DS-CDMA Functional Blocks Using Recycling Integrator Correlators : Matched Filters and Delay Locked-Loops

Abstract

The recycling integrator correlator(RIC)is a novel approach for implementing correlators that consume less power than conventional digital or analog CMOS correlators. The RIC modulates the product of a received signal and a pseudorandom noise(PN)sequence into a bit stream by first order ΔΣ modulation. The accumulated number represents the quantized correlation value. Using RIC's, two functional blocks of a DS-CDMA demodulator targeting IMT-2000, a matched filter(MF)and a delay locked-loop(DLL), are implemented in silicon. Processed in a 0.35-μm double-metal double-poly CMOS process, the RIC-MF and the RIC-DLL respectively dissipate 23mW and 3.4mW at 2-V power supply.