Optimal Receiver Pulse Shaping Filter Design for IS-2000 CDMA Systems
Original Publication Date: 2002-Jan-30
Included in the Prior Art Database: 2002-Jan-30
In CDMA systems (IS-95, IS-2000, etc.), the transmitter pulse shaping filter is a 48-tap FIR filter (known as IS-95 filter) defined in the standards. The received signal using the matched receiver filter has a signal to inter symbol interference ratio (SIR) around 16 dB. In 3G and beyond 3G CDMA systems (1XEV-DO, 1XEV-DV, etc.), higher SIR of the received signal is required so that high order modulation methods can be applied to achieve high data transmission speed. In this paper, we propose a method to design receiver pulse shaping filters for CDMA systems, such that the signal to interference plus noise ratio (SINR) of the received signal is maximized. Numerical examples show that the receiver filters designed using our method can significantly reduce the interference in comparing to the matched receiver filter. Moreover, receiver filters having less taps and higher SIR than the matched filter can be designed using our method. The shorter receiver filters will reduce the power consumption of the mobile units.