System and method for generating reference signal with low peak average power ratio

Patent metadata

Field	Value
Publication number	US-12218871-B2
Application number	US-202318324239-A
Country	US
Kind code	B2
Filing date	May 26, 2023
Priority date	Oct 6, 2020
Publication date	Feb 4, 2025
Grant date	Feb 4, 2025

Abstract

A reference signaling scheme is provided that is based on the use of a Zadoff Chu sequence with cyclic repetition, optionally code division multiplexing precoding, together with frequency domain spectral shaping (FDSS). A specific pulse shape design for the FDSS part of the reference signal scheme in some embodiments involves the use of a raised cosine pulse raised to the power of β. The new solution for generating reference signals has a Low peak average power ratio that matches the PAPR of SC-OQAM, good channel estimation performance, and the ability to implement CDM in the frequency domain to increase multiplexing gain.

First claim

The invention claimed is:

1. A method comprising:
receiving, by an apparatus from a network device, a first signaling indicating a length K sequence;
transmitting, by the apparatus to the network device a reference signal;
wherein the reference signal is obtained from the length K sequence, and the length K sequence is obtained by a cyclicly repeated length p ZC sequence,

where
p is a prime number,
p is larger than K/3,
a largest prime number that is smaller than K is greater than p, and
p is smaller than the largest prime number that is smaller than K.

2. The method of claim 1 , wherein the reference signal is obtained from the length K sequence by:
applying, by the apparatus, pre-coding to the length K sequence to produce a pre-coded sequence;
generating, by the apparatus, a first pulse shaped frequency domain sequence by applying a first frequency domain spectral shaping to the pre-coded sequence.

3. The method of claim 2 , wherein the first frequency domain spectral shaping is a preconfigured FDSS pulse shape or an FDSS pulse shape indicated in a second signalling from the network device.

4. The method of claim 2 , wherein the first pulse shaped frequency domain sequence is generated by applying a raised cosine pulse raised to a power of β≥0.5, or β=0.8.

5. The method of claim 2 wherein applying pre-coding to the length K sequence to produce a pre-coded sequence comprises:
multiplying the length K sequence by an orthogonal cover code.

6. The method of claim 5 wherein the reference signal is obtained from the length K sequence by:
producing a mapped sequence by mapping the first pulse shaped frequency domain sequence to a first subset of a set of subcarriers.

7. The method of claim 6 wherein the orthogonal cover code is one of a set of orthogonal cover codes associated with the first subset of the set of subcarriers.

8. The method of claim 1 further comprising:
performing data signal generation comprising applying second frequency domain spectral shaping to produce a second pulse shaped frequency domain sequence.

9. The method of claim 8 wherein:
applying first frequency domain spectral shaping comprises applying a first pulse shape;
applying second frequency domain spectral shaping also comprises applying the first pulse shape or a second pulse shape that is different from the first pulse shape.

10. The method of claim 1 , wherein
K/3<p<L<K,

where L is the largest prime number that is smaller than K.

11. The method of claim 1 , wherein p is a smallest prime number larger than K/3.

12. A method comprising:
transmitting, by a network device to an apparatus, a first signaling indicating a length K sequence;
receiving, by the network device from the apparatus a reference signal;
wherein the reference signal is obtained from the length K sequence, and the length K sequence is obtained by a cyclicly repeated length p ZC sequence,

where
p is a prime number,
p is larger than K/3,
a largest prime number that is smaller than K is greater than p, and
p is smaller than the largest prime number that is smaller than K.

13. The method of claim 12 , wherein the reference signal is based on a first frequency domain spectral shaping performed by the apparatus using a first frequency domain spectral shaping pulse shape unknown to the network device, the method further comprising:
performing channel estimation to produce a channel estimate that includes the effect of the first frequency domain pulse shape.

14. The method of claim 12 , further comprising:
transmitting signalling to indicate a first frequency domain spectral shaping pulse shape to be used by the apparatus to generate the reference signal;
wherein the reference signal is based on a first frequency domain spectral shaping performed by the apparatus using the first frequency domain pulse shape known to the network device.

15. An apparatus comprising:
a processor and memory, the apparatus configured to:
receive, by the apparatus from a network device, a first signaling indicating a length K sequence;
transmit, by the apparatus to the network device a reference signal;
wherein the reference signal is obtained from the length K sequence, and the length K sequence is obtained by a cyclicly repeated length p ZC sequence,

where
p is a prime number,
p is larger than K/3,
a largest prime number that is smaller than K is greater than p, and
p is smaller than the largest prime number that is smaller than K.

16. The apparatus of claim 15 , wherein the apparatus is configured to obtain the reference signal from the length K sequence by:
applying, by the apparatus, pre-coding to the length K sequence to produce a pre-coded sequence;
generating, by the apparatus, a first pulse shaped frequency domain sequence by applying a first frequency domain spectral shaping to the pre-coded sequence.

17. The apparatus of claim 16 , wherein the first frequency domain spectral shaping is a preconfigured FDSS pulse shape or an FDSS pulse shape indicated in a second signalling from the network device.

18. The apparatus of claim 16 , wherein the apparatus is configured to apply pre-coding to the length K sequence to produce a pre-coded sequence by:
multiplying the length K sequence by an orthogonal cover code.

19. The apparatus of claim 15 further configured to:
perform data signal generation comprising applying second frequency domain spectral shaping to produce a second pulse shaped frequency domain sequence.

20. The apparatus of claim 19 configured to apply the first frequency domain spectral shaping by applying a first pulse shape and to apply the second frequency domain spectral shaping by applying the first pulse shape or a second pulse shape different from the first pulse shape.

21. A network device comprising:
a processor and memory, the network device configured to:
transmit, by a network device to an apparatus, a first signaling indicating a length K sequence;
receive, by the network device from the apparatus a reference signal;
wherein the reference signal is obtained from the length K sequence, and the length K sequence is obtained by a cyclicly repeated length p ZC sequence,

where
p is a prime number,
p is larger than K/3,
a largest prime number that is smaller than K is greater than p, and
p is smaller than the largest prime number that is smaller than K.

22. The network device of claim 21 , wherein the reference signal is based on a first frequency domain spectral shaping performed by the apparatus using a first frequency domain spectral shaping pulse shape unknown to the network device, the network device further configured to:
perform channel estimation to produce a channel estimate that includes the effect of the first frequency domain pulse shape.

Assignees

• Ferdinand Nuwan Suresh
• Jia Ming
• Ma Jianglei
• Abdoli Javad
• Huawei Tech Co Ltd

Inventors

• Ferdinand Nuwan Suresh
• Jia Ming
• Ma Jianglei
• Abdoli Javad

Classifications

• H04L25/0202 Primary

  Channel estimation · CPC title

• H04L27/10

  Frequency-modulated carrier systems, i.e. using frequency-shift keying (H04L27/32 takes precedence) · CPC title

• H04L25/0224

  using sounding signals · CPC title

• H04L27/26536

  Filtering over the entire frequency band, e.g. filtered orthogonal frequency division multiplexing [OFDM] · CPC title

• H04L27/2615

  Reduction thereof using coding · CPC title