| 摘要 |
A communications device and method of communicating using a communications device is disclosed for performing device-to-device communications. The communications device is configured to divide data for transmission into a plurality of data units, to encode a first of the data units, at the communications device for transmission to a destination communications device in accordance with a hybrid automatic repeat request, HARQ, protocol. The encoding provides redundant data, which can improve an integrity of correctly recovering the first data unit when received by the destination communications device and provide an indication of whether the first data unit has been received correctly. The communications device transmits the encoded data unit to the destination communications device, and either receives, from the destination communications device, an acknowledgement message, ACK, indicating that the data unit has been received correctly by the destination communications device, or if, after a predetermined time has elapsed, an ACK message is not received by the communications device, then retransmits at least part of the encoded data unit to the destination communications device in accordance with the HARQ process, the communications device assuming that the destination communications device determined that the data unit was not received correctly in accordance with a decoding process performed by the destination communications device. Alternatively the communications device receives, from the destination communications device, a negative acknowledgement message, NACK, providing an indication that the destination communications device determined that the data unit was not received correctly in accordance with a process of decoding the received encoded data unit performed by the destination communications device, or if, after a predetermined time has elapsed, an ACK message is not received then the communications devices encodes a next one of the data units, and transmitting the next encoded data unit to the destination communications device in accordance with the HARQ protocol. |
