Method and device for determining channel quality indication information
The disclosure provides a method and device for determining Channel quality indication information, which is configured to perform channel measurement based on a reference signal, so as to obtain a CQI information. The method considers the influence of multiple factors on CQI calculation, including selection of a measurement reference signal as well as the influence of multiple complex conditions on CQI calculation, thereby solving the problem that an existing system is unable to obtain accurate Channel quality indication information when using a transmission mode 9 , and enhancing the flexibility and performance of the system.
1. A method for determining Channel Quality Indication (CQI) information, comprising:
transmitting, by a base station (eNodeB), a Channel-State Information-Reference Symbol (CSI-RS) and cell-specific reference signal (CRS) to a terminal (User Equipment (UE));
performing, by the UE, channel measurement according to the CSI-RS or CRS;
determining, by the UE, a CQI reference resource, and determining, by the UE, the CQI value on the CQI reference resource according to the result of the channel measurement;
on a frequency domain, defining the CQI reference resource by a downlink physical resource block corresponding to a frequency band to which the CQI value related; on a time domain, defining the CQI reference resource by a downlink subframe; on a transmission layer domain, defining the CQI reference resource by any Rank Indicator (RI) and Pre-coding Matrix Indicator (PMI) on which the CQI is conditioned,
characterized by the step of:
calculating the CQI, by the UE, by using the CRS as an measuring reference signal if the UE is configured without the PMI/RI by the eNodeB; calculating the CQI, by the UE, by using the CSI-RS as an measuring reference signal if the UE is configured with the PMI/RI by the eNodeB; or
to the CQI reference resource, when there is a configurable measuring subset which is for CSI measurement and is formed by a channel quality information measuring subframe, then the channel measurement or interference measurement is limited to a subframe defined by the measuring subset; configuring said measuring subset by the base station through a signalling or a non-periodic triggering; on the time domain, the downlink subframe of the CQI reference resource needs to be defined in said measuring subset.
2. The method according to claim 1 , wherein when determining the CQI value, assuming that the CSI-RS does not use any resource element of the CQI reference resource.
3. The method according to claim 1 , wherein when determining the CQI value, assuming that a positing reference signal (PRS) does not use any resource element of the CQI reference resource.
4. The method according to claim 1 , wherein to a transmission mode 9 , when the UE is configured without the PMI/RI by the eNodeB, the UE is arranged with N virtual CSI-RS ports, in which case it is assumed that a transmission strategy for a downlink data sharing channel of the CQI reference resource is an N-antenna transmit diversity, wherein the N is a natural number determined by the number of the CRS or CSI-RS ports.
5. The method according to claim 1 , wherein to a transmission mode 9 , when the UE is configured without the PMI/RI by the eNodeB and the number of the CSI-RS ports of the eNodeB is 8 , the UE is arranged with 2 virtual CSI-RS ports, in which case it is assumed that a transmission strategy for a downlink data sharing channel of the CQI reference resource is a 2-antenna transmit diversity.
6. The method according to claim 5 , wherein the CSI-RS ports from 15 to 18 are mapped to a first virtual CSI-RS port, and the CSI-RS ports from 19 to 22 are mapped to a second virtual CSI-RS port.
7. The method according to claim 5 , wherein the CSI-RS ports 15 , 17 , 19 , and 21 are mapped to a first virtual CSI-RS port, and the CSI-RS ports 16 , 18 , 20 , and 22 are mapped to a second virtual CSI-RS port.
8. The method according to claim 1 , wherein to a transmission mode 9 , when the UE is configured without the PMI/RI by the eNodeB and the number of the CSI-RS ports of the eNodeB is 8 , the UE is arranged with 4 virtual CSI-RS ports, in which case it is assumed that a transmission strategy for a downlink data sharing channel of the CQI reference resource is a 4-antenna transmit diversity.
9. The method according to claim 8 , wherein the CSI-RS ports 15 and 16 are mapped to a first virtual CSI-RS port, the CSI-RS ports 17 and 18 are mapped to a second virtual CSI-RS port, the CSI-RS ports 19 and 20 are mapped to a third virtual CSI-RS port, the CSI-RS ports 21 and 22 are mapped to a fourth virtual CSI-RS port.
10. The method according to claim 8 , wherein the CSI-RS ports 15 and 19 are mapped to a first virtual CSI-RS port, the CSI-RS ports 16 and 20 are mapped to a second virtual CSI-RS port, the CSI-RS ports 17 and 21 are mapped to a third virtual CSI-RS port, the CSI-RS ports 18 and 22 are mapped to a fourth virtual CSI-RS port.
11. The method according to claim 1 , wherein to a transmission mode 9 , when the UE is configured without the PMI/RI by the eNodeB and the number of the CSI-RS ports of the eNodeB is 8 , the UE is arranged with 1 virtual CSI-RS port, in which case it is assumed that a transmission strategy for a downlink data sharing channel of the CQI reference resource is single layer transmission.
12. A device for determining Channel Quality Indication (CQI) information, comprising:
a receiving module, which is configured to receive a Channel-State Information-Reference Symbol (CSI-RS) and/or a cell-specific reference signal (CRS) transmitted by a base station (eNodeB);
a measuring module, which is configured to perform channel measurement according to the CSI-RS and/or CRS received by the receiving module;
a determining module, which is configured to determine a CQI reference resource and the condition for calculating the CQI; and
a calculating module, which is configured to calculate a CQI value corresponding to the CSI reference resource according to the condition determined by the determining module and a measurement result of the measuring module,
wherein on a frequency domain, the CQI reference resource is defined by a downlink physical resource block corresponding to a frequency band to which a source CQI value related; on a time domain, the CQI reference resource is defined by a downlink subframe; on a transmission layer domain, the CQI reference resource is defined by any Rank Indicator (RI) and Pre-coding Matrix Indicator (PMI) on which the CQI is conditioned,
characterized by that:
if the UE is configured without the PMI/RI by the eNodeB, the channel measurement is performed by using the CRS as an measuring reference signal, if the UE is configured with the PMI/RI by the eNodeB, the channel measurement is performed by using the CSI-RS as an measuring reference signal; or
to the CQI reference resource, when there is a configurable measuring subset which is for CSI measurement and is formed by a channel quality information measuring subframe, then the channel measurement or interference measurement is limited to a subframe defined by the measuring subset; configuring said measuring subset by the base station through a signalling or a non-periodic triggering; on the time domain, the downlink subframe of the CQI reference resource needs to be defined in said measuring subset.
13. The device according to claim 12 , wherein when calculating the condition of the CQI, the determining module is configured to assume that the CSI-RS does not use any resource element of the CQI reference resource.
14. The device according to claim 12 , wherein when calculating the condition of the CQI, the determining module is configured to assume that a positing reference signal (PRS) does not use any resource element of the CQI reference resource.
15. The device according to claim 12 , wherein the device is arranged in a User Equipment (UE).