# US 11,310,083 B2 · Method and system for selecting important delay taps of channel impulse response

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 11,310,083 B2
- Document ID: US11310083B2
- Status: Granted
- Kind: B2
- Application number: 17/163,581
- Filed: 2021-02-01
- Published: 2021-10-07
- Granted: 2022-04-19
- Earliest claimed: 2020-04-03
- Assignees: Wuhan University
- Applicants: Wuhan University
- Inventors: Yigang He; Yongbo Sui; Liulu He; Chaolong Zhang
- Web page: https://patentgrep.com/patent/US11310083B2

## CPC

- H04L 25/03019: {adaptive, i.e. capable of adjustment during data reception}
- H04L 25/0212: {of impulse response}
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)

## Abstract

A method and a system for selecting important delay taps of channel impulse response are provided, which belong to the field of adaptive transmission technology of wireless communication. The method performs local predictability estimation on all delay taps in the channel impulse response in wireless communication, thereby selecting the important delay taps in the channel impulse response. The disclosure uses recurrence rates of the delay taps to estimate local predictability of the delay taps. Noise delay taps are distinguished from the important delay taps through the local predictability of the delay taps, which improves the identification rate of the important delay taps of the channel impulse response in wireless communication. The disclosure may implement the selection of the important delay taps of the channel impulse response, which provides guarantee for implementing adaptive transmission and adaptive coding of wireless communication.

## Claims

### Claim 1

A method for selecting important delay taps of channel impulse response, comprising:
obtaining an amplitude of each delay tap sampling point according to a channel impulse response;
obtaining an optimal delay and an optimal embedding dimension of the amplitude of each delay tap sampling point according to the amplitude of each delay tap sampling point;
obtaining a reconstructed phase space of each delay tap sampling point based on the optimal delay and the optimal embedding dimension of the amplitude of each delay tap sampling point;
obtaining a selection threshold of each delay tap sampling point according to the reconstructed phase space of each delay tap sampling point;
obtaining a threshold recurrence plot of each delay tap sampling point based on the selection threshold of each delay tap sampling point;
obtaining a recurrence rate of each delay tap sampling point based on the threshold recurrence plot of each delay tap sampling point; and
selecting a plurality of delay taps with recurrence rate magnitudes at front as the important delay taps according to the recurrence rate of each delay tap sampling point.

### Claim 2 (depends on 1)

The method according to claim 1, wherein a selection threshold θi of an i-th delay tap sampling point is obtained from θi=λσi, where λ is a threshold coefficient, and σi is a standard deviation of an amplitude of the i-th delay tap sampling point.

### Claim 3 (depends on 2)

The method according to claim 2, wherein a threshold recurrence plot of the i-th delay tap sampling point is obtained from Pa,b=Ψ(θi−Da,b), where Ψ is a step function, Da,b is an Euclidean distance between an a-th point ξa and a b-th point ξb in a reconstructed phase space of the i-th delay tap sampling point, Da,b=|ξSa−ξb|, where a, b=1, 2, 3, . . . , Kp, Kp=K−(di−1)τi, where K is a total number of pilots, τi is an optimal delay of the amplitude of the i-th delay tap sampling point, and di is an optimal embedding dimension of the amplitude of the i-th delay tap sampling point.

### Claim 4 (depends on 3)

The method according to claim 3, wherein a recurrence rate DET of the i-th delay tap sampling point is calculated from
DET
=
∑
ℓ
=
ℓ
min
K
p
⁢
Σ
⁢
ℓ
⁢
⁢
Q
⁡
(
ℓ
)
∑
a
,
b
=
1
K
p
⁢
P
a
,
b
,
where Q() is a distribution probability with a length parallel to a diagonal in the threshold recurrence plot, min is a diagonal with a minimum length min in the threshold recurrence plot, and Kp is a length of a sequence in the reconstructed phase space.

### Claim 5 (depends on 1)

The method according to claim 1, wherein the step of selecting the plurality of delay taps with the recurrence rate magnitudes at front as the important delay taps according to the recurrence rate of each delay tap sampling point comprises:
sorting the recurrence rate of each delay tap sampling point from large to small, and selecting delay taps corresponding to LT largest recurrence rates, where LT is an actual number of paths in a wireless channel.

### Claim 6 (depends on 2)

The method according to claim 2, wherein the step of selecting the plurality of delay taps with the recurrence rate magnitudes at front as the important delay taps according to the recurrence rate of each delay tap sampling point comprises:
sorting the recurrence rate of each delay tap sampling point from large to small, and selecting delay taps corresponding to LT largest recurrence rates, where LT is an actual number of paths in a wireless channel.

