Browsing by Subject "Detect-and-avoid (DAA)"
Now showing items 1-2 of 2
Publisher and Date:(Elsevier GMBH Urban & Fischer Verlag, 2013)Cognitive radios (CRs) may be sharing multiple frequency bands with primary systems if the CR is a wideband or an ultra wideband (UWB) system. In that case the CR should ensure all the coexisting primary systems in these bands are detected before it can start data transmission. In this work we study the primary system detection performance of a wideband CR assuming that there are multiple coexisting primary systems and that these primary systems may be jointly active. Accordingly we consider the ...
Publisher and Date:(IEEE-INST Electrical Electronics Engineers Inc, 2011)Regulation in Europe and Japan requires the implementation of detect-and-avoid (DAA) techniques in some bands for the coexistence of licensed primary systems and secondary ultra wideband (UWB) systems. In a typical coexistence scenario a primary system may have potentially interdependent uplink-downlink communication channels (e. g. simultaneous uplink-downlink communications in a frequency division duplex system) overlapping with the frequency band of a UWB system. If such interdependencies of ...