Enhanced node B and method of transmitting physical-downlink control channels (PDCCHs) in a LTE-A system
Embodiments of an eNB and method of transmitting PDCCHs are generally described herein. In some embodiments, the eNB may be configured to transmit PDCCHs that are based on a UE-specific reference signal (i.e., a UE-RS). In these embodiments, the UEs may be able to demodulate their PDCCH using a demodulation reference signal (DM-RS) that is specific to the UE (e.g., instead of a common reference signal). The PDCCHs disclosed herein may be suitable the Uu interface of an LTE-A system.
1. A User Equipment (UE) comprising processing circuitry to:
receive, instructions for monitoring a set of downlink control channels; and
monitor, using the instructions, the set of downlink control channels in a UE-specific search space of a downlink subframe, the downlink subframe for monitoring being indicated by higher layer signaling, wherein the set is mapped to regions of resource elements of the UE-specific search space such that at least some resource elements are reserved for a legacy physical downlink control channel (PDCCH) region and some resource elements are reserved for a non-legacy, PDCCH region, the UE is configured to search both the legacy PDCCH region and the non-legacy PDCCH region for downlink control information (DCI), and wherein higher layer signaling instructs the UE to search either of the legacy PDCCH region or the non-legacy PDCCH region for blind decoding, wherein the non-legacy PDCCH region is based on a UE-specific reference signal (UE-RS), wherein a downlink control channel of the set of downlink control channels is distributed across a plurality of enhanced resource element groups (EREGs) in the HE-specific search space, and wherein the UE further comprises a plurality of antenna ports, wherein each EREG of the plurality of EREGs is precoded with a value based on a configuration of the plurality of antenna ports.
2. The UE of claim 1 , wherein the receiving is through higher layer signaling.
3. The UE of claim 1 , wherein
the set is mapped to regions of resource elements of the UE-specific search space such that at least some resource elements are reserved for a cell-specific reference signal.
4. The UE of claim 1 , wherein
the set is mapped to regions of resource elements of the UE-specific search space such that at least some resource elements are reserved for a channel-state information (CSI) reference signals.
5. The UE of claim 1 , wherein the UE comprises a file storage memory.
6. A method of monitoring downlink control channels, the method comprising:
receiving, at a user equipment (UE), instructions for monitoring a set of downlink control channels;
monitoring, using the instructions, the set of downlink control channels in a user equipment (UE)-specific search space of a downlink subframe, the downlink subframe being mapped to reserve at least some resource elements for a legacy physical downlink control channel (PDCCH) region and some resource elements are reserved for a non-legacy PDCCH region, wherein the UE is configured to search both the legacy PDCCH region and the non-legacy PDCCH region for downlink control information (DCI), and wherein the higher layer signaling instructs the UE to search either of the legacy PDCCH region or the non-legacy PDCCH region for blind decoding, wherein the non-legacy PDCCH region is based on a UE-specific reference signal (UE-RS), wherein a downlink control channel of the set of downlink control channels is distributed across a plurality of enhanced resource element groups (EREGs) in the UE-specific search space, and each EREG of the plurality of EREGs is precoded with a value based on a configuration of UE antenna ports.
7. The method of claim 6 , wherein the receiving is through higher layer signaling.
8. The method of claim 6 , wherein the set is further mapped such that
at least some resource elements are reserved for a cell-specific reference signals, and
at least some resource elements are reserved for a channel-specific information (CSI) reference signals.
9. A non-transitory computer-readable medium comprising instructions that, when executed on a machine, cause the machine to:
receive, through higher layer signaling, instructions for monitoring a set of downlink control channels; and
monitor, using the instructions, the set of downlink control channels in a user equipment (UE)-specific search space of a downlink subframe, the downlink subframe being mapped to reserve at least some resource elements for a legacy physical downlink control channel (PDCCH) region and some resource elements are reserved for a non-legacy PDCCH region, wherein the instructions further cause the machine to search both the legacy PDCCH region and the non-legacy PDCCH region for downlink control information (DCI), and wherein the higher layer signaling instructs the machine to search either of the legacy PDCCH region or the non-legacy PDCCH region for blind decoding, wherein the non-legacy PDCCH region is based on a UE-specific reference signal (UE-RS) wherein a downlink control channel of the set of downlink control channels is distributed across a plurality of enhanced resource element groups (EREGs) in the UE-specific search space, and
an EREG of the plurality of EREGs is precoded with a value based on a configuration of UE antenna ports.
10. The non-transitory computer-readable medium of claim 9 comprising instructions that, when executed on the machine, cause the machine to:
decode a downlink control channel of the set of downlink control channels using a UE-specific reference signal, wherein
the set is mapped such that at least some resource elements are reserved for cell-specific reference signals, at least some resource elements are reserved for a channel-specific information (CSI) reference signals, and at least some resource elements are reserved for UE-specific reference signals.