In this paper, we present the motivation for new mm-wave cellular systems, methodology, and hardware for measurements and offer a variety of measurement results that show 28 and 38 GHz frequencies can be used when employing steerable directional antennas at base stations and mobile devices.

2. Background and Literature Review

With the increasing demands on frequency resources, spectrum sharing between the satellite and terrestrial systems becomes prominent, especially when it comes to the millimetre wave (mmWave) bands.

In this paper, we propose a general spectrum sharing framework in satellite and terrestrial networks, through analysing the interference caused by terrestrial cellular systems and non-geostationary (NGEO) systems to geostationary (GEO) systems, respectively, both in the downlink and uplink.

Especially in the spectrum sharing between terrestrial and GEO systems, two scenarios are analysed. In the first scenario, we consider each base station (BS) equipped with one omnidirectional antenna, and in the second scenario, the beamforming scheme is employed at the BSs.

In light of the parameters recommended by the standards and recent results presented in the literature on the mmWave channel model, we calculate the protection area where no cognitive users (terrestrial system or NGEO system) could transmit.

With both the uplink and downlink impairments estimates, the reciprocity calibration coefficients can be obtained. By computer simulation and lab experiment, the performance of the proposed method is evaluated. Channel coding is an essential part of a wireless communication system which helps fight with noise and get correct information delivery. Significant standard bodies like the third Generation Partnership Project (3GPP) and the International Telecommunication Union (ITU) are deciding on wideband station models — a vital initial phase in creating and looking at changed air interface conventions and deciding phantom proficiency (SE) of cutting edge mmWave physical (PHY) layer ideas

For certifiable execution forecasts and framework configuration, channel models ought to be precise and natural, and ought to be founded on repeatable estimations of how directs carry on as a general rule. Better actually, models ought to likewise have some premise in fundamental material science, since the laws of physical science administer radio engendering and help support overall comprehension of station essentials over the tremendous mmWave range. Exact channel models are likewise expected to decide the sign handling engineering and prerequisites at both the transmitter and beneficiary.

3. Research question

The definition of the protection area is to guarantee an outage performance for the GEO system. Outside the protection area, the cognitive transmitters may transmit concurrently with GEO systems. Simulations are conducted to verify the effectiveness of the proposed schemes.

3.1 Does the antenna element on the array can be computed without any implications in the 5G network and how?

This dissertation describes a link-layer protocol called SoftRate that uses the channel BER computed from SoftPHY hints as the feedback to perform bit rate adaptation.

This leads to the fact that each antenna element on the array may observe different sets of clusters, which is not characterised in conventional MIMO channels. As a result, the WSS assumption on antenna arrays does not necessarily hold for massive MIMO channels. The authors in [1], [2]–[3] modelled cluster evolution on the time axis with birth-death processes or Markov processes. However, non-stationary properties of clusters on the array axis have not been studied for massive MIMO channels in the literature.

By and by, this new organisation design and resulting key innovations carry new difficulties to framework level reenactment strategies and systems for 5G frameworks adaption. Initially, for inside capacity request and reenactment speed, the more intricate boundary set up, the more significant fleeting information stockpiling request, colossal communicating data of clients, more assorted execution assessment measurements show up with the application of enormous scope radio wires [2]. Turbo codes is one of the most reliable codes that has been used in many standards such as WiMAX and LTE. However, the decoding process of turbo codes is time-consuming and the decoding latency should be improved to meet the requirement of the future network. Thirdly, the conveyed coordination and self-composed organisation make the change of 4G reproduction devices like asset planning and beamforming vital.

The assessment setting module executes different ITU test situations and gives explicit remote organisation sending climate for framework activity. The channel model which is aligned by step1 incorporates enormous blurring, added substance white Gaussian clamour (AWGN), MIMO channel and temporary blurring. Four commonplace test conditions have been picked with the end goal that extraordinary arrangements are demonstrated, and necessary inquiries in framework plan and execution can be examined. Likewise, to test cutoff points of execution identified with limit and client versatility, the described arrangement situations in the assessment are determined.

3.2 HowFirst-order simplifications of the channel model can be implemented in Matlab?

First-order simplifications of the channel model will not be appropriate with the spherical wavefront instead of plane wavefront assumption. Also, conventional MIMO channel models cannot be directly applied to massive MIMO channels in which different antennas may observe different sets of clusters. These two essential features are hard to be embedded in CBSMs, although they are simple. On the other hand, complex GBSMs can reflect massive MIMO channel characteristics, but many more models for different practical scenarios are yet to be developed. 3-D massive MIMO models, which jointly consider azimuth and elevation angles, are more practical as well as complicated. In summary, new massive MIMO channel models should be developed, having a fair tradeoff between model accuracy and complexity and considering different practical scenarios with specific channel characteristics. On account of building a framework level reproduction to assess full-duplex radio, the circumstances ought to be taken into thought.

