Joint User Detection and Channel Estimation in Grant-Free Random Access for Massive MIMO Systems

Algorithm 2

Joint detection and estimation in COP.

	Require: The received signal , the number of subpreambles , the preamble set and its length .
	Ensure: .
(1)	The BS initializes to an empty set.
(2)	for i = 1: L do
(3)	The BS runs Algorithm 1 to generate with the input of , and .
(4)	The BS counts the numbers of elements in and , denoted as and .
(5)	The BS computes .
(6)	for i = 1: do
(7)	for j = : do
(8)	if then
(9)	The BS appends the average of and to .
(10)	The BS eliminates the original and from .
(11)	end if
(12)	end for
(13)	end for
(14)	end for