Signal transmission method and deviceTechnical Field
The present invention relates to the field of communications technologies, and in particular, to a signal transmission method and apparatus.
Background
In the era of the rapid development of networks, the dependence of User Equipment (UE) on the network is also becoming more and more important. Users need wireless network coverage regardless of walking or staying at home, so that a base station is required to have a strong wireless coverage function.
However, with the development of technology, more and more indoor wireless coverage methods are available, and the solution can be achieved by an indoor distribution system, an outdoor macro station penetrating through an indoor space, or an indoor deployment of a miniaturized base station. However, in the first two methods, the application of the indoor small-sized base station is becoming more and more widespread in consideration of the influence of factors such as cost, site selection, and implementation restriction factors.
For a miniaturized base station, the miniaturized base station mainly applies an internal antenna or a miniaturized external antenna to cover a range from dozens of meters to dozens of meters, and the UE application environment mainly takes the line of sight as the main point. In such an environment, whether the polarization modes of the base station antenna and the UE antenna are matched or not will have a significant impact on the reception performance of the UE.
In the prior art, a vertical polarization antenna and a dual polarization antenna are generally adopted to receive an incoming wave of a UE. When the polarization direction of the incoming wave does not coincide with the polarization direction of the receiving antenna, the received signal becomes small, that is, a polarization loss occurs. For example, when a vertically polarized wave or a horizontally polarized wave is received with a +45 ° polarized antenna, or when a +45 ° polarized wave or a-45 ° polarized wave is received with a vertically polarized antenna, a polarization loss occurs. When the polarization direction of the receiving antenna is completely orthogonal to the polarization direction of the incoming wave, or the horizontally polarized receiving antenna receives the vertically polarized incoming wave, the antenna can not receive the energy of the incoming wave at all, and in this case, the polarization loss is maximum, which is called as complete polarization isolation.
Moreover, for the outdoor antenna application, due to the complexity of the wireless environment, multipath is caused by various refraction and reflection, which may cause the spatial channel to generate a large angular spread near the base station antenna or the UE antenna, thereby causing the signal in a certain polarization direction on the receiving side to be partially coupled to the cross-polarized antenna. That is, even if the UE causes polarization mismatch between the base station antenna and the UE antenna due to hand-holding or placement factors, the loss of signal transmission power may be mitigated due to the confusion between the base station antenna and the UE antenna due to the effect of angle spread.
However, for the line-of-sight environment applied to the indoor miniaturized base station, energy coupling between different polarized signals in the spatial channel is small, and the loss of signal transmission power cannot be compensated due to mismatching of antenna polarization caused by the factor of UE holding or placement indoors.
Therefore, in the prior art, when the antenna of the miniaturized base station and the antenna of the UE perform signal transmission, the polarization direction of the antenna of the base station is not matched with the polarization direction of the antenna of the UE, which causes great loss.
Disclosure of Invention
The embodiment of the invention provides a signal transmission method and a signal transmission device, which are used for realizing that the polarization direction of a base station antenna is matched with the polarization direction of a UE antenna through the adjustment of the position of the base station antenna when the antenna of a base station and the UE antenna carry out signal transmission, thereby reducing the loss in the signal transmission process.
The embodiment of the invention provides a signal transmission method, which comprises the following steps:
when a signal of User Equipment (UE) is received, performing channel estimation on the signal of the UE to obtain a channel estimation value;
determining an adjustment parameter of the antenna position according to the channel estimation value;
and adjusting the position of the antenna according to the adjustment parameter, and performing signal transmission with the UE by using the adjusted antenna.
Specifically, according to the method, when a base station antenna receives a signal of User Equipment (UE), the signal of the UE has a certain polarization direction, channel estimation is carried out on the signal of the UE to obtain a channel estimation value, then an adjustment parameter of an antenna position is determined according to all the channel estimation values, finally the antenna position is adjusted according to the adjustment parameter to enable the polarization direction of the base station antenna to be matched with the polarization direction of the UE antenna, and then the adjusted antenna is utilized to carry out signal transmission with the UE. The method and the device are used for adjusting the position of the base station antenna when the antenna of the base station and the UE antenna transmit signals, so that the polarization direction of the base station antenna is matched with the polarization direction of the UE antenna, and loss in signal transmission is reduced.
Preferably, determining an adjustment parameter of the antenna position according to the channel estimation value includes:
and determining the current position of the antenna, and determining the adjustment parameters of the antenna position according to the channel estimation value and the current position of the antenna.
