TY - THES
AU - Qin, Tao
PY - 2007
TI - Adaptive resource allocation for multiuser OFDM-based cognitive radio systems
KW - Thesis/Dissertation
LA - eng
M3 - Text
AB - Major challenges in the design of next generation wireless communication systems
include harsh propagation environments and scarce resources such as power and
spectrum. Cognitive radio (CR) is a promising concept for improving the utilization
of scarce radio spectrum resources. Orthogonal frequency division multiplexing
(OFDM) is regarded as a technology which is well-matched for CR systems. Dynamic
resource allocation is an important task in such systems.
In this thesis, a novel fair multiuser resource allocation algorithm for OFDM CR
systems is presented. Although not optimal, the algorithm has low computational
complexity. The algorithm attempts to maximize the total transmit bit rate (system
throughput) of a group of secondary (unlicensed or CR) users subject to (1) a total
transmit power constraint for secondary users, (2) a maximum tolerable interference
level which can be tolerated by primary (licensed) users. The algorithm is fair in
the sense that it tries whenever possible to allocate bits to users who have not received
their fair share of service. Simulation results show that the proposed algorithm
achieves a performance close to optimal. The effect on system throughput of changing
various system parameter values is also examined.
A novel cost minimization algorithm for multiuser OFDM cognitive radio systems
is also proposed. The objective is to minimize a cost function which takes into account
the interference power experienced by the primary user as well as the base station
transmit power for secondary users given minimum bit rate requirements for each
secondary user. It is found that the proposed algorithm provides a performance which
is fairly close to optimal. The influence of a relative weight parameter on the base
station (BS) transmit power for secondary users and the primary user interference
power is also discussed.
N2 - Major challenges in the design of next generation wireless communication systems
include harsh propagation environments and scarce resources such as power and
spectrum. Cognitive radio (CR) is a promising concept for improving the utilization
of scarce radio spectrum resources. Orthogonal frequency division multiplexing
(OFDM) is regarded as a technology which is well-matched for CR systems. Dynamic
resource allocation is an important task in such systems.
In this thesis, a novel fair multiuser resource allocation algorithm for OFDM CR
systems is presented. Although not optimal, the algorithm has low computational
complexity. The algorithm attempts to maximize the total transmit bit rate (system
throughput) of a group of secondary (unlicensed or CR) users subject to (1) a total
transmit power constraint for secondary users, (2) a maximum tolerable interference
level which can be tolerated by primary (licensed) users. The algorithm is fair in
the sense that it tries whenever possible to allocate bits to users who have not received
their fair share of service. Simulation results show that the proposed algorithm
achieves a performance close to optimal. The effect on system throughput of changing
various system parameter values is also examined.
A novel cost minimization algorithm for multiuser OFDM cognitive radio systems
is also proposed. The objective is to minimize a cost function which takes into account
the interference power experienced by the primary user as well as the base station
transmit power for secondary users given minimum bit rate requirements for each
secondary user. It is found that the proposed algorithm provides a performance which
is fairly close to optimal. The influence of a relative weight parameter on the base
station (BS) transmit power for secondary users and the primary user interference
power is also discussed.
UR - https://open.library.ubc.ca/collections/831/items/1.0101067
ER - End of Reference