The Design And Implementation For PDT Digital Trunking Base Station Radio Remote Unit

Police Digital Trunking is a kind of special wireless communication standard used in the field of public safety or professional trunking communication in our country.This communication standard is led by the Ministry of Public Security and led by Hytera,together with major domestic wireless network communication manufacturers.according to China's national conditions and application characteristics developed a wide coverage,high efficiency and flexibility of the wireless cluster standards.This paper studies digital multi-carrier on software radio technology,completed the design and implementation for radio remote unit.Compared with traditional private network base station systems,PDT can effectively reduce the volume,power consumption,and cost of base station equipment.It has a more flexible form and is easy to expand and maintain.On the receiving link,the system's receiving sensitivity is improved,and the uplink coverage capability is improved,thus solving the problem of unbalanced uplink and downlink coverage.Through dynamic monitoring of the distribution of uplink signal strength for statistical analysis,the current wireless environment is modeled so that the current radio circuit link scheme is more suitable for the current wireless environment.In this case,it is possible to effectively improve the problem that the multi-carrier receiver does not receive a large dynamic range,and a more economical approach achieves better results.Multi-carrier transmission is realized at the transmitter using a pre-distortion and Doherty power amplifier architecture,and multi-carrier signals are generated on the same transmission link with guaranteed linearity,and the overall efficiency reaches over 35%.With this implementation,the carrier frequency interval can be set closer,which also indirectly improves the spectrum utilization.At the same time,the solution solves the constraint that the narrow-band cavity combiner is limited on the carrier frequency,which can effectively reduce the insertion loss from the power amplifier to the antenna,and significantly improves the system's RF emission efficiency under the same transmit power.The multi-carrier digital trunk transceiver based on software radio technology is in line with the development direction of miniaturization,flexibility,high speed,and fiber optics in wireless communication systems.This is also the direction of future digital trunking communication technology development.Through the research of this paper,the feasibility and superiority of multi-carrier digital trunk transceiver architecture are more clearly verified.With the further development of technology,research and breakthrough more technical problems,multi-carrier digital trunking system has a very broad application prospects.