Bit interleaving of modulation symbol mapping for data carrying reference signals

1 . A wireless device, comprising:

one or more memories storing processor-executable code; and

one or more processors coupled with the one or more memories and individually or collectively operable to execute the code to cause the wireless device to:

generate a set of bits comprising a first plurality of bits corresponding to a first set of resource elements allocated for data transmissions and a second plurality of bits corresponding to a second set of resource elements allocated for data carrying reference signals, wherein the first plurality of bits corresponds to a first coding rate and a first modulation order and the second plurality of bits corresponds to the first coding rate and a second modulation order that is lower than the first modulation order;

write the set of bits comprising the first plurality of bits and the second plurality of bits into a bitstream in accordance with an interleaving table, wherein one or more most significant bits are located in a first subset of rows of the interleaving table and one or more less significant bits are located in a second subset of rows of the interleaving table;

map the first plurality of bits of the bitstream to a plurality of constellation points and the second plurality of bits of the bitstream to a subset of the plurality of constellation points in accordance with the interleaving table, wherein a quantity of the plurality of constellation points is in accordance with the first modulation order, and a quantity of the subset of the plurality of constellation points is in accordance with the second modulation order; and

transmit the bitstream based at least in part on the mapping.

2 . The wireless device of claim 1 , wherein the one or more processors are individually or collectively further operable to execute the code to cause the wireless device to:

select the one or more most significant bits for the second set of resource elements to carry data for the data carrying reference signals; and

select one or more padding bits as the one or more least significant bits for the second set of resource elements, wherein the one or more padding bits correspond to a threshold Euclidean distance with respect to the subset of the plurality of constellation points.

3 . The wireless device of claim 1 , wherein the one or more processors are individually or collectively further operable to execute the code to cause the wireless device to:

select the first subset of the plurality of constellation points from a set of candidate sub-constellations, each sub-constellation of comprising a respective portion of constellation points of the plurality of constellation points.

4 . The wireless device of claim 3 , wherein:

each sub-constellation corresponding to a subset of the second set of resource elements, and

selecting the first subset of the plurality of constellation points is based at least in part on an allocated subset of the second set of resource elements.

5 . The wireless device of claim 3 , wherein the one or more processors are individually or collectively further operable to execute the code to cause the wireless device to:

receive control signaling indicating a first sub-constellation of the set of candidate sub-constellations, wherein selecting the first subset of the plurality of constellation points is based at least in part on the control signaling.

6 . The wireless device of claim 3 , wherein:

each sub-constellation of the set of candidate sub-constellations corresponds to a respective set of padded bits for each data carrying reference signal.

7 . The wireless device of claim 1 , wherein the interleaving table comprises a systematic bit priority mapping interleaver.

8 . A wireless device, comprising:

one or more memories storing processor-executable code; and

one or more processors coupled with the one or more memories and individually or collectively operable to execute the code to cause the wireless device to:

generate a first plurality of bits corresponding to a first set of resource elements allocated for data transmissions and a second plurality of bits corresponding to a second set of resource elements allocated for data-carrying reference signals, wherein the first plurality of bits corresponds to a first coding rate and a first modulation order and the second plurality of bits corresponds to the first coding rate and a second modulation order that is lower than the first modulation order;

write the first plurality of bits and the second plurality of bits into a bitstream in accordance with an interleaving table, wherein the second plurality of bits are located in a first subset of rows of the interleaving table corresponding to most significant bits, and one or more entries in the interleaving table of a second subset of rows corresponding to least significant bits of the second set of resource elements are unoccupied;

map the bitstream to a plurality of constellation points in accordance with the interleaving table, wherein a quantity of the plurality of constellation points is in accordance with the first modulation order; and

transmit the bitstream based at least in part on the mapping.

9 . The wireless device of claim 8 , wherein, to write the second plurality of bits into the bitstream, the one or more processors are individually or collectively operable to execute the code to cause the wireless device to:

write the second plurality of bits into a first column of the interleaving table, wherein the first subset of rows corresponding to the most significant bits of the first column are occupied by the second plurality of bits, and wherein the second subset of rows corresponding to the least significant bits of the first column are unoccupied.

10 . The wireless device of claim 8 , wherein a quantity of rows of the interleaving table is equal to the first modulation order.

