Band-limited DS-CDMA using exponentially weighted despreading sequence

The signal-to-interference ratio (SIR) performance of a band-limited DS-CDMA system using an exponentially-weighted despreading sequence (EWDS) in the receiver is addressed. It is shown that tuning a parameter of the EWDS helps to flatten the in-band spectrum of the received coloured signal, leading to a better performance when the transmission bandwidth is limited. With the constraint of the system transmission bandwidth equal to and twice the chip rate, numerical results show that the SIR of the proposed system can be increased up to 28 and 94%, respectively, when compared with a conventional receiver using a rectangular despreading sequence