JOURNAL OF CHINA UNIVERSITIES OF POSTS AND TELECOM ›› 2017, Vol. 24 ›› Issue (5): 8-15.doi: 10.1016/S1005-8885(17)60228-0

• Wireless • Previous Articles     Next Articles

SFD-AGC algorithm with ADC digitalizing bit fully utilized and stable PAR

Wang Jie, Hu Xiaoguang, Guan Enyi, Ding Zhushun, Yao Yidong, Li Wen   

  1. 1. School of Automation Science and Electrical Engineering, Beihang University, Beijing 100191, China
    2. Beijing Institute of Aerospace Control Devices, Beijing 100039, China
  • Received:2017-04-18 Revised:2017-09-29 Online:2017-10-30 Published:2017-12-18
  • Contact: Wang Jie, E-mail: wangjack2006@126.com E-mail:wangjack2006@126.com
  • About author:Wang Jie, E-mail: wangjack2006@126.com
  • Supported by:
    This work was supported by the Smart In-Building Wireless System Using Flexible Digital Transmission Technology (SWIFT). We would like to extend our sincere gratitude to all members of these projects, especially Dr Li, the project leader of SWIFT in University of Cambridge.

Abstract: Aiming at making full use of analog to digital converter (ADC) digitalizing bit without oversaturation while keeping peak to average ratio (PAR) stable, this paper puts forward a new segmented full-digital (SFD)-automatic gain control (AGC) algorithm for a new long term evolution (LTE) communication system. Segmented digital gain control strategy is adopted to adjust the gain by only one step based on detected power status. Whether the gain needs to be adjusted is determined by current signal state derived from the change ranges of adjacent root mean square (RMS) of input signal, but not the difference between the power level of current signal and target signal. Software simulation and hardware implementing had been conducted with LTE frequency division dual (FDD) uplink signal and the results indicated that the proposed AGC algorithm can judge power status accurately and hence adjust the gain precisely in one step with a short delay, further, it can make full use of ADC digitalizing bit without oversaturation as well as keeping stable PAR. In addition, the mean error vector magnitude (EVM) was confined less than 1.6% to meet the 3rd generation partnership project (3GPP) standard well.

Key words: digitalizing bit, stable PAR, full-digital, segmented AGC, LTE FDD, EVM

CLC Number: