Channel state information reporting for component carriers for which no channel state information was calculated

摘要

The invention relates to a method for reporting channel state information from a user equipment (UE) to a eNodeB. In particular, the channel state information report is generated for all component carriers configured by the UE, independent from whether channel state information was actually calculated or not. If no channel state information is calculated for a specific component carrier, then the channel state information encodes information as to the status of said specific component carrier and thus the reason why no channel state information calculation was performed. For instance, the channel state information may encode that the status of the component carrier is deactivated, allowing the base station to check whether a component carrier is indeed activated or deactivated at the UE side.

主权项

1. A method for reporting channel state information from a user equipment to a base station in a communication system in which a plurality of component carriers are configured for communication between the base station and the user equipment, the method comprising the following steps performed by the user equipment:
calculating channel state information values for each component carrier that is activated, except for at least one activated or deactivated component carrier for which the calculation of channel state information values is not performed, preparing a channel state information message, comprising one data field for each of the plurality of configured component carriers that is deactivated and for each of the plurality of configured component carriers that is activated, wherein the data field for said at least one activated or deactivated configured component carrier comprises predetermined channel state information values encoding the reason why the calculation of the channel state information values was not performed for said at least one activated or deactivated configured component carrier, and wherein the remaining data fields each comprise the calculated channel state information values for the associated component carriers, and transmitting the channel state information message to the base station, wherein the component carriers are respectively composed of a plurality of subbands, and wherein the channel state information values comprise a Modulation and Coding Scheme Index (MCSI) value for all subbands and one offset value for each of the subbands, wherein the MCSI value and each offset value are combined to indicate the effective MCSI value for each subband, and wherein the predetermined channel state information values for the at least one component carrier comprise an MCSI value and offset values for the subbands defined such that the effective MCSI value for at least one subband is outside the range of valid MCSI values.