Multi-resolution csi feedback

Abstract

A method performed by a radio device 6 for Channel State Information (CSI) feedback in a communication system 1 comprising a Radio Access Network (RAN) node 3 comprises receiving, from the RAN node, information about a CSI Reference Signal (RS) resource, a first CSI type and a second CSI type for feedback. The method also comprises receiving, from the RAN node, a CSI feedback request for CSI measurement and feedback of the first CSI type or the second CSI type. The method also comprises measuring CSI of the indicated type based on signals received on the CSI-RS resource. The method also comprises sending, to the RAN node, a CSI report of the requested CSI type. A corresponding method in a RAN node is furthermore presented herein.

1 . A method performed by a radio device for Channel feedback in a communication system comprising a Radio Access Network, RAN, node, the method comprising:
 receiving, from the RAN node, information about a Reference Signal resource, a first feedback type and a second feedback type for feedback based on the resource;   receiving, from the RAN node, a feedback request for measurement and feedback of the first feedback type or the second feedback type;   measuring the indicated type of based on at least one reference signal received in the resource; and   sending, to the RAN node, a report of the requested feedback type.   
     
     
         2 . The method of  claim 1 , wherein:
 the channel feedback comprises Channel State Information, CSI, feedback;   the reference signal resource comprises a CSI Reference Signal, CSI-RS, resource;   the at least one reference signal comprises at 1peast one CSI-RS signal;   the first feedback type and the second feedback type comprise a first CSI type and a second CSI type for feedback, the second CSI type having a higher channel resolution than the first CSI type;   the feedback request for measurement comprises a CSI feedback request for CSI measurement; and   the report of the requested feedback type comprises a CSI report of the requested CSI type.   
     
     
         3 . The method of  claim 1 , wherein the feedback request is dynamically received. 
     
     
         4 . The method of  claim 1 , wherein the information further comprises information about a transmit antenna port layout used in the RAN node. 
     
     
         5 . The method of  claim 4 , wherein the information further comprises information about a first codebook for the first feedback type and a second codebook for the second feedback type, which are both associated with a same antenna port layout, wherein the first codebook and the second codebook are different. 
     
     
         6 . The method of  claim 1 , wherein the reference signal resource is a Non-Zero Power, NZP, Channel State Information-Reference Signal, CSI-RS, resource. 
     
     
         7 . The method of  claim 1 , wherein the information further comprises information about a Zero Power, ZP, Channel State Information-Reference Signal, CSI-RS, resource over which interference is to be measured. 
     
     
         8 . The method of  claim 1 , wherein the information is received semi-statically, over Radio Resource Control, RRC, signaling. 
     
     
         9 . The method of  claim 2 , wherein the second CSI type is an enhanced CSI based on explicit quantization of an estimated channel. 
     
     
         10 . A radio device for feedback in a communication system comprising a Radio Access Network, RAN, node, the radio device comprising:
 processor circuitry;   radio interface; and   storage storing instructions executable by the processor circuitry whereby the radio device is operative to:   receive, from the RAN node, information about a Reference Signal resource, a first feedback type and a second feedback type for feedback based on the resource;   receive, from the RAN node, a feedback request for measurement and feedback of the first feedback type or the second feedback type;   measure the indicated type of based on at least one reference signal received in the resource; and   send, to the RAN node, a report of the requested feedback type.   
     
     
         11 . The radio device of  claim 10 , wherein:
 the channel feedback comprises Channel State Information, CSI, feedback;   the reference signal resource comprises a CSI Reference Signal, CSI-RS, resource;   the at least one reference signal comprises at least one CSI-RS signal;   the first feedback type and the second feedback type comprise a first CSI type and a second CSI type for feedback, the second CSI type having a higher channel resolution than the first CSI type;   the feedback request for measurement comprises a CSI feedback request for CSI measurement; and   the report of the requested feedback type comprises a CSI report of the requested CSI type.   
     
     
         12 . The radio device of  claim 10 , wherein the feedback request is dynamically received. 
     
     
         13 . The radio device of  claim 10 , wherein the information further comprises information about a transmit antenna port layout used in the RAN node. 
     
     
         14 . The radio device of  claim 10 , wherein the information further comprises information about a first codebook for the first feedback type and a second codebook for the second feedback type, which are both associated with a same antenna port layout, wherein the first codebook and the second code book are different. 
     
     
         15 . The radio device of  claim 10 , wherein the reference signal resource is a Non-Zero Power, NZP, Channel State Information-Reference Signal, CSI-RS, resource. 
     
     
         16 . The radio device of  claim 10 , wherein the information further comprises information about a Zero Power, ZP, Channel State Information-Reference Signal, CSI-RS, resource over which interference is to be measured. 
     
     
         17 . The radio device of  claim 10 , wherein the information is received semi-statically, over Radio Resource Control, RRC, signaling. 
     
     
         18 . The radio device of  claim 11 , wherein the second CSI type is an enhanced CSI based on explicit quantization of an estimated channel.