Adaptive resource allocation in NOMA-enabled backscatter communications systems

Abstract

The integration of NOMA with Backscatter communication(BackCom) is a promising   solution   for   developing   a   green   future   wireless   network. However,  system  performance  degrades  with  the  deployment  of  multiple backscatter  devices  (BDs)  in  a  network.  Hence,  energy  efficiency  (EE) maximization   with   proper   resource   allocation   is   among   the   primary concerns. In this regard, this paper proposes an adaptive resource allocation method  for  maximizing  EE  by  simultaneously  optimizing  the  transmission power   from   the   base   station   (BS),   power   allocation   coefficients,   and reflection   coefficients   under   the   constraints   of   maximum   allowable transmission  power  and  minimum  achievable  data  rate.  Specifically,  an iterative  method  based  on  a  parametric  transformation  approach  is  adopted for  maximizing  EE  by  jointly  optimizing  the  coefficients,  inwhich  the power allocation problem to the BDs is solved by an adaptive method that is based  on  improved  proportionate  normalized  least  mean  square  (IPNLMS) algorithm.  Then,  the  system  performance  is  evaluated,  and  the  impact  of different  parameters isalso  studied  it  is  observed  that  EE  is  significantly improvedas compared to the existing scheme, and maximum at n=-0.5.