CQI codepoint reinterpretation

A method in a base station configured to receive, from a wireless device, channel quality information, CQI, that uses a predetermined set of CQI index values, wherein a CQI index value is interpreted by the wireless device and the base station as corresponding to a combination of modulation and coding rate, the method comprising:

• receiving a first one of the CQI index values;
• determining, based on a downlink signal configuration, that the first one of the CQI index values corresponds to no modulation and coding rate that can be used for transmissions to the wireless device from the base station;
• and
• responsive to the determining, interpreting the received first one of the CQI index values to signal information other than a combination of modulating and coding rate,
• wherein determining that the first one of the CQI index values corresponds to no modulation and coding rate that can be used comprises determining that the number of OFDM symbols per subframe occupied by DMRS symbols is not 4 and the configured number of overhead resource elements per resource block is not 18.

A base station configured to receive, from a wireless device, channel quality information, CQI, that uses a predetermined set of CQI index values, wherein a CQI index value is interpreted by the wireless device and the base station as corresponding to a combination of modulation and coding rate, the base station comprising a processing circuitry configured to:

• a receiving module for receiving a first one of the CQI index values;
• a determining module for determining, based on a downlink signal configuration, that the first one of the CQI index values corresponds to no modulation and coding rate that can be used for transmissions to the wireless device from the base station;
• and
• an interpreting module for, responsive to the determining, interpreting the received first one of the CQI index values to signal information other than a combination of modulating and coding rate,
• wherein determining that the first one of the CQI index values corresponds to no modulation and coding rate that can be used comprises determining that the number of OFDM symbols per subframe occupied by DMRS symbols is not 4 and the configured number of overhead resource elements per resource block is not 18.

A wireless device configured to report, to a base station, channel quality information, CQI, using a predetermined set of CQI index values, wherein a CQI index value is interpreted by the wireless device and the base station as corresponding to a combination of modulation and coding rate, the wireless device comprising a processing circuitry configured to:

• a determining module for determining, based on a downlink signal configuration, that a first one of the CQI index values corresponds to no modulation and coding rate that can be used for transmissions to the wireless device from the base station;
• and
• a transmitting module for transmitting the first one of the CQI index values to the base station to signal information other than a combination of modulation and coding rate,
• wherein determining that the first one of the CQI index values corresponds to no modulation and coding rate that can be used comprises determining that the number of OFDM symbols per subframe occupied by DMRS symbols is not 4 and the configured number of overhead resource elements per resource block is not 18.