Preferably, the current position of the antenna includes: the current horizontal included angle of the antenna and the current vertical included angle of the antenna; the current horizontal included angle of the antenna is a first included angle between the projection of the antenna on the horizontal plane and the first direction axis, the current vertical included angle of the antenna is a second included angle between the projection of the antenna on the vertical plane and the second direction axis, the first direction axis and the second direction axis are perpendicular to each other, the first direction axis is located on the horizontal plane, and the second direction axis is located on the vertical plane.
Preferably, performing channel estimation on the signal of the UE to obtain a channel estimation value includes:
dividing the horizontal plane and the vertical plane into N angle intervals respectively to obtain N angle interval combinations, wherein N is equal to the square of N, each angle interval combination comprises an angle interval of the horizontal plane and an angle interval of the vertical plane, and calculating a channel estimation value when the antenna receives signals at a position corresponding to the ith angle interval combination for the ith angle interval combination:
HLS,i＝r(k)·s*(k)·(xsinαicosβi+ycosαi)
wherein HLS,iA channel estimation value representing a combination of the ith angle interval;
r (k) represents that the antenna receives the k signal of the UE;
s*(k) a conjugate transpose representing the kth signal received by the antenna to the UE;
αirepresenting the angle of a vertical plane in the ith angle interval combination;
βirepresenting the angle of the horizontal plane in the ith angle interval combination;
y represents a unit vector on the second directional axis;
x represents a unit vector on the third directional axis.
Specifically, because the base station antenna does not determine the placement position of the UE antenna, the base station antenna needs to perform channel estimation on the corresponding values in all the angle interval combinations when receiving the UE signal, so as to determine which angle interval combination the base station antenna is in, and the loss when receiving the signal of the UE antenna is the minimum.
Preferably, determining the adjustment parameter of the antenna position according to the channel estimation value and the current position of the antenna comprises:
respectively carrying out modulus taking on the obtained N channel estimation values, and respectively taking the angle interval of the horizontal plane and the angle interval of the vertical plane corresponding to the channel estimation value with the maximum modulus as a target horizontal angle and a target vertical angle of antenna adjustment;
determining a horizontal adjustment angle of the antenna according to the current horizontal angle of the antenna and the target horizontal angle; and determining the vertical adjusting angle of the antenna according to the current vertical angle of the antenna and the target vertical angle.
Preferably, when receiving signals of a plurality of different UEs, the method further comprises:
calculating an average value of horizontal adjustment angles of the antennas corresponding to the plurality of different UEs, and finally taking the average value as the horizontal adjustment angle of the antenna;
calculating an average value of the vertical adjustment angles of the antennas corresponding to the different UEs, and finally taking the average value as the vertical adjustment angle of the antenna;
or,
the horizontal adjustment angle of the antenna corresponding to the UE which receives the most signals of the plurality of different UEs is finally used as the horizontal adjustment angle of the antenna;
the vertical adjustment angle of the antenna corresponding to the UE which receives the most different UE signals is finally used as the vertical adjustment angle of the antenna;
or,
the horizontal adjustment angle of an antenna corresponding to the UE which receives the least signals of the plurality of different UEs is finally used as the horizontal adjustment angle of the antenna;
and finally taking the vertical adjustment angle of the antenna corresponding to the UE which receives the least signals of the plurality of different UEs as the vertical adjustment angle of the antenna.
Specifically, by the method, the base station antenna can freely select which UE corresponds to the horizontal adjustment angle and the vertical adjustment angle to be finally used as the horizontal adjustment angle and the vertical adjustment angle of the antenna according to the received signals of a plurality of different UEs.
The embodiment of the invention provides a signal transmission device, which comprises:
the channel estimation unit is used for carrying out channel estimation on a signal of User Equipment (UE) when the signal of the UE is received to obtain a channel estimation value;
a determining unit, configured to determine an adjustment parameter of an antenna position according to the channel estimation value;
and the adjusting unit is used for adjusting the position of the antenna according to the adjusting parameter and transmitting signals with the UE by using the adjusted antenna.
Specifically, with the device, when a base station antenna receives a signal of User Equipment (UE), the signal of the UE has a certain polarization direction, channel estimation is performed on the signal of the UE to obtain a channel estimation value, then adjustment parameters of an antenna position are determined according to all the channel estimation values, finally, the antenna position is adjusted according to the adjustment parameters to enable the polarization direction of the base station antenna to be matched with the polarization direction of the UE, and then, the adjusted antenna is used for signal transmission with the UE. The method and the device are used for adjusting the position of the base station antenna when the antenna of the base station and the UE antenna transmit signals, so that the polarization direction of the base station antenna is matched with the polarization direction of the UE antenna, and loss in signal transmission is reduced.
