A method implemented by a wireless transmit/receive unit (WTRU) for utilizing an enhanced physical downlink control channel (ePDCCH), the method comprising:
the WTRU receiving a configuration, the configuration (i) defining a plurality of ePDCCH resource sets; (ii) defining a demodulation reference signal (DM-RS) scrambling sequence initialization parameter for each of the plurality of ePDCCH resource sets, and (iii) indicating a demodulation timing reference information associated with each of the plurality of ePDCCH resource sets;
the WTRU monitoring at least one search space associated with each of the plurality of ePDCCH resource sets, wherein the at least one search space excludes time and frequency resources occupied by DM-RSs of DM-RS sequences initialized with the DM-RS scrambling sequence initialization parameters for the corresponding ePDCCH resource sets; and
the WTRU receiving at least one ePDCCH transmission via at least one of the plurality of ePDCCH resource sets.
2. The method of claim 1, wherein the demodulation timing reference information comprises information to be used for determining a demodulation timing reference, wherein the demodulation timing reference information comprises a first channel state information reference signal (CSI-RS) associated with a first ePDCCH, and a second CSI-RS associated with a second ePDCCH.
3. The method of claim 1, wherein the demodulation timing reference information comprises an indication of a pair of antenna ports, wherein the pair of antenna ports is quasi co-located for ePDDCH processing.
4. The method of claim 3, wherein the pair of antenna ports are each associated with a common channel state information reference signal (CSI-RS).
5. The method of claim 3, wherein the WTRU assumes that the quasi co-located pair of antenna ports have a common Doppler shift, Doppler spread, average delay, and delay spread.
6. The method of claim 1, wherein each ePDCCH resource set is associated with a different network transmission port.
7. The method of claim 1, wherein the at least one search space is a WTRU-specific search space.
8. A wireless transmit/receive unit (WTRU) comprising:
a processor configured to:
receive a configuration, the configuration (i) defining a plurality of enhanced physical downlink control channel (ePDCCH) resource sets; (ii) defining a demodulation reference signal (DM-RS) scrambling sequence initialization parameter for each of the plurality of ePDCCH resource sets; and (iii) indicating demodulation timing reference information associated with each of the plurality of ePDCCH resource sets;
monitor at least one search space associated with each of the plurality of ePDCCH resource sets, wherein the at least one search space excludes time and frequency resources occupied by DM-RSs of DM-RS sequences initialized with the DM-RS scrambling sequence initialization parameters for the corresponding ePDCCH resource sets; and
receive at least one ePDCCH transmission via at least one of the plurality of ePDCCH resource sets.
9. The WTRU of claim 8, wherein the demodulation timing reference information comprises information to be used for determining a demodulation timing reference, wherein the demodulation timing reference information comprises a first channel state information reference signal (CSI-RS) associated with a first ePDCCH, and a second CSI-RS associated with a second ePDCCH.
10. The WTRU of claim 8, wherein the demodulation timing reference information comprises an indication of a pair of antenna ports, wherein the pair of antenna ports is quasi co-located for ePDCCH processing.
11. The WTRU of claim 10, wherein the pair of antenna ports are each associated with a common channel state information reference signal (CSI-RS).
12. The WTRU of claim 10, wherein the WTRU assumes that the quasi co-located pair of antenna ports have a common Doppler shift, Doppler spread, average delay, and delay spread.
13. The WTRU of claim 8, wherein each ePDCCH resource set is associated with a different network transmission point.
14. The WTRU of claim 8, wherein the at least one search space is a WTRU-specific search space.