Method and device for transmitting positioning reference signal
Disclosed are a method and device for transmitting a positioning reference signal. In the method, a base station maps, according to configuration information of a PRS, a PRS sequence to a time-frequency resource for sending a PRS; and the base station sends the configuration information of the PRS to a terminal, and sends the mapped PRS on the time-frequency resource for sending a PRS.
1. A method for transmitting a positioning reference signal, comprising:
mapping, by a base station, according to configuration information of a positioning reference signal (PRS), a PRS sequence to a time-frequency resource for sending the PRS;
sending, by the base station, the configuration information of the PRS to a terminal; and
sending, by the base station, a mapped PRS on the time-frequency resource for sending the PRS;
wherein the subcarrier spacing of PRSs is Δf PRS =15×2 μ kHz, and μ is equal to one of 0, 1, 2 or 3.
2. The method according to claim 1 , wherein the configuration information of the PRS comprises a PRS resource element (RE) density configuration parameter, and the PRS RE density configuration parameter is configured to indicate a quantity of REs for sending the PRS in PRS resource blocks (RB); or
the configuration information of the PRS comprises PRS frequency domain resource indication information, and the PRS frequency domain resource indication information comprises a start of a downlink resource grid, a start of a PRS bandwidth, the PRS bandwidth, PRS amplitude scaling and PRS RE frequency shift indication information; or
the configuration information of the PRS comprises PRS time domain resource indication information, and the PRS time domain resource indication information comprises slot configuration information in PRS subframes and/or symbol configuration information in PRS slots; wherein, the slot configuration information in the PRS subframes is configured to indicate slots for sending the PRS in the PRS subframes, and the symbol configuration information in the PRS slots is configured to indicate symbols for sending the PRS in the PRS slots.
3. The method according to claim 2 , wherein a bitmap serves as the slot configuration information in the PRS subframes, and the bitmap comprises 2 μ a bits, each bit corresponds to a slot in the PRS subframes; when the bits in the bitmap are set to a specified value, the slots corresponding to the bits set to the specified value are configured to send the PRS; wherein is equal to one of 0, 1, 2, 3 and 4; or
a bitmap serves as the symbol configuration information in the PRS slots, the bitmap comprises N symble slot bits, each bit corresponds to a symbol in the PRS slots, when the bits in the bitmap are set to a specified value, the symbols corresponding to the bits set to the specified value are configured to send the PRS, wherein N symble slot represents a quantity of symbols in a slot; or
the symbol configuration information in the PRS slots is a PRS symbol configuration index in a symbol list, the symbol list comprises N PRS symbol configuration indexes, each PRS symbol configuration index is configured to indicate symbols for sending the PRS in the PRS slots, and a length of the symbol list is log 2 (N) bits, wherein N is an integer greater than or equal to 1.
4. The method according to claim 2 , wherein the PRS RE frequency shift indication information comprises a sequence number of symbols adopted by the PRS, a PRS sequence identity and a PRS RE density configuration parameter.
5. The method according to claim 1 , wherein the PRS sequence is mapped to the frequency domain resource for sending the PRS according to a following formula:
α
k
,
l
(
p
,
μ
)
=
β
P
R
S
γ
l
,
n
s
,
f
(
n
′
)
;
wherein
,
k
=
(
n
+
N
P
R
S
s
t
a
r
t
,
μ
+
N
grid
,
DL
s
t
art
,
μ
)
×
N
SC
R
B
+
N
SC
R
B
c
P
R
S
k
′
+
υ
shift
;
υ
shift
=
(
l
+
N
I
D
P
R
S
)
mod
(
N
SC
R
B
c
PRS
)
;
n
′
=
c
P
R
S
×
(
n
+
N
PRS
start
,
μ
)
+
k
′
;
n
=
0
,
1
,
…
,
N
R
B
P
R
S
-
1
;
k
′
=
0
,
1
,
…
,
c
PRS
-
1
;
wherein, a reference of k is a subcarrier 0 in a common resource block 0 in a common resource block grid, represents a start of a downlink resource grid, N PRS start,μ represents a start of a PRS bandwidth, N RB PRS represents the PRS bandwidth, β PRS represents PRS amplitude scaling, ν shift represents PRS RE frequency shift, l represents a sequence number of orthogonal frequency division multiplexing (OFDM) symbols adopted by the PRS, N ID PRS represents a PRS sequence identity, N SC RB represents a quantity of subcarriers in each PRS RB, c PRS represents a PRS RE density configuration parameter, and γ l,n s,f (n′) represents the PRS sequence with an OFDM symbol sequence number of l in a slot n s,f .
