Method and apparatus for sidelink transmission in wireless communication system
An operating method of a first device which communicates with a second device based on time division duplex (TDD), includes: receiving a first signal from the second device; estimating a channel between the first device and the second device based on the first signal; generating, by applying singular value decomposition (SVD) to the estimated channel, a first orthogonal matrix including one or more left singular vectors, a diagonal matrix including one or more singular values, and a second orthogonal matrix including one or more right singular vectors; selecting at least one right singular vector from the second orthogonal matrix in descending order according to the one or more singular values, a number of the selected at least one right singular vector corresponding to a number of ranks of the channel; and transmitting, to the second device, a precoded physical sidelink shared channel (PSSCH) precoded based on a precoding matrix including the selected at least one right singular vector.
1 . An operating method of a first device which communicates with a second device based on time division duplex (TDD), the operating method comprising:
receiving a first signal from the second device;
estimating a channel between the first device and the second device based on the first signal;
generating, by applying singular value decomposition (SVD) to the channel, a first orthogonal matrix comprising one or more left singular vectors, a diagonal matrix comprising one or more singular values, and a second orthogonal matrix comprising one or more right singular vectors;
selecting at least one right singular vector from the second orthogonal matrix in descending order according to the one or more singular values, a number of the selected at least one right singular vector is equal to a rank number of the channel; and
transmitting, to the second device, a precoded physical sidelink shared channel (PSSCH) precoded based on a precoding matrix comprising the selected at least one right singular vector.
2 . The operating method of claim 1 , wherein the selecting the at least one right singular vector comprises:
receiving, from the second device, channel quality information (CQI) and a rank indicator (RI); and
determining the rank number of the channel based on the RI.
3 . The operating method of claim 2 , wherein the rank number of the channel determined based on the RI is 1 or 2.
4 . The operating method of claim 1 , wherein the first signal is based on a single port, and
wherein the first signal comprises at least one of a PSSCH, a physical sidelink feedback channel (PSFCH), a sidelink primary synchronization signal (P-SSS), a sidelink secondary synchronization signal (S-SSS), or a physical sidelink broadcast channel (PSBCH).
5 . The operating method of claim 4 , wherein a number of rows of the channel is 1, and
wherein the first orthogonal matrix comprises a one by one matrix.
6 . The operating method of claim 1 , wherein the first signal comprises a PSSCH based on N multi-ports, and N is an integer greater than or equal to 2.
7 . The operating method of claim 6 , wherein a number of rows of the channel corresponds to N, and
the first orthogonal matrix comprises an N by N matrix.
8 . The operating method of claim 1 , further comprising:
receiving, from the second device, a physical sidelink feedback channel (PSFCH) indicating acknowledgement of the precoded PSSCH.
9 . The operating method of claim 1 , wherein the estimating the channel comprises estimating the channel from the first device to the second device based on the first signal and the TDD.
10 . An operating method of a first device which communicates with a second device based on time division duplex (TDD), the operating method comprising:
receiving, from the second device, a first signal which is based on a single port or two ports;
estimating a channel matrix between the first device and the second device based on the first signal;
determining a precoding matrix based on the channel matrix, the precoding matrix comprising a number of right singular vectors that is equal to a rank number of the channel matrix; and
transmitting, to the second device, a precoded physical sidelink shared channel (PSSCH) precoded based on the precoding matrix to the second device,
wherein the first signal based on the single port comprises at least one of a single port-PSSCH, a physical sidelink feedback channel (PSFCH), a sidelink primary synchronization signal (P-SSS), a sidelink secondary synchronization signal (S-SSS), or a physical sidelink broadcast channel (PSBCH), and
wherein the first signal based on the two ports comprises a 2 port-PSSCH.
11 . The operating method of claim 10 , wherein the first signal is based on the single port; and
wherein the determining of the precoding matrix comprises:
generating, by applying singular value decomposition (SVD) to the channel matrix, a first orthogonal matrix comprising one left singular vector, a diagonal matrix comprising one or more singular values, and a second orthogonal matrix comprising one or more right singular vectors; and
selecting at least one right singular vector from the second orthogonal matrix in descending order according to the one or more singular values.
12 . The operating method of claim 10 , wherein the first signal is based on the two ports; and
wherein the determining the precoding matrix comprises:
generating, by applying singular value decomposition (SVD) to the channel matrix, a first orthogonal matrix comprising two left singular vectors, a diagonal matrix comprising one or more singular values, and a second orthogonal matrix comprising one or more right singular vectors; and
selecting at least one right singular vector from the second orthogonal matrix in descending order according to the one or more singular values.
13 . The operating method of claim 10 , further comprising:
receiving a transmit precoding matrix indicator (TPMI) from the second device,
wherein the determining the precoding matrix comprises determining the precoding matrix based on the channel matrix and the TPMI.
14 . A first device which communicates with a second device based on time division duplex (TDD), the first device comprising:
a transceiver;
a memory storing instructions; and
a processor communicatively coupled to the transceiver and the memory, and configured to execute the instructions to:
receive a first signal from the second device through the transceiver;
estimate a channel between the first device and the second device based on the first signal;
generate, by applying singular value decomposition (SVD) to the channel, a first orthogonal matrix comprising one or more left singular vectors, a diagonal matrix comprising one or more singular values, and a second orthogonal matrix comprising one or more right singular vectors;
select at least one right singular vector from the second orthogonal matrix in descending order according to the one or more singular values, a number of the selected at least one right singular vector is equal to a rank number of the channel; and
transmit, to the second device through the transceiver, a precoded physical sidelink shared channel (PSSCH) precoded based on a precoding matrix and comprising the selected at least one right singular vector.
15 . The first device of claim 14 , wherein the processor is further configured to:
receive channel quality information (CQI) and a rank indicator (RI) from the second device through the transceiver; and
determine the rank number of the channel based on the RI.
16 . The first device of claim 15 , wherein the rank number of the channel determined based on the RI comprises 1 or 2.
17 . The first device of claim 14 , wherein the first signal is based on a single port, and
wherein the first signal comprises at least one of a PSSCH, a physical sidelink feedback channel (PSFCH), a sidelink primary synchronization signal (P-SSS), a sidelink secondary synchronization signal (S-SSS), and a physical sidelink broadcast channel (PSBCH).
18 . The first device of claim 17 , wherein a number of rows of the channel is 1, and
wherein the first orthogonal matrix comprises a one by one matrix.
19 . The first device of claim 14 , wherein the first signal comprises a PSSCH based on N multi-ports, and N is an integer greater than or equal to 2.
20 . The first device of claim 19 , wherein a number of rows of the channel corresponds to N, and
wherein the first orthogonal matrix comprises an N by N matrix.