TY - JOUR

T1 - Cognitive Multiple Access Network with Outage Margin in the Primary System

A1 - Maham,Behrouz

A1 - Popovski,Petar

A1 - Zhou,Xiangyun

A1 - Hjørungnes,Are

AU - Maham,Behrouz

AU - Popovski,Petar

AU - Zhou,Xiangyun

AU - Hjørungnes,Are

PB - I E E E

PY - 2011

Y1 - 2011

N2 - This paper investigates the problem of spectrally efficient operation of a multiuser uplink cognitive radio system in the presence of a single primary link. The secondary system applies opportunistic interference cancelation (OIC) and decodes the primary signal when such an opportunity is created. We derive the achievable rate in the secondary system when OIC is used. This scheme has a practical significance, since it enables rate adaptation without requiring any action from the primary system. The exact expressions for outage probability of the primary user are derived, when the primary system is exposed to interference from secondary users. Moreover, approximated formulas and tight lower and upper bounds for the ergodic sum-rate capacity of the secondary network are found. Next, the power allocation is investigated in the secondary system for maximizing the sum-rate under an outage constraint at the primary system. We formulate the power optimization problem in various scenarios depending on the availability of channel state information and the type of power constraints, and propose a set of simple solutions. Finally, the analytical results are confirmed by simulations, indicating both the accuracy of the analysis, and the fact that the spectral-efficient, low-complexity, flexible, and high-performing cognitive radio can be designed based on the proposed schemes.

AB - This paper investigates the problem of spectrally efficient operation of a multiuser uplink cognitive radio system in the presence of a single primary link. The secondary system applies opportunistic interference cancelation (OIC) and decodes the primary signal when such an opportunity is created. We derive the achievable rate in the secondary system when OIC is used. This scheme has a practical significance, since it enables rate adaptation without requiring any action from the primary system. The exact expressions for outage probability of the primary user are derived, when the primary system is exposed to interference from secondary users. Moreover, approximated formulas and tight lower and upper bounds for the ergodic sum-rate capacity of the secondary network are found. Next, the power allocation is investigated in the secondary system for maximizing the sum-rate under an outage constraint at the primary system. We formulate the power optimization problem in various scenarios depending on the availability of channel state information and the type of power constraints, and propose a set of simple solutions. Finally, the analytical results are confirmed by simulations, indicating both the accuracy of the analysis, and the fact that the spectral-efficient, low-complexity, flexible, and high-performing cognitive radio can be designed based on the proposed schemes.

UR - http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5967987

U2 - 10.1109/TWC.2011.072511.101867

DO - 10.1109/TWC.2011.072511.101867

JO - I E E E Transactions on Wireless Communications

JF - I E E E Transactions on Wireless Communications

SN - 1536-1276

IS - 10

VL - 10

SP - 3343

EP - 3353

ER -