Next generation wireless networks are expected to provide high data rate and satisfy
the Quality-of-Service (QoS) constraints of the users. A significant component of
achieving these goals is to increase the effi ciency of wireless networks by either optimizing
current architectures or exploring new technologies which achieve that. The
latter includes revisiting technologies which were previously proposed, but due to a
multitude of reasons were ignored at that time. One such technology is relaying which
was initially proposed in the latter half of the 1960s and then was revived in the early
2000s. In this dissertation, we study relaying in conjunction with resource allocation
to increase the effi ciency of wireless networks. In this regard, we differentiate between
conventional relaying and relaying with buffers. Conventional relaying is traditional
relaying where the relay forwards the signal it received immediately. On the other
hand, in relaying with buffers or buffer-aided relaying as it is called, the relay can
store received data in its buffer and forward it later on. This gives the benefit of
taking advantage of good channel conditions as the relay can only transmit when the
channel conditions are good.
The dissertation starts with conventional relaying and considers the problem of
minimizing the total consumed power while maintaining system QoS. After upper
bounding the system performance, more practical algorithms which require reduced
feedback overhead are explored. Buffer-aided relaying is then considered and the joint
user-and-hop scheduler is introduced which exploits multi-user diversity (MUD) and
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multi-hop diversity (MHD) gains together in dual-hop broadcast channels. Next joint
user-and-hop scheduling is extended to the shared relay channel where two source-destination
pairs share a single relay. The benefits of buffer-aided relaying in the
bidirectional relay channel utilizing network coding are then explored. Finally, a new
transmission protocol for overlay cognitive radios is derived. This protocol utilizes
relays with buffers, requires only causal knowledge of the primary's message at the
secondary and incentivizes the primary to cooperate with the secondary and share
its codebook.
| Identifer | oai:union.ndltd.org:kaust.edu.sa/oai:repository.kaust.edu.sa:10754/333202 |
| Date | 10 1900 |
| Creators | Zafar, Ammar |
| Contributors | Alouini, Mohamed-Slim, Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division, Sultan, Ahmed, Ghanem, Bernard, Genton, Marc G., Jafarkhani, Hamid |
| Source Sets | King Abdullah University of Science and Technology |
| Language | English |
| Detected Language | English |
| Type | Dissertation |
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