Improving the average battery lifetime based on uplink multiuser MIMO-OFDM transmissions with subcarrier and power allocation | |
| Author | Karim, Tahia Farim |
| Call Number | AIT Thesis no.TC-13-02 |
| Subject(s) | MIMO systems Orthogonal frequency division multiplexing Cell phone systems |
| Note | A thesis submitted in partial ful llment of the requirements for the degree of Masters of Engineering in Telecommunications, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. TC-13-02 |
| Abstract | Resource allocation in multiuser MIMO-OFDM cellular systems is the focus of this thesis. The main aim of this work is to improve the average battery lifetime of the users, where it is assumed that battery lifetimes are dominated by the transmit powers in the uplink direction. A reduced complexity algorithm for subcarrier and power allocation is developed. As the joint subcarrier and power allocation problem is a complicated, nonlinear combinatorial optimization problem that can not be solved using a standard technique, the main optimization problem is decoupled so that subcarrier and power allocation are done separately. The subcarrier allocation is done based on the maximum subchannel gain of the channel matrix, while a bit-by-bit water lling algorithm is used for power allocation. The main contribution of this thesis work is the proposal to use all the spatial subchannels of a channel matrix, unlike (Zhang & Lataief, 2005b), (Uthansakul & Bialkowski, 2006) and (Zhang & Lataief, 2003) which only consider a single spatial subchannel with the maximum gain on each subcarrier. Simulation results indicate that the proposed scheme is able to better utilize the spatial subchannels and thus signi cantly improve the average battery lifetime while satisfy each user's data rate requirement. Finally, the thesis also explores subcarrier allocation that allows multiple users to share a common subcarrier, where multiaccess interference is removed using zero forcing equalization. Simulation results indicate that sharing of subcarriers can improve the average battery lifetime compared to the no-sharing scheme that allows using only the maximum gain subchannel in each subcarrier. However, this improvement is only present when the antenna correlation is low for the MIMO channel. |
| Year | 2013 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. TC-13-02 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Information and Communications Technologies (DICT) |
| Academic Program/FoS | Telecommunications (TC) |
| Chairperson(s) | Poompat Saengudomlert;Attaphongse Taparugssanagorn; |
| Examination Committee(s) | Ahmed, Kazi M.; |
| Scholarship Donor(s) | AIT Fellowship; |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 2013 |