CmpE 491/492 Projects

Cognitive Radio Frequency Usage Optimization

The static assignment of the frequency bands results in inefficient usage of the spectrum. Dynamic access to the spectrum can be considered as a method for solving spectrum scarcity. The utilization of the spectrum can be as low as 10%. Cognitive Radio (CR) is a paradigm for wireless communication in which either a network or a wireless node changes its transmission or reception parameters to communicate efficiently avoiding interference with licensed or unlicensed users. This alteration of parameters is based on the active monitoring of several factors in the external and internal radio environment, such as radio frequency spectrum, user behavior, and network state.

In this project, the aim is to maximize the spectrum utilization by dynamically using the unused frequency holes in the shared spectrum. The project requires development in OPNET. The implementation part includes entities like; shared spectrum, licensed systems using shared spectrum, unlicensed systems using shared spectrum, broker system, CR base stations, and CR handheld device.

• Shared Spectrum: It is just a two or three dimensional array for representing which frequencies are in use.

• Licensed System: It is just a process that fills part of the shared spectrum for which it has rights to do so.

• Unlicensed System: It is just a process that fills available parts of the shared spectrum in ISM bands.

• Broker System: It is a process that scans the shared spectrum for free frequency slots for CR users.

• CR Base Station: It is a process that advertises the free frequency slots specified by the Broker System.

• CR Handheld Device: It is a process that learns free frequency slots from CR Base Station advertisements and uses them as appropriate. If licensed user tries to use these frequencies, CR user releases the frequency.

In addition to the regular requirements of CMPE492, you are also expected to deliver a preliminary report at the end of the first month. You will be guided by Birkan Yılmaz.

Face Animation for Video Communications in 3G and NGWS (co-advised with Prof. Lale Akarun)
(This project is currently being implemented)

Video communications is an attractive and challenging application for wireless networks. It is expected to gain even more attraction in Turkey with the introduction 3G cellular systems. However, the gross bandwidth requirement of such applications practically limits the use of such services.

In this project, the aim is to minimize the bandwidth requirement by transmitting only the voice of the user and animating his/her face on the other party’s handheld device. The project requires development in OpenGL on mobile handsets. Therefore, familiarity with PDA programming is an advantage.