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

Table 5

Complexity break-up of Gharavi-Alkhansari and Gershman algorithm [11].

Sl. no.	Algorithm statements	Complex flops required	Real flops required
1	𝑆𝑅=1,2,3,…,𝑀𝑅
2	𝐁=𝐈𝑀𝑇
3	for 𝑗=1 to 𝑀𝑅	2𝑀𝑅𝑀𝑇−𝑀𝑅	8𝑀𝑅𝑀𝑇−4𝑀𝑅
4	𝛼𝑗=𝐇𝑗,∶^2
5	end
6	for 𝑛=1 to 𝐿𝑅
7	𝐽=argmax𝛼𝑗
8	𝑗∈𝑆𝑅
9	𝑆𝑅=𝑆𝑅−𝐽
10	If 𝑛<𝐿𝑅
11	1𝐚=𝐿𝑇/𝜌+𝛼𝐽𝐁𝐇^𝐻𝐽,∶	(2𝑀^2𝑇−𝑀𝑇+4)(𝐿𝑅−1)	(6𝑀^2𝑇+2𝑀𝑇)(𝐿𝑅−1)
12	𝐁=𝐁−𝐚𝐚^𝐻	(2𝑀^2𝑇)(𝐿𝑅−1)	(8𝑀^2𝑇−2)(𝐿𝑅−1)
13	for all 𝑗∈𝑆𝑅	(2𝑀𝑇𝑀𝑅+𝑀𝑅)𝐿𝑅−1	8𝑀𝑇−4𝑀𝑅−𝐿𝑅2(𝐿𝑅−1)
14	𝛼𝑗=𝛼𝑗−𝐚^𝐻𝐇^𝐻𝑗,∶^2
15	end
16	end
17	end
18	£𝑅=1,2,3,…,𝑀𝑅−𝑆𝑅