US 2010/0246723 A1 · METHOD FOR ESTIMATING AMOUNT OF DISTORTION IN CFO AND DCO, METHOD FOR COMPENSATING RECEIVED SIGNALS USING THE SAME, AND RECEIVER

Abstract

A received signal delivered through a transmission line can be compensated for CFO and DCO to improve the SNR of the received signal, eventually resulting in an effective improvement in the error rate. In this context, methods for estimating and compensating for CFO and DCO have been studied, for example, using pilot signals or a blind method. However, the methods would require a huge amount of calculations for the estimation of CFO in the presence of DCO, as with the ML method, or never essentially eliminate errors from an estimated value. The received signal has convoluted influences through the transmission line, so that observation of the continual symbols of periodic pilot signals on the frequency axis shows just a phase shift by the CFO. Therefore, the CFO can be analytically found from the continual symbols of periodic pilot signals, thereby allowing the DCO to be estimated and both the CFO and the DCO to be compensated for.

Claims4

Dependent claims

A method for estimating an amount of distortion, comprising the steps of:

receiving a transmitted signal to acquire a received signal;
demodulating the received signal;
converting the demodulated signal into a digital signal;
acquiring (K+L) pieces of data from a portion corresponding to a pilot signal of the digital signal, where K is the number of samples included in one pilot signal symbol of the received signal, and L is DK with D being a predetermined integer value;
and
determining an estimated value of CFO based on Equation (100), where the vector r1 represents L pieces of data starting from the beginning of the acquired data, and the vector r2 represents L pieces of data starting from the (K+1)th data from the beginning of the acquired data,
[
Equation


100
]
Δ


f
=
f
s
2

π


K

arg

{
R
p
}
(
100
)
where Rp is derived from Equation (13), and fs is the sampling frequency,
[
Equation


101
]
R
p
=
1
L

r
1
H

r
2
-
1
L
2

r
1
H

11
T

r
2
.
(
13
)
where the vector 1 is an (L×1) vector with all the elements being one.

70 more elements

A method for estimating an amount of distortion, comprising the steps of:

receiving a transmitted signal to acquire a received signal;
demodulating the received signal;
converting the demodulated signal into a digital signal;
acquiring (K+L) pieces of data from a portion corresponding to a pilot signal of the digital signal, where K is the number of samples included in one pilot signal symbol of the received signal, and L is DK with D being a predetermined integer value;
and
determining an estimated value of DCO based on Equation (14), where the vector r1 represents L pieces of data starting from the beginning of the acquired data, and the vector r2 represents L pieces of data starting from the (K+1)th data from the beginning of the acquired data,
[
Equation


102
]
d
^
=
r
1
H

r
1

1
T

r
2
-
r
1
H

r
2

1
T

r
1
(
Lr
1
H
-
r
1
H

11
T
)

(
r
1
-
r
2
)
.
(
14
)
wherein the vector 1 is an (L×1) vector with all the elements being one.

62 more elements

Dependencies are inferred from the claim text.

Method for estimating amount of distortion in cfo and dco, method for compensating received signals using the same, and receiver

Life of this patent

Method for estimating amount of distortion in cfo and dco, method for compensating received signals using the same, and receiver

Life of this patent

Abstract

Claims4