Efficient signaling of common reference signal shifts and physical downlink control channel region mismatch in coordinated multipoint transmission

Abstract

Information about a set of cells potentially taking part in coordinated multipoint transmission is obtained, information about at least one of reference signal configuration and data region size configuration for each of the set of cells is obtained, further an indication of which of the reference signals configuration and the data region size configuration should be assumed in resource mapping for data is obtained, and data according to the resource mapping is received. Information about at least one of reference signal configuration and data region size configuration for each cell of a set of cells potentially taking part in coordinated multipoint transmission is provided, and an indication of which of the reference signals configuration and the data region size configuration should be assumed in resource mapping for data is provided.

The invention claimed is: 
     
       1. An apparatus comprising:
 circuitry configured to
 obtain information about a set of cells potentially taking part in coordinated mulitpoint transmission; 
 obtain information about a reference signal configuration for each cell of the set of cells; 
 generate and transmit feedback including channel state information and a recommendation of one or more transmitting points selected from among the set of cells; 
 obtain an indication of which reference signal configuration should be assumed in resource mapping for data in response to the feedback, wherein the indication is configured to selectively indicate at least a first state indicating serving cell-only transmission, a second state indicating that the recommendation of the one or more transmitting points selected from among the set of cells is followed, and a third state indicating a configuration different from the first state and the second state; and 
 receive data according to the resource mapping. 
 
 
     
     
       2. The apparatus according to  claim 1 , wherein the reference signal configuration further comprises at least one of a number of reference signal ports and a frequency shift. 
     
     
       3. The apparatus according to  claim 1 , wherein
 the indication of which reference signal configuration should be assumed in resource mapping for data indicates the second state. 
 
     
     
       4. The apparatus according to  claim 1 , wherein the indication of which reference signal configuration should be assumed in resource mapping for data indicates the first state. 
     
     
       5. The apparatus according to  claim 1 , wherein the circuitry is to:
 receive the data according to the resource mapping by performing rate matching around reference signals indicated by the indication of which reference signal configuration should be assumed in resource mapping for data. 
 
     
     
       6. The apparatus according to  claim 1 , wherein the reference signal configurations are different for at least two cells of the set of cells. 
     
     
       7. The apparatus according to  claim 1 , wherein the apparatus is a user equipment. 
     
     
       8. An apparatus comprising:
 circuitry configured to
 provide information about signal configuration for each cell of a set of cells potentially taking part in coordinated multipoint transmission, 
 receive feedback including channel state information and a recommendation of one or more transmitting points selected from among the set of cells; and 
 provide an indication of which reference signal configuration should be assumed in resource mapping for data based on the feedback, wherein the indication is configured to selectively indicate at least a first state indicating serving cell-only transmission, a second state indicating that the recommendation of the one or more transmitting points selected from among the set of cells is followed, and a third state indicating a configuration different from the first state and the second state. 
 
 
     
     
       9. The apparatus according to  claim 8 , wherein the reference signal configuration further comprises at least one of a number of reference signal ports and a frequency shift. 
     
     
       10. The apparatus according to  claim 8 , wherein
 the indication of which reference signal configuration should be assumed in resource mapping for data indicates the second state. 
 
     
     
       11. The apparatus according to  claim 8 , wherein the
 indication of which reference signal configuration should be assumed in resource mapping for the data indicates the first state. 
 
     
     
       12. The apparatus according to  claim 8 , wherein the reference signal configurations are different for at least two cells of the set of cells. 
     
     
       13. The apparatus according to  claim 8 , wherein the apparatus is an enhanced NodeB (eNB). 
     
     
       14. A method comprising:
 obtaining information about a set of cells potentially taking part in coordinated multipoint transmission; 
 obtaining information about a reference signal configuration for each cell of the set of cells; 
 generating and transmitting feedback including channel state information and a recommendation of one or more transmitting points selected from among the set of cells; 
 obtaining an indication of which reference signal configuration should be assumed in resource mapping for data in response to the feedback, wherein the indication is configured to selectively indicate at least a first state indicating serving cell-only transmission, a second state indicating that the recommendation of the one or more transmitting points selected from among the set of cells is followed, and a third state indicating a configuration different from the first state and the second state; and 
 receiving data according to the resource mapping. 
 
     
     
       15. The method according to  claim 14 , wherein the reference signal configuration further comprises at least one of a number of reference signal ports and a frequency shift. 
     
     
       16. The method according to  claim 14 , wherein the indication of which reference signal configuration should be assumed in resource mapping for data indicates the second state. 
     
     
       17. The method according to  claim 14 , wherein the indication of which reference signal configuration should be assumed in resource mapping for data indicates the first state. 
     
     
       18. The method according to  claim 14 , wherein the receiving data according to the resource mapping comprises rate matching around reference signals indicated by the indication of which reference signal configuration should be assumed in resource mapping for data. 
     
     
       19. The method according to,  claim 14 , wherein the reference signal configurations are different for at least two cells of the set of cells. 
     
     
       20. The method according to  claim 14 , wherein the method is performed by a user equipment.