Network node, a wireless device and methods therein for enabling channel estimations in a wireless communications network

A network node for enabling channel estimation in a wireless communications network, the wireless communications network comprising at least a first and a second Access Point, AP, having overlapping cells using contention-based transmission resources of the same frequency, the network node comprising:

• a processor configured to control the first AP to transmit information when at least one of a transmission quality value and a performance value of at least one wireless device served by the first AP is below a determined threshold, the information indicating that wireless devices served by the first AP are not to contend for the contention-based transmission resources when the second AP is transmitting a Null Data Packet, NDP, and when the wireless devices served by the first AP are to transmit feedback information to the second AP corresponding to the NDP transmitted from the second AP and to control the second AP to transmit a NDP;
• and
• the wireless devices served by the first AP estimating an interference channel towards the second AP based on the NDP transmitted from the second AP.

A wireless device for enabling channel estimation in a wireless communications network, the wireless communications network comprising at least a first and a second Access Point, AP, serving overlapping cells using contention-based transmission resources of the same frequency, the wireless device being servable by the first AP, the wireless device comprising:

• a processor configured to receive information from the first AP, the information indicating that the wireless device is not to contend for the contention-based transmission resources when the second AP is transmitting a Null Data Packet, NDP, and when the wireless device served by the first AP is to transmit feedback information to the second AP corresponding to the NDP transmitted from the second AP and to one of refrain from and suppress contending for the contention-based transmission resources when the second AP is transmitting a NDP according to the received information and estimate an interference channel towards the second AP based on the NDP transmitted from the second AP.