A method in a transmitter for transmitting Continuous Phase Modulated, CPM, signals to a receiver, wherein the transmitter and the receiver are comprised in a wireless communications network, and wherein the method comprises: - dividing a sequence of user code bits into a first bit sequence and a second bit sequence, wherein the first and second bit sequences are of equal length; - duplicating the first bit sequence into a third bit sequence, and the second bit sequence into a fourth bit sequence; - mapping the first bit sequence and second bit sequence into a first layer corresponding to a first transmit antenna, and the third bit sequence and the fourth bit sequence into a second layer corresponding to a second transmit antenna; - time reversing one of the respective first and second bit sequences in the first layer, and one of the respective third and fourth bit sequences in the second layer; - mapping 1 to 0 and 0 to 1 in one of the time reversed first or second time reversed bit sequence, or in one of the time reversed third or fourth bit sequence; - formatting the first bit sequence and the second bit sequence into a first burst, and the third bit sequence and the fourth bit sequence into a second burst; - continuous phase modulating the respective first and second bursts; and - transmitting a first CPM signal through the first transmit antenna and a second CPM signal through the second transmit antenna, wherein the first CPM signal corresponds to the continuous phase modulated first burst, and the second CPM signal corresponds to the continuous phase modulated second burst, characterised in that: the CPM modulation index h is an integer and differential encoding of the first and second bursts is not performed before the modulation step. - dividing a sequence of user code bits into a first bit sequence and a second bit sequence, wherein the first and second bit sequences are of equal length; - duplicating the first bit sequence into a third bit sequence, and the second bit sequence into a fourth bit sequence; - mapping the first bit sequence and second bit sequence into a first layer corresponding to a first transmit antenna, and the third bit sequence and the fourth bit sequence into a second layer corresponding to a second transmit antenna; - time reversing one of the respective first and second bit sequences in the first layer, and one of the respective third and fourth bit sequences in the second layer; - mapping 1 to 0 and 0 to 1 in one of the time reversed first or second time reversed bit sequence, or in one of the time reversed third or fourth bit sequence; - formatting the first bit sequence and the second bit sequence into a first burst, and the third bit sequence and the fourth bit sequence into a second burst; - continuous phase modulating the respective first and second bursts; and - transmitting a first CPM signal through the first transmit antenna and a second CPM signal through the second transmit antenna, wherein the first CPM signal corresponds to the continuous phase modulated first burst, and the second CPM signal corresponds to the continuous phase modulated second burst, characterised in that: the CPM modulation index h is an integer and differential encoding of the first and second bursts is not performed before the modulation step.