Reference signal sending method and communication apparatus
A reference signal sending method includes obtaining a frequency-domain cyclic shift factor and a time-domain cyclic shift factor, wherein the frequency-domain cyclic shift factor and the time-domain cyclic shift factor are useable to perform phase rotation on a reference signal sequence. A reference signal sending method further includes generating a second reference signal sequence based on a first reference signal sequence, the frequency-domain cyclic shift factor, and the time-domain cyclic shift factor. A reference signal sending method further includes sending the second reference signal sequence on an antenna port p, wherein p is an element in a set {0, 1, . . . , P−1}, and P is an integer greater than or equal to 1.
1 . A reference signal sending method, comprising:
obtaining a frequency-domain cyclic shift factor and a time-domain cyclic shift factor, wherein the frequency-domain cyclic shift factor and the time-domain cyclic shift factor are useable to perform phase rotation on a reference signal sequence;
generating a second reference signal sequence based on a first reference signal sequence, the frequency-domain cyclic shift factor, and the time-domain cyclic shift factor; and
sending the second reference signal sequence on an antenna port p, wherein p is an element in a set {0, 1, . . . , P−1}, and P is an integer greater than or equal to 1,
wherein the generating the second reference signal sequence based on the first reference signal sequence, the frequency-domain cyclic shift factor, and the time-domain cyclic shift factor comprises:
generating N rs second reference signal sequences in a second reference signal sequence set based on the first reference signal sequence, the frequency-domain cyclic shift factor, and the time-domain cyclic shift factor, wherein the first reference signal sequence and each second reference signal sequence of the N rs second reference signal sequences comprise M rs elements, where N rs ≥1 and is an integer, and M rs ≥1 and is an integer.
2 . The method according to claim 1 , wherein the generating the second reference signal sequence based on the first reference signal sequence, the frequency-domain cyclic shift factor, and the time-domain cyclic shift factor further comprises:
performing phase rotation on an element m of the first reference signal sequence by e j·α F ·m and e j·α T ·t , to obtain an element m of a second reference signal sequence t in the second reference signal sequence set, wherein 0≤m<M rs , 0≤t<N rs , α F is the frequency-domain cyclic shift factor, α T is the time-domain cyclic shift factor, j indicates an imaginary unit, and both m and t are integers.
3 . The method according to claim 2 , wherein the sending the second reference signal sequence comprises:
sending, in one resource unit, the N rs second reference signal sequences in the second reference signal sequence set, wherein the one resource unit comprises N symbols in a time domain, each symbol of the N symbols comprises M subcarriers in a frequency domain, the N rs second reference signal sequences are mapped to N rs symbols of the N symbols, each second reference signal sequence of the N rs second reference signal sequences is mapped to one of the N symbols, each second reference signal sequence of the N rs second reference signal sequences is mapped to M rs subcarriers of one of the N rs symbols, where N≥N rs , M≥M rs , and both N and M are positive integers.
4 . The method according to claim 3 , wherein the one resource unit further comprises one slot in the time domain, the one slot comprises the N symbols; and
the N rs symbols of the N symbols are arranged at equal intervals based on a first value width in the N symbols, or the M rs subcarriers are arranged at equal intervals based on a second value width in the M subcarriers comprised in each symbol of the slot,
wherein the first value width K T satisfies the following formula: K T =N/N rs , where the second value width K F satisfies the following formula: K F =M/M rs , and K T and K F are positive integers.
5 . The method according to claim 3 , wherein the one resource unit further comprises S slots in the time domain, each slot of the S slots comprises N/S symbols, and N/S is an integer; and
the N rs second reference signal sequences are mapped to the N rs symbols of the N symbols comprised in the S slots.
6 . The method according to claim 1 , wherein each of P antenna ports comprised in the set {0, 1, . . . , P−1} corresponds to a combination of one value of the frequency-domain cyclic shift factor and one value of the time-domain cyclic shift factor;
in response to a value, corresponding to each antenna port, of the frequency-domain cyclic shift factor is uniquely determined, a value, corresponding to the antenna port, of the time-domain cyclic shift factor is also uniquely determined; and
combinations, corresponding to two of the P antenna ports, of values of the frequency-domain cyclic shift factor and values of the time-domain cyclic shift factor are different from each other.
