Closed form expressions for the symbol error rate for non-coherent UWB impulse radio systems with energy combining

In this paper, different energy combining schemes for non-coherent UWB impulse radio systems are analysed. Closed form expressions for the Symbol Error Rate (SER) of Pulse Amplitude Modulation (PAM) using a non-coherent energy detection receiver with energy combining in the AWGN and fading channels are presented. The principle of energy combining is based on the fact that the symbol energy is combined in order to take advantage of the path diversity. Equal Gain Combining (EGC), Weighted Gain Combining (WGC) and Selection Combining (SC) are used as combining schemes, and the performance will be verified in AWGN and lognormal multipath UWB fading channels. Energy detection is also used for the detection of spectrum holes in cognitive radio environments.