Communication scheme for channel quality information
View Patent ↗The invention relates to a method for transmitting and a method for reconstructing channel quality information in a communication system. Further, the invention also provides a transmitter and receiver performing these methods, respectively. The invention suggests a scheme for communicating channel quality measures that on the one hand allows for an accurate reconstruction of the channel quality measures at the receiver and on the other hand requires an acceptable transmission overhead. This is achieved by partitioning channel quality measures into at least two partitions and to compress the values partition-wise, for example, by means of a discrete cosine transform and the transmission of only a subset of the resulting coefficients.
1. A method for transmitting a periodic report of channel quality information to a receiving entity within a communication system, the method comprising the steps of:
transmitting a first channel quality information report at a first reporting instance; and
transmitting a second channel quality information report at a second reporting instance;
wherein a change in a channel state triggers a change in a content of the second channel quality information report between a first content and a second content; and
wherein the first content of the second channel quality information report enables a more accurate frequency domain reconstruction of the channel state at the receiving entity than the second content of the second channel quality information report.
2. The method according to claim 1 , wherein the first channel quality information report is transmitted at a first reporting period and the second channel quality information report is transmitted at a second reporting period.
3. The method according to claim 2 , wherein the second channel quality information report is transmitted between the first channel quality information reports.
4. The method according to claim 3 , wherein the first reporting period is different from the second reporting period.
5. The method according to claim 1 , wherein the first content of the second channel quality information report includes a greater number of values/coefficients usable by the receiving entity for the purpose of frequency domain reconstruction than those included in the second content.
6. The method according to claim 1 , wherein the channel state is determined to have changed when the difference between the total energy of one or a plurality of channel quality measures at two time instants is above a threshold.
7. A transmitter for transmitting a periodic report of channel quality information to a receiving entity within a communication system, the transmitter comprising:
a transmitting unit configured to transmit a first channel quality information report at a first reporting instance, and to transmit a second channel quality information report at a second reporting instance;
wherein a change in a channel state triggers a change in a content of the second channel quality information report between a first content and a second content; and
wherein the first content of the second channel quality information report enables a more accurate frequency domain reconstruction of the channel state at the receiving entity than the second content of the second channel quality information report.
8. The transmitter according to claim 7 , wherein the transmitting unit is configured to transmit the first channel quality information report at a first reporting period and to transmit the second channel quality information report at a second reporting period.
9. The transmitter according to claim 8 , wherein the transmitting unit is configured to transmit the second channel quality information report between the first channel quality information reports.
10. The transmitter according to claim 9 , wherein the first reporting period is different from the second reporting period.
11. The transmitter according to claim 7 , wherein the first content of the second channel quality information report includes a greater number of values/coefficients usable by the receiving entity for the purpose of frequency domain reconstruction than those included in the second content.
12. The transmitter according to claim 7 , wherein the channel state is determined to have changed when the difference between the total energy of one or a plurality of channel quality measures at two time instants is above a threshold.
13. An integrated circuit configured to control operation of a transmitter for transmitting a periodic report of channel quality information to a receiving entity within a communication system, the integrated circuit being configured to control the transmitter to:
transmit a first channel quality information report at a first reporting instance;
transmit a second channel quality information report at a second reporting instance;
wherein a change in a channel state triggers a change in a content of the second channel quality information report between a first content and a second content;
wherein the first content of the second channel quality information report enables a more accurate frequency domain reconstruction of the channel state at the receiving entity than the second content of the second channel quality information report.
14. The integrated circuit according to claim 13 , further configured to control the transmitter to transmit the first channel quality information report at a first reporting period and to transmit the second channel quality information report at a second reporting period.
15. The integrated circuit according to claim 14 , further configured to control the transmitter to transmit the second channel quality information report between the first channel quality information reports.
16. The integrated circuit according to claim 15 , wherein the first reporting period is different from the second reporting period.
17. The integrated circuit according to claim 13 , wherein the first content of the second channel quality information report includes a greater number of values/coefficients usable by the receiving entity for the purpose of frequency domain reconstruction than those included in the second content.
18. The integrated circuit according to claim 13 , wherein the channel state is determined to have changed when the difference between the total energy of one or a plurality of channel quality measures at two time instants is above a threshold.