DocumentCode :
738352
Title :
Ergodic Sum-Rate Maximization for Fading Cognitive Multiple-Access Channels Without Successive Interference Cancelation
Author :
Kang, Xin ; Chong, Hon Fah ; Chia, Yeow-Khiang ; Sun, Sumei
Author_Institution :
Institute for Infocomm Research, Singapore
Volume :
64
Issue :
9
fYear :
2015
Firstpage :
4009
Lastpage :
4018
Abstract :
In this paper, the ergodic sum rate of a fading cognitive multiple-access channel (C-MAC) is studied, where a secondary network (SN) with multiple secondary users (SUs) transmitting to a secondary base station shares the spectrum band with a primary user (PU). An interference power constraint (IPC) is imposed on the SN to protect the PU. Under such a constraint and the individual transmit power constraint (TPC) imposed on each SU, we investigate the power allocation strategies to maximize the ergodic sum rate of a fading C-MAC without successive interference cancelation (SIC). In particular, this paper considers two types of constraints: 1) average TPC and average IPC and 2) peak TPC and peak IPC. For the first case, it is proved that the optimal power allocation is dynamic time-division multiple access (D-TDMA), which is exactly the same as the optimal power allocation to maximize the ergodic sum rate of the fading C-MAC with SIC under the same constraints. For the second case, it is proved that the optimal solution must be at the extreme points of the feasible region. It is shown that D-TDMA is optimal with high probability when the number of SUs is large. Moreover, we show that when the SUs can be sorted in a certain order, an algorithm with linear complexity can be used to find the optimal power allocation.
Keywords :
Fading; Hip; Interference; Optimization; Resource management; Scattering; Silicon carbide; Cognitive radio (CR); ergodic sum rate; fading channels; multiple-access channel (MAC); nonconvex optimization; optimal power allocation; spectrum sharing;
fLanguage :
English
Journal_Title :
Vehicular Technology, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9545
Type :
jour
DOI :
10.1109/TVT.2014.2365182
Filename :
6936930
Link To Document :
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