# US 2010/0166131 A1 · Method and apparatus for detecting clock frequency deviation

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

- Number: US 2010/0166131 A1
- Document ID: US20100166131A1
- Status: Published application
- Kind: A1
- Application number: 12/646,671
- Filed: 2009-12-23
- Published: 2010-07-01
- Earliest claimed: 2008-12-26
- Assignees: Huawei Technologies Co., Ltd.
- Inventors: Bo Li; Shiqing Hu; Peng Chen
- Web page: https://patentgrep.com/patent/US20100166131A1

## CPC

- G01R 23/02: Arrangements for measuring frequency, e.g. pulse repetition rate; Arrangements for measuring period of current or voltage
- G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12)

## Abstract

The embodiment of the present disclosure discloses a method and apparatus for detecting frequency deviation of a clock. The method includes: counting the clock to be detected to acquire current counting information; filtering the current counting information to acquire filtered data; and acquiring the frequency deviation of the clock to be detected from the filtered data. According to the embodiments of the present disclosure, the detection accuracy of frequency deviation is improved by filtering the counting information acquired by counting the clock to be detected, and appropriately increasing an amount of information after the filtering, so as to perceive the occurrence of any abnormal dithering, and avoid neglecting of any abnormal condition in periodic or aperiodic queries.

## Claims

### Claim 1

A method for detecting frequency deviation of a clock, comprising:
counting the clock to be detected to acquire current counting information;
filtering the current counting information to acquire filtered data; and
acquiring the frequency deviation of the clock to be detected from the filtered data.

### Claim 2 (depends on 1)

The method according to claim 1, wherein filtering the current counting information comprises acquiring the filtered data based on the current counting information and data acquired after the previous filtering.

### Claim 3 (depends on 1)

The method according to claim 1, wherein filtering the current counting information comprises:
performing a first-order filtering to N based on an equation Pn=a·Pn-1+N,
wherein n is a number of accumulations, N is nth counting information acquired by counting the clock to be detected by a standard frequency clock, Pn−1 is data acquired after n−1th filtering, Pn is data acquired after nth filtering, α is a detection parameter, and 0≦α<1; and
wherein acquiring the frequency deviation of the clock to be detected from the filtered data comprises:
calculating the frequency deviation of the clock to be detected according to the following equation:
Δ


f
=
(
P
n
-
M
1
-
a
)
/
(
M
1
-
a
)
=
(
1
-
a
)

P
n
M
-
1
,
wherein M is counting information acquired by counting the standard frequency clock, and Δf is the frequency deviation of the clock to be detected.

### Claim 4 (depends on 2)

The method according to claim 2, wherein filtering the current counting information comprises:
performing a first-order filtering to N based on an equation Pn=a·Pn-1+N,
wherein n is a number of accumulations, N is nth counting information acquired by counting the clock to be detected by a standard frequency clock, Pn−1 is data acquired after n−1th filtering, Pn is data acquired after nth filtering, α is a detection parameter, and 0≦α<1; and
wherein acquiring the frequency deviation of the clock to be detected from the filtered data comprises:
calculating the frequency deviation of the clock to be detected according to the following equation:
Δ


f
=
(
P
n
-
M
1
-
a
)
/
(
M
1
-
a
)
=
(
1
-
a
)

P
n
M
-
1
,
wherein M is counting information acquired by counting the standard frequency clock, and Δf is the frequency deviation of the clock to be detected.

### Claim 5 (depends on 3)

The method according to claim 3, further comprising:
acquiring next counting information; and
filtering the next counting information according to the process of the filtering.

### Claim 6 (depends on 4)

The method according to claim 4, further comprising:
acquiring next counting information; and
filtering the next counting information according to the process of the filtering.

### Claim 7 (depends on 1)

The method according to claim 1, wherein counting the clock to be detected to acquire the current counting information comprises:
counting the clock to be detected by a HF clock having a standard frequency to acquire the current counting information; or
counting the clock to be detected by a LF clock having a standard frequency and a HF clock to acquire two pieces of current counting information.

