The downlink of UMTS employs variable spreading factor and multicode to support variable data rate transmissions. In multicode and low spreading factor scenarios, interpath interference (IPI) among code channels is a principle factor that needs to be taken into consideration in system design. For example, the RAKE receiver with conventional maximum-ratio-combining suffers greatly from the presence of IPI. We present a new receiver structure that effectively incorporates an optimum combining scheme and dual-antenna diversity to enhance system performance.
Published in:
Communications Letters, IEEE
(Volume:6
,
Issue:
6
)
Date of Publication: June 2002