Weighted aggregation-based method and device for transmitting control signals
An objective of the application is to provide a method and apparatus for transmitting control signals based on weighted aggregation. Specifically, the method comprise: determining aggregation level weight vectors corresponding to control signals to be transmitted by multiple antenna elements corresponding to the common control channel port, and transmitting the control signals through the multiple antenna elements based on the aggregation level weight vectors. Compared with the prior art, the present application implements enhancement of the common control channel coverage in the 3D-MIND system, and solves the problem of coverage holes in 3D-MIMO due to the introduction of a 2D planar array; moreover, the antenna array gains of the present application are more uniformly distributed in the whole EOD (elevation angle of departure) span, and the gains are significant.
1. A method for transmitting control signals from a base station based on weighted aggregation, comprising:
determining respective aggregation level weight vectors corresponding to the control signals to be transmitted by a base station in a three-dimensional (3-D) multiple-input multiple-output (MIMO) system via multiple antenna elements corresponding to a physical downlink control channel (PDCCH) port; and
transmitting the control signals from the base station via the multiple antenna elements corresponding to the PDCCH port based on said respective aggregation level weight vectors.
2. The method according to claim 1 , wherein the determining comprises:
determining weight components in each of said aggregation level weight vectors in the manner below so as to obtain corresponding said aggregation level weight vectors:
w
a
,
n
=
e
j
·
(
n
-
1
)
d
λ
·
2
π
sin
(
θ
a
180
°
π
)
,
n
=
1
,
…
,
N
wherein, w a,n is a weight component for an n-th antenna element and an a-th aggregation level in the multiple antenna elements, d is an antenna element separation, N is a number of antenna elements in the multiple antenna elements, n is an n-th antenna element in the multiple antenna elements, λ is a wavelength adopted for transmitting said control signals, and θ a is a downtilt angle corresponding to the a-th aggregation level.
3. The method according to claim 1 , further comprising:
determining a corresponding basic aggregation level for transmission of the control signals based on a number of antenna elements in the multiple antenna elements and target angular coverage range.
4. The method according to claim 1 , wherein, the method further comprising:
sending the respective aggregation level weight vectors to a corresponding user equipment for blind detection of downlink control information.
5. The method according to claim 1 , wherein the transmitting comprises:
sending the control signals to a corresponding user equipment via the multiple antenna elements corresponding to the PDCCH port based on said respective aggregation level weight vectors.
6. The method according to claim 1 , wherein the aggregation level weight vectors are determined for a corresponding number of aggregation levels associated with the multiple antenna elements and the PDCCH port such that each aggregation level has a corresponding aggregation level weight vector.
7. The method according to claim 6 , wherein the aggregation level weight vectors of a corresponding aggregation level are expressed as follows:
w a =( w a,1 ,w a,2 , . . . ,w a,N )
wherein, N is a number of antenna elements per PDCCH port, a is an aggregation level, and w a is the aggregation level weighting vector corresponding to aggregation level a.
8. The method according to claim 6 , wherein the method further comprises:
determining a downtilt angle corresponding to each aggregation level associated with the multiple antenna elements based on target angular coverage range and aggregation level application information.
9. The method according to claim 1 , wherein the aggregation level weight vectors include discrete Fourier transformation (DFT) vectors.
10. A base station for transmitting control signals based on weighted aggregation, comprises:
at least one processor configured to, determine respective aggregation level weight vectors corresponding to the control signals to be transmitted via multiple antenna elements corresponding to a physical downlink control channel (PDCCH) port in a three-dimensional (3-D) multiple-input multiple-output (MIMO) system; and
a transmitter configured to, transmit the control signals via the multiple antenna elements corresponding to the PDCCH port based on said respective aggregation level weight vectors.
11. The base station according to claim 10 , wherein the at least one processor is configured to:
determine weight components in each of said aggregation level weight vectors in the manner below so as to obtain corresponding said aggregation level weight vectors:
w
a
,
n
=
e
j
·
(
n
-
1
)
d
λ
·
2
π
sin
(
θ
a
180
°
π
)
,
n
=
1
,
…
,
N
wherein, w a,n is a weight component for an n-th antenna element and an a-th aggregation level in the multiple antenna elements, d is an antenna element separation, N is a number of antenna elements in the multiple antenna elements, n is an n-th antenna element in the multiple antenna elements, λ is a wavelength adopted for transmitting said control signals, and θ a is a downtilt angle corresponding to the a-th aggregation level.
12. The base station according to claim 10 , wherein the at least one processor is configured to determine a corresponding basic aggregation level for transmission of the control signals based on a number of antenna elements in the multiple antenna elements and target angular coverage range.
13. The base station according to claim 10 , wherein the transmitter is configured to send the respective aggregation level weight vectors to a corresponding user equipment for blind detection of downlink control information.
14. The base station according to claim 10 , wherein the transmitter is configured to
send the control signals to a corresponding user equipment via the multiple antenna elements corresponding to the PDCCH port based on said respective aggregation level weight vectors.
15. The base station according to claim 10 , wherein the at least one processor is configured to determine the aggregation level weight vectors for a corresponding number of aggregation levels associated with the multiple antenna elements and the PDCCH port such that each aggregation level has a corresponding aggregation level weight vector.
16. The base station according to claim 15 , wherein the aggregation level weight vectors of a corresponding aggregation level are expressed as follows:
w a =( w a,1 ,w a,2 , . . . ,w a,N )
wherein, N is a number of antenna elements per PDCCH port, a is an aggregation level, and w a is the aggregation level weighting vector corresponding to aggregation level a.
17. The base station according to claim 15 , wherein the at least one processor is configured to determine a downtilt angle corresponding to each aggregation level associated with the multiple antenna elements based on target angular coverage range and aggregation level application information.
18. The base station according to claim 10 , wherein the aggregation level weight vectors include discrete Fourier transformation (DFT) vectors.