11 . The wireless device of claim 8 , wherein the one or more processors are individually or collectively further operable to execute the code to cause the wireless device to:

receive control signaling comprising an instruction to write the first plurality of bits and the second plurality of bits according to the interleaving table, and to skip one or more entries of the interleaving table corresponding to the least significant bits of the second set of resource elements.

12 . The wireless device of claim 8 , wherein the interleaving table comprises a systematic bit priority mapping interleaver.

13 . A wireless device, comprising:

one or more memories storing processor-executable code; and

one or more processors coupled with the one or more memories and individually or collectively operable to execute the code to cause the wireless device to:

receive control signaling indicating a first interleaving table and a second interleaving table, the first interleaving table comprising a first quantity of rows corresponding to a first modulation order, and the second interleaving table comprising a second quantity of rows corresponding to a second modulation order;

generate a first plurality of bits corresponding to a first set of resource elements allocated for data transmissions and a second plurality of bits corresponding to a second set of resource elements allocated for data-carrying reference signals, wherein the first plurality of bits corresponds to a first coding rate and the first modulation order and the second plurality of bits corresponds to the first coding rate and the second modulation order that is lower than the first modulation order;

write the first plurality of bits into a bitstream in accordance with the first interleaving table, and the second plurality of bits into the bitstream in accordance with the second interleaving table; and

transmit the bitstream in accordance with the writing.

14 . The wireless device of claim 13 , wherein the one or more processors are individually or collectively further operable to execute the code to cause the wireless device to:

map the first plurality of bits of the bitstream to a first plurality of constellation points in accordance with the first interleaving table, wherein a quantity of the first plurality of constellation points is in accordance with the first modulation order; and

map the second plurality of bits of the bitstream to a second plurality of constellation points in accordance with the second interleaving table and the second modulation order, wherein a quantity of the second plurality of constellation points is in accordance with the second modulation order.

15 . The wireless device of claim 14 , wherein transmitting the bitstream is based at least in part on mapping the first plurality of bits of the bitstream to the first plurality of constellation points, and mapping the second plurality of bits of the bitstream to the second plurality of constellation points.

16 . The wireless device of claim 13 , wherein:

the first interleaving table comprises a first systematic bit priority mapping interleaver, and

the second interleaving table comprises a second systematic bit priority mapping interleaver.

17 . A method for wireless communications at a wireless device, comprising:

generating a set of bits comprising a first plurality of bits corresponding to a first set of resource elements allocated for data transmissions and a second plurality of bits corresponding to a second set of resource elements allocated for data carrying reference signals, wherein the first plurality of bits corresponds to a first coding rate and a first modulation order and the second plurality of bits corresponds to the first coding rate and a second modulation order that is lower than the first modulation order;

writing the set of bits comprising the first plurality of bits and the second plurality of bits into a bitstream in accordance with an interleaving table, wherein one or more most significant bits are located in a first subset of rows of the interleaving table and one or more less significant bits are located in a second subset of rows of the interleaving table;

mapping the first plurality of bits of the bitstream to a plurality of constellation points and the second plurality of bits of the bitstream to a subset of the plurality of constellation points in accordance with the interleaving table, wherein a quantity of the plurality of constellation points is in accordance with the first modulation order, and a quantity of the subset of the plurality of constellation points is in accordance with the second modulation order; and

transmitting the bitstream based at least in part on the mapping.

18 . The method of claim 17 , further comprising:

selecting the one or more most significant bits for the second set of resource elements to carry data for the data carrying reference signals; and

selecting one or more padding bits as the one or more least significant bits for the second set of resource elements, wherein the one or more padding bits correspond to a threshold Euclidean distance with respect to the subset of the plurality of constellation points.

19 . The method of claim 17 , further comprising:

selecting the first subset of the plurality of constellation points from a set of candidate sub-constellations, each sub-constellation of comprising a respective portion of constellation points of the plurality of constellation points.

20 . The method of claim 19 , wherein:

each sub-constellation corresponding to a subset of the second set of resource elements, and

selecting the first subset of the plurality of constellation points is based at least in part on an allocated subset of the second set of resource elements.

21 . The method of claim 19 , further comprising:

receiving control signaling indicating a first sub-constellation of the set of candidate sub-constellations, wherein selecting the first subset of the plurality of constellation points is based at least in part on the control signaling.

22 . The method of claim 19 , wherein each sub-constellation of the set of candidate sub-constellations corresponds to a respective set of padded bits for each data carrying reference signal.

23 . The method of claim 17 , wherein the interleaving table comprises a systematic bit priority mapping interleaver.