### Claim 7 (depends on 3)

The method according to claim 3, wherein the step of selecting the plurality of delay taps with the recurrence rate magnitudes at front as the important delay taps according to the recurrence rate of each delay tap sampling point comprises:
sorting the recurrence rate of each delay tap sampling point from large to small, and selecting delay taps corresponding to LT largest recurrence rates, where LT is an actual number of paths in a wireless channel.

### Claim 8 (depends on 4)

The method according to claim 4, wherein the step of selecting the plurality of delay taps with the recurrence rate magnitudes at front as the important delay taps according to the recurrence rate of each delay tap sampling point comprises:
sorting the recurrence rate of each delay tap sampling point from large to small, and selecting delay taps corresponding to LT largest recurrence rates, where LT is an actual number of paths in a wireless channel.

### Claim 9

A system for selecting important delay taps of channel impulse response, comprising:
an amplitude calculation module, configured to obtain an amplitude of each delay tap sampling point according to a channel impulse response;
a delay and embedding dimension calculation module, configured to obtain an optimal delay and an optimal embedding dimension of the amplitude of each delay tap sampling point according to the amplitude of each delay tap sampling point;
a reconstructed phase space construction module, configured to obtain a reconstructed phase space of each delay tap sampling point based on the optimal delay and the optimal embedding dimension of the amplitude of each delay tap sampling point;
a selection threshold calculation module, configured to obtain a selection threshold of each delay tap sampling point according to the reconstructed phase space of each delay tap sampling point;
a recurrence plot construction module, configured to obtain a threshold recurrence plot of each delay tap sampling point based on the selection threshold of each delay tap sampling point;
a recurrence rate calculation module, configured to obtain a recurrence rate of each delay tap sampling point based on the threshold recurrence plot of each delay tap sampling point; and
a delay tap selection module, configured to select a plurality of delay taps with recurrence rate magnitudes at front as the important delay taps according to the recurrence rate of each delay tap sampling point.

### Claim 10 (depends on 9)

The system according to claim 9, a selection threshold θi of an i-th delay tap sampling point is obtained from θi=λσi, where λ is a threshold coefficient, and σi is a standard deviation of an amplitude of the i-th delay tap sampling point.

### Claim 11 (depends on 10)

The system according to claim 10, wherein a threshold recurrence plot of the i-th delay tap sampling point is obtained from Pa,b=Ψ(θi−Da,b) where Ψ is a step function, Da,b is an Euclidean distance between an a-th point ξa and a b-th point ξb in a reconstructed phase space of the i-th delay tap sampling point, Da,b=|ξa−ξb∥, where a, b=1, 2, 3, . . . , Kp, Kp=K−(di−1)τi, where K is a total number of pilots, τi is an optimal delay of the amplitude of the i-th delay tap sampling point, and di is an optimal embedding dimension of the amplitude of the i-th delay tap sampling point.

### Claim 12 (depends on 11)

The system according to claim 11, wherein a recurrence rate DET of the i-th delay tap sampling point is calculated from
DET
=
∑
ℓ
=
ℓ
min
K
p
⁢
Σ
⁢
⁢
⁢
Q
⁡
(
ℓ
)
∑
a
,
b
=
1
K
p
⁢
P
a
,
b
,
where Q() is a distribution probability with a length parallel to a diagonal in the threshold recurrence plot, min is a diagonal with a minimum length min in the threshold recurrence plot, and Kp is a length of a sequence in the reconstructed phase space.

### Claim 13 (depends on 9)

The system according to claim 9, wherein the delay tap selection module is configured to sort the recurrence rate of each delay tap sampling point from large to small, and select delay taps corresponding to LT largest recurrence rates, where LT is an actual number of paths in a wireless channel.

### Claim 14 (depends on 10)

The system according to claim 10, wherein the delay tap selection module is configured to sort the recurrence rate of each delay tap sampling point from large to small, and select delay taps corresponding to LT largest recurrence rates, where LT is an actual number of paths in a wireless channel.

### Claim 15 (depends on 11)

The system according to claim 11, wherein the delay tap selection module is configured to sort the recurrence rate of each delay tap sampling point from large to small, and select delay taps corresponding to LT largest recurrence rates, where LT is an actual number of paths in a wireless channel.

### Claim 16 (depends on 12)

The system according to claim 12, wherein the delay tap selection module is configured to sort the recurrence rate of each delay tap sampling point from large to small, and select delay taps corresponding to LT largest recurrence rates, where LT is an actual number of paths in a wireless channel.