阅读说明：本技术 用于非正交多址无线通信的参考信号传输技术 (Reference signal transmission techniques for non-orthogonal multiple access wireless communications ) 是由 雷静 R·王 S·朴 N·布衫 J·K·森达拉拉扬 J·B·索里亚加 T·姬 于 2019-02-01 设计创作，主要内容包括：描述了用于无线通信的方法、系统和设备,该方法、系统和设备提供使用公用资源的来自多个非正交多址(NOMA)发射机的并发参考信号传输,诸如解调参考信号(DMRS)传输。不同发射机可以将不同的序列用于参考信号传输,这可允许接收机(诸如无线基站)解码每一个NOMA发射机的参考信号传输并且为每一个NOMA发射机执行信道估计。参考信号传输可以是具有有界定时偏移的异步的或者是准同步的,并且参考信号序列选择可以提供相对可靠的信道估计和相干解调。(Methods, systems, and devices are described for wireless communication that provide concurrent reference signal transmissions, such as demodulation reference signal (DMRS) transmissions, from multiple non-orthogonal multiple access (NOMA) transmitters using common resources. Different transmitters may use different sequences for reference signal transmission, which may allow a receiver (such as a wireless base station) to decode the reference signal transmission of each NOMA transmitter and perform channel estimation for each NOMA transmitter. Reference signal transmission may be asynchronous or quasi-synchronous with bounded timing offsets, and reference signal sequence selection may provide relatively reliable channel estimation and coherent demodulation.)

1. A method for wireless communication, comprising:

receiving, from a base station, an indication of a set of resources for transmission of a reference signal, wherein a plurality of non-orthogonal multiple access (NOMA) transmitters are configured for at least partially concurrent transmission using the set of resources;

identifying a plurality of short sequences to be included in the reference signal based at least in part on the set of resources, each of the plurality of short sequences having a root index and a cyclic shift that provide a cross-correlation with another of the plurality of short sequences that is below a threshold;

concatenating the plurality of short sequences to generate a reference signal sequence for the reference signal; and

transmitting the reference signal to the base station.

2. The method of claim 1, wherein the set of resources includes frequency resources and time resources, and wherein a first short sequence of the plurality of short sequences is applied to a first subset of frequency resources located within a first subset of time resources and a second short sequence of the plurality of short sequences is applied to a second subset of frequency resources located within a second subset of time resources.

3. The method of claim 1, wherein identifying the plurality of short sequences comprises:

determining a root index and a cyclic shift of each short sequence in a plurality of frequency domain resources; and

mapping each of the plurality of short sequences to each of a corresponding plurality of time domain resources.

4. The method of claim 1, wherein the plurality of short sequences each comprise a portion of a linear block code that can be successfully decoded if one or more portions of the linear block code are received in error.

5. The method of claim 4, wherein the linear block code is an error correction code.

6. The method of claim 1, in which the threshold is based at least in part on one or more of: a cell radius of the base station, a multipath delay spread associated with the base station, or any combination thereof.

7. The method of claim 1, wherein the reference signal sequence allows asynchronous reference signal transmission from multiple transmitters.

8. The method of claim 1, wherein identifying the plurality of short sequences comprises:

identifying a codebook containing a set of short sequences based at least in part on the set of resources; and

selecting a subset of the set of short sequences as the plurality of short sequences based at least in part on a User Equipment (UE) identification.

9. The method of claim 1, wherein each of the plurality of short sequences is a Constant Amplitude Zero Autocorrelation (CAZAC) sequence, a pseudo-random noise (PN) sequence, a Kasami sequence, or a Golay sequence.

10. An apparatus for wireless communication, comprising:

means for receiving, from a base station, an indication of a set of resources for transmission of a reference signal, wherein at least one non-orthogonal multiple access (NOMA) transmitter associated with the apparatus is configured for at least partially concurrent transmission using the set of resources;

means for identifying a plurality of short sequences to be included in the reference signal based at least in part on the set of resources, each of the plurality of short sequences having a root index and a cyclic shift that provide a cross-correlation with another of the plurality of short sequences that is below a threshold;

means for concatenating the plurality of short sequences to generate a reference signal sequence for the reference signal; and

means for transmitting the reference signal to the base station.

11. The apparatus of claim 10, wherein the set of resources includes frequency resources and time resources, and wherein a first short sequence of the plurality of short sequences is applied to a first subset of frequency resources located within a first subset of time resources and a second short sequence of the plurality of short sequences is applied to a second subset of frequency resources located within a second subset of time resources.

12. The apparatus of claim 10, wherein the means for identifying the plurality of short sequences determines a root index and a cyclic shift for each short sequence within a plurality of frequency domain resources, and maps each of the plurality of short sequences to each of a corresponding plurality of time domain resources.

13. The apparatus of claim 10, wherein the plurality of short sequences each comprise a portion of a linear block code that can be successfully decoded if one or more portions of the linear block code are received in error.

