High Speed Downlink Packet Access (HSDPA): Higher Data Rates for UMTS

Abstract – High Speed Downlink Packet Access is the first step in the evolution of WCDMA (UMTS) networks. The second step will be to enhance the uplink data rates, improved uplink capacity and reduced uplink delay. The maximum data rate to a user in present WCDMA networks achieved in ideal conditions is limited to 2MB / s. The users hunger for higher data rates gave an impetus to find new ways to get higher data rates beyond 2MB / s. The introduction of HSDPA to the UMTS specification will potentially offer up to 10MB / s data rates while backward compatible with the existing user equipment. The present report will explore the changes required to support HSDPA. Further the different H-ARQ techniques will be seen in depth which is required to ensure that the necessary retransmission is executed quickly and efficiently. I