With the advent of 5g era, mobile Internet and Internet of things business will become the main driving force for the development of mobile communication. At the same time, mobile intelligent terminal will also be defined as personal mobile computing platform, which is required to be able to deal with various computing, business, application and entertainment needs in real time. Therefore, the mobile intelligent terminal chip in 5g era should be continuously upgraded and updated in the software and hardware design of computing architecture, network connection architecture and control system architecture to meet the performance requirements of 5g new technology on chip compatibility, transmission speed and low power consumption performance.

Great development opportunities

Various emerging applications such as high-speed video and voice calls, ultra-high definition video, augmented reality, automatic driving, mobile medicine, Internet of things, intelligent manufacturing and smart city will continue to emerge, and technological innovations such as high-speed voice and image recognition and transmission, intelligent perception, massive data processing, deep learning and narrowband Internet of things (NB IOT) will accelerate, Promote the performance requirements of software and hardware.

After 2020, 5g will lead the development of communication network market. The opportunity of the iteration of international technical standards promotes the continuous acceleration of chip R & D. facing the turning point of 5g technology, enterprises have accelerated the technical reserve, and seize the remaining 2 ~ 3 years to carry out the technical reserve. System integrators and operators shall speed up key technology research and prototype verification. Chip design manufacturers are competing to promote the formation of 5g key technology components, and are committed to becoming the first batch of 5g commercial chip providers in 2020.

In October 2016, Qualcomm announced the launch of the industry’s first 5g modem chip Xiaolong X50. It is expected to start sampling in the second half of 2017 and launch the first batch of commercial terminals in the first half of 2018. At the beginning of this year, Intel has released its 5g baseband scheme and expects a small trial production in the second half of this year. Subsequently, Samsung has also released its 5g RF chip and expects to provide commercial chips next year. In China, the 5g special team established by Huawei Hisilicon has made a lot of terminal chip technology preparations. With the advantage of synchronization with Huawei 5g network equipment, it can form joint commissioning effect faster. It is expected to launch relevant products in 2019. Spreadtrum has also long participated in the formulation of national 5g standards, established a special 5g R & D team, and is expected to launch commercial RF chips meeting 5g standards between 2019 and 2020.

What is the impact of 5g spectrum on chip communication bandwidth?

Technological evolution route

From the perspective of technical characteristics, standard evolution and industrial development, there are two technical routes for technological development in 5g era: 4G evolution air port and 5g new air port.

Based on the 4G framework, 4G evolution technology route introduces enhanced new technologies in frame structure, multiple antennas, multiple access and other aspects, such as miniaturized base station related technology, 3d-mimo, enhanced comp, enhanced relay, FDD and TDD integration, so as to further improve system performance while ensuring compatibility with 4G system, and meet 5g scene, rate, delay and other performance index requirements to a certain extent. For example, the MIMO technology is upgraded to massive MIMO, in which the antenna configuration is increased from 16×16 to 256×256, resulting in the improvement of wireless network coverage and transmission speed.

5g new air interface technology route is mainly to carry out new air interface design for new scenes and new frequency bands, including low-frequency new air interface technology below 6GHz and high-frequency new air interface technology above 6GHz. These new air interface technologies do not need to consider the compatibility with 4G framework. They meet 5g business needs and challenges, especially the needs of high-frequency band and Internet of things scenarios, through new technical scheme design and introduction of innovative technologies.

5g spectrum affects chip communication bandwidth

The most fundamental change between 5g network and 4G network is the expansion of frequency band. 5g network forms effective network coverage in the medium and low frequency band to control and manage users and ensure basic data transmission capacity. The high frequency band and low frequency band are jointly networked to provide users with high-speed data transmission. The low frequency band below 6GHz is based on the existing LTE-A as the basis of 5g radio access network, while the high frequency from 6GHz to 100GHz requires the exploration of key new technologies such as architecture, wireless networking, wireless transmission, new antenna and RF, and the development and utilization of new spectrum.

According to the communication principle, when the spectrum utilization remains unchanged, increasing the bandwidth can increase the data transmission rate. The maximum signal bandwidth of wireless communication is about 5% of the carrier frequency. Therefore, the higher the carrier frequency, the larger the chip signal bandwidth can be achieved. Due to the different spare frequency band and technical basis in various countries, the selection of 5g frequency band is different from that of the main push. For example, the Federal Communications Commission of the United States mainly promotes 28ghz (27.5 ~ 28.35ghz), 37ghz (37 ~ 38.6ghz) and 39ghz (38.6 ~ 40GHz) frequency bands, and expands the existing 57 ~ 64ghz unauthorized frequency band to 71ghz, which can reflect the technical direction of a group of American chip design enterprises represented by Qualcomm. China advocates the application of medium and low frequency band. The intended frequency band mainly includes medium and low frequency bands such as 3.3 ~ 3.6ghz, 4.4 ~ 4.5ghz and 4.8 ~ 4.99ghz, as well as high frequency bands of 25ghz and 39ghz. The main frequency bands are different, which directly affects the technical research and development of domestic communication chip manufacturers such as Hisilicon and Spreadtrum, which is different from those abroad.

New air interface technology determines the new direction of chip development

With the emergence of each generation of mobile communication, the key technologies of air interface will undergo revolutionary changes, such as from analog to digital, from FDMA to TDMA, from CDMA to OFDM and so on. 5g new radio technology (5g new radio) is selected by the international 5g standardization organization 3GPP to standardize the new 5g wireless air interface. Its goal is to improve the data transmission rate, network capacity, delay, mobility, energy efficiency and coverage to a new level. 5g new air interface technology should make full use of the available spectrum to realize networking coverage in low, medium and high frequency bands, so it needs continuous adaptation and upgrading of software and hardware.

