Ambiguity/aliasing cancellation or reduction for staggered reference signals

Patent metadata

Field	Value
Publication number	US-12267197-B2
Application number	US-202217731493-A
Country	US
Kind code	B2
Filing date	Apr 28, 2022
Priority date	Nov 7, 2019
Publication date	Apr 1, 2025
Grant date	Apr 1, 2025

Abstract

An apparatus for a wireless communication system is to transmit a reference signal on a common set of resource elements, REs, the common set of REs used by one or more further apparatuses in the wireless communication system to transmit the reference signal so that the reference signals of the apparatus and of the one or more further apparatuses use the same REs. The reference signal is transmit using OFDM symbols and the same sequence having a zero auto correlation property is applied to each OFDM symbol. A phase correction is applied to an OFDM symbol before transmission, wherein a correction factor of the phase correction depends on a comb factor and a comb offset of the OFDM symbol and is independent of the resource element.

First claim

The invention claimed is:

1. An apparatus for a wireless communication system, the apparatus comprising:
one or more antennas or an antenna array having a plurality of antenna elements, and
a transceiver,
wherein, the apparatus is to transmit a reference signal on a common set of resource elements, REs, the common set of REs used by one or more further apparatuses in the wireless communication system to transmit the reference signal so that the reference signals of the apparatus and of the one or more further apparatuses use the same REs,
wherein the apparatus is to
transmit the reference signal using a plurality of OFDM symbols, each OFDM symbol comprising a comb structure, and some or all of the OFDM symbols comprising different comb offsets, and
apply a same sequence to each OFDM symbol, the sequence comprising a zero auto correlation property, the apparatus and the one or more further apparatuses using for a common RE the same sequence, and

wherein the apparatus is to apply a phase correction to an OFDM symbol before transmission, wherein the phase correction is applied in a time domain or in a frequency domain by multiplying the OFDM symbol with a correction factor e jφ c , and wherein, for reducing phase discontinuities during SRS de-staggering, the correction factor e jφ c depends on a comb factor and the comb offset of the OFDM symbol and is independent of the resource element.

2. The apparatus of claim 1 , wherein
the sequence is a cyclic shifted base sequence,
the apparatus is to apply the same cyclic shifted basis sequence to each OFDM symbol, the cyclic-shifted base sequence comprising a zero auto correlation property, wherein the correction factor e jφ c depends on the comb factor, the comb offset of the OFDM symbol and the cyclic shift of the base sequence and is independent of the resource element.

3. The apparatus of claim 1 , wherein
the sequence is a sequence with no cyclic shift, or the apparatus does not take into account the cyclic shift for a calculation of the correction factor,
the apparatus is to apply the same sequence to each OFDM symbol, the base sequence comprising a zero auto correlation property,
wherein the correction factor e jφ c depends on the comb offset and comb factor of the OFDM symbol only.

4. The apparatus of claim 1 , wherein the REs for the sequence are allocated using
a full staggering resource pattern so that a number of OFDM symbol equals to a transmission comb value K TC , or
a partial staggering resource pattern so that a number of OFDM symbol is less than the transmission comb value K TC .

5. The apparatus of claim 1 , wherein, the apparatus is configured from a network node with at least one of the following higher layer parameters:
K TC comb factor or transmission comb value,
Δk comb offset or relative comb offset value,
n SRS cs,max maximum number of cyclic shifts, and
n SRS cs cyclic shift index.

6. The apparatus of claim 5 , wherein the parameter n SRS cs,max is pre-defined at the apparatus or defined in the 3GPP specifications and known at the apparatus, and hence not configured from the network node and depends on the comb factor, as follows:
n SRS cs,max =8 for K TC =2, or
n SRS cs,max =12 for K TC =4, or
n SRS cs,max =6 for K TC =8.

7. The apparatus of claim 1 , wherein the cyclic shift value for antenna port p i is defined by

α
i

=

2
⁢
π
⁢

n
SRS

cs
,
i

n
SRS

cs
,
max

,
with

n
SRS

cs
,
i

=

(

n
SRS
cs

+

n
SRS

cs
,
max

(

p
i

-
1000

)

N
AP

)

⁢

mod
⁢

n
SRS

cs
,
max

.

8. The apparatus of claim 1 , wherein the apparatus is to be configured via a higher layer with the number of antenna ports N AP .

9. The apparatus of claim 8 , wherein the apparatus is to assume the number of antenna ports N AP to be equal to one if a higher layer parameter for the antenna port number is not provided.

10. The apparatus of claim 1 , wherein the apparatus is configured with the cyclic shifts n SRS cs,i of the sequence, wherein n SRS cs,i is derived from a configuration parameter n SRS cs and wherein the range of n SRS cs,i and the resulting α i may be extended by either allowing a higher range for n SRS cs,i or by multiplying n SRS cs with a factor, like K TC , as follows:

n
SRS

cs
,
i

=

(

n
SRS
cs

+

n
SRS

cs
,
max

(

Assignees

• Fraunhofer Ges Forschung

Inventors

• Alawieh Mohammad
• Eberlein Ernst
• Grossmann Marcus
• Ghimire Birendra

Classifications

• H04W72/0453

  Resources in frequency domain, e.g. a carrier in FDMA · CPC title

• H04L27/2602

  Signal structure · CPC title

• G01S5/06

  Position of source determined by co-ordinating a plurality of position lines defined by path-difference measurements (G01S5/12 takes precedence) · CPC title

• G01S5/0215

  Interference · CPC title

• H04L27/2621 Primary

  Reduction thereof using phase offsets between subcarriers · CPC title