Improving Data Throughput for Cell-Edge Users in a LTE Network Using Up-Link HARQ Relays

It is proposed that up-link relays be used to improve the data throughput for user equipment (UE) near the cell edge in a LTE network. Relay assistance on the up-link occurs when the evolved Node B (eNB) requests a retransmission (HARQ) from the UE at which point the UE and relay transmit simultaneously. The quality of the up-link signal received by the eNB is improved due to a favorable channel through the relay. An analysis and simulation show that relay assistance improves the throughput for a cell-edge user when the average delay per data transport block is allowed to increase. A modification of the up-link power control is recommended when using relays, where the maximum power transmitted by the UE is reduced.