The accurate estimation of clutter covariance matrix (CCM) is essential in designing a radar detector/filter to suppress sea clutter. This estimation might not be easily accomplished because of the scarcity of valid training vectors adjacent to the range cell under test (CUT). We propose a new CCM estimation algorithm that is derived by modeling time-series clutter returns into a clutter Doppler spectrum in the frequency domain and exploiting mutual independence among spectral components. To justify its excellence over the conventional sample covariance matrix (SCM) algorithm, we design two filters—a maximum signal-to-interference-plus-noise ratio (SINR)-based filter and a whitening filter—that use the estimated CCMs and compare their performance in a numerically simulated sea clutter scenario. Comparisons are made by showing the eigenvector spectra of the estimated CCMs and the frequency responses and outputs of the filters. Moreover, SINRs at the target Doppler bin are examined and compared with a theoretical, analytically derived SINR.
As the recent tendency reports, the IPTV Service has an unlimited potential in communication market. It is true that the IPTV service will become the center of interest and will widely deploy in our life. Many service scenarios are announced for efficient IPTV service in standardization meeting. Web-based IPTV service is one of those scenarios. We can serve IPTV service through the internet, and IPTV subscribers can connect the service using the web browser. Here, we can see that the existing Terrestrial / Cable / Satellite TV contents can easily deliver through the internet by integration of web and IP data services. But, it is expected that the number of output channels to the subscribers are less than the number of input channels from existing broadcaster when existing broadcasting services are transmitted through the internet. In general, the output channel is allocated in sequence as follow the subscribers request the contents. If high preference channel is not allocated, it results in high blocking probability. In order to solve that problem, this paper addresses flexible channel allocation algorithm which is designed to reduce the blocking probability and increase the number of channels.
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