6. The method according to claim 5 , wherein the PRS sequence is generated according to a pseudo-random sequence, a size of the downlink resource grid, and the PRS RE density configuration parameter; and
an initial value of the pseudo-random sequence is generated according to a sequence number of slots adopted by the PRS, a sequence number of symbols in corresponding slots, and a PRS sequence identity.
7. The method according to claim 6 , wherein the initial value of the pseudo-random sequence is:
c
init
=
{
2
2
8
+
μ
×
⌊
N
ID
P
R
S
1
0
2
4
⌋
+
2
1
0
×
(
1
4
×
(
n
s
,
f
μ
+
1
)
+
l
+
1
)
×
(
N
ID
P
R
S
mod
1024
+
1
)
+
(
N
ID
P
R
S
mod
1024
)
}
mod
2
3
1
;
wherein, c init represents the initial value of the pseudo-random sequence; n s,f μ represents a slot sequence number within a radio frame for subcarrier spacing configuration μ, μ represents a subcarrier spacing configuration parameter, and μ∈{0,1,2,3,4}; l represents a sequence number of OFDM symbols within a slot n s,f μ ; and N ID PRS represents the PRS sequence identity.
8. The method according to claim 6 , wherein the initial value of the pseudo-random sequence is:
c init =(2 16 ×(14× n s,f μ +l+ 1)×(2 N ID PRS +1)+ N ID PRS )mod 2 31 ;
wherein, c init represents the initial value of the pseudo-random sequence; n s,f μ represents a slot sequence number within a radio frame for subcarrier spacing configuration μ, μ represents a subcarrier spacing configuration parameter, and μ∈{0,1, 2,3,4}; l represents a sequence number of OFDM symbols within a slot n s,f μ ; and N ID PRS represents the PRS sequence identity.
9. A method for transmitting a positioning reference signal, comprising:
obtaining, by a terminal, configuration information of a positioning reference signal (PRS); and
receiving, by the terminal, the PRS on a time-frequency resource for sending the PRS according to the configuration information of the PRS, wherein the PRS is sent by a base station;
wherein the subcarrier spacing of PRSs is Δf PRS =15×2 μ kHz, and μ is equal to one of 0, 1, 2 or 3.
10. The method according to claim 9 , wherein the configuration information of the PRS comprises a PRS resource element (RE) density configuration parameter, and the PRS RE density configuration parameter is configured to indicate a quantity of REs for sending the PRS in PRS resource blocks (RB); or
the configuration information of the PRS comprises PRS frequency domain resource indication information, and the PRS frequency domain resource indication information comprises a start of a downlink resource grid, a start of a PRS bandwidth, the PRS bandwidth, PRS amplitude scaling and PRS RE frequency shift indication information; or
the configuration information of the PRS comprises PRS time domain resource indication information, and the PRS time domain resource indication information comprises slot configuration information in PRS subframes and/or symbol configuration information in PRS slots; wherein, the slot configuration information in the PRS subframes is configured to indicate slots for sending the PRS in the PRS subframes, and the symbol configuration information in the PRS slots is configured to indicate symbols for sending the PRS in the PRS slots.
11. The method according to claim 10 , wherein a bitmap serves as the slot configuration information in the PRS subframes, and the bitmap comprises 2 μ bits, each bit corresponds to a slot in the PRS subframes, when the bits in the bitmap are set to a specified value, the slots corresponding to the bits set to the specified value are configured to send the PRS; and μ is equal to one of 0, 1, 2, 3 and 4; or
a bitmap serves as the symbol configuration information in the PRS slots, the bitmap comprises N symble slot bits, each bit corresponds to a symbol in the PRS slots, when the bits in the bitmap are set to a specified value, the symbols corresponding to the bits set to the specified value are configured to send the PRS, wherein N symble slot represents a quantity of symbols in a slot; or
the symbol configuration information in the PRS slots is a PRS symbol configuration index in a symbol list, the symbol list comprises N PRS symbol configuration indexes, each PRS symbol configuration index is configured to indicate symbols for sending the PRS in the PRS slots, and a length of the symbol list is log 2 (N) bits, and N is an integer greater than or equal to 1.
