# US 2013/0155831 A1 · Method and apparatus for detecting radio signal

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- Number: US 2013/0155831 A1
- Document ID: US20130155831A1
- Status: Published application
- Kind: A1
- Application number: 13/718,810
- Filed: 2012-12-18
- Published: 2013-06-20
- Earliest claimed: 2011-12-20
- Assignees: Postech Academy-Industry Foundation; LG Electronics Inc.
- Inventors: Ki Jun KIM; Joon Ho CHO; Byung Wook HAN
- Web page: https://patentgrep.com/patent/US20130155831A1

## CPC

- H04L 27/26362: {Subcarrier weighting equivalent to time domain filtering, e.g. weighting per subcarrier multiplication (arrangements for removing intersymbol interference at the transmitter end H04L25/03343)}
- H04L 5/0044: {Allocation of payload; Allocation of data channels, e.g. PDSCH or PUSCH}
- H04L 25/03828: {Arrangements for spectral shaping; Arrangements for providing signals with specified spectral properties (partial response systems H04L25/497)}
- H04W 72/04: Wireless resource allocation
- H04W 72/0453: Resources in frequency domain, e.g. a carrier in FDMA
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)

## Abstract

In an aspect, a method for transmitting data in a wireless communication system is provided. A wireless device determines a subcarrier and a subcarrier group to which a data sequence is allocated. The wireless device modulates the data sequence by a transmit filter to generate a data stream. A waveform of the transmit filter is determined based on the subcarrier and the subcarrier group. The wireless device generates a transmission signal based on the data stream. The wireless device transmits the transmission signal through the subcarrier. The transmission signal is cyclostationary.

## Claims

### Claim 1

A method for transmitting data in a wireless communication system, the method comprising:
determining, by a wireless device, a subcarrier and a subcarrier group to which a data sequence is allocated;
modulating, by the wireless device, the data sequence by a transmit filter to generate a data stream, a waveform of the transmit filter determined based on the subcarrier and the subcarrier group;
generating, by the wireless device, a transmission signal based on the data stream; and
transmitting, by the wireless device, the transmission signal through the subcarrier,
wherein the transmission signal is cyclostationary.

### Claim 2 (depends on 1)

The method of claim 1, wherein the data sequence is a sth data sequence allocated to a nth subcarrier group, and the waveform of the transmit filter sn,s(t) is determined by a following equation,
s
n
,
s

(
t
)
=
∑
l
=
1
L

g
~

(
t
)

(
α
n
,
s
,
l


j


2


π

(
f
l
+
n
-
1
2


NT
)

t
+
α
n
,
s
,
l
+
L


-
j


2


π

(
f
l
+
n
-
1
2


NT
)

t
)
where, L is a natural number determined based on a bandwidth of the wireless communication system and a cycle period of the transmission signal, αn,s,l is a complex-valued weighting factor determining a power and a phase of the subcarrier, N is a number of subcarrier groups, T is a cycle period, {tilde over (g)}(t) is a function of which Fourier transform function {tilde over (G)}(f) is defined by a following equation,
G
~

(
f
)

=
Δ


{
g
~

(
t
)
}
=
{
1
,
∀
f
∈
[
0
,
1
2


NT
)
0
,
elsewhere
.
,
and fl is a parameter defined by a following equation,
f
l

=
Δ

l
-
⌊
L
/
2
⌋
-
1
T
where, └ ┘ is a floor function.

### Claim 3 (depends on 2)

The method of claim 2, wherein a frequency characteristic of the transmit filter is symmetry to a center frequency.

### Claim 4 (depends on 1)

The method of claim 1, wherein the data sequence is a sth data sequence allocated to a nth subcarrier group, and the waveform of the transmit filter sn,s(t) is determined by a following equation,
s
n
,
s

(
t
)
=
∑
l
=
1
L

∑
k
=
1
2


NL

[

α
n
,
s
,
l
2


NL


j


2


π

(
2

(
l
-
1
)

N
+
n
)

k
/
(
2


NL
)
+
α
n
,
s
,
l
+
L
2


NL


j


2


π

(
2


lN
-
n
+
1
)

k
/
(
2


NL
)
]

p

(
t
-
kT
c
)
where, L is a natural number determined based on a bandwidth of the wireless communication system and a cycle period of the transmission signal, αn,s,l is a complex-valued weighting factor determining a power and a phase of the subcarrier, N is a number of subcarrier groups, T is a cycle period, p(t) is a sinc pulse of which duration TC is T/(2NL).

