TD-SCDMA, as the third generation mobile communication standard (3G for short) proposed by China, was formally submitted to ITU (International Telecommunication Union) from 1998. It has been more than ten years since it completed a series of international standardization work such as expert group evaluation, ITU approval and publication, integration with 3GPP (3rd generation partnership project) system and introduction of new technical features, thus making TD-SCDMA the first standard. This is an important milestone in the telecom history of China. (Note: 3G*** has three international standards, and the other two are CDMA2000 led by the United States and WCDMA led by Europe. )
Development process of TD-SCDMA
At the beginning of 1998, under the direct leadership of the Science and Technology Department of the Ministry of Posts and Telecommunications at that time, the Institute of Telecommunications Science and Technology organized a team to study and draft a draft proposal for TD-SCDMA in China that met the requirements of IMT-2000. The main features of the draft standard are smart antenna, synchronous code division multiple access, relay switching and time division duplex. On June 30th, 1998, the deadline for ITU to collect the third generation wireless transmission technology candidates for IMT-2000, it was submitted to ITU, thus becoming one of the 15 candidates for IMT-2000. ITU synthesized the evaluation results of all evaluation teams. At the +0999+0 1 Helsinki ITU-RTG8/ 1 th meeting in June 2000 and ITU-R plenary meeting in Istanbul in May 2000, TD-SCDMA was formally accepted as one of the schemes of CDMATDD system.
CWTS (China Wireless Communication Standards Research Group), as a regional standardization organization representing China, joined the 3GPP in May 1999. After four months of full preparation and a lot of coordination work with 3GPPPCG (project coordination group) and TSG (technical specification group), in September of the same year, it was suggested to 3GPP that TD-SCDMA should be included in the work of 3GPP standards and specifications. 1999 12 At the 3GPP conference in Nice, France, China's proposal was accepted by the 3GPP (Radio Access Network) plenary meeting, and it was formally decided to include TD-SCDMA in the work plan of Release 2000 (later split into R4 and R5).
After more than a year, after dozens of working group meetings and discussion of hundreds of submitted manuscripts, at the plenary meeting of RAN in Palm Springs in March 20001,with the official release of the R4 version of 3GPP including TD-SCDMA standard, the integration of TD-SCDMA in 3GPP reached the first goal.
So far, TD-SCDMA has been recognized and accepted by operators and equipment manufacturers all over the world, both in form and in essence, forming a real international standard.
Present situation of TD-SCDMA standard
Since the release of 3GPPR4 in March, 20001,the substantive work of TD-SCDMA standard specification has been mainly completed under the 3GPP system. In more than two years after the release of R4 standard, Datang, together with many other industry operators and equipment manufacturers, revised and improved some contents of TD-SCDMAR4 standard, such as physical layer processing, high-level protocol stack messages, network and interface signaling messages, radio frequency indicators and parameters, conformance testing and so on, through numerous meetings and email group discussions, which made TD-SCDMA R4 standard reach a quite stable and mature level so far.
Under the framework of 3GPP, due to the different duplex modes, all technical features and advantages of TD-SCDMA can be reflected in the air interface physical layer. The difference of physical layer technology is the main difference between TD-SCDMA and WCDMA. In the core network, TD-SCDMA and WCDMA adopt exactly the same standards and specifications, including the same Iu interface between the core network and the wireless access network; TD-SCDMA and WCDMA are also the same in the high-level protocol stack of air interface. These similarities ensure seamless roaming, handover, consistency of service support and QoS guarantee between the two systems, and also ensure that TD-SCDMA and WCDMA maintain considerable consistency in the subsequent development of standard technology.
65438+20061October 20th has been declared as the national communication standard of China. 65438+ 10. It was stipulated by the Ministry of Information Industry as an industry standard, not a national communication standard.
Subsequent development of TD-SCDMA standard
With the rapid development of 3G technology and system, various equipment manufacturers, operators, research institutions, governments and ITU have begun to study the technical development direction after 3G. Among several technical development directions determined by ITU, smart antenna technology and TDD time division duplex technology are considered as the future development trends. Smart antenna and TDD time division duplex technology have been well embodied and applied in the current TD-SCDMA standard system. From this point, we can also see that TD-SCDMA standard technology has considerable development prospects.
In addition, in the release of 3GPP version after R4, TD-SCDMA standard also introduced new technical features to further improve the performance of the system, including: synchronization between base stations through air interface as another backup scheme for base station synchronization, especially suitable for ensuring the reliability of communication networks in emergency; Terminal positioning function, which locates the position of the terminal user by using the arrival angle of the signal through the smart antenna, so as to better provide location-based services; High-speed downlink packet access adopts hybrid automatic retransmission and adaptive modulation and coding to realize high-speed downlink packet service support; Multi-antenna input-output technology (MIMO), which adopts multi-antenna technology of base station and terminal and signal processing to improve the performance of wireless system; The uplink enhancement technology adopts adaptive modulation and coding, hybrid ARQ technology, rapid allocation of dedicated/* * * resources, and corresponding physical layer and high-level signaling support mechanisms to enhance the uplink channel and business capabilities.