Preferably, the determining unit is specifically configured to:
and determining the current position of the antenna, and determining the adjustment parameters of the antenna position according to the channel estimation value and the current position of the antenna.
Preferably, the current position of the antenna includes: the current horizontal included angle of the antenna and the current vertical included angle of the antenna; the current horizontal included angle of the antenna is a first included angle between the projection of the antenna on the horizontal plane and the first direction axis, the current vertical included angle of the antenna is a second included angle between the projection of the antenna on the vertical plane and the second direction axis, the first direction axis and the second direction axis are perpendicular to each other, the first direction axis is located on the horizontal plane, and the second direction axis is located on the vertical plane.
Preferably, the channel estimation unit, when performing channel estimation on the signal of the UE to obtain a channel estimation value, is specifically configured to:
dividing the horizontal plane and the vertical plane into N angle intervals respectively to obtain N angle interval combinations, wherein N is equal to the square of N, each angle interval combination comprises an angle interval of the horizontal plane and an angle interval of the vertical plane, and calculating a channel estimation value when the antenna receives signals at a position corresponding to the ith angle interval combination for the ith angle interval combination:
HLS,i＝r(k)·s*(k)·(xsinαicosβi+ycosαi)
wherein HLS,iA channel estimation value representing a combination of the ith angle interval;
r (k) represents that the antenna receives the k signal of the UE;
s*(k) a conjugate transpose representing the kth signal received by the antenna to the UE;
αirepresenting the angle of a vertical plane in the ith angle interval combination;
βirepresenting the angle of the horizontal plane in the ith angle interval combination;
y represents a unit vector on the second directional axis;
x represents a unit vector on the third directional axis.
Specifically, because the base station antenna does not determine the placement position of the UE antenna, the base station antenna needs to perform channel estimation on a value corresponding to when the signal sent by the UE is received in all angle interval combinations, so as to determine that the loss of receiving the signal sent by the UE is the smallest when the base station antenna is in which angle interval combination.
Preferably, when determining the adjustment parameter of the antenna position according to the channel estimation value and the current position of the antenna, the determining unit is specifically configured to:
respectively carrying out modulus taking on the obtained N channel estimation values, and respectively taking the angle interval of the horizontal plane and the angle interval of the vertical plane corresponding to the channel estimation value with the maximum modulus as a target horizontal angle and a target vertical angle of antenna adjustment;
determining a horizontal adjustment angle of the antenna according to the current horizontal angle of the antenna and the target horizontal angle; and determining the vertical adjusting angle of the antenna according to the current vertical angle of the antenna and the target vertical angle.
Preferably, when signals of a plurality of different UEs are received, the determining unit is further configured to:
calculating an average value of horizontal adjustment angles of the antennas corresponding to the plurality of different UEs, and finally taking the average value as the horizontal adjustment angle of the antenna;
calculating an average value of the vertical adjustment angles of the antennas corresponding to the different UEs, and finally taking the average value as the vertical adjustment angle of the antenna;
or,
the horizontal adjustment angle of the antenna corresponding to the UE which receives the most signals of the plurality of different UEs is finally used as the horizontal adjustment angle of the antenna;
the vertical adjustment angle of the antenna corresponding to the UE which receives the most different UE signals is finally used as the vertical adjustment angle of the antenna;
or,
the horizontal adjustment angle of an antenna corresponding to the UE which receives the least signals of the plurality of different UEs is finally used as the horizontal adjustment angle of the antenna;
and finally taking the vertical adjustment angle of the antenna corresponding to the UE which receives the least signals of the plurality of different UEs as the vertical adjustment angle of the antenna.
Specifically, by the apparatus, the base station antenna can freely select which UE corresponds to the horizontal adjustment angle and the vertical adjustment angle to be finally used as the horizontal adjustment angle and the vertical adjustment angle of the antenna according to the received signals of a plurality of different UEs.
Drawings
Fig. 1 is a schematic flowchart of a signal transmission method according to an embodiment of the present invention;
fig. 2 is a schematic coordinate diagram of a signal transmission method according to an embodiment of the present invention;
fig. 3 is a schematic flowchart of a signal transmission method according to an embodiment of the present invention;
fig. 4 is another schematic coordinate diagram of a signal transmission method according to an embodiment of the present invention;
fig. 5 is a schematic structural diagram of a signal transmission apparatus according to an embodiment of the present invention.
Detailed Description
The embodiment of the invention provides a signal transmission method and a signal transmission device, which are used for matching the polarization direction of a base station antenna with the polarization direction of a UE antenna through the adjustment of the position of the base station antenna when the antenna of a base station and the UE antenna carry out signal transmission, thereby reducing the loss in the signal transmission process.
