A Low Complexity Near-Optimal MIMO Antenna Subset Selection Algorithm for Capacity Maximisation

Table 6

Complexity break-up of Molisch et al. algorithm [6].

Sl. no.	Algorithm statements	Complex flops required	Real flops required
1	𝑆𝑅=1,2,3,…,𝑀𝑅
2	for 𝑗=1 to 𝑀𝑅	2𝑀𝑅𝑀𝑇−𝑀𝑅	8𝑀𝑅𝑀𝑇−4𝑀𝑅
3	𝛾^2𝑗=𝐇𝑗,∶^2
4	end
5	for 𝑝=1 to 𝑀𝑅	(2𝑀𝑇−1)(𝑀^2𝑅−𝑀𝑅)2	(4𝑀𝑇−2)(𝑀^2𝑅−𝑀𝑅)
6	for 𝑞=1 to 𝑀𝑅
7	if 𝑝>𝑞
8	𝛼𝑝,𝑞=𝐇𝑝,∶𝐇^𝐻𝑞,∶
9	end
10	end
11	end
12	for 𝑛=1 to 𝑀𝑅−𝐿𝑅
13	𝑃,𝑄=argmax𝑝,𝑞∈𝑆𝑅𝛼𝑝,𝑞
14	if 𝐇𝑃,∶^2>𝐇𝑄,∶^2
15	𝑆𝑅=𝑆𝑅−𝑄
16	𝛼𝑄,∶=0
17	else
18	𝑆𝑅=𝑆𝑅−𝑃
19	𝛼𝑃,∶=0
20	end
21	end
26	£𝑅=𝑆𝑅