Apparatuses and methods for facilitating joint precoding and probabilistic constellation shaping
Aspects of the subject disclosure may include, for example, identifying a modulation scheme for transmitting data from a transmitter to a receiver, identifying a plurality of symbols associated with the modulation scheme, determining that a transfer function of a filter that is applied at the transmitter imposes an interdependence amongst at least two symbols of the plurality of symbols, determining, based on the transfer function, a joint probability distribution of the plurality of symbols that reduces a signal power of at least one signal that is used to transmit the data subject to a constraint that an information rate associated with the at least one signal is greater than a threshold, and causing the data to be transmitted via the at least one signal from the transmitter to the receiver in accordance with the joint probability distribution. Other aspects are disclosed.
1. A device comprising:
a processing system including a processor; and
memory storing instructions that, when executed by the processing system, facilitate a performance of operations, the operations comprising:
determining that a transfer function of a filter that is applied at a transmitter imposes an interdependence amongst at least two symbols of a plurality of symbols;
determining, based on the transfer function, a joint probability distribution of the plurality of symbols that reduces a signal power of at least one signal that is used to transmit data subject to a constraint that an information rate associated with the at least one signal is greater than a threshold; and
causing the data to be transmitted via the at least one signal from the transmitter to a receiver in accordance with the joint probability distribution.
2. The device of claim 1 , wherein the filter comprises an equalizer.
3. The device of claim 1 , wherein the operations further comprise:
identifying a second transfer function associated with a communication medium that is between the transmitter and the receiver; and
selecting the transfer function for the filter based on the second transfer function.
4. The device of claim 3 , wherein a third transfer function associated with the transmitter corresponds to an inversion of the second transfer function, and wherein the transfer function is subsumed within the third transfer function.
5. The device of claim 3 , wherein the communication medium includes air, and wherein the at least one signal includes a wireless signal.
6. The device of claim 3 , wherein the communication medium includes fiber, and wherein the at least one signal includes an optical signal.
7. The device of claim 3 , wherein the operations further comprise:
identifying a third transfer function associated with a digital to analog converter (DAC) of the transmitter; and
identifying a fourth transfer function associated with an amplifier of the transmitter,
wherein the selecting of the transfer function for the filter is further based on the third transfer function and the fourth transfer function.
8. The device of claim 1 , wherein the operations further comprise:
identifying a modulation scheme for transmitting the data from the transmitter to the receiver;
identifying the plurality of symbols as being associated with the modulation scheme,
wherein the identifying of the modulation scheme is based on a selection of the modulation scheme from a plurality of modulation schemes.
9. The device of claim 8 , wherein the modulation scheme is based on pulse amplitude modulation.
10. The device of claim 1 , wherein the plurality of symbols is arranged as a constellation of symbols, and wherein the at least two symbols are adjacent symbols within the constellation.
11. The device of claim 1 , wherein the determining that the joint probability distribution of the plurality of symbols that reduces a signal power of at least one signal that is used to transmit the data is further subject to a second constraint that a first marginal probability mass function (PMF) of a first symbol of the at least two symbols is equal to a second marginal PMF of a second symbol of the at least two symbols.
12. The device of claim 1 , wherein the determining of the joint probability distribution is based on a use of a distribution matching (DM) algorithm.
13. The device of claim 12 , wherein the DM algorithm includes a use of arithmetic coding (AC).
14. The device of claim 12 , wherein the DM algorithm includes a use of constant composition distribution matching (CCDM) or multiset-partition distribution matching (MPDM).
15. The device of claim 12 , wherein the DM algorithm is based on a use of graph theory, and wherein the operations further comprise:
generating a plurality of shaped bits and at least one unshaped bit based on the plurality of symbols; and
generating a plurality of output symbols based on the plurality of shaped bits and the at least one unshaped bit,
wherein the causing of the data to be transmitted via the at least one signal is based on the plurality of output symbols.
16. The device of claim 1 , wherein the determining of the joint probability distribution is based on a use of a probabilistic constellation shaping (PCS) algorithm.
17. The device of claim 16 , wherein the PCS algorithm includes a use of enumerative sphere shaping (ESS) or shell mapping (SM).
18. A non-transitory computer-readable storage medium comprising instructions that, when executed by a processing system including a processor, facilitate a performance of operations, the operations comprising:
determining that a transfer function associated with a source of information imposes an interdependence amongst symbols of a plurality of symbols;
identifying, based on the determining, a joint probability distribution of the plurality of symbols that satisfies an objective function that seeks to reduce a signal power of a signal that is used to convey the information and increase an information rate associated with the information; and
causing the information to be transmitted from the source to a destination in accordance with the identifying of the joint probability distribution.
19. The non-transitory computer-readable storage medium of claim 18 , wherein the plurality of symbols is associated with a constellation of symbols, and wherein the source obtains first information of the information from a first client device and obtains second information of the information from a second client device.
20. A method comprising:
obtaining, by a first processing system including a first processor, information from a plurality of client devices;
mapping, by the first processing system, the information to a first plurality of symbols;
applying, by the first processing system, a first function to the first plurality of symbols to generate a second plurality of symbols, wherein the first function corresponds to an inversion of a second function associated with a communication channel that couples the first processing system and a second processing system that includes a second processor; and
transmitting, by the first processing system, the information to the second processing system in accordance with the second plurality of symbols such that the second processing system is able to recover the information in a lossless manner,
wherein the first function imposes an interdependence amongst the symbols of the second plurality of symbols, and
wherein the first function is selected such that one of:
a signal power of signals that are used to transmit second information to the second processing system is reduced subject to a first constraint that an information rate of the second information is greater than a first threshold, or
the information rate is increased subject to a second constraint that the signal power is less than a second threshold,
wherein the second information includes the information.