Abstract: A communication system (100) transmits data packets from a sender (120A) to a receiver (130A) using hybrid automatic repeat request processes. The sender redundantly encodes each packet, divides the packet into subpackets, and sends the subpackets to the receiver in a time-interlaced manner. When the receiver returns a positive acknowledgement of a subpacket using an acknowledgement channel, the sender terminates transmission of the subpackets. The sender interprets the signals on the acknowledgement channel using a metric resulting from correlation of the signals with positive and negative acknowledgement symbols. The sender interprets low correlation of the acknowledgement channel signal with both positive and negative acknowledgement symbols as a preamble miss, and terminates transmission of the subpackets. After termination, the packet may be rescheduled for transmission.