Cognitive Radio Thesis for Research Scholars.
Cognitive radio networks can sense electromagnetic environment with the help of spectrum. Researchers can focus on detecting unused spectrum. One of the major disadvantages in Cognitive Radio is the collision of licensed user frequency band. Research can be done to overcome this drawback by introducing signal detection techniques.
Challenges Faced in Cognitive Radio.
Cognitive Radio Thesis can be framed based on following challenges faced in cognitive radio networks. We help to improve implementation process for cognitive radio thesis modules.
- Detection, false alarm and miss detection probability.
- Topology changes, Layer attack..
- Clustering.
- Manufacturing costs.
- Scalability.
- Channel allocation, Cooperative sensing.
- Fault tolerance, Handoff.
- QoS.
- Power consumption.
- Security, Sensing technique.
Dynamic Spectrum Access in Cognitive Radio.
Once the spectrum sensing is over the process of DSA is enabled. Bandwidth can be expanded and the unused spectral band is reduced.
Approaches of DSA:
- Command and control model.
- Exclusive use model.
- Open sharing model.
- Common access model.
Command and Control Model: Spectrum users can get spectrum in abundant. As the rule of spectrum access is in control this model.
Long Term Exclusive Use Model: It is used to decide who gets to own spectrum and the time duration of their usage. It also controls speed, frequency and bandwidth of spectrum. It is further divided into fixed and flexible use type.
- Fixed Use Type: the license type of primary users is fixed in this type.
- Flexible Use Type: in this type the license type can be changed.
Exclusive Use Model: Licensed and unlicensed user policy can be regulated by this model. There are two different models which gives efficient spectrum allocation and usages. They are long term exclusive use model and dynamic exclusive use model.
Dynamic Exclusive Use Model: It maintains the scale of time, space, frequency and dimension. It is further classified into three types that are used to manage marketing information.
- Secondary Market: It is also known as spectrum leasing. The rights of spectrum usage from primary user can be transmitted to secondary user.
- Homogeneous Multi Operator Sharing Via Real-Time Secondary Market: This model allows the primary user to share their spectrum with secondary users. The main positive aspect of this method is to assign client system and base station by making use of current technologies.
- Heterogeneous Multi Operator Sharing Via Real Time Secondary Market: Service providers like radio, cellular and TV broadcasting can share their spectrum through this model. It also gives guarantee for spectrum usage and allocation.
Open Sharing Model: It gives a list of frequent spectrum sharers. By approaches like spectrum underlay and overlay primary users can share spectrum with secondary users.
Spectrum Underlay: Ultra wide band system is used for spectrum allocation. It protects the signal of primary users with spectral masking. This process is performed in a short span that’s why it’s called as spectrum underlay.
Advantages:
- Very conservative.
- Breaks the barriers of flexible and secondary use.
Disadvantages:
- Not suitable for aggressive spectrum usage.
- Spectrum Overlay:
Spectrum Overlay: The unused radio spectrum called white space is removed through this method.
Advantages: Allows secondary access of spectrum availability. Identify the secondary user spectrum usage.
Disadvantages: Needs exclusive knowledge about other signals.
Cognitive Radio Thesis Topics. |
|---|
| Architecture and communication protocols for cognitive radio network enabled hospital |
| Advances on Security Threats and Countermeasures for Cognitive RadioNetworks: A Survey |
| On Green-Energy-Powered Cognitive Radio Networks |
| Beamforming Duality and Algorithms for Weighted Sum Rate Maximization in Cognitive Radio Networks |
| Comparative study of routing protocols in Cognitive Radio Networks |
| Cognitive Adaptive Medium Access Control in Cognitive Radio Sensor Networks |