Impact of RF impairments on HSDPA performance

An important feature of HSDPA (high speed downlink packet access) for WCDMA is to provide very high data rates, up to several Mb/s in the downlink. In order to achieve these high data rates, a good receiver design is needed. Further, from a terminal perspective, the receiver design needs to be efficient from a cost, current and size perspective. A direct conversion receiver fulfills these criteria. However, such a receiver design often suffers from DC-offset and I/Q gain and phase mismatch, degrading the receiver performance. In this paper we make an analysis of how such impairments affect the performance in HSDPA. It is furthermore shown in the paper that by doing a good receiver design the implementation losses due to direct conversion impairments can be made small providing a possibility to make cost efficient HSDPA terminals with good receiver performance.