Reduction of peak to average power ratio

Patent metadata

Field	Value
Publication number	US-10944605-B2
Application number	US-201916706838-A
Country	US
Kind code	B2
Filing date	Dec 9, 2019
Priority date	Dec 9, 2018
Publication date	Mar 9, 2021
Grant date	Mar 9, 2021

Abstract

A method for Peak to Average Power Ratio (PAPR) reduction at an input of analog to digital converter (ADC) of the receiver, the method includes mapping, by a mapper, an input symbol to an output symbol that maintains a peak power constraint at the input of the ADC; wherein the mapping is responsive to previously transmitted symbols; transmitting the output symbol by the transmitter; receiving, by the receiver, a received symbol that represents the output symbol; and de-mapping the received symbol, by a de-mapper of the receiver, to a de-mapped symbol that represents the input symbol.

First claim

We claim:

1. A method for Peak to Average Power Ratio (PAPR) reduction at an input of analog to digital converter (ADC) of a receiver, the method comprising:
mapping, by a mapper, an input symbol to an output symbol that maintains a peak power constraint at the input of the ADC; wherein the mapping is responsive to previously transmitted symbols;
transmitting the output symbol by a transmitter;
receiving, by the receiver, a received symbol that represents the output symbol; wherein the receiving may include analog to digital conversion by the ADC; and
de-mapping the received symbol, by a de-mapper of the receiver, to a de-mapped symbol that represents the input symbol.

2. The method according to claim 1 wherein the mapping comprises imposing a Markovian symbol distribution at an output of the transmitter.

3. The method according to claim 1 wherein the mapping comprises:
determining whether a transmission of an output symbol that equals the input symbol will cause to a deviation from the peak power constraint at the input of the ADC; and
when determining that the deviation from the peak constraint then selecting as the output symbol a selected candidate symbol out of a set of candidates symbols that when transmitted the peak power constraint at the ADC input is satisfied.

4. The method according to claim 3 comprising selecting the selected output symbol of the set, the selected output symbol of the set has a lowest Hamming distance from the input symbol, out of the set of candidates symbols.

5. The method according to claim 3 comprising calculating the set of candidates symbols.

6. The method according to claim 1 wherein the mapping is set regardless of a maximization of entropy.

7. The method according to claim 1 wherein the mapping is responsive to a channel impulse response and to a maximal power allowed by the input of the ADC.

8. The method according to claim 1 wherein the de-mapping comprises applying a reduced complexity BJCR process on the received symbol, wherein the branches probabilities of each state in a trellis are calculated on the fly.

9. The method according to claim 3 , wherein the selecting comprises using a channel-state dependent mapping table comprising, for each current channel state, quantized values of probabilities of a next channel state to become sk, given that the current state is sk−1.

10. A method for Peak to Average Power Ratio (PAPR) reduction at an input of analog to digital converter (ADC) of a receiver, the method comprising:
mapping, by a mapper, an input symbol to an output symbol that maintains a peak power constraint at the input of the ADC; wherein the mapping is responsive to previously transmitted symbols;
wherein the mapping comprises selecting as the output symbol a selected candidate symbol out of a set of candidates symbols that when transmitted the peak power constraint at the ADC input is satisfied, when determining whether a transmission of an output symbol that equals the input symbol will cause to a deviation from the peak power constraint at the input of the ADC.

11. A system, comprising:
a transmitter that comprises (a) a mapper that is configured to map an input symbol to an output symbol that maintains a peak power constraint at an input of an analog to digital converter (ADC) of a receiver; wherein the mapper is configured to map in response to previously transmitted symbols; and (b) a transmission circuit that is configured to transmit the output symbol; and
a receiver that comprises (a) an interface that is configured to receive a received symbol that represents the output symbol; and (b) a de-mapper that is configured to de-map the received symbol, to a de-mapped symbol that represents the input symbol.

12. At least one non-transitory computer readable medium that stores instructions for Peak to Average Power Ratio (PAPR) reduction at an input of an analog to digital converter (ADC) of a receiver of a system, wherein the instructions, once executed by the system, cause the system to:
perform a mapping, by a mapper of a transmitter of the system, an input symbol to an output symbol that maintains a peak power constraint at the input of the ADC; wherein the mapping is responsive to previously transmitted symbols;
transmit the output symbol by the transmitter;
receive, by the receiver, a received symbol that represents the output symbol; and
de-map the received symbol, by a de-mapper of the receiver, to a de-mapped symbol that represents the input symbol.

13. The at least one non-transitory computer readable medium according to claim 12 wherein the mapping comprises imposing a Markovian symbol distribution at an output of the transmitter.

14. The at least one non-transitory computer readable medium according to claim 12 wherein the mapping comprises:
determining whether a transmission of an output symbol that equals the input symbol will cause to a deviation from the peak power constraint at the input of the ADC; and
when determining that the deviation from the peak constraint then selecting as the output symbol a selected candidate symbol out of a set of candidates symbols that when transmitted the peak power constraint at the ADC input is satisfied.

15. The at least one non-transitory computer readable medium according to claim 14 that stores instructions for selecting the selected output symbol of the set, the selected output symbol of the set has a lowest Hamming distance from the input symbol, out of the set of candidates symbols.

16. The at least one non-transitory computer readable medium according to claim 14 that stores instructions for calculating the set of candidates symbols.

17. The at least one non-transitory computer readable medium according to claim 12 wherein the mapping is set regardless of a maximization of entropy.

18. The at least one non-transitory computer readable medium according to claim 12 wherein the mapping is responsive to a channel impulse response and to a maximal power allowed by the input of the ADC.

19. The at least one non-transitory computer readable medium according to claim 12 wherein the de-map comprises applying a reduced complexity BJCR process on the received symbol, wherein the branches probabilities of each state in a trellis are calculated on the fly.

20. The at least one non-transitory computer readable medium according to claim 14 wherein the selecting comprises using a channel-state dependent mapping table comprising, for each current channel state, quantized values of probabilities of a next channel state to become sk, given that a current state is sk−1.

Assignees

• Univ Ramot
• Ramot At Tel Aviv Univ

Inventors

• Raphaeli Dani
• Levi Or

Classifications

• H04L25/03343

  Arrangements at the transmitter end · CPC title

• H04L27/3411

  reducing the peak to average power ratio or the mean power of the constellation; Arrangements for increasing the shape gain of a signal set · CPC title

• H04L27/3809

  Amplitude regulation arrangements · CPC title

• H04L27/366

  Arrangements for compensating undesirable properties of the transmission path between the modulator and the demodulator · CPC title

• H04L27/2615 Primary

  Reduction thereof using coding · CPC title