Low peak-to-average power ratio precoded reference signal design for multiple-input, multiple-output transmissions

An apparatus for wireless communication, comprising:

• means for identifying a plurality of time domain reference signal symbol sets for transmission via a plurality of antennas in a symbol period, wherein each of the plurality of time domain reference signal symbol sets is associated with an antenna port;
• means for performing respective time to frequency domain transforms on the plurality of time domain reference signal symbol sets over respective time to frequency domain transform sizes to obtain a plurality of frequency domain signals, wherein, for the respective time to frequency domain transforms, respective time domain reference signal symbol sets are mapped to respective subsets of time domain inputs of the respective time to frequency domain transforms;
• means for mapping the plurality of frequency domain signals to respective subsets of a set of subcarriers:
• means for performing respective frequency to time domain transforms on the plurality of mapped frequency domain signals to obtain a plurality of time domain waveforms;
• and
• means for transmitting the plurality of time domain waveforms to a receiver via the plurality of antennas in the symbol period.

An apparatus for wireless communication, comprising:

• a processor;
• memory in electronic communication with the processor;
• and
• instructions stored in the memory and operable, when executed by the processor, to cause the apparatus to:
• identify a plurality of time domain reference signal symbol sets for transmission via a plurality of antennas in a symbol period, wherein each of the plurality of time domain reference signal symbol sets is associated with an antenna port;
• perform respective time to frequency domain transforms on the plurality of time domain reference signal symbol sets over respective time to frequency domain transform sizes to obtain a plurality of frequency domain signals, wherein, for the respective time to frequency domain transforms, respective time domain reference signal symbol sets are mapped to respective subsets of time domain inputs of the respective time to frequency domain transforms;
• map the plurality of frequency domain signals to respective subsets of a set of subcarriers;
• perform respective frequency to time domain transforms on the plurality of mapped frequency domain signals to obtain a plurality of time domain waveforms;
• and
• transmit the plurality of time domain waveforms to a receiver via the plurality of antennas in the symbol period.

A non-transitory computer readable medium storing code for wireless communication, the code comprising instructions executable by a processor to:

• identify a plurality of time domain reference signal symbol sets for transmission via a plurality of antennas in a symbol period, wherein each of the plurality of time domain reference signal symbol sets is associated with an antenna port;
• perform respective time to frequency domain transforms on the plurality of time domain reference signal symbol sets over respective time to frequency domain transform sizes to obtain a plurality of frequency domain signals, wherein, for the respective time to frequency domain transforms, respective time domain reference signal symbol sets are mapped to respective subsets of time domain inputs of the respective time to frequency domain transforms;
• map the plurality of frequency domain signals to respective subsets of a set of subcarriers;
• perform respective frequency to time domain transforms on the plurality of mapped frequency domain signals to obtain a plurality of time domain waveforms;
• and
• transmit the plurality of time domain waveforms to a receiver via the plurality of antennas in the symbol period.