Method in a transmit node adapted for communication in a wireless communication system, said wireless communication system being adapted for using time-frequency resource elements, RE, for transmission of information; said method comprising the steps of: - generating at least one first receiver specific demodulation reference signal, PDSCH-DMRS, associated with a receiver specific data channel signal, PDSCH; - generating at least one second receiver specific demodulation reference signal, e-PDCCH-DMRS, associated with a receiver specific control channel signal, e-PDCCH; - transmitting said receiver specific control channel signal concurrently with said associated second receiver specific demodulation reference signal; and - transmitting said receiver specific data channel signal concurrently with said associated first receiver specific demodulation reference signal; - dynamically allocating said receiver specific data channel signal and said receiver specific control channel signal to different physical resource blocks, PRBs, wherein: - said first receiver specific demodulation reference signal is generated by using a first sequence of symbols {a p ( k)}, k =0,1,..., L -1 for modulating time-frequency resource elements at fixed positions within physical resource blocks used for transmission of data channel signals at a transmit antenna port p; - said second receiver specific demodulation reference signal is generated by using a second sequence of symbols { b u,p ( k)}, k= 0,1,..., L -1 for modulating time-frequency resource elements at fixed positions within physical resource blocks used for transmission of receiver specific control channel signals at a transmit antenna port p, said second sequence of symbols {b u,p ( k)} being a u -th sequence from a set of U sequences that can be allocated to one or more receiver nodes in said wireless communication system; and wherein said first sequence of symbols {a p ( k)}, k =0,1,...,L-1 is different from said second sequence of symbols {b u,p ( k)}, k =0,1,...,L-1. - generating at least one first receiver specific demodulation reference signal, PDSCH-DMRS, associated with a receiver specific data channel signal, PDSCH; - generating at least one second receiver specific demodulation reference signal, e-PDCCH-DMRS, associated with a receiver specific control channel signal, e-PDCCH; - transmitting said receiver specific control channel signal concurrently with said associated second receiver specific demodulation reference signal; and - transmitting said receiver specific data channel signal concurrently with said associated first receiver specific demodulation reference signal; - dynamically allocating said receiver specific data channel signal and said receiver specific control channel signal to different physical resource blocks, PRBs, wherein: - said first receiver specific demodulation reference signal is generated by using a first sequence of symbols {a p ( k)}, k =0,1,..., L -1 for modulating time-frequency resource elements at fixed positions within physical resource blocks used for transmission of data channel signals at a transmit antenna port p; - said second receiver specific demodulation reference signal is generated by using a second sequence of symbols { b u,p ( k)}, k= 0,1,..., L -1 for modulating time-frequency resource elements at fixed positions within physical resource blocks used for transmission of receiver specific control channel signals at a transmit antenna port p, said second sequence of symbols {b u,p ( k)} being a u -th sequence from a set of U sequences that can be allocated to one or more receiver nodes in said wireless communication system; and