12. The method according to claim 10 , wherein the PRS RE frequency shift indication information comprises a sequence number of symbols adopted by the PRS, a PRS sequence identity and a PRS RE density configuration parameter.
13. The method according to claim 9 , wherein the PRS sequence is mapped to the frequency domain resource for sending the PRS according to a following formula:
α
k
,
l
(
p
,
μ
)
=
β
P
R
S
γ
l
,
n
s
,
f
(
n
′
)
;
wherein
,
k
=
(
n
+
N
P
R
S
s
t
a
r
t
,
μ
+
N
grid
,
DL
s
t
art
,
μ
)
×
N
SC
R
B
+
N
SC
R
B
c
P
R
S
k
′
+
υ
shift
;
υ
shift
=
(
l
+
N
I
D
P
R
S
)
mod
(
N
SC
R
B
c
PRS
)
;
n
′
=
c
P
R
S
×
(
n
+
N
PRS
start
,
μ
)
+
k
′
;
n
=
0
,
1
,
…
,
N
R
B
P
R
S
-
1
;
k
′
=
0
,
1
,
…
,
c
PRS
-
1
;
wherein, a reference of k is a subcarrier 0 in a common resource block 0 in a common resource block grid, N grid,DL start,μ represents a start of a downlink resource grid, N PRS start,μ represents a start of a PRS bandwidth, N RB PRS represents the PRS bandwidth, β PRS represents PRS amplitude shift scaling, ν shift represents PRS RE frequency shift, l represents a sequence number of orthogonal frequency division multiplexing (OFDM) symbols adopted by the PRS, N ID PRS represents a PRS sequence identity, N SC RB represents a quantity of subcarriers in each PRS RB, c PRS represents a c PRS RE density configuration parameter, and γ l,n s,f (n′) represents the PRS sequence with an OFDM symbol sequence number of l in a slot n s,f .
14. The method according to claim 13 , wherein the PRS sequence is generated according to a pseudo-random sequence, a size of the downlink resource grid, and the PRS RE density configuration parameter; and
an initial value of the pseudo-random sequence is generated according to a sequence number of slots adopted by the PRS, a sequence number of symbols in corresponding slots, and a PRS sequence identity.
15. The method according to claim 14 , wherein the initial value of the pseudo-random sequence is:
c
init
=
{
2
2
8
+
μ
×
⌊
N
ID
P
R
S
1
0
2
4
⌋
+
2
1
0
×
(
1
4
×
(
n
s
,
f
μ
+
1
)
+
l
+
1
)
×
(
N
ID
P
R
S
mod
1024
+
1
)
+
(
N
ID
P
R
S
mod
1024
)
}
mod
2
3
1
;
wherein, c init represents the initial value of the pseudo-random sequence; n s,f μ represents a slot sequence number within a radio frame for subcarrier spacing configuration μ, μ represents a subcarrier spacing configuration parameter, and μ∈{0,1,2,3,4}; l represents a sequence number of OFDM symbols within a slot n s,f μ ; and N ID PRS represents the PRS sequence identity.
16. The method according to claim 14 , wherein the initial value of the pseudo-random sequence is:
c init =(2 16 ×(14× n s,f μ +l+ 1)×(2 N ID PRS +1)+ N ID PRS )mod 2 31 ;
wherein, c init represents the initial value of the pseudo-random sequence; n s,f μ represents a slot sequence number within a radio frame for subcarrier spacing configuration μ, μ represents a subcarrier spacing configuration parameter, and μ∈{0,1,2,3,4}; l represents a sequence number of OFDM symbols within a slot n s,f μ ; and N ID PRS represents the PRS sequence identity.
17. A base station, comprising: a processor and a memory;
wherein the processor is configured to read a program in the memory to perform the method according to claim 1 .
18. A terminal, comprising: a processor and a memory;
wherein the processor is configured to read a program in the memory to perform the method according to claim 9 .