Method for transmitting and receiving a signal to protect against erroneous feedback information
View Patent ↗A method for providing precoding weights for data symbols of data control subframes includes generating a downlink frame having control subframes which individually correspond to one of a plurality of downlink data subframes, and inserting weight information into each of the control subframes, such that the weight information is to be applied to data symbols present in the corresponding one of the data subframes. The method further includes transmitting the control subframes and the inserted weight information to a receiving device.
1. A method for receiving signals at a user equipment (UE) configured to operate in a closed loop multi input multi output (MIMO) mode, the method comprising:
reporting feedback information used to indicate first type weights to a base station at a sub frame N, wherein N is an integer;
receiving feed forward information used to indicate second type weights from the base station at a sub frame N+a, where “a” is equal to or greater than 1, through a downlink control channel, wherein the second type weights are determined in consideration of the feedback information;
receiving downlink signals, to which the second type weights are applied, from the base station at the sub frame N+a through a physical downlink shared channel;
decoding the downlink signals using the second type weights and a MIMO scheme when the second type weights are different from the first type weights; and
decoding the downlink signals using the first type weights and the MIMO scheme when the second type weights are identical to the first type weights.
2. The method of claim 1 , wherein the downlink signals are received by the UE from the base station via two antennas.
3. The method of claim 2 , wherein the first type weights comprise w 1 and w 2 , and wherein w 1 is a constant real value, and w 2 is a complex variable selected from four options.
4. The method of claim 3 , wherein the downlink signals are received by the UE from the base station via two streams.
5. The method of claim 4 , wherein the second type weights comprise v 11 , v 21 , v 12 and v 22 , and wherein v 11 and v 21 are applied to a first stream of the two streams, and v 12 and v 22 are applied to a second stream of the two streams.
6. The method of claim 5 , wherein weights of v 11 and v 21 , and weights of v 12 and v 22 are orthogonal to each other.
7. A method for transmitting signals from a base station to a user equipment (UE) configured to operate in a closed loop multi input multi output (MIMO) mode, the method comprising:
receiving feedback information used to indicate first type weights from the UE at a sub frame N, wherein N is an integer;
transmitting feed forward information used to indicate second type weights to the UE at a sub frame N+a, where “a” is equal to or greater than 1, through a downlink control channel, wherein the second type weights are determined in consideration of the feedback information;
applying the second type weights to downlink signals on a physical downlink shared channel of the subframe N+a when the second type weights are different from the first type weights;
applying the first type weights to the physical downlink shared channel when the second type weights are identical to the first type weights; and
transmitting the downlink signals to the UE at the sub frame N+a through the physical downlink shared channel.
8. The method of claim 7 , wherein the downlink signals to which the second type weights were applied are transmitted via two antennas.
9. The method of claim 8 , wherein the first type weights comprise w 1 and w 2 , and wherein w 1 is a constant real value, and w 2 is a complex variable selected from four options.
10. The method of claim 9 , wherein the downlink signals to which the second type weights were applied are transmitted via two streams.
11. The method of claim 10 , wherein the second type weights comprise v 11 , v 21 , v 12 and v 22 , and wherein v 11 and v 21 are applied to a first stream of the two streams, and v 12 and v 22 are applied to a second stream of the two streams.
12. The method of claim 11 , wherein weights of v 11 and v 21 , and weights of v 12 and v 22 are orthogonal to each other.
13. A user equipment (UE) for receiving signals and configured to operate in a closed multi input multi output (MIMO) mode, the UE comprising:
a transmitter configured to transmit feedback information used to indicate first type weights to a base station at a sub frame N, wherein N is an integer;
a receiver configured to receive feed forward information used to indicate second type weights from the base station at a sub frame N+a, where “a” is equal to or greater than 1, through a downlink control channel, wherein the second type weights are determined in consideration of the feedback information, and to receive downlink signals, to which the second type weights are applied, from the base station at the sub frame N+a through a physical downlink shared channel; and
a processor configured to:
decode the downlink signals using the second type weights and a MIMO scheme when the second type weights are different from the first type weights; and
decode the downlink signals using the first type weights and the MIMO scheme when the second type weights are identical to the first type weights.
14. The UE of claim 13 , wherein the downlink signals are received by the UE from the base station via two antennas.
15. The UE of claim 14 , wherein the first type weights comprise w 1 and w 2 , and wherein w 1 is a constant real value, and w 2 is a complex variable selected from four options.
16. The UE of claim 15 , wherein the downlink signals are received by the UE from the base station via two streams.
17. The UE of claim 16 , wherein the second type weights comprise v 11 , v 21 , v 12 and v 22 , and wherein v 11 and v 21 are applied to a first stream of the two streams, and v 12 and v 22 are applied to a second stream of the two streams.
18. The UE of claim 17 , wherein weights of v 11 and v 21 , and weights of v 12 and v 22 are orthogonal to each other.
19. A base station for transmitting signals to a user equipment (UE) configured to operate in a closed loop multi input multi output (MIMO) mode, the base station comprising:
a receiver configured to receive feedback information used to indicate first type weights from the UE at a sub frame N, wherein N is an integer;
a transmitter configured to transmit feed forward information used to indicate second type weights to the UE at a sub frame N+a, where “a” is equal to or greater than 1, through a downlink control channel, wherein the second type weights are determined in consideration of the feedback information, and to transmit downlink signals to the UE at the sub frame N+a through a physical downlink shared channel; and
a processor configured to:
apply the second type weights to the downlink signals on the physical downlink shared channel of the sub frame N+a when the second type weights are different from the first type weights; and
apply the first type weights to the physical downlink shared channel when the second type weights are identical to the first type weights.
20. The base station of claim 19 , wherein the downlink signals to which the second type weights were applied are transmitted via two antennas.
21. The base station of claim 20 , wherein the first type weights comprise w 1 and w 2 , and wherein w 1 is a constant real value, and w 2 is a complex variable selected from four options.
22. The base station of claim 21 , wherein the downlink signals to which the second type weights were applied are transmitted via two streams.
23. The base station of claim 22 , wherein the second type weights comprise v 11 , v 21 , v 12 and v 22 , and wherein v 11 and v 21 are applied to a first stream of the two streams, and v 12 and v 22 are applied to a second stream of the two streams.
24. The base station of claim 23 , wherein weights of v 11 and v 21 , and weights of v 12 and v 22 are orthogonal to each other.