Tristate requests for flexible packet retransmission
View Patent ↗Extending acknowledgement messages from two states to at least three states is described, whereby such messages constitute a packet quality indication (PQI) reflecting quality or usability of the received signal. In an HARQ system, a transmitting station can flexibly select a better alternative for the next information to transmit on the basis of such PQI. One aspect includes determining how best to correct an unsuccessful packet transmission based on quality information about the specific packet. Implementing apparatus and procedures are described.
1. A method of transmitting data packets from a subject mobile station (MS) to a base station (BS) in a wireless communication system, comprising:
a) transmitting signals from the subject MS to the BS;
b) receiving a plurality of feedback signals from the BS, each of the feedback signals indicating at which one of a plurality of selectable reception quality levels the BS received a particular signal from the subject MS, wherein the feedback signal indicates, with a single symbol, at which of the plurality of selectable reception quality levels the particular signal was received by the BS;
c) responding to a first of the feedback signals by transmitting a subsequent data packet that is incrementally redundant of a previous data packet; and
d) responding to a second of the feedback signals by transmitting a subsequent data packet that is substantially identical to a previous data packet.
2. The method of claim 1 , further comprising responding to a third of the feedback signals by terminating transmission of a previous data packet.
3. The method of claim 1 , wherein the particular signal is the previous data packet.
4. The method of claim 1 , wherein the feedback signal is an acknowledgement for purposes of an automatic retransmission protocol.
5. The method of claim 1 , wherein the single symbol distinguishes between a plurality of reception quality levels by corresponding differences in phasing, and indicates at least one reception quality level by transmission at zero amplitude.
6. The method of claim 1 , wherein the particular signal is a data packet having a packet transmission duration, and wherein the feedback signal is received within a time that is not greater than three packet transmission durations after the data packet has fully arrived.