In foreign countries, LTE (Long Term Evolution) is a mobile communication system developed by the 3GPP organization as a long-term evolution of UMTS technology. The standard was officially launched and launched at the 3GPP Toronto TSG RAN#26 conference held in December 2004; Therefore, LTE FDD technology has been gradually developed and commercialized on a global scale. In China, TD-LTE (Time Division Long Term Evolution) is a 4G mobile communication standard independently proposed by China. It has successfully tested and tested two scale trial networks in 2011 and 2012 respectively. In the future, large-scale commercial use will be obtained at home and abroad. The two standard standards of LTE FDD and TD-LTE are based on OFDM (Orthogonal Frequency Division Multiplexing) technology, and the crowding of 2G and 3G spectrums around the world has led to the dispersion of wireless spectrum in the LTE era. At the same time, the two standards support MIMO (Multiple Input Multiple Output) and Beam-forming (beamforming) technologies at the RF end, which set new requirements for the physical layout and performance indicators of the base station antenna.
2. TD-LTE base station antenna solution
1. TD-LTE base station antenna overview
The TD-LTE base station antenna continues the mainstream design concept of TD-SCDMA in the 3G era, that is, the 8-antenna technology supports beamforming. In the future application of TD-LTE, the F (1880 ~ 1920 MHz) and D (2500 ~ 2690 MHz) frequency bands will be used as the selected frequency bands for wide coverage and continuous urban coverage, respectively, while also considering the compatibility of TD-SCDMA and the future. The need for base station antenna tilt adjustment after deep coverage. The overall shape of the TD-LTE base station antenna will reflect the trend of broadband, electrical regulation and independent adjustment. As a leading supplier of TD-SCDMA base station antenna solutions, Tongyu Communication will launch a series of new base station antenna products in response to the development needs of TD-LTE.
2. TD-LTE base station antenna selection in different scenarios
According to the characteristics of the existing TD-LTE station, the base station antenna analysis and model selection are given under various scenarios.
1) Scene 1 - Intensive urban F segment or D segment LTE separate networking
Such scenarios generally require macro station coverage, which has the characteristics of high-intensive traffic and large data traffic. The coverage distance generally requires more than 500 m, and there is anti-interference requirement in the neighboring area. This scenario can use a conventional gain FAD antenna (Tongyu model TYDA-202616D4T0/3/6/9) and a conventional gain FA antenna (Tongyu model TYDA-2015D4T0/3/6/9). In the case of inconvenient adjustment of the mechanical tilt angle, you can use the FA ESC antenna (Tongyu model TYDA-2015DE4, support 0 ~ 14 degrees power down) or FAD broadband ESC antenna (Tongyu model TYDA-202616DE4, support 2 ~ 12 degree electric downdip range).
2) Scene 2 - Intensive urban F-segment LTE networking, compatible with TD-SCDMA
Such scenarios require macro station coverage, featuring high-intensive traffic and large data traffic. The coverage distance is generally required to be more than 500m, and F/A interference is severe. The original TD-SCDMA and the new TD-LTE after the upgrade may be inconsistent with the equipment provider. This scenario can use a conventional gain FAD antenna, a conventional gain FA antenna, and an FA electrical adjustment antenna. In the case of inconsistent equipment vendors, the F/A built-in combiner antenna (Tongyu model TYDA-1914/2015D4T6-BC) can be used.
3) Scenario 3 - D-band LTE networking in dense urban area, compatible with TD-SCDMA
This scenario also requires macro station coverage, high-intensive traffic and large data traffic characteristics, and the coverage distance usually requires more than 500m. The D-band coverage distance is significantly shorter than the conventional F-band, and TD-SCDMA and the upgraded D-band TD-LTE equipment vendors may be inconsistent. Such a scenario can use a conventional gain FAD antenna, an external combiner scheme, or an internal combiner FAD antenna (Tongyu model TYDA-2015/2616D4T0/3/6/9-BC). After the TD-SCDMA and TD-LTE services are greatly improved, in order to meet the network planning and optimization of two different systems, the base station antenna downtilt angle needs to be independently adjusted in the FA and D sections without interference, and FA is needed. /D built-in integrated independent electrical adjustment antenna (Tongyu model TYDA-2015/2616DE4-BC).
4) Scenario 4: LTE network in F or D segment of hotspot area, compatible with TD-SCDMA, micro station or street station coverage
The micro-station or street station coverage requirement is to support high-density data traffic with a small coverage distance, generally 200 to 300 m. It is recommended to use a miniaturized FAD eight antenna (Tongyu model TYDA-202615D4T0/3/6/9, size 652 * 320 * 105mm).