Specifically, when the base station antenna receives an incoming wave sent by the UE antenna, the incoming wave has a certain polarization direction, and in order to make the polarization direction of the base station antenna consistent with the polarization direction of the incoming wave, the position of the base station antenna needs to be adjusted, so that the position of the base station antenna is consistent with the position of the UE antenna, and thus the polarization direction of the base station antenna is matched with the polarization direction of the UE antenna, thereby reducing loss in the signal transmission process. Polarization refers to a vector characteristic of the electromagnetic wave during transmission, i.e., a vibration direction, for example, horizontal polarization refers to a vibration direction of the electromagnetic wave being a horizontal direction, and vertical polarization refers to a vibration direction of the electromagnetic wave being a vertical direction.
Referring to fig. 1, a signal transmission method provided in an embodiment of the present invention includes:
s101, when a signal of User Equipment (UE) is received, performing channel estimation on the signal of the UE to obtain a channel estimation value;
the signal transmission method in the embodiment of the present invention is to perform channel estimation on a signal of a UE when the antenna of a base station performs signal transmission with the antenna of the UE and the antenna of the base station receives the signal transmitted by the antenna of the UE, so as to obtain a channel estimation value.
Specifically, when the base station antenna receives a signal transmitted by the UE antenna, the placement position of the UE antenna is not determined, that is, the horizontal position and the vertical position of the UE antenna are not known. The base station antennas are required to perform channel estimation for all its possible horizontal and vertical directions.
The method comprises the steps of dividing a horizontal plane and a vertical plane where a base station antenna is located into N angle intervals respectively to obtain N angle interval combinations, wherein N is equal to the square of N, each angle interval combination comprises an angle interval of the horizontal plane and an angle interval of the vertical plane, and channel estimation is carried out on each angle interval combination. For example, for the ith angle interval combination, the channel estimation value when the antenna receives the signal at the position corresponding to the ith angle interval combination is calculated:
HLS,i＝r(k)·s*(k)·(xsinαicosβi+ycosαi)
wherein HLS,iRepresenting a channel estimate;
r (k) represents that the antenna receives the k signal of the UE;
s*(k) a conjugate transpose representing the kth signal received by the antenna to the UE;
αirepresenting the angle of a vertical plane in the ith angle interval combination;
βirepresenting the angle of the horizontal plane in the ith angle interval combination;
x represents a unit vector on a third direction axis, and the third direction axis is vertical to the vertical plane;
y represents a unit vector on a second directional axis, which means an axis perpendicular to the horizontal plane.
S102, determining an adjustment parameter of the antenna position according to the channel estimation value;
before determining the adjustment parameter of the antenna position, the current position of the antenna also needs to be determined, and the current position of the antenna includes: the current horizontal included angle of the antenna and the current vertical included angle of the antenna; the current horizontal included angle of the antenna is a first included angle between the projection of the antenna on the horizontal plane and the first direction axis, the current vertical included angle of the antenna is a second included angle between the projection of the antenna on the vertical plane and the second direction axis, the first direction axis and the second direction axis are perpendicular to each other, the first direction axis is located on the horizontal plane, and the second direction axis is located on the vertical plane.
Specifically, referring to fig. 2, the first direction axis is the Z axis in the figure, the second direction axis is the Y axis in the figure, the first included angle is the β included angle in the figure, and the second included angle is the α included angle in the figure.
It should be noted that, in the method for determining the current position of the antenna in the embodiment of the present invention, a gravity sensing sensor and a vibration device are used to measure the position of the antenna. Specifically, when the base station antenna is started or restarted in initial installation, the vibration device is automatically activated to enable the base station antenna to act, and the gravity sensor obtains the horizontal and vertical angles of a space coordinate system where the antenna is located through the action of the antenna. Referring to fig. 2, a first included angle β between a projection of the antenna on a horizontal plane and a Z axis of a first direction axis is a current horizontal angle of the antenna, and a second included angle α between a projection of the antenna on a vertical plane and a Y axis of a second direction axis is a current vertical angle of the antenna.
Wherein, according to the channel estimation value, determining an adjustment parameter of the antenna position comprises: and determining the current position of the antenna, and determining the adjustment parameters of the antenna position according to the channel estimation value and the current position of the antenna.
