Journal of Computer Networks and Communications

Research Article

Cognitive Code-Division Channelization with Admission Control

Algorithm 1

Proposed joint admission control and resource allocation algorithm.
 1: Select an arbitrary initial signature set for 𝑀 requesting secondary links.
 2: Calculate 𝐐 𝑖 by (15).
 3: Obtain 𝐔 and Ξ› through eigendecomposition of 𝐇 𝑇 𝑖 , 𝑖 𝐇 𝑖 , 𝑖 .
 4: Update 𝐬 𝑖 using (17).
 5: Repeat Step 2–4 until the secondary signature set converges.
 6: Calculate the matrix 𝐀 by (6).
 7: 𝑑 = 0 ; initialize 𝐄 ( 0 ) with 𝑐 𝟏 , where 𝑐 is a small constant.
 8: 𝑑 = 𝑑 + 1 .
 9: 𝐟 𝐨 𝐫 𝑖 = 1 , 2 , … do
10:  Update 𝐸 𝑖 ( 𝑑 ) ← m i n { 𝐸 m a x , 𝛾 𝐸 𝑖 ( 𝑑 βˆ’ 1 ) / S I N R 𝑖 ( 𝑑 βˆ’ 1 ) }
11: end for
12: Repeat Step 6–11 until 𝐄 converges to a stationary bit-energy vector.
13: Calculate 𝛼 𝑖 ( 𝐄 ) , 𝛽 𝑖 ( 𝐄 ) and πœ‚ 𝑖 ( 𝐄 ) by (21), (22) and (26), respectively.
14: βˆ‘ 𝐒 𝐟 𝑖 ∈ β„³ 𝑔 𝑗 , 𝑖 𝐸 𝑖 ≀ 𝐼 𝑗 βˆ€ 𝑗 = 1 , 2 , … , 𝐾 𝐭 𝐑 𝐞 𝐧
15:    𝐒 𝐟 ( 𝐈 βˆ’ 𝛾 𝐀 ) 𝐄 β‰₯ 𝐛 then
16:    F l a g _ c o n s t r a i n t s _ s a t i s fi e d ← 1
17:  else
18:   Remove the secondary link 𝑖 r e m o v e = a r g m a x 𝑖 ∈ β„³ { m a x ( 𝛼 𝑖 ( 𝐄 ) , 𝛽 𝑖 ( 𝐄 ) ) } .
19:  end if
20: else
21:  if  ( 𝐈 βˆ’ 𝛾 𝐀 ) 𝐄 β‰₯ 𝐛 then
22:   Remove the secondary link 𝑖 r e m o v e = a r g m a x 𝑖 ∈ β„³ { πœ‚ 𝑖 ( 𝐄 ) 𝐸 𝑖 } .
23:  else
24:   Remove the secondary link 𝑖 r e m o v e = a r g m a x 𝑖 ∈ β„³ { [ m a x ( 𝛼 𝑖 ( 𝐄 ) , 𝛽 𝑖 ( 𝐄 ) ) + πœ‚ 𝑖 ( 𝐄 ) ] 𝐸 𝑖 } .
25:  end if
26: end if
27: Repeat Step 1–26 until F l a g _ c o n s t r a i n t s _ s a t i s fi e d = 1 .