Resolving colliding signals
Systems and methods are disclosed herein that relate to transmitting and receiving a transmission when there is a collision between the transmission and reserved resource elements. In some embodiments, a radio access node for a cellular communications network is disclosed, wherein the radio access node comprises a transceiver, a processor, and memory storing instructions executable by the processor whereby the radio access node is operable to transmit, via the transceiver, a downlink transmission to a wireless device using one or more Physical Resource Blocks (PRBs) that comprise reserved Resource Elements (REs) by puncturing the downlink transmission at positions of the reserved REs. In some embodiments, the downlink transmission is an Enhanced Physical Downlink Control Channel (EPDCCH) transmission or a Physical Downlink Shared Channel (PDSCH) transmission. Further, in some embodiments, the reserved REs are REs utilized for one or more CSI-RSs.
1. A wireless device operable in a cellular communications network, the wireless device comprising:
a transceiver;
a processor in communication with the transceiver; and
memory storing instructions executable by the processor to cause the wireless device is operable to:
receive a downlink transmission from a radio access node on one or more Physical Resource Blocks (PRBs) based on an assumption by the wireless device that the downlink transmission is first mapped to Resource Elements (REs) in one or more PRBs and then reference symbols are mapped to a subset of the REs in the one or more PRBs that are reserved REs such that the downlink transmission is punctured by the reference symbols at positions of the reserved REs, wherein the downlink transmission is a physical downlink channel transmission.
2. The wireless device of claim 1 , wherein the wireless device is further operable to increase the number of aggregated enhanced Control Channel Elements (eCCEs).
3. The wireless device of claim 1 , wherein receiving the downlink transmission comprises receiving the downlink transmission at a reduced code rate when the downlink transmission is punctured by the reference symbols at positions of the reserved REs.
4. The wireless device of claim 1 , wherein the physical downlink channel transmission is a Physical Downlink Shared Channel (PDSCH) transmission.
5. The wireless device of claim 4 , wherein the reference symbols are Channel State Information Reference Signal (CSI-RS) reference symbols.
6. The wireless device of claim 1 , wherein the physical downlink channel transmission is an Enhanced Physical Downlink Control Channel (EPDCCH) transmission.
7. The wireless device of claim 6 , wherein the reference symbols are Channel State Information Reference Signal (CSI-RS) reference symbols.
8. A wireless device operable in a cellular communications network, the wireless
device comprising:
a transceiver;
a processor in communication with the transceiver; and
memory storing instructions executable by the processor to cause the wireless device is operable to:
obtain an indicator that is indicative of whether reserved Resource Elements, REs, are present in a subframe in which a physical downlink channel transmission is transmitted from a radio access node to the wireless device;
determine whether reserved REs are present in the subframe based on the indicator; and upon determining that reserved REs are present in the subframe, attempt reception of the physical downlink channel transmission based on an assumption that reserved REs are present in the subframe.
9. The wireless device of claim 8 , wherein the indicator comprises time-domain information regarding the presence of reserved REs.
10. The wireless device of claim 8 , wherein the indicator comprises information that indicates which REs are reserved REs.
11. The wireless device of claim 8 , wherein the instructions are further executable by the processor to cause the wireless device to, upon determining that reserved REs are not present in the subframe, attempt reception of the physical downlink channel transmission based on an assumption that reserved REs are not present in the subframe.
12. The wireless device of claim 8 , wherein the physical downlink channel transmission is an Enhanced Physical Downlink Control Channel (EPDCCH) transmission.
13. The wireless device of claim 8 , wherein the reserved REs are REs utilized for one or more Channel State Information Reference Signals (CSI-RS s).
14. The wireless device of claim 8 , wherein the physical downlink channel transmission is a Physical Downlink Shared Channel (PDSCH) transmission.
15. The wireless device of claim 14 , wherein the reserved REs are REs utilized for one or more Channel State Information Reference Signals (CSI-RS s).
16. A radio access node operable in a cellular communications network, the radio access node comprising:
a transceiver;
a processor in communication with the transceiver; and
memory storing instructions executable by the processor to cause the radio access node to perform operations comprising:
transmitting a downlink transmission to a wireless device using one or more Physical Resource Blocks (PRBs) that comprise reserved Resource Elements (REs) by first mapping the downlink transmission to REs in the one or more PRBs and then mapping reference symbols to a subset of the REs in the one or more PRBs that are the reserved REs such that the downlink transmission is punctured by the reference symbols at positions of the reserved REs, the downlink transmission being a physical downlink channel transmission.
17. The radio access node of claim 16 , wherein transmitting the downlink transmission comprises transmitting the downlink transmission at a reduced code rate when the downlink transmission is punctured by the reference symbols at positions of the reserved REs.
18. The radio access node of claim 16 , wherein the physical downlink channel transmission is a Physical Downlink Shared Channel (PDSCH) transmission.
19. The radio access node of claim 18 , wherein the reference symbols are Channel State Information Reference Signal (CSI-RS) reference symbols.
20. The radio access node of claim 16 , wherein the physical downlink channel transmission is an Enhanced Physical Downlink Control Channel (EPDCCH) transmission.