### Claim 8 (depends on 1)

The method according to claim 1, wherein filtering the current counting information comprises:
performing a first-order filtering to N based on an equation Pn=a·Pn-1+N, the filtered data calculated as
P
n
=
N
1
-
a
,
wherein n is a number of accumulations, N is nth counting information acquired by counting the clock to be detected by a standard frequency clock, Pn-1 is data acquired after (n−1)th filtering, Pn is data acquired after nth filtering, α is a detection parameter, and 0≦α<1.

### Claim 9 (depends on 2)

The method according to claim 2, wherein filtering the current counting information comprises:
performing a first-order filtering to N based on an equation Pn=a·Pn-1+N, the filtered data calculated as
P
n
=
N
1
-
a
,
wherein n is a number of accumulations, N is nth counting information acquired by counting the clock to be detected by a standard frequency clock, Pn-1 is data acquired after (n−1)th filtering, Pn is data acquired after nth filtering, α is a detection parameter, and 0≦α<1.

### Claim 10

An apparatus for detecting frequency deviation of a clock, comprising:
a counting unit, adapted to count the clock to be detected to acquire current counting information;
a filtering unit, adapted to filter the current counting information acquired by the counting unit to acquire filtered data; and
an acquiring unit, adapted to acquire the frequency deviation of the clock to be detected from the data filtered by the filtering unit.

### Claim 11 (depends on 10)

The apparatus according to claim 10, wherein the filtering unit is further adapted to acquire the filtered data based on the current counting information and data acquired after the previous filtering.

### Claim 12 (depends on 10)

The apparatus according to claim 10, wherein
the filtering unit is further adapted to perform a first-order filtering to N based on an equation Pn=a·Pn-1+N,
wherein n is a number of accumulations, N is nth counting information acquired by counting the clock to be detected by a standard frequency clock, Pn−1 is data acquired after n−1th filtering, Pn is data acquired after nth filtering, α is a detection parameter, and 0≦α<1;
the acquiring unit is further adapted to calculate the frequency deviation of the clock to be detected according to the following equation:
Δ


f
=
(
P
n
-
M
1
-
a
)
/
(
M
1
-
a
)
=
(
1
-
a
)

P
n
M
-
1
,
wherein M is counting information acquired by counting the standard frequency clock, and Δf is the frequency deviation of the clock to be detected.

### Claim 13 (depends on 11)

The apparatus according to claim 11, wherein
the filtering unit is further adapted to perform a first-order filtering to N based on an equation Pn=a·Pn-1+N,
wherein n is a number of accumulations, N is nth counting information acquired by counting the clock to be detected by a standard frequency clock, Pn−1 is data acquired after n−1th filtering, Pn is data acquired after nth filtering, α is a detection parameter, and 0≦α<1;
the acquiring unit is further adapted to calculate the frequency deviation of the clock to be detected according to the following equation:
Δ


f
=
(
P
n
-
M
1
-
a
)
/
(
M
1
-
a
)
=
(
1
-
a
)

P
n
M
-
1
,
wherein M is counting information acquired by counting the standard frequency clock, and Δf is the frequency deviation of the clock to be detected.

### Claim 14 (depends on 10)

The apparatus according to claim 10, wherein the counting unit is further adapted to count the clock to be detected by an HF clock having a standard frequency to acquire the current counting information, or count the clock to be detected by an LF clock having a standard frequency and an HF clock to acquire two pieces of current counting information.

### Claim 15 (depends on 12)

The apparatus according to claim 12, wherein the filtering unit is a filter.

### Claim 16 (depends on 13)

The apparatus according to claim 13, wherein the filtering unit is a filter.

### Claim 17 (depends on 15)

The apparatus according to claim 15, wherein the filter comprises an accumulator and a multiplier.

### Claim 18 (depends on 16)

The apparatus according to claim 16, wherein the filter comprises an accumulator and a multiplier.

### Claim 19 (depends on 11)

The apparatus according to claim 11, wherein the filtering unit is further adapted to perform a first-order filtering to N based on an equation Pn=a·Pn-1+N, the filtered data calculated as
P
n
=
N
1
-
a
,
wherein n is a number of accumulations, N is nth counting information acquired by counting the clock to be detected by a standard frequency clock, Pn-1 is data acquired after (n−1)th filtering, Pn is data acquired after nth filtering, α is a detection parameter, and 0≦α<1.