Journal of Xidian University

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Method of sparse multi-user detection in non-orthogonal multiple access

LI Yanlong1,2;CHEN Xiao1;ZHAN Deman1,2;WANG Junyi1   

  1. (1. Ministry of Education Key Lab. of Cognitive Radio and Information Processing , Guilin Univ. of Electronic Technology, Guilin 541004, China;
    2. Science and Technology on Information Transmission and Dissemination in Communication Networks Laboratory, The 54th Research Institute of China Electronics Technology Group Corporation, Shijiazhuang 050081, China)
  • Received:2016-06-15 Online:2017-06-20 Published:2017-07-17

Abstract:

For the features of the uplink non-orthogonal multiple access (NOMA) system for 5G in the future, in which the number of connected users is huge in the multi-user detection, the active users within a given time are rare and the signals are sparse. A non-orthogonal multiple access system Chips Mapper-CDMA is designed by taking advantage of compressive sensing theory and the demand of the NOMA system of 5G. Combined with the compressive sensing technique, it detects the active users and data of the uplink NOMA system. It greatly reduces the control signaling overhead and transmission delay because the active users do not send the active status information to the base station and do not need to interact with the base station in advance. Simulation results show that the system can not only take advantage of compressive sensing theory to detect the active users and data reliably, but also achieve overload. Under the circumstances in which active users are sparse, the overload rate can be up to 300%, which greatly improves the spectrum efficiency.

Key words: non-orthogonal multiple access, multi-user detection, compressive sensing, overload