A method and user node for maintaining a connection with a network node when operating in a multi-carrier mode using a first filter configuration to receive multiple frequency carriers simultaneously for downlink communication. The user node applies a mode switching scheme comprising first intervals for the multi-carrier mode and second intervals for a single carrier mode using a second filter configuration to receive a single carrier for the downlink communication. In this case, the user node switches temporarily from the multi-carrier mode to operate in the single carrier mode during the second intervals according to the mode switching scheme. Thereby the user node is enabled to maintain the connection by receiving messages and/or control signalling from the network node over the single frequency carrier during the second intervals, for example when the multi-carrier mode is highly disturbed by interference.