5G technology trends and challenges to radio management

The fifth generation mobile communication (5G) refers to a new generation of mobile communication system for mobile communication development in 2020, with ultra-high spectrum utilization and ultra-low power consumption, and is higher than 4G system in terms of transmission rate and resource utilization. 10 times, its wireless coverage performance and user experience will also be significantly improved. 5G will be closely integrated with other wireless mobile communication technologies to form a new generation of ubiquitous mobile information networks, meeting the development needs of mobile Internet traffic by 1000 times in the next 10 years.

New trends in 5G technology development

Millimeter wave communication technology

With the rapid development of wireless communication, especially personal mobile communication, the low-end frequency of the radio spectrum has become saturated, even with the use of Gaussian filtered minimum shift keying (GMSK) modulation or various multiple access techniques to expand the capacity of the communication system, Improving the utilization of spectrum can not meet the needs of future communication development. Therefore, high-speed, broadband wireless communication is bound to develop new spectrum resources to the high-end microwave frequency band. The millimeter wave frequency range is 30 GHz to 300 GHz. Due to its short wavelength, narrow bandwidth, narrow beam, good confidentiality, high transmission quality, and all-weather communication, it can effectively solve many problems faced by high-speed broadband wireless access. Distance communication has broad application prospects.

At present, millimeter wave communication technology is mainly applied to point-to-point communication and satellite communication or broadcasting systems on the ground. Among them, the point-to-point millimeter wave communication on the ground is generally used for relay communication with high security requirements. The millimeter wave itself has strong concealment and anti-interference. At the same time, due to the attenuation of millimeter waves in the atmosphere and the use of small-diameter antennas, extremely narrow beams and small side lobes can be obtained, so the interception of millimeter-wave communication is obtained. And interference becomes very difficult.

Spectrum sharing technology

The spectrum sharing technology mainly provides the mechanism for providing dynamic spectrum access for a variety of services in a limited spectrum without changing the existing spectrum allocation, including service-based spectrum avoidance mechanism, location-based and electromagnetic environment-based intelligent spectrum selection. Mechanisms, etc., to achieve coexistence of different services, to achieve multiple cognitive users to work together, and thus provide a good user experience and efficient spectrum utilization.

Currently, the fastest-growing spectrum sharing technology is cognitive radio technology. Cognitive radio, also known as smart radio, is characterized by flexibility, intelligence, and reconfigurability. By perceiving the external environment and using artificial intelligence technology to learn from the environment, it can purposely change certain operational parameters (such as transmission). Power, carrier frequency and modulation techniques, etc., adapt their internal state to the statistical changes of the received wireless signals, enabling highly reliable communication at any time, anywhere, and efficient use of wireless spectrum resources with limited heterogeneous network environments. The core idea of ​​cognitive radio is to achieve dynamic spectrum allocation (DSA: dynamic spectrum allocaTIon) and spectrum sharing (Spectrum Sensing) and intelligent learning capabilities of the system.

In cognitive radio, secondary users dynamically search for spectrum holes for communication. This technique is called dynamic spectrum access. When the primary user occupies a certain licensed frequency band, the secondary user must exit from the frequency band to search for other idle frequency bands to complete their own communication.

Massive MIMO

The rapid development of 5G requires that the network must address capacity limitations and challenges in some existing communication systems, such as network reliability, coverage, energy efficiency, and latency. Massive MIMO (Multiple Input Multiple Output) is an implementation of 5G technology that enables greater wireless data traffic and connection reliability by using a large number of antennas (more than 64) on the base transceiver station (BTS). This approach fundamentally changes the existing standard base transceiver architecture. The existing standard uses only a sector topology of up to 8 antennas. With hundreds of antenna elements, massive MIMO can use the precoding technology set to concentrate energy onto the target mobile terminal, reducing radiated power. By directing infinite energy to specific users, reducing radiated power while reducing interference to other users, the transmission speed and anti-jamming performance of the 5G network are improved, enabling the network to accommodate more users and have higher reliability and Higher energy efficiency.

PufangTech`s SCADA radio modems have air data rates of 19200bps in 25KHz channel spacing and 9600bps in 12.5KHz. For master station of SCADA system, RS232 interface port is usually standard, while RS485 is often adopted by slave station.