US2022030635A1PendingUtilityA1
Enhanced PRACH Preamble Format
Est. expiryMar 25, 2034(~7.7 yrs left)· nominal 20-yr term from priority
H04W 74/004H04L 5/0048H04L 5/0007H04W 74/0833H04W 72/0453H04W 72/02H04W 72/0446H04W 74/006
65
PatentIndex Score
0
Cited by
0
References
0
Claims
Abstract
The present invention relates to a user terminal, UE, in a wireless communication system (1). The user terminal (4a, 4b) comprises a receiver unit (5a, 5b), a transmitter unit (6a, 6b) configured to transmit data in transmit sub-frames occurring at defined sub-frame intervals, and a control unit (7a, 7b) configured to control the receiver circuit (5a, 5b) and the transmitter circuit (6a, 6b). The control unit (7a, 7b) is also configured to create a PRACH, Physical Random-Access Channel, preamble (27) as an uplink transmission to a node (2) that is arranged to receive communication from the user terminal in said sub-frames. This communication comprises OFDM, Orthogonal Frequency-Division Multiplexing, based symbols (20). The control unit (7a, 7b) is configured to create each PRACH preamble (27) such that is comprises a sequence of a plurality of identical random access sequences (s(n)), where each random access sequence (s(n)) has the same length in time as each one of the OFDM based symbols (20a, 20b, 20c). The present invention also relates to a corresponding method.
Claims
exact text as granted — not AI-modified1 .- 15 . (canceled)
16 . A user terminal (UE) configured to operate in a wireless communication system, the user terminal comprising:
a transmitter circuit configured to transmit data in sub-frames, wherein each sub-frame comprises a plurality of Orthogonal Frequency-Division Multiplexing (OFDM) symbols; a control circuit operably coupled to the transmitter circuit and configured to:
create a Physical Random-Access CHannel (PRACH) preamble from a plurality of repetitions of a random access sequence, wherein the random access sequence has the same length in time as one of the OFDM symbols; and
cause the transmitter circuit to transmit the PRACH preamble during one sub-frame.
17 . The user terminal of claim 16 , wherein the PRACH preamble further comprises a cyclic prefix that precedes the plurality of repetitions of the random access sequence.
18 . The user terminal of claim 16 , wherein the PRACH preamble further comprises a part of the random access sequence that follows the plurality of repetitions of the random access sequence.
19 . The user terminal of claim 18 , wherein a length in time of the part and at least a subset of the repetitions preceding the part, is the same as a length in time of a sequential plurality of Fast Fourier Transform (FFT) windows used for receiving a plurality of the OFDM symbols by a base station in the wireless communication system.
20 . The user terminal of claim 16 , wherein:
the random access sequence is based on a Zadoff-Chu sequence, the u th root Zadoff-Chu sequence is defined as
x
u
(
n
)
=
e
-
j
π
un
(
n
+
1
)
N
ZC
,
0
≤
n
≤
N
ZC
-
1
,
N ZC is a length of the Zadoff-Chu sequence and is a prime number;
a time-continuous representation, s short (t), of the random access sequence is defined by
s
short
(
t
)
=
β
PRACH
∑
k
=
0
N
ZC
-
1
∑
n
=
0
N
ZC
-
1
x
u
(
n
)
·
e
-
j
2
π
nk
N
ZC
·
e
j
2
π
(
k
+
k
0
)
Δ
f
t
;
0≤t<T short , β PRACH is an amplitude-scaling factor in order to conform to the transmit power of PRACH, k 0 =n PRB RA N sc RB −N RB UL N sc RB /2, and Δf is the sub-carrier spacing; and
a location of the PRACH preamble in the frequency domain is based on n PRB RA ; N sc RB is a resource block size in the frequency domain; and N RB UL is an uplink bandwidth configuration expressed in multiples of N sc RB .
21 . A method for a user terminal (UE) configured to operate in a wireless communication system, the method comprising:
creating a Physical Random-Access Channel (PRACH)preamble from a plurality of repetitions of a random access sequence, wherein the random access sequence has the same length in time as one Orthogonal Frequency-Division Multiplexing (OFDM) symbol used by the UE to transmit data during sub-frames, wherein each sub-frame comprises a plurality of the OFDM symbols; and transmitting the PRACH preamble during one sub-frame.
22 . The method of claim 21 , wherein the PRACH preamble further comprises a cyclic prefix that precedes the plurality of repetitions of the random access sequence.
23 . The method of claim 21 , wherein the PRACH preamble further comprises a part of the random access sequence that follows the plurality of repetitions of the random access sequence.
24 . The user terminal of claim 23 , wherein a length in time of the part and at least a subset of the repetitions preceding the part, is the same as a length in time of a sequential plurality of Fast Fourier Transform (FFT) windows used for receiving a plurality of the OFDM symbols by a base station in the wireless communication system.
25 . The method of claim 21 , wherein:
the random access sequence is based on a Zadoff-Chu sequence, the u th root Zadoff-Chu sequence is defined as
x
u
(
n
)
=
e
-
j
π
un
(
n
+
1
)
N
ZC
,
0
≤
n
≤
N
ZC
-
1
,
N ZC is a length of the Zadoff-Chu sequence and is a prime number;
a time-continuous representation, s short (t), of the random access sequence is defined by
s
short
(
t
)
=
β
PRACH
∑
k
=
0
N
ZC
-
1
∑
n
=
0
N
ZC
-
1
x
u
(
n
)
·
e
-
j
2
π
nk
N
ZC
·
e
j
2
π
(
k
+
k
0
)
Δ
f
t
;
0≤t<T short , β PRACH is an amplitude-scaling factor in order to conform to the transmit power of PRACH, k 0 =n PRB RA N sc RB −N RB UL N sc RB /2, and Δf is the sub-carrier spacing; and
a location of the PRACH preamble in the frequency domain is based on n PRB RA ; N sc RB is a resource block size in the frequency domain; and N RB UL is an uplink bandwidth configuration expressed in multiples of N sc RB .
