Technical field of wireless transmission
The main research direction in the field of wireless transmission technology is the research on key technologies of accessing various mobile communication systems, including GSM(GPRS, EDGE, GERAN), WCDMA(R99, HSDPA, HSUPA, HSPA+, LTE, etc. ), CDMA( 1X, DO, etc. ) and WiMAX (802. 16e, 20001.100010001083
RTT (Radio Transmission Technology) includes various air interface physical layer technologies, such as modulation and demodulation, channel coding and decoding, link adaptation technology, interference suppression and elimination, OFDM and multi-antenna transmission and reception.
RRM (Radio Resource Management) includes some traditional RRM technologies (such as power control, handover, scheduling, congestion control, admission, etc.). ) and future RRM technologies, such as public radio resource management, adaptive RRM and cross-layer design, to improve the overall network performance and user QoS experience.
At the same time, the link simulation verification of RTT algorithm and the system simulation verification of RMM algorithm in wireless communication, as well as the laboratory and field performance test verification of related products, including algorithm prototype verification, algorithm optimization verification, version performance evaluation and so on.
At present, the access technology algorithms of Huawei wireless communication system products are provided by the Communication Access Technology Laboratory, including GSM chip algorithm, WCDMA R99 chip algorithm, HSDPA chip algorithm, HSUPA chip algorithm, WiMAX and LTE baseband algorithm, RRM algorithm of G/C/W/WiMAX and so on. , and has completed more than 300 patents. At present, the algorithm performance and competitiveness of the laboratory have reached the first-class level in the industry, and Huawei wireless products have been successfully commercialized in dozens of countries around the world. The operators entering include not only mobile operators in emerging markets, but also developed countries and regions such as Spain, Hong Kong, the Netherlands and Portugal. Customers include the world's leading mobile operators (such as Vodafone, Orange and KPN) and the leading mobile operators in the region (such as Etisalat in UAE, Malaysia Telecom and Hong Kong Sunday).
Intermediate frequency field
The IF modules of Huawei's wireless communication products are all provided by IF Lab. At present, the performance and competitiveness of IF modules have reached the first-class level in the industry, and some products have been at the forefront of the industry. The main research direction in this field is the related radio frequency technology of the new generation broadband wireless mobile communication base station, with emphasis on power amplifier, filter and miniaturization. The laboratory has continuously invested in the intermediate frequency field, conducted in-depth research on TT, ET, EER, Class X and switching power amplifiers, and conducted extensive and in-depth cooperation and joint development with domestic and foreign universities, consulting companies and top suppliers in the industry.
Testing field
Performance testing field
Laboratory/field performance testing is responsible for the RTT/RRM algorithm laboratory/field performance verification and product wireless performance evaluation of all Huawei wireless communication products. At present, it has become a first-class wireless performance field verification laboratory in the industry, with the first high-speed magnetic levitation field in the industry. Huawei's communication access technology fully meets the requirements of 430km/h high-speed magnetic levitation. WCDMA products verified by magnetic levitation have been successful in the Vodafone high-speed rail project in Spain, and the network performance index far exceeds that of friends.
Engineering testing field
In engineering testing, the laboratory conducts various reliability tests and engineering field research on the initial products transformed from communication access technology achievements. The test contents include electromagnetic compatibility, safety and environmental reliability test, and engineering realization scheme research.
Electromagnetic compatibility test includes EMI electromagnetic interference and EMS electromagnetic sensitivity. Safety is the ability to verify that products do not have accidents during their life cycle, so as to avoid casualties, occupational diseases, equipment damage or property losses; Environmental reliability test mainly simulates various environmental conditions that products may encounter in the process of work, storage and transportation, so as to verify or improve the environmental adaptability of products, including low temperature, high temperature, temperature change, damp heat, temperature shock, thermal test, mechanical vibration and so on. The research in engineering field involves the installability and installation capacity baseline in engineering field. The reliability test of Huawei wireless communication access laboratory has been recognized by many international authorities and established cooperative relations with many international certification bodies.
Wireless communication software field
In terms of the reliability of wireless communication access network, besides the reliability indexes such as the mean time between failures (MTBF) of the network elements themselves, more and more attention is paid to the disaster tolerance at the network element level, the smooth upgrade of the network and the reliability indexes of the transmission network. At present, some technologies have been accumulated, such as A-FLEX, BSC pool, active/standby switching, load sharing, and automatic software upgrade, which can be used as the basis for the study of disaster tolerance and smooth upgrade of network elements.
The development of CPU chip plays a vital role in the high integration and high performance of equipment. Since Gordon Moore put forward Moore's Law in 1965, the development of CPU has basically followed Moore's Law. However, as the size of the transistor is getting smaller and smaller, when it is below 90nm, the leakage current increases and the power consumption of the transistor increases sharply. With the increasing difficulty of frequency upgrade, many manufacturers turn the development of CPU to multi-core. The multi-core processors introduced by mainstream manufacturers such as Intel, AMD, Freescale and IBM are all based on 64-bit architecture, and MIPS camp is the pioneer of multi-core.
