The equalization performance of RAKE receiver in UWB system

RAKE receiver is often used to collect multipath energy and alleviate fading through diversity, especially in the ultra-wide band (UWB) radio system, which has extremely low power spectral density (p.s.d.) of transmission signal and experiences strong frequency selective fading. In this paper, RAKE receiver is analyzed for its performance of channel shortening by deriving the delay spread of an equivalent channel after maximal-ratio combination. It´s shown from the analytically analysis that the RAKE receiver can partially equalize the channel, hence can significantly reduce the complexity of the equalizer follow ed-up.