Specifically, the obtained N channel estimation values are respectively subjected to modulus extraction, and the angle interval of the horizontal plane and the angle interval of the vertical plane corresponding to the channel estimation value with the maximum modulus are obtainedRespectively serving as a target horizontal angle and a target vertical angle for antenna adjustment; determining a horizontal adjustment angle of the antenna according to the current horizontal angle and the target horizontal angle of the antenna; and determining the vertical adjustment angle of the antenna according to the current vertical angle and the target vertical angle of the antenna. Wherein, the horizontal adjustment angle of the antenna and the vertical adjustment angle of the antenna are adjustment parameters of the antenna position, and the horizontal adjustment angle can be thetatargetIndicating that vertical adjustment angle can be usedAnd (4) showing.
S103, adjusting the position of the antenna according to the adjustment parameter, and performing signal transmission with the UE by using the adjusted antenna.
When the antenna is adjusted in position according to the adjustment parameter, when the antenna receives signals of a plurality of different UEs, different adjustment parameters of the antenna can be determined according to different requirements. Wherein, several conditions are included:
(1) in order to reduce the loss of all different UEs in the signal transmission process, an average value of horizontal adjustment angles of antennas corresponding to the multiple different UEs may be calculated, and the average value is finally used as the horizontal adjustment angle of the antenna; and calculating an average value of the vertical adjustment angles of the antennas corresponding to the plurality of different UEs, and finally taking the average value as the vertical adjustment angle of the antenna.
(2) In order to reduce the loss of all the UE which sends or receives the signals with the most signals in the signal transmission process, the horizontal adjustment angle of the antenna corresponding to the UE which receives the signals with the most signals of the plurality of different UEs is finally used as the horizontal adjustment angle of the antenna; and finally taking the vertical adjustment angle of the antenna corresponding to the UE which receives the most different UE signals as the vertical adjustment angle of the antenna.
The method for judging the UE which sends or receives the signals most comprises the following steps: the base station may perform the determination by using the obtained throughput information of the uplink UE as a standard during the uplink processing. Of course, there are many methods for determining the UE that transmits or receives the most signals, and the embodiment of the present invention is not limited in particular.
(3) In order to reduce the loss of all the different UEs in the signal transmission process of the UE which sends or receives the minimum signal, the horizontal adjustment angle of the antenna corresponding to the UE which receives the minimum signal of the multiple different UEs is finally used as the horizontal adjustment angle of the antenna; and finally taking the vertical adjustment angle of the antenna corresponding to the UE which receives the least signals of the plurality of different UEs as the vertical adjustment angle of the antenna.
The method for judging the UE with the least sending or receiving signals comprises the following steps: the base station may perform the determination by using the block error rate BLER and/or the out-of-step information of the uplink UE as a standard during the uplink processing. Of course, there are many methods for determining the UE that has the least transmitted or received signal, and the embodiment of the present invention is not limited in particular.
Next, embodiment 1 describes in detail a signal transmission method provided by an embodiment of the present invention.
Example 1
Referring to fig. 3, a signal transmission method provided in an embodiment of the present invention includes the steps of:
s301, when the base station is started, the current horizontal angle and the current vertical angle of the external antenna are obtained through the gravity sensing sensor.
S302, the base station obtains an optimization strategy and parameters of channel estimation.
Wherein, the parameters of the channel estimation comprise: and during channel estimation, the horizontal plane and the vertical plane of the antenna are respectively divided into n values of a plurality of angle intervals and a period T of channel estimation.
The calculation of the channel estimation is performed in units of a period T, and the calculated value of the channel estimation may be weighted-averaged in the period T.
The optimization strategy of the channel estimation comprises the following steps: and reducing the loss of all different UEs in the signal transmission process, or reducing the loss of all different UEs in the signal transmission process of the UE which sends or receives the signals most, or reducing the loss of all different UEs in the signal transmission process of the UE which sends or receives the signals least.
Specifically, when the antenna receives signals of a plurality of different UEs, different requirements for polarization matching of the different UEs need to be considered, so the following optimization strategy may be available.
(1) In order to reduce the loss of all different UEs in the signal transmission process, an average value of horizontal adjustment angles of antennas corresponding to the multiple different UEs may be calculated, and the average value is finally used as the horizontal adjustment angle of the antenna; calculating an average value of the vertical adjustment angles of the antennas corresponding to the different UEs, and finally taking the average value as the vertical adjustment angle of the antenna;
(2) in order to reduce the loss of all the UE which sends or receives the signals with the most signals in the signal transmission process, the horizontal adjustment angle of the antenna corresponding to the UE which receives the signals with the most signals of the plurality of different UEs is finally used as the horizontal adjustment angle of the antenna; and finally taking the vertical adjustment angle of the antenna corresponding to the UE which receives the most different UE signals as the vertical adjustment angle of the antenna.
