Device and method to reduce power amplifier power consumption

An apparatus of a wireless device, the apparatus comprising:

• memory;
• and
• processing circuitry, the processing circuitry configured to:
• map a plurality of data symbols to sub-carriers for a multiplexed transmission;
• generate a composite multiplexed signal from the plurality of data symbols;
• divide the plurality of data symbols into a first group of data symbols and a second group of data symbols based at least partly on the composite multiplexed signal;
• generate a first multiplexed signal from the first group of data symbols for amplification by a first power amplifier;
• and
• generate a second multiplexed signal from the second group of data symbols for amplification by a second power amplifier, wherein the first and second groups of data symbols provide a lower power ratio of the first multiplexed signal than the composite multiplexed signal, the processing circuitry further configured to:
• initialize the second group of data symbols to an empty group;
• initialize the first group of data symbols to include the plurality of data symbols;
• for a predetermined number of iterations:
• generate a first set of sub-carrier values, wherein values of the sub-carriers mapped to the plurality of data symbols of the second group are set to zero and values of the sub-carriers mapped to the plurality of data symbols of the first group are set to the corresponding data symbols;
• generate a first multiplexed signal based on the first set of sub-carrier values;
• clip the first multiplexed signal based on a predetermined threshold;
• determine a difference signal between the first multiplexed signal and the clipped first multiplexed signal;
• generate a second set of sub-carrier values based on a Fourier Transform (FT) of the difference signal;
• determine a particular data symbol for inclusion in the second group based at least partly on the second set of sub-carrier values;
• and
• include the determined data symbol in the second group and exclude the determined data symbol from the first group.

An apparatus of a wireless device, the apparatus comprising:

• memory;
• and
• processing circuitry, the processing circuitry configured to:
• map a plurality of data symbols to sub-carriers for a multiplexed transmission;
• generate a composite multiplexed signal from the plurality of data symbols;
• divide the plurality of data symbols into a first group of data symbols and a second group of data symbols based at least partly on the composite multiplexed signal;
• generate a first multiplexed signal from the first group of data symbols for amplification by a first power amplifier;
• and
• generate a second multiplexed signal from the second group of data symbols for amplification by a second power amplifier, wherein the first and second groups of data symbols provide a lower power ratio of the first multiplexed signal than the composite multiplexed signal, the processing circuitry further configured to:
• map the plurality of data symbols to the sub-carriers in accordance with a predetermined mapping;
• set values of the sub-carriers to which the data symbols of the second group are mapped to zero to generate the first multiplexed signal;
• and
• set values of the sub-carriers to which the data symbols of the first group are mapped to zero to generate the second multiplexed signal.

An apparatus of a wireless device, the apparatus comprising:

• memory;
• and
• processing circuitry, the processing circuitry configured to:
• map a plurality of data symbols to sub-carriers for a multiplexed transmission;
• generate a composite multiplexed signal from the plurality of data symbols;
• divide the plurality of data symbols into a first group of data symbols and a second group of data symbols based at least partly on the composite multiplexed signal;
• generate a first multiplexed signal from the first group of data symbols for amplification by a first power amplifier;
• and
• generate a second multiplexed signal from the second group of data symbols for amplification by a second power amplifier, wherein the first and second groups of data symbols provide a lower power ratio of the first multiplexed signal than the composite multiplexed signal, the processing circuitry further configured to:
• when a modulation size of the data symbols is greater than or equal to a modulation size threshold:
• divide the plurality of data symbols into the first and second groups of data symbols;
• generate the first multiplexed signal for the amplification by the first power amplifier;
• and
• generate the second multiplexed signal for the amplification by the second power amplifier, and
• when the modulation size of the data symbols is less than the modulation size threshold:
• generate the composite multiplexed signal for amplification by the second power amplifier.

A non-transitory computer-readable storage medium that stores instructions for execution by one or more processors to perform operations to generate signals for one or more power amplifiers, the operations to configure the one or more processors to:

• map a plurality of data symbols to sub-carriers for an orthogonal frequency division multiplexing (OFDM) transmission;
• generate a composite OFDM signal based on the plurality of data symbols;
• clip the composite OFDM signal in accordance with a predetermined threshold;
• determine a difference signal between the composite OFDM signal and the clipped composite OFDM signal;
• determine sub-carrier magnitudes of the difference signal based on a Fourier Transform (FT) of the difference signal;
• and
• based on the sub-carrier magnitudes of the difference signal, divide the plurality of data symbols into a first group of data symbols and a second group of data symbols for generation of a first OFDM signal for amplification by a first power amplifier and a second OFDM signal for amplification by a second power amplifier, wherein selection of the first and second groups of data symbols from the plurality of data symbols is made in accordance with a peak-to-average power ratio (PAPR) criterion in which a PAPR of the first OFDM signal is lower than a PAPR of the second OFDM signal and is lower than a PAPR of the composite OFDM signal.

A method of signal generation, the method comprising:

• mapping a plurality of data symbols to sub-carriers for an orthogonal frequency division multiplexing (OFDM) transmission;
• generating a composite OFDM signal from the plurality of data symbols;
• clipping the composite OFDM signal based on a predetermined threshold;
• determining a difference signal between the composite OFDM signal and the clipped composite OFDM signal;
• determining sub-carrier magnitudes of the difference signal based on a Fourier Transform (FT) of the difference signal;
• and
• dividing the data symbols into the first and second groups of data symbols based at least partly on the sub-carrier magnitudes of the difference signal;
• generating a first OFDM signal from the first group of data symbols for amplification by a first power amplifier;
• and
• generating a second OFDM signal from the second group of data symbols for amplification by a second power amplifier,
• wherein the data symbols of the first and second groups are selected to provide a lower power ratio of the first OFDM signal than the second OFDM signal and a lower power ratio of the first OFDM signal than a reference power ratio of a composite OFDM signal based on the first and second groups of data symbols.