4G changes life, 5G changes society, but this change is not so easy.
2020 is the first year of global 5G commercialization as defined by the ITU, and China is a year earlier. According to the China Academy of Information and Communications Technology, domestic 5G mobile phone shipments from January to April 2021 will be 91.267 million units, accounting for 72.7% of the overall market, a year-on-year increase of 38.4%. This reflects, to a certain extent, the speed at which 5G communications are advancing at the individual user level.
However, 5G is not limited to mobile phones. In the era of the Internet of Everything, highways must be built in advance. Therefore, 5G is indisputably the first of new infrastructure. Compared with 4G, 5G has clearly planned three application scenarios at the initial stage: enhanced mobile broadband, its peak rate will be more than 10 times that of 4G network; massive machine communication will realize the whole process from consumption to production, from people to people. The full scene coverage of objects; ultra-reliable and low-latency communication, the communication response speed will be reduced to millisecond level.
The beautiful imagination for applications in various vertical industries derived from this is like a science fiction novel, and the premise that supports the realization of this novel is a towering base station that does not look so romantic.
New changes in 5G base station construction
All good things ahead, the road will always be twists and turns. In the industry, the shortcomings of 5G base stations are ridiculed as "three 3s of coverage, cost, and power consumption", that is, 3 times the cost, 3 times the power consumption, and 1/3 coverage. In this regard, Wenjing, an outstanding technical expert of Texas Instruments (TI), analyzed that part of the reason is due to the high frequency and high performance of 5G MM, the use of Massive MIMO technology, and the need for 32-channel, 64-channel and other multi-channel architectures. The increase in the number of hardware channels directly leads to cost, The power consumption and volume indicators have increased exponentially. Operators urgently need to significantly reduce site construction costs and operating costs, so higher requirements are placed on chip integration, power consumption and cost.
TI is one of the first semiconductor manufacturers to participate in China's 5G construction. Vic, regional sales manager of Texas Instruments China's major customers, introduced that looking at the world, China's 5G construction is at the forefront. As of 2020, China has deployed more than 700,000 5G base stations. Completed large-capacity coverage of some key cities. In 2021, it is planned to build 840,000 units, complete the wider area layout, and focus on 700MHz 4T4R networking. Through more advanced process nodes, more innovative design architecture, and larger-scale integration, TI has been striving to achieve the goals of high integration, low power consumption, and low cost. In fact, each generation of TI products will achieve about 30% improvement in power consumption under the same scale through process evolution/design architecture innovation.
Evolving Architecture
As the last link and the most critical equipment of wireless communication, RRU unit is like a bridge in the air, which ensures accurate and real-time delivery of information. Although the RF front-end is only a pipeline in a 5G base station, and the real brain is a processor such as ASIC/FPGA, the human body cannot perform normal activities without healthy pipelines to deliver nutrients and data to the brain. The RF signal processing and modulation of the RRU is as complex as the blood vessels and nerves in the human body. The RF front-end is a very challenging and crucial area in the RRU.
In a traditional superheterodyne system, after the receiver receives a signal at RF frequency, it downconverts the signal to a lower intermediate frequency (IF), where it is digitized, filtered, and then demodulated. The RF front end requires complex Signal chain processing. With the advancement of ADC and DAC converter technology, analog frequency conversion can be converted into digital direct frequency conversion, thereby omitting the intermediate frequency link, making the overall hardware design of the RF direct acquisition transceiver much simpler, so the overall size is smaller and the design cost. lower. "The discrete ADC, DAC, modulator, demodulator, Serdes, clock, DVGA and other functional modules in the traditional discrete superheterodyne system are integrated into a single chip, which provides the realization of 5G Massive MIMO multi-channel architecture. Physical possibilities." Wenjing sees this innovation as critical for Massive MIMO, which may reach hundreds of channels in the future.
The changes brought by high integration to users are huge. As the number of channels continues to increase, the throughput increases, but the overall module size of the RRU only increases slightly.
Taking TI's AFE7920 as an example, it is a 4T4R2F (4 transmit, 4 receive, 2 feedback paths) RF direct-sampling architecture dual-band transceiver. The transmit chain is mainly composed of RFDACs with a maximum sampling rate of 12GSPS, and supports the first/second Nyquist mode. The receiving and feedback links are mainly composed of RFADCs with a maximum sampling rate of 3GSPS; the transceiver links support independent DSA gain control, 8 pairs of 29.5 GSPS Serdes are interconnected with the host, and an on-board high-frequency clock with low-frequency input is integrated. Compared with the previous generation product, the power consumption of this product is reduced by 30%.
Beautiful digital RF direct acquisition
TI has many years of accumulation in the field of analog/digital mixed RF signals. AFE7920 is a digital RF direct acquisition chip developed based on TI's rich experience, which has many advantages over pure analog integration.
