Comparison between RAKE and frequency domain detectors in ultra-wideband indoor communications

In this paper we propose an innovative communication scheme for impulse radio ultra-wideband systems which is based on both the introduction of the cyclic prefix at the transmitter and the use of a frequency domain detector at the receiver. Two different approaches based on the Zero Forcing (ZF) and the Minimum Mean Square Error (MMSE) criteria have been investigated. We have compared our frequency domain approach with the classical RAKE, considering an illustrative scenario where a base station transmits to several mobile terminals in an indoor environment characterized by severe multipath propagation. The results show that the receiver based on the MMSE criterion achieves the best performance with respect to the other schemes, irrespective of the number of active terminals. Hence, the proposed approach is well suited in indoor wireless environment where multipath propagation tends to increase the effects of both the inter-path and the inter-user interference.