New multiple access technology and advanced modulation coding

In 5g communication, the key to ultra-high data throughput is UWB signal modulation (generally considered to be more than 500MHz). In order to transmit more information in a limited frequency band, it is necessary to be based on new baseband chip multiple access technology and signal coding technology.

Through superimposed transmission, the new multiple access technology can not only improve the number of user connections, but also effectively improve the spectral efficiency of the system, but also effectively reduce the transmission delay. In addition to the OFDMA (orthogonal frequency division multiple access) technology adopted by LTE, the new multiple access technologies also include SCMA (sparse code multiple access technology), PDMA (pattern division multiple access technology), Musa (multi-user shared access technology), noma (non orthogonal multiple access technology), etc.

Advanced modulation and coding adopts high-order modulation mode and higher code rate, which can provide high spectral efficiency and code length under the conditions of large bandwidth and good channel, and ensure the high-speed rate demand of 5g transmission. Well known coding methods include the control channel polar code (polarization code) mainly promoted by Huawei and the data channel LDPC (low density parity check code) mainly promoted by Qualcomm.

Multi frequency multi-mode structure of new carrier and antenna technology

High speed data transmission and high-density connection are the core objectives of 5g technology, and its key technologies are mainly aimed at RF transmission technology and network technology. In order to meet the 5g technology goal, the multi-mode and multi frequency RF chip based on filter bank needs to use new physical layer technology, in which the typical representative is large-scale antenna technology on the one hand and new multi carrier technology on the other hand.

Large scale MIMO technology is an antenna system that uses multiple antennas at the transmitting end to send signals independently, and uses multiple antennas at the receiving end to receive and recover the original information. Due to the use of multi antenna system, the transmission path of signal increases, so as to realize spatial multiplexing, which can effectively improve the spectral efficiency and reliability of the system. At the same time, by concentrating the beam in a very narrow range, the interference and transmission power are greatly reduced, so as to improve the power efficiency.

New multi carrier technology, including f-ofdm technology, ufmc technology and fbmc technology. They all realize more efficient utilization of frequency band by optimizing the design of filter. Therefore, they correspond to different filter hardware designs.

Full duplex network technology

Full duplex wireless communication technology is considered as one of the most potential technologies to further tap spectrum resources in 5g communication. Different from the traditional time division duplex (TDD) or frequency division duplex (FDD), full duplex technology aims to allow two-way data transmission between devices at the same time. Therefore, full duplex technology can theoretically double the utilization of wireless spectrum resources, At the same time, the same frequency full duplex can also bring great benefits to the physical layer design of wireless networks. The main problem faced by the same frequency full duplex technology is the huge self interference caused by simultaneous transceiver in the same frequency band. At present, the same frequency full duplex communication has become possible through technical means such as analog end interference cancellation, digital end interference cancellation and antenna cancellation. In addition, another technical challenge facing the same frequency full duplex technology is the support for MIMO system. For multi antenna system, the complexity of self interference cancellation will increase sharply with the increase of the number of system antennas, resulting in great difficulties in system design.

Millimeter wave technology requires RF chips

Millimeter wave is an electromagnetic wave with a wavelength of millimeter order, and its frequency is about 30ghz ~ 300GHZ. The high transmission rate and high network capacity required by 5g mobile communication need more spectrum resources to provide support. Millimeter wave communication technology is one of the important technical directions of 5g mobile communication because of its rich spectrum resources and strong directionality.

In millimeter wave communication system, because of the high propagation loss of millimeter wave signal, RF chip should have high sensitivity to weak signal. At the same time, in order to ensure that CMOS devices can respond quickly to weak millimeter wave signals, it is also necessary to increase the working current of the chip, so as to increase the power consumption of the chip. On the other hand, because the wavelength of millimeter wave signal is close to or less than the length of equipment conductor, the “transmission line effect” may occur when the line impedance does not match, and various signal distortions such as signal reflection, interference, attenuation and superposition may occur, which greatly affects the signal propagation. Therefore, millimeter wave transmission line effect must be considered in the design of RF chip in order to ensure the normal operation of the chip.

Measures and suggestions

Strengthen organizational leadership and improve the coordination and guarantee mechanism

Strengthen the guidance, organization and implementation of international standard construction, technical R & D cooperation, intellectual property protection, pilot application and promotion, etc. Improve the coordination and promotion mechanism related to the development of mobile intelligent terminal chip industry, focus on strengthening cooperation on 5g standards and frequencies, support the communication and dialogue between relevant institutions and countries, and ensure the rapid promotion of mobile intelligent terminal chip industrialization.

Strengthen technology research and development to achieve core technology breakthrough

Give full play to the supporting role of equipment manufacturing enterprises and network operators in international standard formulation and R & D, and actively promote the establishment of a technological innovation system with enterprises as the main body and the combination of industry, University and research. Give play to the leading role of scientific research institutions and universities in basic research, establish an effective coordination mechanism, and support the R & D and industrialization of key core technologies of 5g mobile intelligent terminal, especially weak links such as chips and key components. At the same time, strengthen standard formulation and intellectual property protection, build an independent intellectual property system, and strengthen China’s core competitiveness in the field of 5g communication.

Promote industrial chain innovation synergy

Make overall plans for major special projects of 5g communication industry, strengthen integration and innovation research with industrial Internet, Internet of things and other application fields, integrate industry university research resources such as terminal manufacturing, chip R & D and network equipment manufacturing, and carry out R & D and application demonstration and verification of key technology products. We will promote the construction of public service platforms, support telecommunications enterprises, Internet enterprises and industry users to strengthen cooperation, actively explore new technologies, new formats and new models, and provide support services in common technology R & D, intellectual property rights, talent training and market promotion for industrial development.

        Editor in charge: Tzh

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