Welcome to this blog post, this week we are going to speak about some of the most important aspects to understand 5G standard:
As the main candidate technology of IMT2020 (International Mobile Telecommunications-2020), 5GNR is rapidly advancing under the unified coordination of 3GPP. According to the plan, the first 5G standard was frozen last year, which provides operators with a feasible solution for initial deployment of 5G.
5GNR is the abbreviation of 5G New Radio. It is the hottest research and development focus of today’s communication industry. In addition to competition among enterprises, the competition between industrial policies between countries and countries is also fierce. The spectrum is the battlefield for direct confrontation.
It seems that 5G is 1G more than 4G. In fact, 5G is far more than 4G in many aspects. It can be said that 4G is still in the final stage of quantitative change, and 5G has undergone qualitative changes. A popular saying is that, a “structural” change has taken place.
In addition to improving the user experience and further reducing traffic costs in the enhanced Mobile Broadband (eMBB), 5G is also aimed at the Internet of Things and vertical industries, including the massive Machine Type Communications (mMtc) IoT and Ultra Reliable Low Latency Communications (URLLC) business. See below for a description of ITU’s business types for IMT2020 technology:
The first version of the 5GNR standard (3GPP Release 15) supports Enhanced Mobile Broadband (eMBB), and also supports partial uRLLC functionality. The mMTC will likely be included in the second edition of the 5G NR standard.
NO.1 New spectrum and new bandwidth introduce more signal quality issues
The business needs of the next 5-10 years require 5G to provide higher speeds, such as online games, streaming content distribution, and so on where it can only provide image quality at lower resolutions now due to the limitations of 4G technology. If you are a mobile game enthusiasts, even if you can tolerate the jagged sense of the picture, probably you will not tolerate the regret that others have already PK your game character out while you’re waiting for the stuttering. In addition, even a cell phone with a good signal, the delay is usually in the tens of milliseconds, which is still a noticeable delay. When most people realize this, 5G is coming.
In order to achieve higher speeds and lower latency, 5G plans to use larger bandwidth signals and higher spectrum. Up to now, the global spectrum range defined by 5GNR Release 15 has reached 52.6GHz, and more spectrum is sought in the 100GHz range. Besides, the subcarrier bandwidth has been as high as 400MHz, and it is also possible to achieve greater bandwidth by carrier aggregation. At the same time, the degradation of signal quality due to problems such as path loss, flatness, phase noise, and linearity is a difficulty and challenge that must be solved by 5G.
NO.2 Advanced beamforming technology requires system design
In order to further improve the spectrum efficiency and overcome the propagation loss, 5G large-scale antenna base stations generally adopt beamforming technology. The base station needs to find the mobile phone through beam scanning, and then establish a service interaction between the mobile phone and the base station through the service beam signal. This is a very attractive design, while for sure, very complicated to implement. Questions about whether the beam uses the same frequency or different frequency, beam parameters, signal quality, end-to-end performance, OTA RF performance, etc. seem to be a little simple, however, from the system design and simulation stage must be considered. A successful system design can significantly reduce risks at all stages of the product life cycle.
NO.3 Waveforms and variable parameter sets affect signal peak-to-average ratio
5G NR Release 15 uses CP-OFDM waveforms and adapts to a flexible and variable parameter set. Variable parameter sets can multiplex services of different levels and delays and allow for larger subcarrier spacing in the millimeter wave band. Since the signal no longer maintains orthogonality, the problems of large peak-to-average ratio and subcarrier interference are introduced. In the upstream channel, the UE’s transmit power is limited and the power efficiency requirements are high, so the DFT-S-OFDM waveform is used to reduce the peak-to-average ratio of the signal.
NO.4 Millimeter wave requires OTA test
The 5G frequency band is extended to millimeter waves. When taking the advantages of large wave bandwidth and rich spectrum resources of millimeter waves, we also face the problem that traditional test methods are no longer applicable. The typical millimeter wave base station, the antenna and the chips can no longer be applied to the conduction test in the frequency band below 6 GHz. A new OTA air interface test is imperative.
NO.5 Coexistence interference problem of dual-connected, multi-standard signals
In the early stage of 5G, it faces the issue of coexistence and simultaneous connection with the LTE system. After 5G commercial, the signals such as 3G, 2G, Wifi, and BT, would still exist for a long time. Due to spectrum fragmentation, the problem of signal coexistence interference becomes more and more obvious. Therefore, for harmonics, spurs, adjacent channel interference and other issues, it is necessary to strengthen monitoring and evaluation.
NO.6 Changes in the core network: Intelligent, cloud, virtualization
The 5G service types are more diverse, and they need the core network to be more flexible, intelligent, and reconfigurable. The 5G network slicing technology is used to cope with service diversity and reduce network costs, enabling operators to dynamically optimize network parameter configuration for a certain service or region, thereby improving network capabilities and improving the real user experience. Cloud RAN centralizes baseband processing in the cloud, which is very effective for dynamic optimization of power consumption and network capacity.
NO.7 5G innovation is still on the road
The structural changes of 5G bring wireless networks a broader business scenario. Large-scale antennas, beamforming, millimeter-wave techniques, and network slicing are all new technologies introduced to address new business needs. However, 5G’s innovation road has not stopped. 5G will continue to introduce new technologies for new business needs and new business models brought by the future 10 years of social progress, and this will bring great opportunities to people in communication field.
The Future Intelligence Lab is a joint research institute of artificial intelligence, Internet and brain science established by artificial intelligence scientists and related institutions of the Academy of Sciences. The main tasks of the future intelligent laboratory include: establishing an AI intelligent system IQ evaluation system, conducting world artificial intelligence IQ evaluation; developing an Internet (city) cloud brain research plan, building an Internet (city) cloud brain technology and enterprise map, to enhance the enterprise, Industry and city intelligence level services.
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