Adaptive transmission modes for transparent relay

摘要

There is transmitted to a user equipment UE in a first subframe of a radio frame a downlink shared channel DSCH according to a first relay-transmission mode (e.g., mode A or A′ in the examples); then switch to a second relay-transmission mode (e.g., mode C or C′ in the examples) within the radio frame based on a channel quality of the DSCH. After switching, then transmit to the UE, in a subsequent subframe of the radio frame, the DSCH according to the second relay-transmission mode. In this embodiment the HARQ process is synchronous and non-adaptive for mode C: the eNB re-transmits packets to the UE in a predetermined fashion to be concurrent with transmission of those same packets from the relay node, as scheduled by the eNB. In this embodiment the eNB receives the UE's NACK for the data that is to be retransmitted via relay through the relay node.

主权项

1. A method comprising:
transmitting to a user equipment in a first subframe of a radio frame on at least one downlink shared channel according to a first relay-transmission mode; switching to a second relay-transmission mode within the radio frame based on a channel quality of the downlink shared channel; after switching, transmitting to the user equipment in a subsequent subframe of the radio frame on the at least one downlink shared channel according to the second relay-transmission mode; and for the case of a packet re-transmission according to the second relay-transmission mode, re-transmitting the packet to the user equipment in a pre-determined manner so as to be concurrent with transmission of a same packet from a relay node; wherein transmitting in the first subframe comprises transmitting a common reference signal on the at least one downlink shared channel with no dedicated reference signal according to the first relay-transmission mode; and transmitting in the subsequent subframe comprises transmitting a dedicated reference signal on the at least one downlink shared channel according to the second relay-transmission mode.