Rate assignment with rate splitting for interference cancellation friendly new air interface
A new air interface that is interference cancellation friendly is proposed. In one novel aspect, a novel code rate assignment with rate splitting is proposed. In one embodiment, a base station decomposes a codeword {x 1 } into two codewords {x 1a } and {x 1b }. The two codewords are applied with different code rates and/or modulation orders. More specifically, the code rate or modulation order of codeword {x 1a } is set appropriately so that a victim UE can decode and cancel {x 1a } under the channel quality of the victim UE. Typically, the channel quality of a victim UE is poorer than the channel quality of the intended UE. As a result, the MCS for {x 1a } can be lower than the MCS for {x 1b } such that the victim UE is able to apply CWIC to decode and cancel {x 1a }.
1. A method, comprising:
scheduling a data transmission carrying a plurality of information bits for an intended user equipment (UE) over an allocated resource block by a base station;
determining a first channel condition of the intended UE and a second channel condition of a victim UE;
performing rate splitting by separating the plurality of information bits into two codewords, wherein a first codeword is applied with a first code rate based on the first channel condition, and wherein a second codeword is applied with a second code rate base on the second channel condition; and
transmitting the two codewords to the intended UE over the allocated resource block in the same data transmission of multi-user multiple-input multiple-output (MU-MIMO), wherein the base station performs rate splitting such that the victim UE can apply codeword-level interference cancellation for the MU-MIMO transmission.
2. The method of claim 1 , wherein the first codeword is formed from a first transport block, and wherein the second codeword is formed from a second transport block.
3. The method of claim 1 , wherein the first and the second codewords are formed from a transport block.
4. The method of claim 1 , wherein the first channel condition has a higher channel quality than the second channel condition, and wherein the first code rate is higher than the second code rate.
5. The method of claim 1 , wherein the first codeword is applied with a first modulation order, and wherein the second codeword is applied with a second modulation order.
6. The method of claim 5 , wherein the first channel condition is better than the second channel condition, and wherein the first modulation order is higher than the second modulation order.
7. The method of claim 1 , wherein the second code rate is determined based on the second channel condition such that the victim UE can decode the second codeword and apply codeword-level interference cancellation.
8. The method of claim 1 , wherein the base station determines the first and the second channel conditions by performing channel estimation.
9. The method of claim 1 , wherein the base station determines the first and the second channel conditions by receiving channel station information from the intended UE and the victim UE.
10. A base station, comprising:
a scheduler that schedules a data transmission carrying a plurality of information bits for an intended user equipment (UE) over an allocated resource block;
a channel estimation circuit that determines a first channel condition of the intended UE and a second channel condition of a victim UE;
a control circuits that performs rate splitting by separating the plurality of information bits into two codewords, wherein a first codeword is applied with a first code rate based on the first channel condition, and wherein a second codeword is applied with a second code rate base on the second channel condition; and
a transmitter that transmits the two codewords to the intended UE over the allocated resource block in the same data transmission of multi-user multiple-input multiple-output (MU-MIMO), wherein the base station performs rate splitting such that the victim UE can apply codeword-level interference cancellation for the MU-MIMO transmission.
11. The base station of claim 10 , wherein the first codeword is formed from a first transport block, and wherein the second codeword is formed from a second transport block.
12. The base station of claim 10 , wherein the first and the second codewords belong to a transport block.
13. The base station of claim 10 , wherein the first channel condition has a higher channel quality than the second channel condition, and wherein the first code rate is higher than the second code rate.
14. The base station of claim 10 , wherein the first codeword is applied with a first modulation order, and wherein the second codeword is applied with a second modulation order.
15. The base station of claim 14 , wherein the first channel condition is better than the second channel condition, and wherein the first modulation order is higher than the second modulation order.
16. The base station of claim 10 , wherein the second code rate is determined based on the second channel condition such that the victim UE can decode the second codeword and apply codeword-level interference cancellation.
17. The base station of claim 10 , wherein the base station determines the first and the second channel conditions by performing channel estimation.
18. The base station of claim 10 , wherein the base station determines the first and the second channel conditions by receiving channel station information from the intended UE and the victim UE.