DocumentCode :
1447899
Title :
Design and Analysis of Downlink Spectrum Sharing in Two-Tier Cognitive Femto Networks
Author :
Cheng, Shin-Ming ; Ao, Weng Chon ; Tseng, Fan-Min ; Chen, Kwang-Cheng
Author_Institution :
Nat. Taiwan Univ., Taipei, Taiwan
Volume :
61
Issue :
5
fYear :
2012
fDate :
6/1/2012 12:00:00 AM
Firstpage :
2194
Lastpage :
2207
Abstract :
In two-tier networks consisting of a macrocell overlaid with femtocells in cochannel deployment and closed-access policy, spatial reuse is achieved at the price of severe intratier and cross-tier interference from concurrent transmissions. The interference causes significant performance degradation, particularly when coordination among base stations (BSs) is infeasible. Cognitive radio (CR) is a promising technique for interference mitigation, where femto-BSs with cognitive information accomplish concurrent transmissions while meeting a per-tier outage constraint. This paper studies the role of information sensed at femto-BSs on the transmission capacity. By exploiting different cognitive information, we propose spectrum-sharing schemes between macrocell and femtocell, as well as among femtocells, to improve spatial reuse gain. Bounds on the maximum intensity of simultaneously transmitting femtocells that satisfy a given per-tier outage constraint in these schemes are theoretically derived via a stochastic geometry model. We conduct simulations to evaluate the performance of the proposed schemes in terms of transmission capacity. The results confirm that, when femto-BSs acquire the knowledge of user channel statistics or user location information, significant spatial reuse gain can be achieved by exploiting the avoidance region and multiuser diversity.
Keywords :
cochannel interference; cognitive radio; error statistics; femtocellular radio; interference suppression; stochastic processes; closed-access policy; cochannel deployment; cognitive radio; concurrent transmission; cross-tier interference; downlink spectrum sharing; femtocells; interference mitigation; macrocell overlaid; multiuser diversity; per-tier outage constraint; spatial reuse gain; spectrum-sharing scheme; stochastic geometry model; transmission capacity; two-tier cognitive femto network; user channel statistics; user location information; Downlink; Femtocells; Interference; Macrocell networks; Radio frequency; Resource management; Signal to noise ratio; Cognitive radio (CR); downlink capacity; femtocell; spectrum sharing; stochastic geometry;
fLanguage :
English
Journal_Title :
Vehicular Technology, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9545
Type :
jour
DOI :
10.1109/TVT.2012.2187692
Filename :
6151866
Link To Document :
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