Multi-core is a major turning point in processor technology. Multi-core will double the cost performance of single board, greatly improving integration and cost competitiveness. The research and application of multi-core technology has been widely carried out in the field of data communication and security. At present, Huawei has also carried out some research on the application of multi-core in wireless access systems. The application of multi-core in HSPA+ has made some achievements, which can adapt to the increasing processing requirements of HSPA rate in the future without changing the hardware: 14.44Mbps, 4× 14.44Mbps or even more than 100Mbps.
Product engineering field
Electromagnetic compatibility, safety and lightning protection, environmental reliability technology
EMC technology
The low-cost demand and fast delivery of communication products are inevitable in the future. To solve these problems, it is necessary to carry out fine design and simulation evaluation technology in the design process. Electromagnetic compatibility simulation technology has a broad development space. As the basic technology research of electromagnetic compatibility, the electromagnetic compatibility design and power supply integrity (PI)/ signal integrity (SI) of integrated circuits need to be further developed.
IEC/IEEE has issued relevant technical standards for electromagnetic compatibility of integrated circuits. Electromagnetic compatibility is controlled in the IC design stage, which is an important link in future product design, especially for end products. If we choose the scheme with good IC EMC performance, the later product design will save a lot of resources. In ASIC and FPGA design, we need to pay attention to EMC design.
With the existence of various wireless systems and the wide application of high-speed interconnection in wireless access systems, the compatibility between wireless access systems and the electromagnetic interference in the systems have become the key issues to be solved. Electromagnetic compatibility in the system directly affects the performance of wireless access system.
Many years ago, Huawei invested heavily in building the first anechoic room and EMC test system in the field of domestic communication equipment manufacturers, and accumulated rich experience in EMC design convenience. The laboratory has been recognized by more than ten institutions at home and abroad. At the same time, we have established good cooperative relations with domestic and foreign research institutions, including EMC simulation evaluation technology, EMC design and test technology of high-speed ic, PI/SI technology of PCB, electromagnetic interference analysis and suppression technology, etc.
Environmental reliability technology
In the field of communication, the traditional reliability testing technology is being challenged. Due to the manufacturing cost, many mature methods cannot be adopted. Highly accelerated life test/HASS)/ HASA are widely used in the industry to improve the reliability of products. In the aspect of environmental stress screening, stress reduction is carried out according to the environmental stress profile of products, and dynamic screening technology is developed and applied.
In terms of corrosion protection, such as the analysis of the influence of damp heat, high temperature, salt spray and harmful gases on product life, accelerated life verification technology provides a method to verify the expected life of products in a short time with less cost.
Safety and lightning protection technology
According to data analysis, the electricity charges of street cabinets in many European countries are much more expensive than those of central computer rooms. Because of this, and the inconvenience of local power supply in some places, power supply technology has a certain application market. Due to transmission loss, remote power supply technology will develop to higher power supply voltage, such as high voltage DC power supply technology, which poses new challenges to lightning protection and safety protection.
Huawei has many years of successful application experience in lightning protection and grounding design of communication equipment, and its lightning protection testing ability has reached the advanced level in the communication field. Through participating in the formulation of international and domestic standards and extensive cooperation and exchanges with technical experts of major international telecom operators, lightning protection of communication equipment has entered the advanced ranks of the industry, ensuring the safe operation of wireless access products.
Efficient heat dissipation technology Energy-saving and efficient heat dissipation technology In order to adapt to the harsh environment such as extreme high temperature and extreme low temperature, outdoor base stations (including outdoor cabinets, cabinets and simple computer rooms) mainly adopt air conditioning heat dissipation technology, and air conditioning energy consumption is high, accounting for more than 30% of operating costs. In this technical research, direct air cooling, high-efficiency heat exchange, compound liquid cooling and high-efficiency phase change heat dissipation are used to study the low energy consumption, low cost and high-efficiency heat dissipation technology of outdoor base stations and realize product application.
The application research of new materials has the advantages of good thermal conductivity/electrical performance, light weight, non-toxicity, environmental protection, recyclability, regeneration and low cost, which can meet the miniaturization technical requirements and multi-scene application requirements of the fourth generation communication system, facilitate transportation and installation, and solve the heat dissipation and shielding problems of communication products.
Process reliability technology
With the development of communication products to miniaturization, high density and low cost, board-level assembly technology and its reliability technology occupy an increasingly important position in product competition.
In 2000, Huawei set up a research team to study single board assembly technology, PCB technology, reliability &; The failure analysis technology process laboratory is committed to achieving the readiness of key technologies in high-density assembly, PCB, RF and other fields, and building low-cost, differentiated and fractured competitiveness for products.
At present, the laboratory has a complete set of SMT and micro-assembly test lines, a complete board-level reliability test and simulation platform and material physical failure analysis equipment, which can carry out the following technical research: primary/secondary assembly process, PCB reliability test, material micro-morphology observation, component identification, performance test, board interconnection reliability test/simulation/failure analysis, etc.
Chip field
Mobile communication equipment chip lab started the development of mobile communication equipment chips from 1998, and has successfully delivered a number of GSM chips, WCDMA chips and so on. The scale of chips developed has ranged from hundreds of thousands to tens of millions. The process is from 350 nm to 65 nm; ; From the initial single logic chip to the introduction of SOC technology, it has accumulated a deep foundation for chip research and development.