Resource allocation and fairness for downlink shared data channels

For delay tolerant data users on multiplexed downlink channels, one has to consider how to make the most efficient possible allocation of resources without wasting resources or precluding other user´s transmission. Most data scheduling algorithms rely on channel quality feedback for prioritizing. The reliability of channel quality feedback depends on the scheduling latency even if the feedback is error free. The degree of unreliability depends on users channel speed and amount increases with user mobility. Uncertainty about the user´s channel condition affects our ability to prioritize the user appropriately. Secondly, not all users have infinite buffers. Hence, a small amount of data may need to be transmitted over an uncertain channel. Inability to track the channel variations forces a hedging strategy for reliable channel reception that consists of transmitting to the user over an extended period of time. We assume availability of user velocity or Doppler estimates and propose two proactive transmission and scheduling schemes for small data payloads to deal with channel feedback unreliability: time interlaced packet (TIP) transmission and contiguous time spreading (CTS). This results in improved user perceived throughput under uncertain channel quality and small payload conditions.