7 . The method according to claim 1 , wherein the frequency-domain cyclic shift factor (α F ) and the time-domain cyclic shift factor (α T ) are respectively represented by the following formulas:
α
F
=
±
2
π
N
F
×
β
F
,
α
T
=
±
2
π
N
T
×
β
T
,
wherein
α F is the frequency-domain cyclic shift factor, N F is an integer, β F is an integer, a value range of β F is [0, N F −1], α T is the time-domain cyclic shift factor, N T is an integer, β T is an integer, and a value range of β T is [0, N T −1].
8 . A reference signal receiving method, comprising:
obtaining a frequency-domain cyclic shift factor and a time-domain cyclic shift factor, wherein the frequency-domain cyclic shift factor and the time-domain cyclic shift factor are useable to perform phase rotation on a reference signal sequence;
receiving a second reference signal sequence from an antenna port p of a transmitter, wherein p is an element in a set {0, 1, . . . , P−1}, and P is an integer greater than or equal to 1; and
demodulating the second reference signal sequence based on the frequency-domain cyclic shift factor and the time-domain cyclic shift factor,
wherein the demodulating the second reference signal sequence based on the frequency-domain cyclic shift factor and the time-domain cyclic shift factor comprises:
demodulating N rs second reference signal sequences in a second reference signal sequence set based on the frequency-domain cyclic shift factor and the time-domain cyclic shift factor.
9 . The method according to claim 8 , wherein
an element m of a second reference signal sequence t in the second reference signal sequence set is obtained by performing phase rotation on an element m of a first reference signal sequence by e j·α F ·m and e j·α T ·t , the first reference signal sequence and each second reference signal sequence of the N rs second reference signal sequences comprise M rs elements, where N rs ≥1 and is an integer, M rs ≥1 and is an integer, 0≤m<M rs , 0≤t<N rs , α F is the frequency-domain cyclic shift factor, α T is the time-domain cyclic shift factor, j indicates an imaginary unit, and both m and t are integers.
10 . The method according to claim 9 , wherein the receiving the second reference signal sequence from the antenna port p of the transmitter comprises:
receiving the N rs second reference signal sequences in the second reference signal sequence set in one resource unit, wherein the one resource unit comprises N symbols in a time domain, each symbol of the N symbols comprises M subcarriers in a frequency domain, the N rs second reference signal sequences are mapped to N rs symbols of the N symbols, each second reference signal sequence of the N rs second reference signal sequences is mapped to one of the N symbols, each second reference signal sequence of the N rs second reference signal sequences is mapped to M rs subcarriers of one of the N rs symbols, N≥N rs , M≥M rs , and both N and M are positive integers.
11 . The method according to claim 10 , wherein the one resource unit further comprises one slot in the time domain, the one slot comprises the N symbols; and
the N rs symbols of the N symbols are arranged at equal intervals based on a first value width in the N symbols, or the M rs subcarriers are arranged at equal intervals based on a second value width in the M subcarriers comprised in each symbol of the slot,
wherein the first value width K T satisfies the following formula: K T =N/N rs , where the second value width K F satisfies the following formula: K F =M/M rs , and K T and K F are positive integers.
12 . The method according to claim 10 , wherein the one resource unit further comprises S slots in the time domain, each slot of the S slots comprises N/S symbols, and N/S is an integer; and
the N rs second reference signal sequences are mapped to the N rs symbols of the N symbols comprised in the S slots.
13 . The method according to claim 8 , wherein each of P antenna ports comprised in the set {0, 1, . . . , P−1} corresponds to a combination of one value of the frequency-domain cyclic shift factor and one value of the time-domain cyclic shift factor;
in response to a value, corresponding to each antenna port, of the frequency-domain cyclic shift factor is uniquely determined, a value, corresponding to the antenna port, of the time-domain cyclic shift factor is also uniquely determined; and
combinations, corresponding to two of the P antenna ports, of values of the frequency-domain cyclic shift factor and values of the time-domain cyclic shift factor are different from each other.
