Generation and reception of signals comprising cyclically shifted orthogonal basis functions

Patent metadata

Field	Value
Publication number	US-2023128676-A1
Application number	US-202218067469-A
Country	US
Kind code	A1
Filing date	Dec 16, 2022
Priority date	Jun 19, 2020
Publication date	Apr 27, 2023
Grant date	—

Abstract

Various embodiments of this disclosure relate to generation and reception of signals comprising cyclically shifted basis functions. A device may obtain a set of modulation symbols and modulate a plurality of basis functions based on the set of modulation symbols to generate a signal. The plurality of basis functions may comprise cyclically shifted versions of a basis function and a periodic autocorrelation function of the basis function may comprise an ideal (e.g., perfect) periodic autocorrelation function.

First claim

What is claimed is:

1 . A device for generating a signal, comprising:
at least one processor; and one or more memories including computer instructions that, when executed by the at least one processor, cause the device to perform operations comprising: obtaining a set of modulation symbols; and modulating a plurality of basis functions, based on the set of modulation symbols, to generate the signal, wherein: the plurality of basis functions comprise cyclically shifted versions of a basis function, and a periodic autocorrelation function of the basis function comprises a perfect periodic autocorrelation function.

2 . The device according to claim 1 , wherein the basis function comprises a Björck sequence, a Frank sequence, a generalized chirp-like sequence (GCL), a Zadoff-Chu sequence, a constant amplitude zero-autocorrelation (CAZAC) sequence, a modulatable CAZAC sequence, or a binary-to-biphase transformation of a maximum length sequence.

3 . The device according to claim 1 , wherein the plurality of basis functions excludes chirps generated by orthogonal chirp division multiplexing.

4 . The device according to claim 1 , wherein the plurality of basis functions excludes chirps generated by chirp convolved data transmission.

5 . The device according to claim 1 , wherein the basis function comprises a chirp signal configured with a phase being variable based on a bivariate quadratic polynomial p(m, n)=αm 2 +αn 2 −2αnm+βn−βm+γ of a modulation symbol index m and a basis function time index n=0, 1, . . . , N−1, where α, β and γ are real-valued coefficients, wherein:
a zeroth degree coefficient γ is independent of the maximum number of the plurality of basis functions, and
N is an integer, where N is larger than or equal to a number of the set of modulation symbols.

6 . The device according to claim 1 , wherein the operations further comprise summing the plurality of modulated basis functions.

7 . The device according to claim 1 , wherein the operations further comprise:
generating the signal s[n] in a time domain based on a circular convolution

s
~

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n
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=

∑

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=
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x
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TX

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-

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⁡
(

mod
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,

where x[m] comprises the set of modulation symbols, g TX [n−m(mod N)] is an mth cyclically shifted basis function, and wherein the basis function g TX [n], =0, 1, . . . , N−1, satisfies

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2

·

δ
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,

where δ[k] is a Kronecker delta function δ[k]=1 for k=0 and δ[k]=0 for k≠0, m is a modulation symbol index, t is an integer, (⋅)* is a complex conjugate operator, (mod N) is a modulo-N operator, and |⋅| denotes absolute value.

8 . The device according to claim 1 , wherein the operations further comprise:
generating the signal s[n] in a time domain based on a convolution

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n
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=

∑

m
=
0

N
-
1

x
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m
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TX

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m

Assignees

• Huawei Tech Co Ltd

Inventors

• Berggren Fredrik
• Popovic Branislav M

Classifications

• H04L27/2634

  Inverse fast Fourier transform [IFFT] or inverse discrete Fourier transform [IDFT] modulators in combination with other circuits for modulation · CPC title

• H04L27/103 Primary

  Chirp modulation (for spread spectrum techniques H04B1/69) · CPC title

• H04L27/2639

  Modulators using other transforms, e.g. discrete cosine transforms, Orthogonal Time Frequency and Space [OTFS] or hermetic transforms · CPC title

• H04L27/2613 Primary

  Structure of the reference signals · CPC title