Signal power reduction systems and methods
A method of reducing transmission power for an encoded data stream includes the steps of receiving an incoming data stream having equal probability for a plurality of incoming data bits, assigning a symbol scheme to the received data bits of the incoming data stream according to probabilities of occurrence of individual ones of the received data bits, and transmitting an outgoing data stream according to the assigned symbol scheme having a second average transmit power, different than the first average transmit power, for a plurality of outgoing symbols.
1. A signal transmission system for reducing transmission power for an encoded data stream, comprising:
a receiver configured to receive an incoming data stream having a first average transmit power for a plurality of incoming data bits;
a symbol scheme processor configured to assign a symbol scheme, implementing a non-uniform number of bits per symbol, to at least a portion of the incoming data bits according to probabilities of occurrence of the incoming data bits;
a memory communicatively coupled to the symbol scheme processor and the receiver for storing the incoming data stream; and
a transmitter configured to transmit an outgoing data stream comprising a plurality of outgoing symbols according to the assigned symbol scheme at a second average transmit power.
2. The system of claim 1 , wherein the memory includes at least one lookup table.
3. The system of claim 1 , wherein the probabilities of occurrence are determined for sequences of incoming data bits.
4. The system of claim 1 , wherein the assigned symbol scheme produces a non-integer entropy value for a number of bits assigned to one or more symbols.
5. The system of claim 1 , wherein, the symbol scheme processor determines, during the assigning process, if higher power symbols are to be less probable than lower power symbols.
6. The system of claim 1 , wherein:
the receiver receives the incoming data stream at a first bandwidth; and
the transmitter transmits the outgoing data stream at a second bandwidth greater than the first bandwidth.
7. The system of claim 1 , wherein the symbol scheme processor assigns a symbol scheme that is of a lesser state scheme relative to a symbol scheme having equal probability states.
8. The system of claim 1 , wherein the symbol scheme processor assigns a symbol scheme utilizing a 3-state scheme.
9. The system of claim 1 , wherein the symbol scheme processor assigns a symbol scheme which represents a one-dimensional constellation diagram.
10. The system of claim 1 , wherein the symbol scheme processor assigns an Amplitude Shift Keying (ASK) symbol scheme to the incoming data stream.
11. The system of claim 1 , wherein a ratio of the second average transmit power to the first average transmit power is 3:5 or lower.
12. The system of claim 1 , wherein a ratio of the second average transmit power to the first average transmit power is 1:2 or lower.
13. The system of claim 1 , wherein the receiver receives the incoming data stream encoded using an encoding scheme including at least one of quadrature amplitude modulation (QAM), quadrature phase shift keying (QPSK), amplitude shift keying (ASK), and binary amplitude shift keying (BASK).
14. The system of claim 1 , wherein the transmitter transmits a first portion of the plurality of outgoing symbols at lower power than a second portion of the plurality of outgoing symbols.
15. The system of claim 1 , wherein the incoming data stream includes an incoming symbol scheme implementing a uniform number of bits per symbol.
16. The system of claim 1 , wherein the symbol scheme implements a non-integer number of bits per symbol.
17. The system of claim 16 , wherein the non-integer number of bits per symbol is selected from the group consisting of 1.5 and 1.811.
18. The system of claim 1 , wherein the probabilities of occurrence are for individual incoming data bits.
19. A method of reducing transmission power for an encoded data stream comprising the steps of:
receiving an incoming data stream having a first average transmit power for a plurality of incoming data bits;
assigning a symbol scheme, implementing a non-uniform number of bits per symbol, to at least a portion of the incoming data bits according to probabilities of occurrence of the incoming data bits; and
transmitting an outgoing data stream comprising a plurality of outgoing symbols according to the assigned symbol scheme at a second average transmit power.
20. The method of claim 19 , further comprising, in the step of assigning, determining the probabilities of occurrence of sequences of the incoming data bits.
21. The method of claim 19 , further comprising, in the step of assigning, determining the probabilities of occurrence of individual incoming data bits.
22. The method of claim 19 , wherein in the step of assigning, higher power symbols are determined to be less probable than lower power symbols.
23. The method of claim 19 , wherein:
the step of receiving comprises receiving the incoming data stream at a first bandwidth; and
the step of transmitting comprises transmitting the outgoing data stream at a second bandwidth greater than the first bandwidth.
24. The method of claim 19 , wherein the assigned symbol scheme is a lesser state scheme relative to a symbol scheme having equal probability states.
25. The method of claim 24 , wherein the assigned symbol scheme is a 3-state scheme.