14 . The method according to claim 8 , wherein the frequency-domain cyclic shift factor (α F ) and the time-domain cyclic shift factor (α T ) are respectively represented by the following formulas:
α
F
=
±
2
π
N
F
×
β
F
,
α
T
=
±
2
π
N
T
×
β
T
,
wherein
α F is the frequency-domain cyclic shift factor, N T is an integer, β F is an integer, a value range of β F is [0, N F −1], α T is the time-domain cyclic shift factor, N T is an integer, β T is an integer, and a value range of β T is [0, N T −1].
15 . A communication apparatus, comprising:
at least one processor and at least one non-transitory memory, wherein the non-transitory memory is configured to store non-transitory instructions, and in response to the at least one processor executing the non-transitory instructions, causes the communication apparatus to:
obtain a frequency-domain cyclic shift factor and a time-domain cyclic shift factor, wherein the frequency-domain cyclic shift factor and the time-domain cyclic shift factor are useable to perform phase rotation on a reference signal sequence;
generate a second reference signal sequence based on a first reference signal sequence, the frequency-domain cyclic shift factor, and the time-domain cyclic shift factor;
send the second reference signal sequence on an antenna port p, wherein p is an element in a set {0, 1, . . . , P−1}, and P is an integer greater than or equal to 1; and
generate N rs second reference signal sequences in a second reference signal sequence set based on the first reference signal sequence, the frequency-domain cyclic shift factor, and the time-domain cyclic shift factor, wherein the first reference signal sequence and each second reference signal sequence of the N rs second reference signal sequences comprise M rs elements, where N rs ≥1 and is an integer, and M rs ≥1 and is an integer.
16 . The communication apparatus according to claim 15 , wherein the at least one processor is further configured to execute the non-transitory instructions, further causing the communication apparatus to:
perform phase rotation on an element m of the first reference signal sequence by e j·α F ·m and e j·α T ·t , to obtain an element m of a second reference signal sequence t in the second reference signal sequence set, wherein 0≤m<M rs , 0≤t<N rs , α F is the frequency-domain cyclic shift factor, α T is the time-domain cyclic shift factor, j indicates an imaginary unit, and both m and t are integers.
17 . The communication apparatus according to claim 16 , wherein the at least one processor is further configured to execute the non-transitory instructions, further causing the communication apparatus to:
send, in one resource unit, the N rs second reference signal sequences in the second reference signal sequence set, wherein the one resource unit comprises N symbols in a time domain, each symbol of the N symbols comprises M subcarriers in a frequency domain, the N rs second reference signal sequences are mapped to N rs symbols of the N symbols, each second reference signal sequence of the N rs second reference signal sequences is mapped to one of the N symbols, each second reference signal sequence of the N rs second reference signal sequences is mapped to M rs subcarriers of one of the N rs symbols, where N≥N rs , M≥M rs , and both N and M are positive integers.
18 . The communication apparatus according to claim 17 , wherein the resource unit further comprises one slot in the time domain, the one slot comprises the N symbols; and
the N rs symbols of the N symbols are arranged at equal intervals based on a first value width in the N symbols, or the M rs subcarriers are arranged at equal intervals based on a second value width in the M subcarriers comprised in each symbol of the slot,
wherein the first value width K T satisfies the following formula: K T =N/N rs , where the second value width K F satisfies the following formula: K F =M/M rs , and K T and K F are positive integers.
19 . The communication apparatus according to claim 17 , wherein the one resource unit further comprises S slots in the time domain, each slot of the S slots comprises N/S symbols, and N/S is an integer; and
the N rs second reference signal sequences are mapped to the N rs symbols of the N symbols comprised in the S slots.
20 . The communication apparatus according to claim 15 , wherein each of P antenna ports comprised in the set {0, 1, . . . , P−1} corresponds to a combination of one value of the frequency-domain cyclic shift factor and one value of the time-domain cyclic shift factor;
in response to a value, corresponding to each antenna port, of the frequency-domain cyclic shift factor is uniquely determined, a value, corresponding to the antenna port, of the time-domain cyclic shift factor is also uniquely determined; and
combinations, corresponding to two of the P antenna ports, of values of the frequency-domain cyclic shift factor and values of the time-domain cyclic shift factor are different from each other.