A method for a first wireless communication apparatus of a communication system operating in a hardened channel environment, wherein the first wireless communication apparatus is comprised in a network node, and a second and one or more third wireless communication apparatuses are comprised in respective user equipments of a plurality of user equipments associated with the network node, the method comprising: determining respective transmission powers to be used by each of the second and one or more third wireless communication apparatuses of the communication system for transmission of respective signals carrying control information, wherein the signals carrying control information and being transmitted by the second wireless communication apparatus are based on an identity of the second wireless communication apparatus; characterized in that participating in communication involving the signals transmitted using the determined transmission powers, wherein said participation comprises receiving the signals; and using the determined transmission powers to discriminate between the second wireless communication apparatus and one or more third wireless communication apparatus, further comprising: determining the identity of at least the second wireless communication apparatus based on the respective determined transmission powers and on channel estimates in relation to each of the user equipments; and resolving a collision between the second wireless communication apparatus and the one or more third wireless communication apparatus by: performing a channel estimation based on the received signals, wherein the channel estimation is a superposition of channels between the first wireless communication apparatus and each of the wireless communication apparatuses involved in the collision; and transmitting a response, to each of the wireless communication apparatuses involved in the collision, using precoding that is based on the channel estimation. determining respective transmission powers to be used by each of the second and one or more third wireless communication apparatuses of the communication system for transmission of respective signals carrying control information, wherein the signals carrying control information and being transmitted by the second wireless communication apparatus are based on an identity of the second wireless communication apparatus; characterized in that participating in communication involving the signals transmitted using the determined transmission powers, wherein said participation comprises receiving the signals; and using the determined transmission powers to discriminate between the second wireless communication apparatus and one or more third wireless communication apparatus, further comprising: determining the identity of at least the second wireless communication apparatus based on the respective determined transmission powers and on channel estimates in relation to each of the user equipments; and resolving a collision between the second wireless communication apparatus and the one or more third wireless communication apparatus by: performing a channel estimation based on the received signals, wherein the channel estimation is a superposition of channels between the first wireless communication apparatus and each of the wireless communication apparatuses involved in the collision; and transmitting a response, to each of the wireless communication apparatuses involved in the collision, using precoding that is based on the channel estimation. performing a channel estimation based on the received signals, wherein the channel estimation is a superposition of channels between the first wireless communication apparatus and each of the wireless communication apparatuses involved in the collision; and transmitting a response, to each of the wireless communication apparatuses involved in the collision, using precoding that is based on the channel estimation. <EOS>