US 8,897,121 B2Granted

Frequency offset compensation and equalization method and device in an orthogonal frequency division multiplexing system

AssigneeZte Corporation

InventorShaoning Xiao

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Abstract

A method is disclosed for frequency offset compensation and equalization in an orthogonal frequency division multiplexing system. The method comprises: acquiring a channel estimation value h and a frequency offset value f at a reference symbol; acquiring a Toeplitz matrix M(f) based on the frequency offset value f; performing phase compensation on the channel estimation value h to obtain a channel estimation value h′ at a data symbol; and acquiring an estimation value of a transmitted symbol x based on M(f) and h′. A device is also disclosed for frequency offset compensation and equalization in the orthogonal frequency division multiplexing system. The device comprises a channel estimation unit, a frequency offset acquisition unit, a channel compensation unit and an equalization estimation unit.

Claims13

Dependent claims

A method for frequency offset compensation and equalization in an orthogonal frequency division multiplexing system comprising:

acquiring a channel estimation value h and a frequency offset value f at a reference symbol;
acquiring a Toeplitz matrix M(f) based on the frequency offset value f;
performing phase compensation on the channel estimation value h to obtain a channel estimation value h′ at a data symbol;
and
acquiring an estimation value of a transmitted symbol x based on M(f) and h′;
wherein M(f)=(ak,l),
a
k
,
l
=
{
{
sin
⁡
(
π
⁢
⁢
γ
)
N
⁢
⁢
sin
⁡
(
π
⁢
⁢
γ
N
)
}
⁢
exp
⁡
(
j
⁢
⁢
π
⁢
⁢
γ
⁢
N
-
1
N
)
,
when
⁢
⁢
k
=
l
{
sin
⁡
(
π
⁢
⁢
γ
)
N
⁢
⁢
sin
⁡
(
π
⁡
(
l
-
k
+
γ
)
N
)
}
⁢
exp
⁡
(
-
j
⁢
⁢
π
⁢
l
-
k
N
)
⁢
exp
⁡
(
j
⁢
⁢
π
⁢
⁢
γ
⁢
N
-
1
N
)
,
when
⁢
⁢
k
≠
l
or
when |k−l|>C, ak,l=0, C is a predetermined constant, and when |k−l|≦C,
a
k
,
l
=
{
{
sin
⁡
(
π
⁢
⁢
γ
)
N
⁢
⁢
sin
⁡
(
π
⁢
⁢
γ
N
)
}
⁢
exp
⁡
(
j
⁢
⁢
π
⁢
⁢
γ
⁢
N
-
1
N
)
,
when
⁢
⁢
k
=
l
{
sin
⁡
(
π
⁢
⁢
γ
)
N
⁢
⁢
sin
⁡
(
π
⁡
(
l
-
k
+
γ
)
N
)
}
⁢
exp
⁡
(
-
j
⁢
⁢
π
⁢
l
-
k
N
)
⁢
exp
⁡
(
j
⁢
⁢
π
⁢
⁢
γ
⁢
N
-
1
N
)
,
when
⁢
⁢
k
≠
l
k and l are sub-carrier identifiers, a value range of which is 0 to m−1, m is the number of sub-carriers used by frequency offset estimation,
γ
=
f
F
,
F is an interval between the sub-carriers, N is the number of Fast Fourier Transform (FFT) points of one Orthogonal Frequency Division Multiplexing (OFDM) symbol.

248 more elements

A device for frequency offset compensation and equalization in an orthogonal frequency division multiplexing system comprising:

a channel estimation unit configured to acquire a channel estimation value h and a frequency offset value f at a reference symbol;
a frequency offset acquisition unit configured to acquire a Toeplitz matrix M(f) based on the frequency offset value f;
a channel compensation unit configured to perform phase compensation on the channel estimation value h to obtain a channel estimation value h′ at a data symbol;
and
an equalization estimation unit configured to acquire an estimation value of a transmitted symbol x based on M(f) and h′
wherein
M
⁡
(
f
)
=
(
a
k
,
l
)
,
⁢
a
k
,
l
=
{
{
sin
⁡
(
π
⁢
⁢
γ
)
N
⁢
⁢
sin
⁡
(
π
⁢
⁢
γ
N
)
}
⁢
exp
⁡
(
j
⁢
⁢
π
⁢
⁢
γ
⁢
N
-
1
N
)
,
when
⁢
⁢
k
=
l
{
sin
⁡
(
π
⁢
⁢
γ
)
N
⁢
⁢
sin
⁡
(
π
⁡
(
l
-
k
+
γ
)
N
)
}
⁢
exp
⁡
(
-
j
⁢
⁢
π
⁢
l
-
k
N
)
⁢
exp
⁡
(
j
⁢
⁢
π
⁢
⁢
γ
⁢
N
-
1
N
)
,
when
⁢
⁢
k
≠
l
or
when |k−l|>C, ak,l=0, C is a predetermined constant, and when |k−l|≦C,
a
k
,
l
=
{
{
sin
⁡
(
π
⁢
⁢
γ
)
N
⁢
⁢
sin
⁡
(
π
⁢
⁢
γ
N
)
}
⁢
exp
⁡
(
j
⁢
⁢
π
⁢
⁢
γ
⁢
N
-
1
N
)
,
when
⁢
⁢
k
=
l
{
sin
⁡
(
π
⁢
⁢
γ
)
N
⁢
⁢
sin
⁡
(
π
⁡
(
l
-
k
+
γ
)
N
)
}
⁢
exp
⁡
(
-
j
⁢
⁢
π
⁢
l
-
k
N
)
⁢
exp
⁡
(
j
⁢
⁢
π
⁢
⁢
γ
⁢
N
-
1
N
)
,
when
⁢
⁢
k
≠
l
k and l are sub-carrier identifiers, a value range of which is 0 to m−1, m is the number of sub-carriers used by frequency offset estimation,
γ
=
f
F
,
F is an interval between the sub-carriers N is the number of Fast Fourier Transform (FFT) points of one Orthogonal Frequency Division Multiplexing (OFDM) symbol.

262 more elements

Dependencies are inferred from the claim text.

Facts

Application: 13/576,814Filed 27 Jan 2011
Priority: CN 2010 1 018362924 May 2010
Published: US 2012/0300610 A129 Nov 2012
Granted: 25 Nov 2014
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

H04L 27/2657
Synchronisation arrangements: carrier synchronisation
H04L 25/022
Channel estimation: of frequency response
H04L 25/023
With direct estimation from sounding signals: with extension to other symbols
H04L 27/2695
Link with other circuits, i.e. special connections between synchronisation arrangements and other circuits for achieving synchronisation: with…