With the full support of the government and operators, TD-SCDMA industrial alliance and industrial chain have been basically established, product development has been further promoted, and more and more equipment manufacturers have participated in the development camp of TD-SCDMA products. With the large-scale development and field test of equipment, TD-SCDMA standard will be further verified and strengthened.
In order to accelerate the industrialization of TD-SCDMA and form a complete industrial chain and multi-vendor supply environment at an early date, the TD-SCDMA industrial alliance was established in Beijing on June 30th, 2002. The number of TD-SCDMA industry alliance members has grown from 7 at the beginning to 30 at present, covering all links of TD-SCDMA industry chain from systems, chips, terminals to test instruments.
The nature of the alliance:
TD-SCDMA Industry Alliance is a voluntary social organization composed of enterprises and institutions actively engaged in the research, development, production, manufacturing and service of TD-SCDMA standards and products.
Alliance purpose:
Integrate and coordinate industrial resources, improve the R&D and manufacturing level of mobile communication enterprises within the alliance, promote the rapid and healthy development of TD-SCDMA communication industry, and realize the popularization and application of TD-SCDMA in China and the global communication market.
Alliance business scope:
TD-SCDMA industry alliance mainly focuses on TD-SCDMA technology to promote and improve standards, as well as industry management and coordination, to promote resource sharing and mutual benefit among enterprises. It is suggested that the government should formulate major industrial policies that are beneficial to the development of TD-SCDMA and enhance the group competitiveness of communication enterprises within the alliance.
Within the TD-SCDMA industrial alliance, a unified intellectual property management policy is implemented, and technical information and market information are highly shared. Promote the rapid and healthy development of TD-SCDMA industry through close communication and reasonable division of labor.
Alliance members:
Institute of Telecommunications Science and Technology (Datang Telecom Science and Technology Industry Group)
Huali group co., ltd
Huawei technologies co., ltd.
Lenovo (Beijing) Limited
Shenzhen zhongxing communication co., ltd
China Electronic Information Industry Group Corporation
China Putian information industry group company
Beijing Tianqi technology co., ltd
Chongqing changyuan xinke co., ltd.
Hisense Group Limited
Ming Kai Information Technology Co., Ltd.
Xi an Haitian antenna technology co., ltd
Zhanxun Communication (Shanghai) Co., Ltd.
Beijing zhong Chuang Xin ce technology co., ltd
Hubei Zhong You Science and Technology Industry Co., Ltd.
Alcatel Shanghai bell co., ltd
Shanghai dibite industry co., ltd
UT starcom company
Yinghuada (Shanghai) Electronics Co., Ltd.
Zhongshan tongyu communication equipment co., ltd
Qingdao Haier communication co., ltd
Shanghai ketai century technology co., ltd
Wuhan post and telecommunications science study institute
TCL group
Guangzhou xinyou communication equipment co., ltd
Andrew Telecom Equipment (China) Co., Ltd.
Ding Xin Communication (Shanghai) Co., Ltd.
Beijing Xinghe Liangdian Communication Software Co., Ltd.
Jingxin Communication Technology (Guangzhou) Co., Ltd.
China Electronics Technology Group Corporation No.14 Institute
Mobi Antenna Technology (Shenzhen) Co., Ltd.
Ruidike Micro-electrons (Shanghai) Co., Ltd.
Beijing Han Ming Xin tong technology co., ltd
Ningbo Bird Company Limited
China electronics technology group company no.41 institute
Yiyang xintong co., ltd
Shenzhen changfang network technology co., ltd
Yulong Computer Communication Technology (Shenzhen) Co., Ltd.
Simitong Information Technology (Shanghai) Co., Ltd.
Qi Long Holdings Limited.
Advantages and disadvantages of TD in China and its switching technology in the United States and Europe
superiority
1. High spectrum utilization, TD, carrier frequency 1.6M W, carrier frequency 10 M.
2. The requirement for power control is low, TD 0 ~ 200 MHz W 1500 MHz.
3. The so-called antenna classification is introduced by using smart antenna and joint test, but the effect needs to be verified.
4. It avoids the slight influence of different services on the coverage area in respiratory effects TD, and is easy for network planning.
Disadvantages:
1. TD with high synchronization requirements needs GPS synchronization, and the accuracy of synchronization affects whether the whole system works normally.
2. The limited code resource TD is only 16 code, which is far less than the number of codes required by business requirements.
3. Interference: uplink and downlink, there may be interference between this cell and neighboring cells.
4. the moving speed is slow TD120km/hw500km/h.