What is meant by spectrum sensing?
Spectrum sensing is the process of periodically monitoring a specific frequency band, aiming to identify presence or absence of primary users.
What is meant by spectrum sensing in cognitive radio networks?
Spectrum sensing is one of the most important components of cognitive radio networks. Spectrum sensing enables a cognitive radio to have information about its environment and spectrum availability. The most widely used spectrum sensing methods are energy detection and matched filter detection.
Why is spectrum sensing needed?
Spectrum sensing is a key function of cognitive radio to prevent the harmful interference with licensed users and identify the available spectrum for improving the spectrum’s utilization. However, detection performance in practice is often compromised with multipath fading, shadowing and receiver uncertainty issues.
What are the benefits of cognitive radio?
Cognitive radio helps:
- Overcome radio spectrum scarcity.
- Avoid intentional radio jamming scenarios.
- Switch to power saving protocol.
- Improve satellite communications.
- Improves quality of service (QoS)
What is cooperative spectrum sensing?
Cooperative sensing is a solution to enhance the detection performance, in which secondary users collaborate with each other to sense the spectrum to find the spectrum holes.
What is the other name for spectrum sensing cognitive radio that adapts the transmission frequency bandwidth and time according to the environment?
Dynamic Spectrum Access
Figure 1: Spectrum Usage A “spectrum-sensing cognitive radio,” only adapts the transmission frequency, bandwidth, and time according to the environment. Such cognitive radio is also often called Dynamic Spectrum Access (DSA) networks.
What is cognitive radio network?
Cognitive radio (CR) is a form of wireless communication in which a transceiver can intelligently detect which communication channels are in use and which are not. It instantly moves into vacant channels while avoiding occupied ones. It does not cause any interference to the licensed user.
What are the advantages and disadvantages of cognitive radio?
➨It offers better spectrum utilization and efficiency. ➨It improves link reliability. ➨It is lower in cost. ➨It uses advanced network topologies.
What is cognitive radio system?
Cognitive radio system (CRS) is a radio system which is aware of its operational and geographical environment, established policies, and its internal state. It is able to dynamically and autonomously adapt its operational parameters and protocols and to learn from its previous experience.
What is non cooperative spectrum sensing?
It enables the secondary user (SU) to detect the presence/absence of primary user (PU) and plan its transmission strategy accordingly. The aim of SS is to detect the presence or absence of PU in a certain frequency band and allow or prevent the SU’s transmission on the basis of sensing result.
What is spectrum bandwidth?
Bandwidth is the portion of the spectrum that a given telecommunications system can use. For example, a system that operates on frequencies between 150 and 200 MHz has a bandwidth of 50 megahertz. An important distinction in spectrum technology is the difference between narrowband and broadband.