The growth in the number of voice over IP (VoIP) users on the Internet makes it the service with the highest interest to be provided by cellular operators. On the other hand, it demands very strict QoS control, which becomes even more complicated in wireless networks, because packets can be lost due to radio link transmission errors, as well as network congestion. Within this paradigm, scheduling strategies appear as the most suitable solution to cope with QoS guarantees under high loads, where the resources should be carefully distributed among the users in order to fulfill their QoS requirements. This work comprises the proposal and evaluation of some scheduling algorithms aiming to improve system capacity and QoS guarantees for speech users in HSDPA. The results show that the scheduling algorithms that mix fairness with channel information to get improvements of the multi-user diversity provide the best performance.