(3) In order to reduce the loss of all the different UEs in the signal transmission process of the UE which sends or receives the minimum signal, the horizontal adjustment angle of the antenna corresponding to the UE which receives the minimum signal of the multiple different UEs is finally used as the horizontal adjustment angle of the antenna; and finally taking the vertical adjustment angle of the antenna corresponding to the UE which receives the least signals of the plurality of different UEs as the vertical adjustment angle of the antenna.
S303, whether the antenna automatic adjustment switch op _ switch is turned on, if so, execute step S304, otherwise, execute step S309.
The antenna automatic adjusting switch is used for the base station to select whether the antenna needs to be automatically adjusted or not.
S304, whether the UE reports the mobility measurement, if so, execute step S309, otherwise execute step S305.
The mobility measurement is, for example, Long Term Evolution (LTE), and mainly refers to EVENT a and EVENT B EVENTs defined in 36.331 in the existing communication protocol. When the base station receives the event, the base station performs a handover process.
If the polarization of the base station antenna is matched with that of the UE antenna, the method is also applied when the channel communication condition is good, so that the application range of the indoor miniaturized base station is considered to be dozens of meters mainly, and the method is only used when the UE does not have any mobility measurement report. For example, when the UE is at the edge of a cell and the received signal is not good, the UE reports the mobility measurement.
S305, according to the parameters of the channel estimation determined in the step S302, dividing the horizontal plane and the vertical plane where the antenna is located into N values of a plurality of angle intervals respectively, and forming N angle interval combinations in total, wherein N is N2. And combining the N angle intervals, and calculating a channel estimation value when the corresponding position receives the signal of the UE when the antenna adopts the angle interval combination respectively.
S306, judging whether the channel estimation period T is reached, if so, executing the step S307, otherwise, executing the step S305.
And S307, within the period time T, according to the optimization strategy of the channel estimation determined in the step S302, performing modulus taking on the obtained N channel estimation values respectively, and taking the angle interval of the horizontal plane and the angle interval of the vertical plane corresponding to the channel estimation value with the maximum modulus as a target horizontal angle and a target vertical angle of antenna adjustment respectively.
S308, determining a horizontal adjustment angle of the antenna according to the current horizontal angle and the target horizontal angle of the antenna; determining a vertical adjustment angle of the antenna according to the current vertical angle and the target vertical angle of the antenna; and adjusting the position of the antenna according to the determined horizontal adjustment angle and the determined vertical adjustment angle.
S309, the antenna of the base station and the UE carry out signal transmission.
Example 2
Embodiment 2 describes in detail the channel estimation method described in the embodiment of the present invention.
Specifically, there are many channel estimation methods in the prior art, and the embodiment of the present invention describes in detail a calculation process of the channel estimation value by using a matched filtering algorithm.
Referring to fig. 4, suppose that a base station cell utilizes a dual-polarized antenna with an included angle ± α with a vertical plane for transmission, a UE antenna is assumed to be placed perpendicular to a horizontal plane, and the included angle between the UE antenna and the horizontal plane is β.
Specifically, the X axis represents a horizontal reference direction of a third direction axis, the Y axis represents a vertical reference direction of a second direction axis, the Z axis represents a main beam reference direction of a dual-polarized antenna of the third direction axis, point O is an intersection point of X, Y and the Z axis, α represents an included angle between a projection of the dual-polarized antenna 1 on an XOY plane and the Y axis, i.e., a vertical included angle, and β represents an included angle between a projection of an incoming wave of the UE on the XOZ plane and the Z axis, i.e., a horizontal included angle.
For example, assume that α is 45 ° for the dual-polarized antenna 1, and α is 45 ° for the dual-polarized antenna 2.
When the UE transmits a probe signal s (k) to the base station antenna by using the UE antenna, the probe signals s (k) transmitted by the UE antenna and received by the dual-polarized antenna 1 at the α angle and the dual-polarized antenna 2 at the- α angle of the base station are r1(k) And r2(k) In that respect Then
r1(k)＝s(k)·(xsinαcosβ+ycosα)
r2(k)＝-s(k)·(xsinαcosβ+ycosα)
Wherein X represents a unit vector on the X-axis of the third directional axis; y represents a unit vector on the Y-axis of the second directional axis.
The base station antenna needs to be tuned to the received signal r1(k) And r2(k) Performing channel estimation by using a channel estimation formula in the prior art, HLS＝r1(k)·s*(k) And performing channel estimation on signals transmitted by the UE and received on each antenna.