There is also a type of scenario that needs to support high-density data traffic with a coverage distance of about 200m or less. The demand scenario is very sensitive to the size of the antenna and RRU. It should be solved by "small-sized dual-channel RRU+ miniaturized ultra-thin dual-channel antenna". For the solution, it is recommended to use a miniaturized ultra-thin FA antenna (Tongyu model TDI-182010DM-A, size 290*100*15mm).
5) Scenario 5 - Macro station small density F or D segment LTE networking, compatible with TD-SCDMA
Such scenes are generally distributed in mountain villages, coastal open spaces, rural areas or suburban junctions, and their traffic volume and data flow are relatively small, covering a distance of more than 1km. High-gain FAD antennas (Tongyu model TYDA-202618D4T6) are recommended for this type of scenario to reduce the cost of building stations. The F, A, and D band gains support 16, 16.5, and 18dBi, respectively, which is the highest gain in the industry. At the same time, in order to meet the needs of network planning, it is necessary to maintain the same vertical beamwidth of the high gain FAD antenna as the conventional gain FAD antenna.
6) Scenario 6-F or D-segment LTE networking, compatible with DCS and TD-SCDMA
Such scenarios generally require macro station coverage, support high-intensive traffic and data traffic, covering distances of more than 500m, and is also an important coverage area for GSM. This scenario is recommended to use a wideband dual channel antenna (Tongyu model TDJ-172718D-65PT0/3/6/9) and a broadband dual channel ESC antenna (Tongyu model TDJ-172718DE-65P).
III. FDD LTE base station antenna solution
Globally, as the traditional 3G system occupies the majority share, as a continuation, the use of the natural LTE FDD system will be more extensive than TD-LTE. Since the traditional 2G and 3G services still occupy the mainstream, their spectrum resources will continue to be used for a long time in the future. The congestion of the wireless spectrum will cause the spectrum distribution of the LTE FDD system to be scattered around the world. As a base station antenna, in response to the development of LTE, the primary task is to develop ultra-wideband (1710 ~ 2690MHz) and ultra-double broadband antenna (698 ~ 960 / 1710 ~ 2690MHz), so that all mobile communication systems include 700MHz, 800MHz, 900MHz, 1800MHz, Full coverage at 2.1 GHz, 2.3 GHz, 2.5 GHz, and 2.6 GHz.
A major technical feature of LTE FDD is the adoption of MIMO technology, which objectively requires the base station antenna to support multiple ports of the same frequency. At the same time, in order to cope with the high-density data traffic after the development of LTE, multi-port backup is a good choice for future communication expansion. . In addition, the phenomenon of a large number of antennas shared by many overseas operators in the same region is common, making the ultra-wideband multi-port base station antenna a trend of LTE FDD solutions. As a leader in the development of wideband phase shifters and multi-port base station antennas, Tongyu Communications will introduce a wide variety of ultra-wideband multi-port base station antennas in response to the development of LTE FDD technology.
Ultra-wideband base station antenna, dual-band antenna is 698 ~ 960 / 1710 ~ 2690MHz (Tongyu typical model TDJ-609015 / 172717DE-65F), tri-band antenna should be different base station antenna width needs shoulder side class 1710 ~ 2690 / 698 ~ 960 /1710～2690MHz (Tongyu typical model TTB-609015/172717/172717DE-65F) and coaxial class 698～960/1710～2690/1710～2690MHz (Tongyu typical model TTB-609017/172717/172717DE-65F), The quad-band antenna has dual-band shoulder-to-shoulder type 698~960/1710~2690&698~960/1710~2690MHz (Tongyu typical model TDQ-609015/172717DE-65F), and the five-band antenna has a low four high 1710~2690/1710~2690/ 698 ~ 960 / 1710 ~ 2690/1710 ~ 2690MHz (Tongyu typical model TQB-609017 / Q172717DE-60F), six-band antenna has three-band shoulders 698 ~ 960 / 1710 ~ 2690/1710 ~ 2690&698 ~ 960 / 1710 ~ 2690 / 1710 ~ 2690MHz (Tongyu typical model TQB-D609017 / Q172717DE-60F). At the same time, due to the different coverage distance requirements, various multi-port ultra-wideband antennas have serialized products with different gain files.
Based on the characteristics of domestic TD-LTE and foreign LTE FDD development, this paper briefly describes the characteristics of base station antennas under two major standards, proposes two types of LTE system base station antenna solutions, and Tongyu communication base station antennas in two different types of systems. Recommended model selected.