On the Approximate Analysis of Energy Detection over n*Rayleigh Fading   Channels through Cooperative Spectrum Sensing
  In this letter, we consider the problem of energy detection of unknown signals in an intervehicular communication (IVC) system over n*Rayleigh fading channels (also known as cascaded Rayleigh). Novel tight approximations for the probability of detection are derived for the no-diversity and the maximum ratio combining (MRC)) diversity schemes. Moreover, we investigate the system performance when cooperative spectrum sensing (CSS) is considered with and without imperfect reporting channels. The analytical results show that the detection reliability is decreased as the fading severity parameter n increases but reliability is substantially improved when CSS employs MRC schemes. 
Yahia Alghorani, Georges Kaddoum, Sami Muhaidat, and Samuel Pierre
cs.IT math.IT