Great progress has been made in TD-LTE technology R&D and industrialization

TD-LTE as China's leading new generation of broadband mobile communication technology standards, since the completion of the R8 version of the standardization at the end of 2008, entered the equipment development and testing phase. In the past two years, almost all domestic and international mainstream manufacturers have actively joined the TD-LTE R&D and industrialization work, and the progress of R&D has been accelerating. The national “New Generation Broadband Wireless Mobile Communication Network” major project has set up LTE R&D and industrialization projects to comprehensively lay out the TD-LTE industrial chain R&D and provide key support for key links such as system equipment, terminal chips, test instruments, and test verification.

R&D Industrialization Unified Organization

Test Verification Expands in Phases

The Ministry of Industry and Information Technology has established a TD-LTE working group to organize the TD-LTE R&D, industrialization and test verification work, study the direction of technological development, coordinate the progress of the industry, formulate test plans and plans, organize the implementation of test verification, and review technologies. Standardize, evaluate technical summary, coordinate major issues, and promote internationalization.

TD-LTE test verification is divided into three stages: proof of concept, technical test and scale technology test. The concept verification phase was completed in August 2009. The peak rate, transmission delay, coverage, and basic OFDM+MIMO transmission were verified in an indoor ideal channel environment and a simple environment of 1 to 2 base stations in the external field. The test results at this stage show that the hardware processing capabilities of the network equipment can meet the basic requirements of a 2×2 antenna TD-LTE system.

In September 2009, TD-LTE test validation entered the technical trial phase. Technical tests include single system, air interface interoperability, network interface consistency and interoperability, key technologies, networking performance, and other test contents, which are based on the principles of system first, terminal, first lab, and field first. The TD-LTE working group has established a TD-LTE public test and verification platform at the MTNet Lab of the Institute of Telecommunication Research, Ministry of Industry and Information Technology, and can support up to 12 network vendor tests. At the same time, under the strong support of China Mobile, the TD-LTE working group established a test site with 5 manufacturers, 25 base stations, and 75 communities in Huairou District and Shunyi District of Beijing. For each vendor, Huairou/Shunyi Outfield and MTNet Lab share a core network. This test and verification platform has played a role in the process of technological development and industrialization of TD-LTE.

2.3G equipment development is basically completed

2.6G start verification

From September 2009 to August 2010, the testing of 2.3GHz single-system, network interface and field key technologies has been basically completed. Huawei, ZTE, Datang, Shanghai Bell, Nokia-Siemens, Motorola, Ericsson, Putian, New Post, and Fiberhome all participated in the 2.3GHz TD-LTE test verification. This phase of the test verifies that most 2x2 antenna 2.3GHz TD-LTE base station equipments of most network manufacturers have achieved most of the functions of the air interface and network interface, meet the 2.3GHz RF specifications and hardware requirements, and have basic Operation and maintenance capabilities. In particular, the featured technical functions of LTE, such as frequency selective scheduling, open-loop and closed-loop MIMO, transmission and handover in a flat network architecture, have been implemented.

In the Huairou Shunyi, the key technology test of the 2.3 GHz external field was performed. The key technologies of TD-LTE OFDM, MIMO, and flat network architecture were verified under 9 to 15 cell conditions. Some devices achieved better performance. However, on the whole, the TD-LTE network equipment provider's previous research and development focus is still focused on the realization of the function, and only recently has it gradually turned to the optimization of the performance. Therefore, MIMO adaptive and receiving, multi-user adaptive scheduling and other technology algorithms and There is also significant room for improvement in performance. In addition, key technologies such as TD-LTE co-frequency networking, smart antennas, adaptive scheduling, and other key technologies have been studied in depth under the organization of the TD-LTE work group core units such as the Institute of Telecommunication Research, the Ministry of Industry and Information Technology and China Mobile. Enhanced technology research and development.

The research and development of 2.6GHz TD-LTE equipment by network vendors is also in full swing. The biggest difference between the 2.6GHz system and the 2.3GHz system is that it will use 8-channel smart antenna technology. 8-channel TD-LTE equipment can use 8×2 single-stream beamforming and dual-stream beamforming in the downlink, and use 1×8 diversity reception in the uplink. If it can be implemented well, it can cover the TD-LTE system and system. The capacity has obviously improved, and it is also the common development direction of TD-LTE and LTE FDD in the future. However, the 8-channel smart antenna system poses greater challenges to the hardware capabilities and software algorithms of the device. After active research and development, some network vendors have already implemented 8-channel TD-LTE base stations before September 2010, and through preliminary tests by MTNet Lab, they have verified the 8-channel beamforming function and radio frequency indicators, and are currently further debugging. Prepare for performance testing. At the same time, the industry has also conducted many discussions on how to implement multi-band networking and sharing of antennas, radio frequency, and network resources at 2.6 GHz, 2.3 GHz, and other frequency bands that may use TD-LTE.

Terminal chip R&D

Industrialization accelerates

In the past year, great progress has been made in the development of TD-LTE terminal chips, but it still lags behind the development of network equipment. The TD-LTE chip is basically the same as the LTE FDD on the hardware platform, and can be used universally to provide a good foundation for the TD-LTE/LTE FDD co-chip. Therefore, in addition to the traditional TD-SCDMA chip manufacturers, WCDMA and WiMAX are traditionally used. The main international chip company and some emerging terminal chip manufacturers have also joined the research and development of TD-LTE terminal chips.

Some of the leading chip manufacturers have entered the stage of ASIC chip streaming. They are improving and consolidating through multiple tapeouts, fixing hardware architecture, fully verifying chip code and software platforms, and evolving to a mature terminal form. Some manufacturers have completed the first tapeout, and developed data cards and CPE equipment based on the first version of the chip. They participated in the 2.3 GHz terminal chip test and air interface IoT test organized by the TD-LTE working group in the MTNet laboratory. Already able to support most of the basic functions of TD-LTE, the performance is relatively stable. Some of the leading manufacturers will soon complete the second tapeout, support 2.6GHz, gradually support beamforming, and unify into the mainstream form of data cards.

On the whole, the development of the entire TD-LTE chip is still a weak link, and the follow-up R&D pressure is still huge, and the industry still faces challenges. There is still a big gap between the functions and performance of some vendors' chips. The power consumption of the chips is a problem that needs to be solved in the future. The implementation of the LTE/3G/2G multi-mode chip has yet to be defined. Since the second half of 2010, based on the principles of helping the superior, encouraging the leading, and accelerating, the support and promotion of the TD-LTE terminal chip industry has been increased, and the progress of research and development has been further accelerated.

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