Method and apparatus for resource mapping and code division multiplexing
The present disclosure discloses a method and an apparatus for resource mapping and code division multiplexing. In the present disclosure, each cell selects a mapping scheme among at least two mapping schemes to implement resource mapping, which effectively reduces interference imposed on reference signal symbols of users at the edge of a cell; vector switching is performed for an orthogonal matrix to obtain multiple different codeword sequences and implement codeword design, so that a problem that the output power of reference signal symbols is unbalanced can be effectively alleviated.
1. A channel estimation value obtaining method in a wireless telecommunication system, comprising:
receiving, by a user equipment, reference signal symbols of each space layer sent by a transmitter;
wherein the reference signal symbols of each space layer were multiplexed on each reference signal sub-carrier according to a codeword sequence that is corresponding to each reference signal sub-carrier, the codeword sequence is one of a plurality of different codeword sequences, the codeword sequences were obtained by vector switching for a selected orthogonal matrix, and the codeword sequences are corresponding to each reference signal sub-carrier;
obtaining, by the user equipment, a channel estimation value required for demodulating user data.
2. The method according to claim 1 , wherein the codeword sequences were obtained by vector switching for a selected orthogonal matrix comprises:
column vector switching for a 4-dimensional orthogonal matrix W to obtain 4 different codeword sequences, wherein:
W(:,m) represents a column vector corresponding to column m of the orthogonal matrix W, m ranges from 1 to 4, and A=W(:,1), B=W(:,2), C=W(:,3), and D=W(:,4);
the 4 different codeword sequences are:
W 1 =[A, B, C, D];
W 2 =[B, A, D, C];
W 3 =[C, D, A, B] or [C, D, B, A];
W 4 =[D, C, B, A] or [D, C, A, B].
3. The method according to claim 1 , wherein the codeword sequences were obtained by vector switching for a selected orthogonal matrix comprises:
row vector switching for a 4-dimensional orthogonal matrix W to obtain 4 different codeword sequences, wherein:
W′(m,:) represents a row vector corresponding to row m of the orthogonal matrix W, m ranges from 1 to 4, A′=W′(1,:), B′=W′(2,:), C′=W′(3,:), D′=W′(4,:);
the 4 different codeword sequences are:
W
1
′
=
[
A
′
B
′
C
′
D
′
]
;
W
2
′
=
[
B
′
A
′
D
′
C
′
]
;
W
3
′
=
[
C
′
D
′
A
′
B
′
]
or
[
C
′
D
′
B
′
A
′
]
;
W
4
′
=
[
D
′
C
′
B
′
A
′
]
or
[
D
′
C
′
A
′
B
′
]
.
4. A codeword design apparatus in a wireless telecommunication system, comprising:
a receiver, configured to receive reference signal symbols of each space layer sent by a transmitter;
wherein the reference signal symbols of each space layer were multiplexed on each reference signal sub-carrier according to a codeword sequence that is corresponding to each reference signal sub-carrier, the codeword sequence is one of a plurality of different codeword sequences, the codeword sequences were obtained by vector switching for a selected orthogonal matrix, and the codeword sequences are corresponding to each reference signal sub-carrier;
a processor, configured to obtain a channel estimation value required for demodulating user data.
5. The apparatus according to claim 4 , wherein the codeword sequences were obtained by vector switching for a selected orthogonal matrix comprises:
column vector switching for a 4-dimensional orthogonal matrix W to obtain 4 different codeword sequences, wherein:
W(:,m) represents a column vector corresponding to column m of the orthogonal matrix W, m ranges from 1 to 4, and A=W(:,1), B=W(:,2), C=W(:,3), and D=W(:,4);
the 4 different codeword sequences are:
W 1 =[A, B, C, D];
W 2 =[B, A, D, C];
W 3 =[C, D, A, B] or [C, D, B, A];
W 4 =[D, C, B, A] or [D, C, A, B].
6. The apparatus according to claim 4 , wherein the codeword sequences were obtained by vector switching for a selected orthogonal matrix comprises:
row vector switching for a 4-dimensional orthogonal matrix W to obtain 4 different codeword sequences, wherein:
W′(m,:) represents a row vector corresponding to row m of the orthogonal matrix W, m ranges from 1 to 4, A′=W′(1,:), B′=W′(2,:), C′=W′(3,:), D′=W′(4,:);
the 4 different codeword sequences are:
W
1
′
=
[
A
′
B
′
C
′
D
′
]
;
W
2
′
=
[
B
′
A
′
D
′
C
′
]
;
W
3
′
=
[
C
′
D
′
A
′
B
′
]
or
[
C
′
D
′
B
′
A
′
]
;
W
4
′
=
[
D
′
C
′
B
′
A
′
]
or
[
D
′
C
′
A
′
B
′
]
.
7. The method according to claim 2 , wherein the codeword sequences are corresponding to each reference signal sub-carrier comprises:
the 4 different codeword sequences W 1 , W 2 , W 3 , and W 4 are corresponding to each reference signal sub-carrier by turns.
8. The method according to claim 3 , wherein the codeword sequences are corresponding to each reference signal sub-carrier comprises:
the 4 different codeword sequences W 1 ′, W 2 ′, W 3 ′ and W 4 ′ are corresponding to each reference signal sub-carrier by turns.
9. The apparatus according to claim 5 , wherein the codeword sequences are corresponding to each reference signal sub-carrier comprises:
the 4 different codeword sequences W 1 , W 2 , W 3 , and W 4 are corresponding to each reference signal sub-carrier by turns.
10. The apparatus according to claim 6 , wherein the codeword sequences are corresponding to each reference signal sub-carrier comprises:
the 4 different codeword sequences W 1 ′, W 2 ′, W 3 ′ and W 4 ′ are corresponding to each reference signal sub-carrier by turns.