A method, performed by a radio network node, for transmission of broadcast information in a subframe of a frame, which is to be received by a receiver in a wireless communication system, wherein a cell-specific reference signal, CRS, is not transmitted in the subframe, • defining a first set of antenna ports for a first set of time-frequency resources and defining a second set of antenna ports for a second set of time-frequency resources, wherein in the subframe: ∘ the first set of time-frequency resources is assigned to a Demodulation Reference signal, DM-RS, the DM-RS being defined for a demodulation of data of a data channel, the data also being provided in the subframe, and ∘ the second set of time-frequency resources, different to the first set of time-frequency resources, in the subframe is used for the broadcast information, wherein the second set of time-frequency resources coincides with further time-frequency resources of the DM-RS, so that the further time-frequency resources of the DM-RS are re-used as the second set of time-frequency resources of the broadcast information and so that the second set of time-frequency resources corresponds to, as the second set of antenna ports, antenna ports of the further time-frequency resources of the DM-RS; • wherein a relation is defined between a number of layers used for a transmission of the data on the data channel and the first set of antenna ports of the DM-RS in the subframe, wherein the relation is applicable either to all time-frequency resources in the subframe, or to those resource block pairs (310-1, 310-2) comprising the broadcast information, wherein in the relation each transmission rank v corresponds to a certain first set of antenna ports of the DM-RS, and the relation is: Transmission rank v DM-RS antenna ports 1 7 2 7,8 3 7,8,11 4 7,8,11,13 Transmission rank v DM-RS antenna ports 1 9 2 9,10 3 9,10,12 4 9,10,12,14 • transmitting the subframe to the receiver, thereby transmitting the broadcast information on the defined second set of antenna ports, thereby using said second set of time-frequency resources exclusively, such that they are unused for any other antenna port. • defining a first set of antenna ports for a first set of time-frequency resources and defining a second set of antenna ports for a second set of time-frequency resources, wherein in the subframe: ∘ the first set of time-frequency resources is assigned to a Demodulation Reference signal, DM-RS, the DM-RS being defined for a demodulation of data of a data channel, the data also being provided in the subframe, and ∘ the second set of time-frequency resources, different to the first set of time-frequency resources, in the subframe is used for the broadcast information, wherein the second set of time-frequency resources coincides with further time-frequency resources of the DM-RS, so that the further time-frequency resources of the DM-RS are re-used as the second set of time-frequency resources of the broadcast information and so that the second set of time-frequency resources corresponds to, as the second set of antenna ports, antenna ports of the further time-frequency resources of the DM-RS; ∘ the first set of time-frequency resources is assigned to a Demodulation Reference signal, DM-RS, the DM-RS being defined for a demodulation of data of a data channel, the data also being provided in the subframe, and ∘ the second set of time-frequency resources, different to the first set of time-frequency resources, in the subframe is used for the broadcast information, wherein the second set of time-frequency resources coincides with further time-frequency resources of the DM-RS, so that the further time-frequency resources of the DM-RS are re-used as the second set of time-frequency resources of the broadcast information and so that the second set of time-frequency resources corresponds to, as the second set of antenna ports, antenna ports of the further time-frequency resources of the DM-RS; • wherein a relation is defined between a number of layers used for a transmission of the data on the data channel and the first set of antenna ports of the DM-RS in the subframe, wherein the relation is applicable either to all time-frequency resources in the subframe, or to those resource block pairs (310-1, 310-2) comprising the broadcast information, wherein in the relation each transmission rank v corresponds to a certain first set of antenna ports of the DM-RS, and the relation is: Transmission rank v DM-RS antenna ports 1 7 2 7,8 3 7,8,11 4 7,8,11,13 Transmission rank v DM-RS antenna ports 1 9 2 9,10 3 9,10,12 4 9,10,12,14 • transmitting the subframe to the receiver, thereby transmitting the broadcast information on the defined second set of antenna ports, thereby using said second set of time-frequency resources exclusively, such that they are unused for any other antenna port.