Two-user opportunistic scheduling using hierarchical modulations in wireless networks with heterogenous average link gains

Handle URI:
http://hdl.handle.net/10754/561457
Title:
Two-user opportunistic scheduling using hierarchical modulations in wireless networks with heterogenous average link gains
Authors:
Hossain, Md Jahangir; Alouini, Mohamed-Slim ( 0000-0003-4827-1793 ) ; Bhargava, Vijay K.
Abstract:
Our contribution, in this paper, is two-fold. First, we analyze the performance of a hierarchical modulation-assisted two-best user opportunistic scheduling (TBS) scheme, which was proposed by the authors, in a fading environment where different users have different average link gains. Specifically, we present a new expression for the spectral efficiency (SE) of the users and using this expression, we compare the degrees of fairness (DOF) of the TBS scheme with that of classical single user opportunistic scheduling schemes, namely, absolute carrier-to-noise ratio (CNR) based single-best user scheduling (SBS) and normalized CNR based proportional fair scheduling (PFS) schemes. The second contribution is that we propose a new hybrid two-user opportunistic scheduling (HTS) scheme based on our earlier proposed TBS scheme. This HTS scheme selects the first user based on the largest absolute CNR value among all the users while the second user is selected based on the ratios of the absolute CNRs to the corresponding average CNRs of the remaining users. The total transmission rate i.e., the constellation size is selected according to the absolute CNR of the first best user. The total transmission rate is then allocated among these selected users by joint consideration of their absolute CNRs and allocated number of information bit(s) are transmitted to them using hierarchical modulations. Numerical results are presented for a fading environment where different users experience independent but non-identical (i.n.d.) channel fading. These selected numerical results show that the proposed HTS scheme can considerably increase the system's fairness without any degradation of the link spectral efficiency (LSE) i.e., the multiuser diversity gain compared to the classical SBS scheme. These results also show that the proposed HTS scheme has a lower fairness in comparison to the PFS scheme which suffers from a considerable degradation in LSE. © 2010 IEEE.
KAUST Department:
Electrical Engineering Program; Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division; Communication Theory Lab
Publisher:
Institute of Electrical and Electronics Engineers
Journal:
IEEE Transactions on Communications
Issue Date:
Mar-2010
DOI:
10.1109/TCOMM.2010.03.080238
Type:
Article
ISSN:
00906778
Sponsors:
This work, in part, has been presented in the IEEE International Conference on Communication (ICC'08), Beijing, China. It is supported in part by the Li Tze Fong Memorial Fellowship; in part by the Natural Sciences and Engineering Council of Canada (NSERC) Canada; and in part by the Qatar foundation for Education, Science, and Community development.
Appears in Collections:
Articles; Electrical Engineering Program; Communication Theory Lab; Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division

Full metadata record

DC FieldValue Language
dc.contributor.authorHossain, Md Jahangiren
dc.contributor.authorAlouini, Mohamed-Slimen
dc.contributor.authorBhargava, Vijay K.en
dc.date.accessioned2015-08-02T09:11:52Zen
dc.date.available2015-08-02T09:11:52Zen
dc.date.issued2010-03en
dc.identifier.issn00906778en
dc.identifier.doi10.1109/TCOMM.2010.03.080238en
dc.identifier.urihttp://hdl.handle.net/10754/561457en
dc.description.abstractOur contribution, in this paper, is two-fold. First, we analyze the performance of a hierarchical modulation-assisted two-best user opportunistic scheduling (TBS) scheme, which was proposed by the authors, in a fading environment where different users have different average link gains. Specifically, we present a new expression for the spectral efficiency (SE) of the users and using this expression, we compare the degrees of fairness (DOF) of the TBS scheme with that of classical single user opportunistic scheduling schemes, namely, absolute carrier-to-noise ratio (CNR) based single-best user scheduling (SBS) and normalized CNR based proportional fair scheduling (PFS) schemes. The second contribution is that we propose a new hybrid two-user opportunistic scheduling (HTS) scheme based on our earlier proposed TBS scheme. This HTS scheme selects the first user based on the largest absolute CNR value among all the users while the second user is selected based on the ratios of the absolute CNRs to the corresponding average CNRs of the remaining users. The total transmission rate i.e., the constellation size is selected according to the absolute CNR of the first best user. The total transmission rate is then allocated among these selected users by joint consideration of their absolute CNRs and allocated number of information bit(s) are transmitted to them using hierarchical modulations. Numerical results are presented for a fading environment where different users experience independent but non-identical (i.n.d.) channel fading. These selected numerical results show that the proposed HTS scheme can considerably increase the system's fairness without any degradation of the link spectral efficiency (LSE) i.e., the multiuser diversity gain compared to the classical SBS scheme. These results also show that the proposed HTS scheme has a lower fairness in comparison to the PFS scheme which suffers from a considerable degradation in LSE. © 2010 IEEE.en
dc.description.sponsorshipThis work, in part, has been presented in the IEEE International Conference on Communication (ICC'08), Beijing, China. It is supported in part by the Li Tze Fong Memorial Fellowship; in part by the Natural Sciences and Engineering Council of Canada (NSERC) Canada; and in part by the Qatar foundation for Education, Science, and Community development.en
dc.publisherInstitute of Electrical and Electronics Engineersen
dc.subjectAdaptive modulationsen
dc.subjectAnd degrees of fairnessen
dc.subjectHierarchical constellationsen
dc.subjectMultiuser diversityen
dc.subjectOpportunistic schedulingen
dc.subjectSpectral efficiencyen
dc.titleTwo-user opportunistic scheduling using hierarchical modulations in wireless networks with heterogenous average link gainsen
dc.typeArticleen
dc.contributor.departmentElectrical Engineering Programen
dc.contributor.departmentComputer, Electrical and Mathematical Sciences and Engineering (CEMSE) Divisionen
dc.contributor.departmentCommunication Theory Laben
dc.identifier.journalIEEE Transactions on Communicationsen
dc.contributor.institutionInstitut National de la Recherche Scientifique, INRS-EMT, 800, Gauchetiere W., Montreal H5A 1K6, Canadaen
dc.contributor.institutionDepartment of Electrical and Computer Engineering, University of British Columbia, Vancouver, Canadaen
kaust.authorAlouini, Mohamed-Slimen
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