Norsheila Fisal

CSI Feedback Model in the Context of Adaptive Cognitive Radio Systems

Cognitive radio has the ability to sense the environment and adapt its behavior to optimize communication features, such as quality of service in the presence of interference and noise. In physical layer to achieve this goal, different phases of sensing, channel estimation, and configuration selection are necessary. The sensing part measures the interference level, recognize the spectrum holes, and send this information to Channel estimator. In the next step, channel state information (CSI) is used for data detection and also sent to the transmitter through a limited feedback. CSI feedback consists of achievable rate, SNR value, modulation or coding schemes (MCS). Feedback link improves the system performance in the cost of complexity and delay. In this paper, we present and compare different feedback schemes for cognitive radio and study the channel capacity when an imperfect feedback link is corrupted by noise and delay.

Performance analysis for cooperative relay with power control scheme over fading channel

Performance of a system is determined by the probability of error of the channel. In this paper, the error probability of cooperative relay channel is analyzed for Quadrature Phase Shift Keying (QPSK) using simple linear block coding. Focusing on a network with single source to destination with one relay station, the upper bound of symbol error rate (SER) is derived. A power control scheme is also proposed to improve the performance of the system. Computer simulations confirm the presented mathematical analysis.

Performance Analysis of H.264 video over Error-prone Transmission Environment

Wireless multimedia technology has witnessed a rapid development in recent years due to explosive growth in communication, commerce and entertainment services. Undoubtedly, future wireless communication systems will eventually integrated a broad range of multimedia services such as voice, video, and data. This will have a profound impact on the way individuals communicate and access information. It is very obvious that video communication has been very much popular due its high bandwidth demand for a video data to be efficiently transported across wireless network. The dynamic nature of the channel condition has to be considered while designing such systems in order to ultimately support effective video applications over error-prone transmission environment. This paper critically analyse the performance of H.264 transmitted video over error-prone transmission environment. Also, we examine the profound impact of the unpredicted channel condition on the video quality.