• Complex Interference Situation: With the presenting of full-duplex, the genuine obstruction may happen resulting from: the high DL self-impedance to UL signal, the between client UL-DL impedance, between BS DL to UL obstruction and between cell between client UL-to-DL impedance in multi-cell network;

• Additional Analog or Digital Circuits: The impact of planning simple and computerised self-impedance cancellation circuits ought to be contemplated;

• Combination With MIMO: The primer technique of utilising full-duplex for single communicate reception apparatus and get reception apparatus has been investigated, yet the receiving wire configuration joining MIMO with full-duplex stays a key challenge.

3.3 What is the significance of Channel Quality Index for 5G wavefront in Space-Time-Frequency Correlation Function?

However, in [3], the impact of the spherical wavefront on Non-Line-of-Sight NLOS components was missing, characteristics of cluster appearance and disappearance were not studied in detail, and non-stationarities on the time axis were omitted. A 3-D non-stationary twin-cluster channel model was proposed in [51] for massive MIMO systems considering spherical wavefront and non-stationarities on both time and array axes. However, AoAs and AoDs were assumed independent, channel characteristics such as power imbalance on the antenna array and Space-Time-Frequency Correlation Function (STFCF) were not investigated in [5].

SoftRate also uses a heuristic to identify patterns of SoftPHY hints that correspond to transient interference and eliminates the effect of such interference in computing the BER feedback.

The streaming PHY also enables the link layer to perform a jointly-optimal bit rate adaptation and channel access decision. It must be noted that the exposed terminal problem becomes more complicated when we consider the presence of heterogeneous bit rates at the various senders.

4. Approach

The throughput at this best transmit bit rate may drop for each sender when the other node starts simultaneous transmission, due to the added noise from the concurrent transmission rate decisions, possibly picking different bit rates based on who else is transmitting concurrently.

However, it is also possible that when both nodes send concurrently at a rate lower than the optimal, say, 18 Mbps, the additional “slack” to tolerate noise available at the lower bit rate enables them to perform concurrent transmissions successfully.

In this case, the nodes should transmit concurrently at 18 Mbps, rather than share the channel at 24 Mbps and achieve an effective throughput of only 12 Mbps.

That is, for best system performance in this example, S should transmit to R at 18 Mbps when ES is transmitting, and at 24 Mbps otherwise.

4.1 Methodology

With the client/server architectural style, the system separates the user (client) and the application (server). A reverse interleave address generator is proposed that can reduce the decoding time and a low latency parallel turbo decoder has been implemented on a FPGA platform. The simulation and experiment results prove the effectiveness of the address generator and show that there is a trade-off between latency and throughput with a limited hardware resource. Apart from the above contributions, this thesis also investigated multi-user precoding for MIMO VLC systems. As a green and secure technology, VLC is achieving more and more attention and could become a part of 5G network especially for indoor communication. For indoor scenario, the MIMO VLC channel could be easily ill-conditioned. Hence, it is important to study the impact of the channel state to the precoding performance. A channel state estimation method is proposed based on the signal to interference noise ratio (SINR) of the users’ received signal. Simulation results show that it can enhance the capacity of the indoor MIMO VLC system.

A component-based architectural style separates the system functions and system logic into multiple subtasks. This makes the functions reusable since the system functionality is defined into separate functions. Furthermore, this makes functions independent from each other since there is low dependency. Some of the pros with a component-based architectural structure:

• The development of features can be done independently from each other since the functions have a low dependency.

• Parts of the system can be reused since they are implemented separately from the other functionality of the system.

• Third-party functions can be implemented, which can reduce the cost of the development. Some of the drawbacks with a component-based architectural style can be:

• If a new technology is implemented into an existing system, a component-based architecture is of no use since all components are outdated.

• Problems with migration to other system and compatibility with other platforms.

To implement this type of architecture, the developers need a good knowledge of the business or have resources that have expertise in a particular domain. With a domain-driven design, some of the benefits are:

• The same technical language can be used in the whole development team since the domain specifies the language.

• The system is easy to update and adapt since the domain model is often flexible. With a domain-driven design architecture, some of the drawbacks could be:

• The design could become costly since the architecture forces the design to be specific to the domain.

• Should only be used in systems that can benefit on the domain’s complexity.

Similar to the layered architecture is n-tier/3-tier, where the layers are instead tiers. The difference is that in the tier architecture, each tier runs on a separate computer. Some of the pros of tier architecture are that:

• It can easily be maintained since the system is divided into separate tiers that can be changed independently.

• The system can be scaled on each tier separate from the other tiers in the system. Some of the cons with tier architecture are:

• Since different parts of the system can be run on different machines, and the system could be dependent on remote servers.

