Optimal power policy and throughput analysis in cognitive broadcast networks under primary's outage constraint

This paper focuses on a spectrum-sharing based cognitive radio fading broadcast channel (BC) with a singleantenna secondary base station (SBS) and M secondary receivers (SRs) concurrently utilizing the same spectrum band with one delay-sensitive primary user (PU). The quality-of-service requirement in the primary network is given by the primary user's outage probability constraint (POC). We address the optimal power allocation problem for the ergodic sum capacity (ESC) maximization in the secondary BC network subject to a POC and an average transmit power constraint at SBS. Optimality conditions reveal that in each fading block SBS will choose only one SR with the highest channel power gain and allocate the block to that user. Furthermore, if PU's power strategy is assumed to be ON-OFF with constant power when ON, the secondary network throughput scaling for largeM in Rayleigh fading is also investigated. It is shown that the secondary sum throughput in Rayleigh fading BC scales like O(log(logM)). Numerical results support the theoretical results derived in the paper.

[1]  David Tse,et al.  Optimal power allocation over parallel Gaussian broadcast channels , 1997, Proceedings of IEEE International Symposium on Information Theory.

[2]  Jamie S. Evans,et al.  Service-Outage Capacity Maximization in Cognitive Radio , 2011, 2011 IEEE International Conference on Communications (ICC).

[3]  Babak Hassibi,et al.  On the capacity of MIMO broadcast channels with partial side information , 2005, IEEE Transactions on Information Theory.

[4]  Shuguang Cui,et al.  On Ergodic Sum Capacity of Fading Cognitive Multiple-Access and Broadcast Channels , 2008, IEEE Transactions on Information Theory.

[5]  M. R. Leadbetter,et al.  Extremes and Related Properties of Random Sequences and Processes: Springer Series in Statistics , 1983 .

[6]  Hazer Inaltekin,et al.  Throughput Scaling in Cognitive Multiple Access Networks with Power and Interference Constraints , 2011, 2011 IEEE International Conference on Communications (ICC).

[7]  Roy D. Yates,et al.  Service outage based power and rate allocation for parallel fading channels , 2003, IEEE Transactions on Information Theory.

[8]  J. Galambos.  Review: M. R. Leadbetter, Georg Lindgren and Holger Rootzen, Extremes and related properties of random sequences and processes , 1985 .

[9]  Ying-Chang Liang,et al.  Investigation on multiuser diversity in spectrum sharing based cognitive radio networks , 2008, IEEE Communications Letters.

[10]  Giuseppe Caire,et al.  Optimum power control over fading channels , 1999, IEEE Trans. Inf. Theory.

[11]  Babak Hassibi,et al.  On the capacity of MIMO broadcast channel with partial side information , 2003, The Thrity-Seventh Asilomar Conference on Signals, Systems & Computers, 2003.

[12]  Shuguang Cui,et al.  Dynamic Resource Allocation in Cognitive Radio Networks , 2010, IEEE Signal Processing Magazine.

[13]  Andrea J. Goldsmith,et al.  Capacity and optimal resource allocation for fading broadcast channels - Part I: Ergodic capacity , 2001, IEEE Trans. Inf. Theory.

[14]  Joseph Mitola,et al.  Cognitive Radio An Integrated Agent Architecture for Software Defined Radio , 2000 .