Uplink HARQ-ack feedback for MTC

A method of operation of a network node for signaling Hybrid Automatic Repeat Request Acknowledgment, HARQ-ACK, feedback for an uplink data transmission sent from a wireless device to a radio network node, the method comprising:

• obtaining HARQ-ACK feedback for the uplink data transmission;
• encoding the HARQ-ACK feedback obtained on to an unused bit combination of a resource block assignment field in a downlink control channel, wherein a plurality of bit combinations for the resource block assignment field are unused for resource block assignment for the wireless device and the unused bit combination is one of the plurality of bit combinations that is predefined as being an indication of a positive HARQ-ACK for all uplink HARQ processes including the specific uplink HARQ process associated with the uplink data transmission and including the HARQ-ACK feedback obtained;
• and
• transmitting the downlink control channel to the wireless device.

A method performed by a wireless device for receiving Hybrid Automatic Repeat Request Acknowledgment, HARQ-ACK, feedback signaling for an uplink data transmission sent from the wireless device to a radio network node, the method comprising:

• receiving a downlink control channel from the radio network node;
• decoding the downlink control channel;
• determining if an unused bit combination of a resource block assignment field in the downlink control channel indicates a positive HARQ-ACK, wherein a plurality of bit combinations for the resource block assignment field are unused for resource block assignment for the wireless device and the unused bit combination is one of the plurality of bit combinations that is predefined as being an indication of a positive HARQ-ACK for a specific uplink HARQ process associated with the uplink data transmission,
• determining the uplink data was correctly received by the radio network node responsive to the unused bit combination of the resource block assignment field in the downlink control channel indicates a positive HARQ-ACK.