### Claim 5 (depends on 1)

The method of claim 1, wherein the subcarrier group is determined based on the subcarrier by a following rule.
1st subcarrier group={1,2N, 2N+1,4N,4N+1, . . . , 2N(L−1)+1,2NL}th subcarrier
2nd subcarrier group={2,2N−1,2N+2,4N−1,4N+2, . . . , 2N(L−1)+2,2NL−1}th subcarrier
nth subcarrier group={n,2N−(n−1),2N+n,4N−(n−1), . . . , 2N(L−1)+n,2NL−(n−1)}th subcarrier

### Claim 6

A wireless device in a wireless communication system, the wireless device comprising:
a radio frequency (RF) unit for receiving a radio signal; and
a processor, operatively coupled with the radio frequency unit, configured to:
determine a subcarrier and a subcarrier group to which a data sequence is allocated;
modulate the data sequence by a transmit filter to generate a data stream, a waveform of the transmit filter determined based on the subcarrier and the subcarrier group;
generate a transmission signal based on the data stream; and
transmit the transmission signal through the subcarrier,
wherein the transmission signal is cyclostationary.

### Claim 7 (depends on 6)

The wireless device of claim 6, wherein the data sequence is a sth data sequence allocated to a nth subcarrier group, and the waveform of the transmit filter sn,s(t) is determined by a following equation,
s
n
,
s

(
t
)
=
∑
l
=
1
L

g
~

(
t
)

(
α
n
,
s
,
l


j


2


π

(
f
l
+
n
-
1
2


NT
)

t
+
α
n
,
s
,
l
+
L


-
j


2


π

(
f
l
+
n
-
1
2


NT
)

t
)
where, L is a natural number determined based on a bandwidth of the wireless communication system and a cycle period of the transmission signal, αn,s,l is a complex-valued weighting factor determining a power and a phase of the subcarrier, N is a number of subcarrier groups, T is a cycle period, {tilde over (g)}(t) is a function of which Fourier transform function {tilde over (G)}(f) is defined by a following equation,
G
~

(
f
)

=
Δ


{
g
~

(
t
)
}
=
{
1
,
∀
f
∈
[
0
,
1
2


NT
)
0
,
elsewhere
.
,
and fl is a parameter defined by a following equation,
f
l

=
Δ

l
-
⌊
L
/
2
⌋
-
1
T
where, └ ┘ is a floor function.

### Claim 8 (depends on 7)

The wireless device of claim 7, wherein a frequency characteristic of the transmit filter is symmetry to a center frequency.

### Claim 9 (depends on 6)

The wireless device of claim 6, wherein the data sequence is a sth data sequence allocated to a nth subcarrier group, and the waveform of the transmit filter sn,s(t) is determined by a following equation,
s
n
,
s

(
t
)
=
∑
l
=
1
L

∑
k
=
1
2


NL

[

α
n
,
s
,
l
2


NL


j


2


π

(
2

(
l
-
1
)

N
+
n
)

k
/
(
2


NL
)
+
α
n
,
s
,
l
+
L
2


NL


j


2


π

(
2


lN
-
n
+
1
)

k
/
(
2


NL
)
]

p

(
t
-
kT
c
)
where, L is a natural number determined based on a bandwidth of the wireless communication system and a cycle period of the transmission signal, αn,s,l is a complex-valued weighting factor determining a power and a phase of the subcarrier, N is a number of subcarrier groups, T is a cycle period, p(t) is a sinc pulse of which duration TC is T/(2NL).

### Claim 10 (depends on 9)

The wireless device of claim 9, wherein the subcarrier group is determined based on the subcarrier by a following rule.
1st subcarrier group={1,2N, 2N+1,4N,4N+1, . . . , 2N(L−1)+1,2NL}th subcarrier
2nd subcarrier group={2,2N−1,2N+2,4N−1,4N+2, . . . , 2N(L−1)+2,2NL−1}th subcarrier
nth subcarrier group={n,2N−(n−1),2N+n,4N−(n−1), . . . , 2N(L−1)+n,2NL−(n−1)}th subcarrier