Previous investigations on capacity of secondary users in spectrum-sharing environments have determined the capacity of a secondary link based on the interference power threshold set at the primary receiver. In contrast to these previous works, we show that the capacity of a secondary link is determined based on a geographical relationship expressed as the ratio of the distance between the primary receiver and secondary transmitter to the distance between the secondary transmitter and receiver. Proceeding from that and in an effort, to enhance the capacity of the secondary user, which is limited by this distance-ratio, we adopt a secondary transmitter with antennas. Furthermore, we analyze the capacity achieved using a simple antenna selection process.
Bibliographical noteFunding Information:
This work was supported by the Korea Science and Engineering Foundation through the NRL Program (Grant R0A-2007-000-20043-0).
This research was supported by the MKE (Ministry of Knowledge Economy), Korea, under the ITRC(Information Technology Research Center) support program supervised by the NIPA (National IT Industry Promotion Agency)(NIPA-2009-(C1090-0902-0005)). Digital Object Identifier 10.1109/TWC.2010.02.081339
All Science Journal Classification (ASJC) codes
- Computer Science Applications
- Electrical and Electronic Engineering
- Applied Mathematics