When the specific channel estimation is performed, because the base station antenna does not know the placement mode of the terminal antenna, the channel estimation needs to be performed on all directions of a horizontal plane and a vertical plane where the base station antenna is located, wherein the horizontal plane and the vertical plane are respectively divided into N angle intervals, each angle space is an interval, and N angle interval combinations are obtained, wherein N is equal to the square of N, and each angle interval combination comprises an angle interval of the horizontal plane and an angle interval of the vertical plane. Channel estimation is then performed for each combination of angle intervals. Then, for the ith angle interval combination, calculating a channel estimation value when the dual-polarized antenna 1 receives signals at a position corresponding to the ith angle interval combination:
HLS,i＝r(k)·s*(k)·(xsinαicosβi+ycosαi)
wherein HLS,iA channel estimation value representing a combination of the ith angle interval;
r (k) represents that the antenna receives the k signal of the UE;
s*(k) a conjugate transpose representing the kth signal received by the antenna to the UE;
αirepresenting the angle of a vertical plane in the ith angle interval combination;
βirepresenting the angle of the horizontal plane in the ith angle interval combination;
x represents a unit vector on the X axis;
y represents a unit vector on the Y-axis.
Then, performing modular calculation on the channel estimation values obtained by combining the N angle intervals, and respectively taking the angle interval of the horizontal plane and the angle interval of the vertical plane corresponding to the channel estimation value with the maximum module value as a target horizontal angle and a target vertical angle of antenna adjustment; determining a horizontal adjustment angle of the antenna according to the current horizontal angle of the antenna and the target horizontal angle; and determining the vertical adjusting angle of the antenna according to the current vertical angle of the antenna and the target vertical angle.
For example, when 15 °, N is 12, N is 144. That is, when each angle space is divided into 12 angle sections by 15 ° at intervals, a combination of 144 angle sections is obtained. Assuming that the second angle interval combination is calculated as a channel estimation value with α ═ 30 ° and β ═ 30 °, the channel estimation value of dual-polarized antenna 1 in the second angle interval combination is:
HLS,2＝r(k)·s*(k)·(xsin30°cos30°+ycos30°)
wherein X represents a unit vector on the X axis, Y represents a unit vector j on the Y axis, r (k) represents that the antenna receives the kth signal of the UE, s*(k) Representing the conjugate transpose of the k-th signal received by the antenna to the UE.
Then to HLSModulo to obtain abc (H)LS,2)。
After the 144 angle interval combination is subjected to modulus calculation, all the modulus values are compared, and then the angle interval of the horizontal plane and the angle interval of the vertical plane for the angle interval combination with the maximum modulus value are determined. For example, when calculating when α2＝30°，β2When the angle is 30 °, the corresponding channel estimation modulus is the largest, and when the dual-polarized antenna 1 of the base station performs signal transmission with the UE, the projection of the dual-polarized antenna 1 of the base station on the XOY plane and the Y axis are determinedShould be 30 deg. and the projection onto the XOZ plane should be at an angle of 30 deg. to the Z axis.
And the angle section of the horizontal plane for the angle section combination with the maximum module value is used as the target adjustment value of the antenna on the horizontal plane, and the angle section of the vertical plane for the angle section combination is used as the target adjustment value of the antenna on the vertical plane, wherein the target adjustment value on the horizontal plane is thetatargetIndicating, for target adjustment values on vertical planeAnd (4) showing. Then thetatarget＝βi,When alpha isi＝30°，βiWhen the combined modulus of the angle interval corresponding to 30 ° is the maximum, θtarget＝30°，
The current position of the dual-polarized antenna 1 is known, that is, an included angle between the dual-polarized antenna 1 and a vertical plane is 45 degrees, and an included angle between the dual-polarized antenna 1 and a horizontal plane is β 90 degrees; and because of the target adjustment value theta on the horizontal planetarget30 DEG, target adjustment value on vertical planeTherefore, the adjustment parameters of the dual-polarized antenna 1 are as follows: the horizontal plane needs to be adjusted by an angle of 60 degrees (60 degrees to 90 degrees to 30 degrees), and the vertical plane needs to be adjusted by an angle of 15 degrees (15 degrees to 45 degrees to 30 degrees).
Similarly, the calculation process of the adjustment parameters of the dual-polarized antenna 2 is the same as the calculation process of the adjustment parameters of the dual-polarized antenna 1, and is not described herein again.
Embodiment 2 describes in detail the channel estimation of the UE signal received by the base station using matched filtering, however, there are many channel estimation algorithms in the prior art, and the embodiment of the present invention is only illustrated by using matched filtering, and if other algorithms are used, the same algorithm that can achieve the effect also belongs to the protection scope of the present invention.
Since the base station corresponds to a plurality of antennas, it is possible to simultaneously perform channel estimation for a plurality of antennas when performing channel estimation.
