Peak to average power ratio reduction in multichannel digital front-ends (DFES)

1. A method comprising:

reducing peak-to-average-power ratio (PAPR) during multichannel transmission in a transmitter, the reducing comprising:

generating based on an input that is to be transmitted, a plurality of frequency-domain symbols, with each one of said plurality of frequency-domain symbols corresponding to a particular one of a plurality of subcarriers associated with said multichannel transmission;

assigning said plurality of subcarriers to a plurality of channels used for said multichannel transmission, wherein a number of said plurality of channels is less than a number of said plurality of subcarriers;

generating a plurality of time-domain signals corresponding to said plurality of channels; and

applying an adjustment to at least one of said plurality of time-domain signals, wherein said adjustment is based on boundaries between at least two of said frequency-domain symbols;

generating adjusted and unadjusted waveforms for two or more of said plurality of time-domain signals, wherein generating said adjusted waveforms comprises application of said adjustment to said two or more of said plurality of time-domain signals; and

selecting between the generated adjusted waveforms based on particular criteria.

2. The method of claim 1 , wherein said adjustment comprises sign inversion.

3. The method of claim 1 , wherein said multichannel transmission is based on orthogonal frequency division multiplexing (OFDM), and said plurality of frequency-domain symbols comprise OFDM symbols.

4. The method of claim 1 , wherein said particular criteria comprises lowest peak, when said adjustment comprises sign inversion.

5. The method of claim 1 , comprising communicating information relating to said PAPR reduction to enable handling, at receive-side, of an output corresponding to said plurality of time-domain signals.

6. The method of claim 5 , wherein said information comprise sign descrambling related information, when said adjustment comprises sign inversion.

7. The method of claim 5 , comprising providing said information by configuring one or more spare carriers associated with said plurality of channels.

8. A system comprising:

a transmitter configured for reducing peak-to-average-power ratio (PAPR) during multichannel transmission, said transmitter comprising:

an input processing circuit that is operable to generate, based on an input that is to be transmitted, a plurality of frequency-domain symbols, wherein each one of said plurality of frequency-domain symbols corresponds to a particular one of a plurality of subcarriers associated with said multichannel transmission; and

a multichannel processing circuit that is operable to:

assign said plurality of subcarriers to a plurality of channels used for said multichannel transmission, wherein a number of said plurality of channels is less than number of said plurality of subcarriers; and

generate a plurality of time-domain signals corresponding to said plurality of channels; and

a peak-to-average-power ratio (PAPR) reduction circuit that is operable to:

apply an adjustment to at least one of said plurality of time-domain signals, wherein said adjustment is based on boundaries between at least two of said frequency-domain symbols;

generate adjusted and unadjusted waveforms for two or more of said plurality of time-domain signals, wherein generating said adjusted waveforms comprises application of said adjustment to said two or more of said plurality of time-domain signals; and

select between the generated adjusted waveforms based on particular criteria.

9. The system of claim 8 , wherein said adjustment comprises sign inversion.

10. The system of claim 8 , wherein said multichannel transmission is based on orthogonal frequency division multiplexing (OFDM), and said plurality of frequency-domain symbols comprise OFDM symbols.

11. The system of claim 8 , wherein said particular criteria comprises lowest peak, when said adjustment comprises sign inversion.

12. The system of claim 8 , wherein said transmitter is operable to communicate information relating to said PAPR reduction to enable handling, at receive-side, of an output corresponding to said plurality of time-domain signals.

13. The system of claim 12 , wherein said information comprise sign descrambling related information, when said adjustment comprises sign inversion.

14. The system of claim 12 , wherein said peak-to-average-power ratio (PAPR) reduction circuit is operable configure one or more spare carriers associated with said plurality of channels to provide said information relating to said PAPR reduction.

15. A system comprising:

a peak-to-average-power ratio (PAPR) reduction circuit operable to reduce peak-to-average-power ratio (PAPR) during multichannel transmission, said PAPR reduction circuit comprising:

a plurality of channel processing circuits, wherein:

each of the plurality of channel processing circuits is operable to process a corresponding one of a plurality time-domain signals;

each one of said plurality time-domain signals corresponds to a particular one of a plurality of channels associated with said multichannel transmission;

said plurality time-domain signals is generated based on assigning of a plurality of frequency-domain symbols to said plurality of channels; and

a number of said plurality of channels is less than a number of said plurality of frequency-domain symbols;

one or more signal adjustment circuits, wherein each one or more signal adjustment circuits is operable to apply an adjustment to an output of a corresponding one of said plurality of channel processing circuits, said adjustment being based on boundaries between at least two of said frequency-domain symbols; and

a selection circuit operable to select, when more than one of the signal adjustment circuits are used, between outputs of said one or more signal adjustment circuits, based on particular selection criteria.

16. The system of claim 15 , wherein said multichannel transmission is based on orthogonal frequency division multiplexing (OFDM), and said plurality of frequency-domain symbols comprise OFDM symbols.

17. The system of claim 15 , wherein said adjustment comprises sign inversion.

18. The system of claim 15 , wherein said particular criteria comprises lowest peak, when said adjustment comprises sign inversion.