Methods, devices and computer readable medium for transmission of reference signal
Embodiments of the present disclosure relate to methods, devices and computer readable mediums for resource selection. The method comprises generating a sequence of a reference signal for Physical Sidelink Shared Channel, PSSCH based on a scrambling identity derived from a Physical Sidelink Control Channel, PSCCH; determining a time-domain resource based on the frequency-domain resource and partially based on an overlap relationship between a first set of resources allocated for the PSCCH and a second set of resources allocated for the PSSCH; and mapping the sequence to the time-domain resource and the frequency-domain resource for transmitting the reference signal. In this way, the reference signal could be transmitted via PSSCH efficiently in a case that the resources allocated for PSCCH is overlapped with the resources allocated for PSSCH.
1. A method implemented at a terminal device, the method comprising:
generating a sequence of demodulation reference signals (DMRS) for a Physical Sidelink Shared Channel (PSSCH), wherein,
a resource for, transmission of the PSSCH and a Physical Sidelink Control Channel (PSCCH) associated with the PSSCH, starts from a first starting position in a first slot,
the PSCCH carries information scheduling the PSSCH,
a first set of symbols, starting from a second starting position in the first slot, is allocated for the PSCCH within the resource,
the second starting position is no earlier in time domain than the first starting position, and
a second set of possible symbols of the DMRS, within the resource, includes the second starting position;
mapping the sequence to a third set of one or more symbols from the second set, wherein each index of the one or more symbols is defined relative to the first starting position; and
transmitting the DMRS.
2. The method of claim 1 , wherein the third set is determined based on a duration of the resources.
3. The method of claim 1 , wherein a first symbol within the third set is the second starting position.
4. The method of claim 3 , wherein in the time domain, a second symbol within the third set is four symbols after the first symbol in a case where number of the one or more symbols in the third set is two.
5. The method of claim 3 , wherein in the time domain,
a second symbol within the third set is three symbols after the first symbol, and
a third symbol within the third set is three symbols after the second symbol in a case where number of the one or more symbols in the third set is three.
6. The method of claim 3 , wherein in the time domain,
a second symbol within the third set is four symbols after the first symbol, and
a third symbol within the third set is four symbols after the second symbol in a case where number of the one or more symbols in the third set is three.
7. The method of claim 3 , wherein in the time domain,
a second symbol within the third set is five symbols after the first symbol, and
a third symbol within the third set is five symbols after the second symbol in a case where number of the one or more symbols in the third set is three.
8. The method of claim 3 , wherein in the time domain,
a second symbol within the third set is three symbols after the first symbol,
a third symbol within the third set is three symbols after the second symbol, and
a fourth symbol in within the third set is three symbols after the third symbol, in a case where number of the one or more symbols in the third set is four.
9. The method of claim 1 , wherein the sequence of the DMRS is
r
(
n
)
=
1
2
(
1
-
2
c
(
2
n
)
)
+
j
1
2
(
1
-
2
c
(
2
n
+
1
)
)
,
wherein a pseudo-random sequence c(i) is initialized with c init =(2 17 (N symb slot n s,f μ +l+1)(2N ID +1)+2N ID )mod 2 31 , where l is an orthogonal frequency division multiplexing (OFDM) symbol number within the slot, n s,f μ is the slot number within a frame, and Nip is derived from the PSCCH.
10. The method of claim 1 , wherein the first set comprises three symbols.
11. A terminal device comprising:
a controller configured to:
generate a sequence of a demodulation reference signal (DMRS) for a Physical Sidelink Shared Channel (PSSCH), wherein,
for a resource for, transmission of the PSSCH and a Physical Sidelink Control Channel (PSCCH) associated with the PSSCH, starts from a first starting position in a first slot,
the PSCCH carries information scheduling the PSSCH,
a first set of symbols, starting from a second starting position in the first slot, is allocated for the PSCCH within the resource,
the second starting position is no earlier in time domain than the first starting position, and
a second set of possible symbols of the DMRS, within the resource, includes the second starting position; and
map the sequence to a third set of one or more symbols from the second set, wherein each index of the one or more symbols is defined relative to the first starting position; and
a transceiver configured to transmit the DMRS.
12. The terminal device of claim 11 , wherein the third set is determined based on a duration of the resource.
13. The terminal device of claim 11 , wherein a first symbol within the third set is the second starting position.
14. The terminal device of claim 13 , wherein in the time domain, a second symbol within the third set is four symbols after the first symbol in a case where number of the one or more symbols in the third set is two.
15. The terminal device of claim 13 , wherein in the time domain, a second symbol within the third set is three symbols after the first symbol, and
a third symbol within the third set is three symbols after the second symbol in a case where number of the one or more symbols in the third set is three.
16. The terminal device of claim 13 , wherein in the time domain,
a second symbol within the third set is four symbols after the first symbol, and
a third symbol within the third set is four symbols after the second symbol in a case where number of the one or more symbols in the third set is three.
17. The terminal device of claim 13 , wherein in the time domain,
a second symbol within the third set is five symbols after the first symbol, and
a third symbol within the third set is five symbols after the second symbol in a case where number of the one or more symbols in the third set is three.
18. The terminal device of claim 13 , wherein in the time domain,
a second symbol within the third set is three symbols after the first symbol,
a third symbol within the third set is three symbols after the second symbol, and
a fourth symbol within the third set is three symbols after the third symbol, in a case where number of the one or more symbols in the third set is four.
19. The terminal device of claim 11 , wherein the sequence of the DMRS is
r
(
n
)
=
1
2
(
1
-
2
c
(
2
n
)
)
+
j
1
2
(
1
-
2
c
(
2
n
+
1
)
)
,
wherein a pseudo-random sequence c(i) is initialized with c init =(2 17 (N symb slot n s,f μ +l+1)(2N ID +1)+2N ID )mod 2 31 , where l is an orthogonal frequency division multiplexing (OFDM) symbol number within the slot, n s,f μ is the slot number within a frame, and N ID is derived from the PSCCH.
20. The terminal device of claim 11 , wherein the first set comprises three symbols.