First, operators usually have an instantaneous bandwidth requirement of up to 400MHz in the sub 6GHz band, and at least 400MHz/800MHz in the millimeter wave band. TI's transceivers can support up to 800MHz bandwidth, meeting all Sub 6GHz and some millimeter wave application requirements.
Second, full-scene support enables platform normalization. Compared with 4G, the form of 5G base station is more abundant, including macro station, small station, Massive MIMO, etc. The same chip can support different base station forms, allowing customers to reduce development costs and launch products on the market faster.
It also supports mixed mode. A 4T4R single-mode chip is split into two independent 2T2Rs carrying different frequency bands to realize a single-chip mixed-mode scenario. For example, 2T2R TDD+2T2R FDD, etc. Furthermore, the ultra-high sampling rate of the RF direct-sampling architecture makes dual-band digital remote possible, enabling channel-level dual-band transmission and reception, such as 1.8GHz+2.1GHz dual-band applications in macro station scenarios (from ASIC /FPGA, receive 1.8GHz and 2.1GHz baseband signals respectively, realize digital combination inside the chip, and finally carry out dual-band transmission through the same transmission channel, receiving is its reverse operation), the radio frequency of the two frequency bands is extended The distance can reach 3GHz to meet the needs of customers in different aspects.
In addition, the digital RF direct sampling technology does not require mirroring and local oscillator calibration, which simplifies the development of the entire system. It also provides a chip self-checking and alarm mechanism, and flexible settings for system functions such as antenna calibration and green energy saving.
Wenjing emphasized that for technologies such as Massive MIMO and beamforming, although the important thing is the algorithm, the RF direct sampling technology only provides hardware implementation for the algorithm. But without chips with high integration and high synergy between channels, next-generation antenna technologies such as Massive MIMO will only be on paper.
5G sees China, RF direct acquisition transceivers see TI
In 2017, China's first-generation 4G MIMO base station adopted TI's 4T4R RF direct acquisition chip, and China's first-generation 5G base station also adopted TI's RF signal chain solution. It is worth mentioning that many of the demand for this series of products came from Chinese customers, and Wenjing participated in and led the product definition. This is also the difference between TI and its competitors, that is, the focus of 5G product definition is China, which is closer to the needs of Chinese customers. This is also one of the manifestations of TI's 35 years of deep cultivation in China.
TI has played an extremely important role in the construction of 5G base stations in China, spanning 2G/3G/4G/5G networks, including macro stations, Massive MIMO, small stations and other station types. And TI is constantly improving its products to support more channels, greater bandwidth and lower power consumption to meet the constantly updated needs of customers. TI's newly released AFE8092 8T8R RF direct-acquisition multi-band transceiver is based on the AFE7920 through further architectural innovation. While improving the integration, it once again achieved a 30% reduction in power consumption in the same scenario. Compared with 4T4R products, it can better meet the needs of Massive MIMO.
In order to cope with the complex 5G communication architecture, the evolution of active antenna systems is much faster than before. These include the need to reduce signal chain size and complexity while providing wide bandwidth and multiple frequencies; high-density power management that can operate at high ambient temperatures; and network synchronization through packet-based fronthaul interfaces. In addition to the highly integrated analog front end, TI also provides power supplies, clocks, MCUs, amplifiers, interfaces, etc. to achieve a full system solution.
Not long ago, the Ministry of Industry and Information Technology announced the "5G Application "Sail" Action Plan (2021-2023)" and officially solicited opinions. The goal is to significantly improve the development level of 5G applications in my country by 2023, and the comprehensive strength will continue to increase; The penetration rate of 5G personal users exceeds 40%, and the number of users exceeds 560 million; 5G network access traffic accounts for more than 50%, and the utilization efficiency of 5G network has been significantly improved; the average annual growth rate of 5G IoT terminal users exceeds 200%.
5G base stations are the cornerstone of new information infrastructure. TI has a complete range of analog and embedded processing products, strong local manufacturing and R&D capabilities, and a nationwide product distribution and sales network to help Chinese customers achieve lower latency and higher data. The high-speed 5G system promotes more innovative applications and empowers China's new infrastructure. TI has been rooted in China for 35 years, and has always been consistent in meeting future challenges with Chinese customers.
The integrated circuit is very small, and the world of "heart" can be bigger.
About Texas Instruments (TI)
Texas Instruments (TI) (NASDAQ: TXN) is a global semiconductor company that designs, manufactures, tests and sells analog and embedded processing chips for industrial, automotive, personal electronics, communications Markets such as devices and enterprise systems. We are committed to making electronics more affordable and creating a better world through semiconductor technology. Today, each generation of innovation builds on the previous generation, making our technology smaller, faster, more reliable, and more affordable, enabling semiconductors to be widely used in electronics. This is the advancement of engineering. . This is exactly what we have been doing for decades and now.
