Adaptive Modulation in OSA-based Cognitive Radio Networks
  Opportunistic spectrum access is based on channel state information and can lead to important performance improvements for the underlying communication systems. On the other hand adaptive modulation is also based on channel state information and can achieve increased transmission rates in fading channels. In this work we propose the combination of adaptive modulation with opportunistic spectrum access and we study the anticipated effects on the performance of wireless communication systems in terms of achieved spectral efficiency and power consumption. 
F. Foukalas, G. T. Karetsos, G. K. Karagiannidis
cs.NI cs.IT math.IT