Technology Research And Realization Of Digital Intermediate Frequency In The RF Repeater

In the cellular mobile communication system,the repeater are widely used in the 2G and 3G networks as a mobile communication optimization of critical equipment.It plays an important role in enhancing the signal coverage and reducing network operating costs.As one of the most important component in the repeater,its performance of the IF system determines the specifications of repeater and the design of program determines the cost of repeater.In this thesis,a design of IF system with the digital IF technology is proposed based on the softwarec radio and IF system.It meets the repeater's standards of YD/T 1337-2005,YD/T 1241-2002 and YD/T 1554-2007 and so on.The design has a high IF frequency,its maximum bandwidth is up to 24MHz. It has the function of selecting bandwith and frequency of the GSM repearter, CDMA repearter and WCDMA repeater.It has some advantages that the analog IF system is not.Based on the theoretical analysis,the thesis tests and verifies the program using the MATLAB software.At the same time ,the thesis presents the hardware design system and analyses the design ideas of the AD9516,AD80141,DAC5687 and other devices.In software design system,this thesis are divided into FPGA and MCU design.The thesis proposes a new AGC design. The design improves the system dynamic range and provides the space for the upgrade.Now,we debug the whole system.At the same time,the thesis analyzes some problems encountered in debugging. Finally,the thesis analyzes the test result.The test result proved that the system can achieve the optional frequency and band of the GSM repearter, CDMA repearter and WCDMA repeater.The system has good stability and flexibility.At the same time,the system has good specifications and has laid a good foundation for the related to product development.