Constellation shaping with fixed-to-fixed shaping encoding
This disclosure describes systems, methods, and devices related to fixed-to-fixed shaping encoding. A device may determine a mapping table associated with uniformly distributed bits into amplitudes with desired probabilities. The device may predict a number of output bits for an input block. The device may apply padding as needed based on the predicted number of output bits.
1. A device, the device comprising processing circuitry coupled to storage, the processing circuitry configured to:
generate payload bits to be sent to a station device;
divide the payload bits into a first plurality of blocks of K bits each, where K is a positive integer;
pass each of the first plurality of blocks of K bits through a shaping encoder, to generate a second plurality of blocks of shaped output bits, wherein the second plurality of blocks of shaped output bits having a variable block size;
select a number N of output bits having a fixed size, wherein N is a positive integer,
generate a third plurality of blocks of N bits, wherein each block of the N is comprised of a block of shaped output bits and a number of overhead bits;
generate a physical layer (PHY) protocol data unit (PPDU) comprising the third plurality of blocks of N bits; and
cause to transmit, to the station device, the PPDU on the physical layer.
2. The device of claim 1 , wherein the number N of output bits is based on a probability of overflow associated with an overhead bit percentage of K bits.
3. The device of claim 2 , wherein the processing circuitry is further configured to determine the number of overhead bits based on requirements for low overflow.
4. The device of claim 1 , wherein the processing circuitry is further configured to:
determine that at least one of the second plurality of blocks of shaped output bits is larger than the selected number N of output bits; and
transmit, to the station device, the PPDU on a physical layer without a last set of bits of a last block of K bits.
5. The device of claim 1 , wherein padding is applied when at least one of the second plurality of blocks of shaped output bits is smaller than the selected number N of output bits.
6. The device of claim 5 , wherein the processing circuitry is further configured to:
determine that at least one of the second plurality of blocks of shaped output bits is smaller than the selected number N of output bits; and
add one or more padding bits to the at least one of the second plurality of blocks of shaped output bits.
7. The device of claim 5 , wherein the padding comprises one or more random bits.
8. The device of claim 5 , wherein the padding comprises a repetition of a portion of at least one of the first plurality of blocks of K bits.
9. The device of claim 1 , further comprising a transceiver configured to transmit and receive wireless signals.
10. The device of claim 9 , further comprising an antenna coupled to the transceiver.
11. A non-transitory computer-readable medium storing computer-executable instructions which when executed by one or more processors result in performing operations comprising:
generating payload bits to be sent to a station device;
dividing the payload bits into a first plurality of blocks of K bits each, where K is a positive integer;
passing each of the first plurality of blocks of K bits through a shaping encoder, to generate a second plurality of blocks of shaped output bits, wherein the second plurality of blocks of shaped output bits having a variable block size;
selecting a number N of output bits having a fixed size, wherein N is a positive integer,
generating a third plurality of blocks of N bits, wherein each block of the N is comprised of a block of shaped output bits and a number of overhead bits;
generating a physical layer (PHY) protocol data unit (PPDU) comprising the third plurality of blocks of N bits; and
causing to transmit, to the station device, the PPDU on the physical layer.
12. The non-transitory computer-readable medium of claim 11 , wherein the number N of output bits is based on a probability of overflow associated with an overhead bit percentage of K bits.
13. The non-transitory computer-readable medium of claim 12 , wherein the operations further comprise determining the number of overhead bits based on requirements for low overflow.
14. The non-transitory computer-readable medium of claim 11 , wherein the operations further comprise:
determining that at least one of the second plurality of blocks of shaped output bits is larger than the selected number N of output bits; and
transmitting, to the station device, the PPDU on a physical layer without a last set of bits of a last block of K bits.
15. The non-transitory computer-readable medium of claim 11 , wherein padding is applied when at least one of the second plurality of blocks of shaped output bits is smaller than the selected number N of output bits.
16. The non-transitory computer-readable medium of claim 15 , wherein the operations further comprise:
determining that at least one of the second plurality of blocks of shaped output bits is smaller than the selected number N of output bits; and
adding one or more padding bits to the at least one of the second plurality of blocks of shaped output bits.
17. The non-transitory computer-readable medium of claim 15 , wherein the padding comprises one or more random bits.
18. The non-transitory computer-readable medium of claim 15 , wherein the padding comprises a repetition of a portion of at least one of the first plurality of blocks of K bits.
19. A method comprising:
generating, by one or more processors, payload bits to be sent to a station device;
dividing the payload bits into a first plurality of blocks of K bits each, where K is a positive integer;
passing each of the first plurality of blocks of K bits through a shaping encoder, to generate a second plurality of blocks of shaped output bits, wherein the second plurality of blocks of shaped output bits having a variable block size;
selecting a number N of output bits having a fixed size, wherein N is a positive integer,
generating a third plurality of blocks of N bits, wherein each block of the N is comprised of a block of shaped output bits and a number of overhead bits;
generating a physical layer (PHY) protocol data unit (PPDU) comprising the third plurality of blocks of N bits; and
causing to transmit, to the station device, the PPDU on the physical layer.
20. The method of claim 19 , wherein the number N of output bits is based on a probability of overflow associated with an overhead bit percentage of K bits.