Cognitive radio network is discussing how to enhance frequency reuse by
allowing the unlicensed users to utilize the frequency bands of licensed users
when these bands are not currently being used. Generally speaking, we called
these unlicensed users as secondary users and these licensed users as primary
users. In order to enhance frequency reuse, the secondary users need to monitor
the spectrum continuously to avoid possible interference with the primary users,
and once the primary users are found to be active, the secondary users are
required to vacate the frequency bands. Therefore, spectrum sensing plays a
significant important role in cognitive radio network. There are two probability
values associated with spectrum sensing: probability of detection and probability
of false alarm. The higher the probability of detection means the better theprimary users are protected. However, from the secondary users¡¦ perspective, the
lower the probability of false alarm, the more chances the frequency bands can
be reused when it is available, thus the higher the achievable throughput for the
secondary network.
In this thesis, we study the problem of designing the sensing duration to
maximize the achievable throughput for the secondary network under the
constraint that the primary user is sufficiently protected. We formulate the
sensing-throughput tradeoff problem mathematically, and use energy detection
¡]ED¡^[4] sensing scheme to prove that the formulated problem indeed has oneoptimal sensing time that yields the highest throughput for the secondary
network. We also discuss the case of two secondary users with the concept of
cooperative systems.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0215111-152835 |
| Date | 15 February 2011 |
| Creators | Shih, Li-Huang |
| Contributors | Jieh-Chian Wu, Ju-Ya Chen, Ching-Pio Hung |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0215111-152835 |
| Rights | unrestricted, Copyright information available at source archive |
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