Referring to fig. 5, an embodiment of the present invention provides a signal transmission apparatus, including:
a channel estimation unit 51, configured to perform channel estimation on a signal of a user equipment UE when the signal of the UE is received, to obtain a channel estimation value;
a determining unit 52, configured to determine an adjustment parameter of an antenna position according to the channel estimation value;
and an adjusting unit 53, configured to perform position adjustment on the antenna according to the adjustment parameter, and perform signal transmission with the UE by using the adjusted antenna.
Preferably, the determining unit 52 is specifically configured to:
and determining the current position of the antenna, and determining the adjustment parameters of the antenna position according to the channel estimation value and the current position of the antenna.
Preferably, the current position of the antenna includes: the current horizontal included angle of the antenna and the current vertical included angle of the antenna; the current horizontal included angle of the antenna is a first included angle between the projection of the antenna on the horizontal plane and the first direction axis, the current vertical included angle of the antenna is a second included angle between the projection of the antenna on the vertical plane and the second direction axis, the first direction axis and the second direction axis are perpendicular to each other, the first direction axis is located on the horizontal plane, and the second direction axis is located on the vertical plane.
Preferably, the channel estimation unit 51, when performing channel estimation on the signal of the UE to obtain a channel estimation value, is specifically configured to:
dividing the horizontal plane and the vertical plane into N angle intervals respectively to obtain N angle interval combinations, wherein N is equal to the square of N, each angle interval combination comprises an angle interval of the horizontal plane and an angle interval of the vertical plane, and calculating a channel estimation value when the antenna receives signals at a position corresponding to the ith angle interval combination for the ith angle interval combination:
HLS,i＝r(k)·s*(k)·(xsinαicosβi+ycosαi)
wherein HLS,iA channel estimation value representing a combination of the ith angle interval;
r (k) represents that the antenna receives the k signal of the UE;
s*(k) a conjugate transpose representing the kth signal received by the antenna to the UE;
αirepresenting the angle of a vertical plane in the ith angle interval combination;
βirepresenting the angle of the horizontal plane in the ith angle interval combination;
y represents a unit vector on the second directional axis;
x represents a unit vector on the third directional axis.
Preferably, when determining the adjustment parameter of the antenna position according to the channel estimation value and the current position of the antenna, the determining unit 52 is specifically configured to:
respectively carrying out modulus taking on the obtained N channel estimation values, and respectively taking the angle interval of the horizontal plane and the angle interval of the vertical plane corresponding to the channel estimation value with the maximum modulus as a target horizontal angle and a target vertical angle of antenna adjustment;
determining a horizontal adjustment angle of the antenna according to the current horizontal angle of the antenna and the target horizontal angle; and determining the vertical adjusting angle of the antenna according to the current vertical angle of the antenna and the target vertical angle.
Preferably, when receiving signals of a plurality of different UEs, the determining unit 52 is further configured to:
calculating an average value of horizontal adjustment angles of the antennas corresponding to the plurality of different UEs, and finally taking the average value as the horizontal adjustment angle of the antenna;
calculating an average value of the vertical adjustment angles of the antennas corresponding to the different UEs, and finally taking the average value as the vertical adjustment angle of the antenna;
or,
the horizontal adjustment angle of the antenna corresponding to the UE which receives the most signals of the plurality of different UEs is finally used as the horizontal adjustment angle of the antenna;
the vertical adjustment angle of the antenna corresponding to the UE which receives the most different UE signals is finally used as the vertical adjustment angle of the antenna;
or,
the horizontal adjustment angle of an antenna corresponding to the UE which receives the least signals of the plurality of different UEs is finally used as the horizontal adjustment angle of the antenna;
and finally taking the vertical adjustment angle of the antenna corresponding to the UE which receives the least signals of the plurality of different UEs as the vertical adjustment angle of the antenna.
The channel estimation unit 51, the determination unit 52 and the adjustment unit 53 may be implemented by physical devices such as a processor and a transceiver.
In summary, a signal transmission method provided in the embodiment of the present invention includes, first, when a base station antenna receives a signal of a user equipment UE, performing channel estimation on the signal of the UE to obtain a channel estimation value, then determining an adjustment parameter of an antenna position according to all the channel estimation values, finally performing position adjustment on the antenna according to the adjustment parameter, and performing signal transmission with the UE by using the adjusted antenna. The method and the device are used for adjusting the position of the base station antenna when the antenna of the base station and the UE antenna transmit signals, so that the polarization direction of the base station antenna is matched with the polarization direction of the UE antenna, and loss in signal transmission is reduced.
As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, optical storage, and the like) having computer-usable program code embodied therein.
The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.