Tackle the Intricacies of 5G

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Without question, 5G wireless communications continues to dominate the headlines, as a host of companies are involved with the standard in some capacity. Last December, the non-standalone (NSA) 5G New Radio (NR) specification was released by the 3GPP. And very soon, the 5G standalone (SA) version will be completed.

“The 3GPP standards are specified in periodic releases,” explained Ken Karnofsky, senior strategist for signal processing applications at MathWorks. “Release 15 marks the start of the 5G standard. Release 15 has been further divided into two phases: 5G NSA (December 2017) and 5G SA (June 2018).

“The 5G NSA specification introduces 5G NR radio access technologies that will work with the existing LTE network infrastructure,” Karnofsky added. “This will enable faster commercialization of 5G NR technologies. 5G SA will introduce a new network architecture that will work alongside the LTE network.”

In terms of what this all means to MathWorks, Karnofsky noted, “Because the NSA standardization has been accelerated, MathWorks is seeing a rapid shift from research to design of 5G radio access technologies across the supply chain. Meeting the accelerated timelines calls for new tools and workflows to design and verify the highly integrated and adaptive signal processing, RF, and antenna devices in 5G NR.”

The 5G Vision

With the activity surrounding the 5G NSA and SA specifications, the vision for 5G is vast in scope. “The 5G vision aims to provide much faster mobile broadband service (>10 Gbps) for applications such as immersive video and virtual reality,” said Karnofsky. “It also aims to provide ultra-reliable and low-latency (<1 ms) communication for safety-critical applications, such as connected autonomous vehicles, as well as massive machine-type connectivity for Internet of Things (IoT) applications.”

Karnofsky added, “Release 15 addresses only the first use case—enhanced mobile broadband service—so the product development activity is concentrated in the mobile device and infrastructure supply chain. 3GPP is organizing working groups to study and define the requirements for the low-latency and machine-type use cases. Before those technologies mature, we will see cellular communications introduced into cars and IoT devices based on current LTE standards such as cellular vehicle-to-everything (C-V2X) and NB-IoT.”

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Shown is the resource grid for 5G downlink shared channel (PDSCH). The 5G NR physical layer supports flexible subcarrier spacing for wider channel widths and higher transmission rates. (© 1984-2018 The MathWorks, Inc.)

MathWorks’ 5G Library

MathWorks recently introduced its 5G Library, which is a free, downloadable add-on for LTE System Toolbox. The 5G Library enables engineers to explore the behavior and performance of 5G radio access technologies as defined by the Release 15 3GPP NR standard V15.0 (figure).

Included in the 5G Library are 5G channel models (TR 38.901) and physical layer algorithms defined in the initial 5G standard. It supports 5G Cyclic-Prefix OFDM (CP-OFDM) waveforms with filtering and windowing techniques for spectral shaping. The 5G NR frame numerology with flexible subcarrier spacing—as well as new channel coding schemes, such as LPDC and polar codes—are supported in the 5G Library. Another feature is the 5G link-level simulation reference design, which enables designers to measure 5G link throughputs.

“The 5G physical layer will depart from 4G LTE in a number of ways that improve spectral efficiency and data rates,” Karnofsky explained. “One distinctive feature is a significant jump in the number of active antennas and antenna arrays, as well as the related issues of beamforming, millimeter-wave RF signal processing, and power amplifier (PA) linearization.

“With the 5G Library and related tools for baseband, RF, and antenna design,” he added, “MATLAB provides a flexible framework development of proprietary physical layer algorithms, accelerating link-level simulations and automating verification of massive multiple-input, multiple-output (MIMO) antenna and RF designs.”

More Thoughts from Ken Karnofsky

To meet emerging 5G mobile broadband requirements, RF and digital engineers must address system performance changes and partition designs between RF/analog and digital components.

As advanced radios integrate RF and digital technologies to a degree never seen before, RF and digital engineers need to understand how the RF front end affects system performance. Moreover, they must know how to partition designs between RF/analog and digital components to meet the performance and efficiency requirements of emerging 5G technologies.

Emerging approaches are also adding fuel to the fire. Take, for example, technologies being developed for 5G, such as massive MIMO, mmWave, and the latest modulation schemes that require innovative combinations of new baseband technologies and RF architectures. Or consider IoT devices that require power-efficient RF modules to add wireless connectivity. These technologies only deepen the need for highly integrated design environments and flexible connectivity to prototyping and test hardware.

Advances in technology are presenting certain challenges for design environments and prototyping and test hardware. These challenges have spurred advances in modeling and simulation software including improved integration of RF, antenna, and digital modeling and simulation; faster simulation of complex RF architectures to facilitate rapid design exploration; and connectivity to a range of SDR and RF test hardware to accelerate and lower the cost of prototyping and design verification.

New design architectures and algorithms will affect every aspect of 5G systems, from antennas to RF electronics to baseband algorithms. The performance of these subsystems is so tightly coupled that they must be designed and evaluated together.