14. The apparatus of claim 10, wherein the means for identifying the plurality of short sequences identifies a codebook containing a set of short sequences based at least in part on the set of resources, and selects a subset of the set of short sequences as the plurality of short sequences based at least in part on a User Equipment (UE) identification.

15. The apparatus of claim 10, wherein each of the plurality of short sequences is a Constant Amplitude Zero Autocorrelation (CAZAC) sequence, a pseudo-random noise (PN) sequence, a Kasami sequence, or a Golay sequence.

16. An apparatus for wireless communication, comprising:

a processor;

a memory in electronic communication with the processor; and

instructions stored in the memory and executable by the processor to cause the apparatus to:

receive, from a base station, an indication of a set of resources for transmission of a reference signal, wherein at least one non-orthogonal multiple access (NOMA) transmitter associated with the apparatus is configured for at least partially concurrent transmission using the set of resources;

identifying a plurality of short sequences to be included in the reference signal based at least in part on the set of resources, each of the plurality of short sequences having a root index and a cyclic shift that provide a cross-correlation with another of the plurality of short sequences that is below a threshold;

concatenating the plurality of short sequences to generate a reference signal sequence for the reference signal; and

transmitting the reference signal to the base station.

17. The apparatus of claim 16, wherein the set of resources comprises frequency resources and time resources, and wherein a first short sequence of the plurality of short sequences is applied to a first subset of frequency resources located within a first subset of time resources and a second short sequence of the plurality of short sequences is applied to a second subset of frequency resources located within a second subset of time resources.

18. The apparatus of claim 16, wherein the instructions to cause the apparatus to identify the plurality of short sequences comprise instructions to cause the apparatus to:

determining a root index and a cyclic shift of each short sequence in a plurality of frequency domain resources; and

mapping each of the plurality of short sequences to each of a corresponding plurality of time domain resources.

19. The apparatus of claim 16, wherein the plurality of short sequences each comprise a portion of a linear block code that can be successfully decoded if one or more portions of the linear block code are received in error.

20. The apparatus of claim 19, wherein the linear block code is an error correction code.

21. The apparatus of claim 16, in which the threshold is based at least in part on one or more of: a cell radius of the base station, a multipath delay spread associated with the base station, or any combination thereof.

22. The apparatus of claim 16, wherein the reference signal sequence allows asynchronous reference signal transmission from multiple transmitters.

23. The apparatus of claim 16, wherein the instructions to cause the apparatus to identify the plurality of short sequences comprise instructions to cause the apparatus to:

identifying a codebook containing a set of short sequences based at least in part on the set of resources; and

selecting a subset of the set of short sequences as the plurality of short sequences based at least in part on a User Equipment (UE) identification.

24. The apparatus of claim 16, wherein each of the plurality of short sequences is a Constant Amplitude Zero Autocorrelation (CAZAC) sequence, a pseudo-random noise (PN) sequence, a Kasami sequence, or a Golay sequence.

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

receiving, from a base station, an indication of a set of resources for transmission of a reference signal, wherein at least one non-orthogonal multiple access (NOMA) transmitter operatively coupled to the processor is configured for at least partially concurrent transmission using the set of resources;

identifying a plurality of short sequences to be included in the reference signal based at least in part on the set of resources, each of the plurality of short sequences having a root index and a cyclic shift that provide a cross-correlation with another of the plurality of short sequences that is below a threshold;

concatenating the plurality of short sequences to generate a reference signal sequence for the reference signal; and

transmitting the reference signal to the base station.

26. The non-transitory computer-readable medium of claim 25, wherein the set of resources includes frequency resources and time resources, and wherein a first short sequence of the plurality of short sequences is applied to a first subset of frequency resources located within a first subset of time resources and a second short sequence of the plurality of short sequences is applied to a second subset of frequency resources located within a second subset of time resources.

27. The non-transitory computer-readable medium of claim 25, wherein code comprising instructions to identify the plurality of short sequences further comprises instructions to: the method includes determining a root index and a cyclic shift for each short sequence within a plurality of frequency domain resources and mapping each of the plurality of short sequences to each of a corresponding plurality of time domain resources.

28. The non-transitory computer-readable medium of claim 25, wherein the plurality of short sequences each comprise a portion of a linear block code that can be successfully decoded if one or more portions of the linear block code are received in error.

29. The non-transitory computer-readable medium of claim 25, wherein code comprising instructions to identify the plurality of short sequences further comprises instructions to: identifying a codebook containing a set of short sequences based at least in part on the set of resources, and selecting a subset of the set of short sequences as the plurality of short sequences based at least in part on a User Equipment (UE) identification.

30. The non-transitory computer-readable medium of claim 25, wherein each of the plurality of short sequences is a Constant Amplitude Zero Autocorrelation (CAZAC) sequence, a pseudo-random noise (PN) sequence, a Kasami sequence, or a Golay sequence.