Circular buffer rate matching for polar codes
Methods are proposed herein to perform rate matching for polar codes via circular buffering of the polar encoded bits. Embodiments are directed to methods of operation of a transmitting node in a wireless system including performing polar encoding of a set of information bits in accordance with a polar sequence of length N B to thereby generate N B coded bits. The method can further include interleaving the coded bits to thereby provide an interleaved coded bit sequence, and storing the interleaved coded bit sequence into a circular buffer of length N B . According to certain embodiments, the method can further include extracting N coded bits for transmission from the circular buffer. N can be greater than, equal to, or less than N B .
1. A method of operation of a transmitting node in a wireless system, comprising:
performing polar encoding of a set of K information bits in accordance with a polar sequence of length N B to thereby generate N B coded bits;
interleaving the coded bits to thereby provide an interleaved coded bit sequence, wherein interleaving the coded bits comprises adaptively interleaving the coded bits based on one or more link parameters and/or one or more system parameters such that the coded bits are ordered in the interleaved coded bit sequence according to a ranking;
storing the interleaved coded bit sequence into a circular buffer of length N B , wherein the coded bits are stored in an order of decreasing ranking in the circular buffer; and
extracting N coded bits for transmission from the circular buffer consecutively in an order of decreasing ranking.
2. The method of claim 1 , wherein N>=N B , and (N−N B ) coded bits are repeated.
3. The method of claim 1 , wherein N<=N B , and no coded bits are repeated.
4. The method of claim 1 , wherein extracting the N coded bits from the circular buffer comprises adaptively extracting the N coded bits from the circular buffer consecutively according to a sequence of the coded bits, where the sequence specifies the order the coded bits are written into the circular buffer.
5. The method of claim 1 , wherein extracting the N coded bits from the circular buffer comprises adaptively extracting the N coded bits from the circular buffer based on one or more link parameters and/or one or more system parameters.
6. The method of claim 5 , wherein extracting the N coded bits from the circular buffer comprises adaptively extracting the N coded bits from the circular buffer based on a code rate K/N.
7. The method of claim 6 , wherein extracting the N coded bits from the circular buffer comprises adaptively extracting the N coded bits from the circular buffer based on the code length N and a mother code of length N B .
8. The method of claim 1 , further comprising, prior to performing polar encoding of the set of information bits, adaptively selecting the information bit location based on one or more link parameters and/or one or more system parameters.
9. The method of claim 8 , wherein the step of adaptively selecting the information bit location comprises adaptively selecting based on a code rate KIN.
10. The method of claim 8 , wherein the step of adaptively selecting the information bit location comprises adaptively selecting based on the code length N and a mother code of length N B .
11. The method of claim 1 , wherein the one or more link parameters comprise a number of information bits K to be transmitted, a code length N to be used for transmission, and a code rate R=K/N to be used for transmission.
12. The method of claim 1 , wherein the one or more system parameters comprise a parameter that indicates whether the transmission is an uplink transmission or downlink transmission, a parameter related to radio resource allocation, a parameter related to waveform to be used for the transmission, a parameter related to redundancy versions, and/or a parameter related to receiver capability.
13. The method of claim 1 , further comprising:
interleaving the N coded bits extracted from the circular buffer to provided N interleaved coded bits; and
modulating the N interleaved coded bits to provide a plurality of symbols.
14. The method of claim 13 , further comprising interleaving the plurality of symbols.
15. A transmitting node comprising:
at least one transmitter; and
processing circuitry adapted to cause the transmitting node to:
perform polar encoding of a set of K information bits in accordance with a polar sequence of length N B to thereby generate N B coded bits;
interleave the coded bits to thereby provide an interleaved coded bit sequence, wherein interleaving the coded bits comprises adaptively interleaving the coded bits based on one or more link parameters and/or one or more system parameters such that the coded bits are ordered in the interleaved coded bit sequence according to a ranking;
store the interleaved coded bit sequence into a circular buffer of length N B , wherein the coded bits are stored in an order of decreasing ranking in the circular buffer; and
extract N coded bits for transmission from the circular buffer consecutively in an order of decreasing ranking.
16. The transmitting node of claim 15 , wherein the transmitting node is a User Equipment (UE).
17. The transmitting node of claim 15 , wherein the transmitting node is a network node.