Data receiving and transmitting method with coding type determination
View Patent ↗Disclosed is a data communication system transmitting data using adaptive modulation at an acknowledged data transfer mode simultaneously. The present invention includes a first step of monitoring variation of radio environments by a receiving end receiving packets sequentially, a second step of determining a coding type to be varied in accordance with the variation of the radio environments in the receiving end so as to inform a transmitting end of the determined coding type, and a third step of forwarding sequentially the corresponding packets with a transfer rate in accordance with the determined coding type in the transmitting end.
1. A method of receiving downward link data transferred from a communication system with coding type determination in a user terminal, the method comprising:
a first step of monitoring variation of radio environments from the terminal receiving downward link packets sequentially;
a second step of informing the system of a coding type to be changed and sequence numbers of retransmission packets to be received by using the coding type after determining the coding type in accordance with the variation of the radio environments; and
a third step of receiving sequentially the retransmission packets with a transfer rate in accordance with the coding type,
wherein the second step is carried out so that the terminal informs the system the sequence numbers of the retransmission packets to be received with the transfer rate, wherein the terminal generates a control message including the coding type and the sequence numbers to be transmitted to the system, wherein the terminal generates the sequence numbers of packets except reassembled packets to be transferred from a second layer to a higher layer of the terminal.
2. The method of claim 1 , wherein the system checks the transmitted control message and then transmits substantially instantly a response message corresponding to the control message to the terminal.
3. The method of claim 1 , wherein the system regenerates the retransmission packets corresponding to the sequence numbers in accordance with the coding type included in the control message and forwards the regenerated retransmission packets with the transfer rate to the terminal.
4. The method of claim 3 , further comprising the step of receiving repeatedly the regenerated retransmission packets that failed to be received by the terminal after having received a response message in response to the control message.
5. A downward link data receiving and transmitting method with coding type determination, the method comprising:
a first step of monitoring a variation of radio environments in a user terminal receiving downward link packets sequentially;
a second step of having the terminal determine a coding type to be varied in accordance with the variation of the radio environments if lost packets due to the variation of the radio environments among the downward link packets exist;
a third step of having the terminal transmit a control message for informing a variation of the coding type and the lost packets to a communication system; and
a fourth step of having the system retransmit the lost packets repeatedly after having transmitted a response message corresponding to the control message of the terminal,
wherein the third step is carried out in a manner that the terminal transmits the control message including the variation of the coding type, a latest sequence number of the packets received by the terminal, and sequence numbers of the lost packets to the system except the reassembled packets to be transferred from a second layer to a higher layer of the terminal,
wherein the fourth step is carried out in a manner that the system stops transmitting the downward link packets after the last retransmitted packet is received by the terminal.
6. The method of claim 5 , wherein the first step is carried out in a manner that the terminal receives the downward link packets and monitors signal strength and signal quality of the received downward link packets so as to check the lost packets due to the variation of the radio environments.
7. The method of claim 5 , wherein the terminal decodes the already received downward link packets into a previous coding type before variation after having transmitted the control message.
8. The method of one of claim 5 , wherein the system retransmits the lost packets to the terminal with a transfer rate in accordance with the varied and determined coding type.
9. The method of claim 5 , after the fourth step, further comprising a step of informing the system of the coding type which is varied and determined by the terminal if the lost packets transmitted from the system are normally received.
10. The method of claim 9 , wherein the system retransmits the lost packets to the terminal with a transfer rate in accordance with the varied and determined coding type.