26 . A base station configured to operate in a wireless communication system, the base station comprising:
a receiver circuit configured to receive samples of uplink transmissions from user terminals (UEs); and a control circuit operably coupled to the receiver circuit and configured to:
cause the receiver circuit to receive uplink samples comprising a sub-frame; and
process the uplink samples with a plurality of repetitions of an FFT window, to selectively extract either of the following:
uplink data from a plurality of Orthogonal Frequency-Division Multiplexing (OFDM) symbols comprising the subframe, wherein each OFDM symbol has the same length in time as the FFT window; or
a Physical Random-Access Channel (PRACH) preamble transmitted by a user terminal (UE), wherein the PRACH preamble comprises a plurality of repetitions of a random access sequence, wherein the random access sequence has the same length in time as one of the OFDM symbols.
27 . The base station of claim 26 , wherein the PRACH preamble further comprises a cyclic prefix that precedes the plurality of repetitions of the random access sequence.
28 . The base station of claim 26 , wherein the PRACH preamble further comprises a part of the random access sequence that follows the plurality of repetitions of the random access sequence.
29 . The base station of claim 28 , wherein a length in time of the part and at least a subset of the repetitions preceding the part, is the same as a length in time of a sequential plurality of Fast Fourier Transform (FFT) windows used for receiving a plurality of the OFDM symbols by a base station in the wireless communication system.
30 . The base station of claim 26 , wherein:
the random access sequence is based on a Zadoff-Chu sequence, the u th root Zadoff-Chu sequence is defined as
x
u
(
n
)
=
e
-
j
π
un
(
n
+
1
)
N
ZC
,
0
≤
n
≤
N
ZC
-
1
,
N ZC is a length of the Zadoff-Chu sequence and is a prime number;
a time-continuous representation, s short (t), of the random access sequence is defined by
s
short
(
t
)
=
β
PRACH
∑
k
=
0
N
ZC
-
1
∑
n
=
0
N
ZC
-
1
x
u
(
n
)
·
e
-
j
2
π
nk
N
ZC
·
e
j
2
π
(
k
+
k
0
)
Δ
f
t
;
0≤t<T short , β PRACH is an amplitude-scaling factor in order to conform to the transmit power of PRACH, k 0 =n PRB RA N sc RB −N RB UL N sc RB /2, and Δf is the sub-carrier spacing; and
a location of the PRACH preamble in the frequency domain is based on n PRB RA ; N sc RB is a resource block size in the frequency domain; and N RB UL is an uplink bandwidth configuration expressed in multiples of N sc RB .
31 . A method for a base station configured to operate in a wireless communication system, the method comprising:
receiving uplink samples comprising a sub-frame; and processing the uplink samples with a plurality of repetitions of an FFT window, to selectively extract either of the following:
uplink data from a plurality of Orthogonal Frequency-Division Multiplexing (OFDM) symbols comprising the subframe, wherein each OFDM symbol has the same length in time as the FFT window; or
a Physical Random-Access Channel (PRACH) preamble transmitted by a user terminal (UE), wherein the PRACH preamble comprises a plurality of repetitions of a random access sequence, wherein the random access sequence has the same length in time as one of the OFDM symbols.
32 . The method of claim 31 , wherein the PRACH preamble further comprises a cyclic prefix that precedes the plurality of repetitions of the random access sequence.
33 . The method of claim 31 , wherein the PRACH preamble further comprises a part of the random access sequence that follows the plurality of repetitions of the random access sequence.
34 . The method of claim 33 , wherein a length in time of the part and at least a subset of the repetitions preceding the part, is the same as a length in time of a sequential plurality of Fast Fourier Transform (FFT) windows used for receiving a plurality of the OFDM symbols by a node in the wireless communication network.
35 . The method of claim 31 , wherein:
the random access sequence is based on a Zadoff-Chu sequence, the u th root Zadoff-Chu sequence is defined as
x
u
(
n
)
=
e
-
j
π
un
(
n
+
1
)
N
ZC
,
0
≤
n
≤
N
ZC
-
1
,
N ZC is a length of the Zadoff-Chu sequence and is a prime number;
a time-continuous representation, s short (t), of the random access sequence is defined by
s
short
(
t
)
=
β
PRACH
∑
k
=
0
N
ZC
-
1
∑
n
=
0
N
ZC
-
1
x
u
(
n
)
·
e
-
j
2
π
nk
N
ZC
·
e
j
2
π
(
k
+
k
0
)
Δ
f
t
;
0≤t<T short , β PRACH is an amplitude-scaling factor in order to conform to the transmit power of PRACH, k 0 =n PRB RA N sc RB −N RB UL N sc RB /2, and Δf is the sub-carrier spacing; and
a location of the PRACH preamble in the frequency domain is based on n PRB RA ; N sc RB is a resource block size in the frequency domain; and N RB UL is an uplink bandwidth configuration expressed in multiples of N sc RB .Join the waitlist — get patent alerts
Track US2022030635A1 — get alerts on status changes and closely related new filings.
We store only your email — no account needed. See our privacy policy.