• Run time of the system could be dependent on the network traffic if the different tiers are at remote locations.

5. Impact Statement

Shortly after the development of the NSS started, a list of requested features and functionality was received from our supervisor. This list can be viewed in Appendix B. The list was used as criteria for what the NSS end product should contain as a finished product. The investigation and prediction of new trends and technologies for mobile cellular networks is of utmost importance for researchers and network providers to quickly identify promising developments. With the verge of the fifth generation of mobile communications (5G), networks become more and more heterogeneous and dynamic while the amount of active users within a cell keeps ever increasing. Therefore, the search for more efficient network layouts and configurations attracts massive attention while on the other hand becomes more and more complex. In this contribution, we present the Vienna 5G system level simulator, which allows to perform numerical performance evaluation of large-scale multi-tier networks, with numerous types of network nodes. The simulator is based on MATLAB and is implemented in a modular fashion, to conveniently investigate arbitrary network and parameter constellations, which can be enhanced effortlessly. We first discuss the distinguishing aspects of our simulator platform, describe its structure, and then showcase its functionality by demonstrating the key aspects in more detail.Once these were developed to the point that the user interface could be used to initiate a simulation, the work of implementing features from the previously stated feature list could begin. The requested features were not sorted in any prioritised order, but it was still possible to conclude that some features were more important or useful to have than others. Also noticeable was the fact that some features depended on others to be useful. For instance, the usefulness of being able to plot the results of a load on a link is significantly reduced if the simulated load created by the nodes are fixed and cannot be changed.

Aside from the requested features, there was some missing functionality that was realised to be, at least as necessary as the assumed essential features. This included functionality like: being able to reset a simulation without having to open a new instance of the NSS and being able to have more than one data-generating node in the same network.

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Flow chart of 5G wireless communication in a user equipment device

6. Projected Timeline:

Task

Projected Monthly Timeline

June 20

July 20

Aug 20

Sep 20

Oct 20

Nov 20

Dec 20

Jan 21

Feb 21

Mar 21

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May 21

Chapter1

Introduction

a. Aim and Objectives

b. Research questions

c. Background of the Research

d. Gaps in current research

Chapter 2

II. Literature Review

a. Literature related to issues and challenges faced in the adoption of 5G technology in Australia.

b. Literature about the solutions observed for overcoming the issues faced in the wide-scale adoption of 5G wireless technology.

Chapter 3

III. Research Methodology Method of collecting data and its justification will be provided in this section. Data relevant to the research paper will be collected in this section.

Chapter 4

IV. Analysis of data collected

a. Data collected will be analysed as per the variables determined in research objectives.

b. Important findings

Chapter 5

V. Discussion

a. A discussion of the findings and data analysed

Chapter 6.

VI. Conclusion and Recommendations

Compiling the dissertation and submitting the first completed draft

Editing the final dissertation and making modifications wherever required.

7. References

1.Wu, J., Zhang, Y., Zukerman, M., & Yung, E. (2015). Energy-efficient base stations sleep mode techniques in green cellular networks: A survey. IEEE Communications Surveys & Tutorials, 17(2), 803–826.

2.Cisco Systems, Inc. (2014). Cisco visual networking index: Global mobile data traffic forecast update, 2013–2018.

3.Osseiran, A., Boccardi, F., Braun, V., Kusume, K., Marsch, P., Maternia, M., et al. (2014). Scenarios for 5G mobile and wireless communications: The vision of the METIS project. IEEE Communications Magazine, 52(5), 26–35.

4.Wang, R., Hu, H., & Yang, X. (2014). Potentials and challenges of C-RAN supporting multi-RATs toward 5G mobile networks. IEEE Access, 2, 1187–1195.

5.GSMA Intelligence. (2016). Understanding 5G: Perspectives on future technological advancements in mobile, 2014. Retrieved June 30, 2016 from https://gsmaintelligence.com/research/?file=141208-5g.pdf

6.Onoe, S. (2016). Evolution of 5G mobile technology toward 2020 and beyond. In 2016 IEEE International Solid-State Circuits Conference (ISSCC) (pp. 23–28).

7.Agiwal, M., Roy, A., & Saxena, N. (2016). Next generation 5G wireless networks: A comprehensive survey. IEEE Communications Surveys & Tutorials, 99, 2016.

8.Rappaport, T. S., Sun, S., Mayzus, R., Zhao, H., Azar, Y., Wang, K., et al. (2013). Millimeter wave mobile communications for 5G cellular: It will work!. IEEE Access, 1, 335–349.

9.Abrol, A., & Jha, R. K. (2016). Power optimisation in 5G networks: A step towards GrEEn communication. IEEE Access, 4, 1355–1374.