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|Title: ||Cross-layer design of admission control policies in code division multiple access communications systems utilizing beamforming|
|Authors: ||Sheng, Wei|
|Keywords: ||Cross-layer design|
|Issue Date: ||2008|
|Series/Report no.: ||Canadian theses|
|Abstract: ||To meet growing demand for wireless access to multimedia traffic, future generations of wireless networks need to provide heterogenous services with high data rate and guaranteed quality-of-service (QoS). Many enabling technologies to ensure QoS
have been investigated, including cross-layer admission control (AC), error control and congestion control.
In this thesis, we study the cross-layer AC problem. While previous research focuses on single-antenna systems, which does not
capitalize on the significant benefits provided by multiple antenna
systems, in this thesis we investigate cross-layer AC policy for a code-division-multiple-access (CDMA) system with antenna arrays at the base station (BS). Automatic retransmission request (ARQ)
schemes are also exploited to further improve the spectral efficiency.
In the first part, a circuit-switched network is considered and an exact outage probability is developed, which is then employed to derive the optimal call admission control (CAC) policy by formulating a constrained semi-Markov decision process (SMDP). The derived optimal policy can maximize the system throughput with
guaranteed QoS requirements in both physical and network layers.
In the second part, a suboptimal low-complexity CAC policy is
proposed based on an approximate power control feasibility condition (PCFC) and a reduced-outage-probability algorithm. Comparison between optimal and suboptimal CAC policies shows that the suboptimal CAC policy can significantly reduce the computational
complexity at a cost of degraded performance.
In the third part, we extend the above research to packet-switched networks. A novel SMDP is formulated by incorporating ARQ protocols. Packet-level AC policies are then
proposed. The proposed policies exploit the error control capability provided by ARQ schemes, while simultaneously
guaranteeing QoS requirements in the physical and packet levels.
In the fourth part, we propose a connection admission control policy
in a connection-oriented packet-switched network, which can guarantee QoS requirements in physical, packet and connection levels. By considering joint optimization across different layers,
the proposed optimal policy provides a flexible way to handle multiple QoS requirements, while at the same time, maximizing the overall system throughput.|
|Description: ||Thesis (Ph.D, Electrical & Computer Engineering) -- Queen's University, 2008-08-05 16:21:40.431|
|Appears in Collections:||Queen's Theses & Dissertations|
Electrical and Computer Engineering Graduate Theses
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