CN104639476B - Suppress the method and upcoming base station of TD LTE interference at crossed slot - Google Patents
Suppress the method and upcoming base station of TD LTE interference at crossed slot Download PDFInfo
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Abstract
The embodiment of the invention discloses a kind of method and upcoming base station of suppression TD LTE interference at crossed slot.Present invention method includes：Upcoming base station obtains uplink reference signals from user equipment and the local uplink reference signals of user equipment to estimate the channel information of the uplink channel information of uplink reference signals and upstream data. signals；The downlink reference signal of the downlink reference signal from adjacent area at cross time-slot and adjacent area is obtained to estimate descending interference channel information that descending interference channel information and upstream data. signals that cross time-slot uplink reference signals are subject to are subject to；Upcoming base station calculates adjacent area uplink interference noise statisticses information according to resulting data, and the descending interference channel information and adjacent area uplink interference noise statisticses information that channel information, upstream data. signals always according to upstream data. signals are subject to calculate equalizing coefficient；Upcoming base station is handled the upward signal that upcoming base station receives using equalizing coefficient.The present invention can reduce interference at crossed slot.
Description
Technical Field
The invention relates to the technical field of communication, in particular to a method for inhibiting TD-LTE cross time slot interference and an uplink base station.
Background
In the TD-LTE system, uplink and downlink links are allocated to the same frequency spectrum to respectively occupy different time periods, so that the proportion of uplink and downlink resources can be flexibly allocated, and the resources are configured according to the proportion of uplink services and downlink services.
However, if the traffic of two adjacent base stations is different, the use of different timeslot matching schemes will bring interference specific to the TD-LTE system, which is represented by base station to base station interference and mobile station to mobile station interference, and this interference is called cross timeslot interference.
Research shows that the interference in the cross time slot is very serious, especially the interference between the base station and the base station seriously affects the communication quality, although the cross time slot can normally work in the cell which bears the downlink task, the cell which bears the uplink service can hardly work normally in the cross time slot.
Disclosure of Invention
The embodiment of the invention provides a method for inhibiting TD-LTE cross time slot interference and an uplink base station, which are used for reducing the cross time slot interference.
The first aspect of the embodiments of the present invention provides a method for suppressing TD-LTE cross slot interference, including:
an uplink base station acquires an uplink reference signal from user equipment and the uplink reference signal local to the user equipment, and a downlink reference signal from a neighboring cell and the downlink reference signal local to the neighboring cell at a cross time slot;
the uplink base station estimates uplink channel information of the uplink reference signal and channel information of an uplink data signal according to the uplink reference signal from the user equipment and the uplink reference signal local to the user equipment;
the uplink base station estimates downlink interference channel information received by the uplink reference signal and downlink interference channel information received by the uplink data signal in a cross time slot according to the downlink reference signal from the adjacent cell and the downlink reference signal local to the adjacent cell;
the uplink base station calculates the statistics information of the uplink interference noise of the adjacent region according to the obtained data, and also calculates the equalization coefficient according to the channel information of the uplink data signal, the downlink interference channel information suffered by the uplink data signal and the statistics information of the uplink interference noise of the adjacent region;
and the uplink base station processes the uplink signal received by the uplink base station by adopting the equalization coefficient.
With reference to the first aspect of the present invention, in a first implementation manner of the first aspect of the present invention, after the estimating, by the uplink base station, the uplink channel information of the uplink reference signal and the channel information of the uplink data signal according to the uplink reference signal from the user equipment and the uplink reference signal local to the user equipment, the method further includes:
the uplink base station calculates a difference value of signal-to-interference-plus-noise ratios before and after the cross time slot conversion according to a least square estimation value of uplink channel information of the uplink reference signal from the user equipment and an estimation value of the uplink channel information of the uplink reference signal from the user equipment;
the calculating, by the uplink base station, the neighbor uplink interference noise statistic information according to the obtained data specifically includes:
judging whether the difference value of the signal to interference plus noise ratios of the uplink base station before and after the cross time slot conversion is larger than a threshold value;
if so, the uplink base station calculates the statistical information of the uplink interference noise of the adjacent region according to the least square estimation value of the uplink channel information of the uplink reference signal, the estimation value of the uplink channel information of the uplink reference signal and the estimation value of the downlink interference channel information received by the uplink reference signal;
and if not, the uplink base station calculates the uplink interference noise statistical information of the adjacent region according to the least square estimation value of the uplink channel information of the uplink reference signal and the estimation value of the uplink channel information of the uplink reference signal.
With reference to the first implementation manner of the first aspect of the embodiment of the present invention, in a second implementation manner of the first aspect of the embodiment of the present invention, the downlink reference signal from the neighboring cell is a downlink reference signal sent by the neighboring cell in a MIMO mode of TM3, TM4, or TM 6;
the method further comprises the following steps:
the uplink base station also acquires a precoding matrix;
the uplink base station also multiplies the precoding matrix and downlink interference channel information suffered by the uplink reference signal to calculate equivalent downlink interference channel information suffered by the uplink reference signal;
the uplink base station also multiplies the precoding matrix and downlink interference channel information received by the uplink data signal to calculate equivalent downlink interference channel information received by the uplink data signal;
and when the uplink base station respectively calculates the statistics information and the balance coefficient of the uplink interference noise of the adjacent regions, the uplink base station adopts the equivalent downlink interference channel information received by the uplink reference signal to replace the downlink interference channel information received by the uplink reference signal, and adopts the equivalent downlink interference channel information received by the uplink data signal to replace the downlink interference channel information received by the uplink data signal.
With reference to the first aspect of the embodiment of the present invention, in a third implementation manner of the first aspect of the embodiment of the present invention, when the downlink reference signal from the neighboring cell is a downlink reference signal sent by the neighboring cell in a MIMO mode of TM2,
the acquiring, by the uplink base station, the local downlink reference signal of the neighboring cell specifically includes:
the uplink base station acquires the Cell ID and the port information of the neighboring Cell;
and the uplink base station generates the local downlink reference signal of the neighbor Cell according to the Cell ID and the port information of the neighbor Cell.
With reference to the first aspect of the embodiments, in a fourth implementation manner of the first aspect of the embodiments of the present invention,
the acquiring, by the uplink base station, the local downlink reference signal of the neighboring cell specifically includes:
the uplink base station acquires downlink information at a cross time slot;
and the uplink base station generates the local downlink reference signal of the adjacent region according to the downlink information.
A second aspect of the embodiments of the present invention provides an uplink base station, including:
an obtaining unit, configured to obtain an uplink reference signal from a user equipment and the uplink reference signal local to the user equipment, and a downlink reference signal from a neighboring cell and the downlink reference signal local to the neighboring cell at a cross timeslot;
a first calculating unit, configured to estimate uplink channel information of an uplink reference signal and channel information of an uplink data signal according to the uplink reference signal from the user equipment and the uplink reference signal local to the user equipment;
a second calculating unit, configured to estimate, according to the downlink reference signal from the neighboring cell and the local downlink reference signal of the neighboring cell, downlink interference channel information suffered by the uplink reference signal and downlink interference channel information suffered by the uplink data signal on a cross timeslot;
a third calculating unit, configured to calculate uplink interference noise statistical information of a neighboring cell according to the obtained data, and further calculate an equalization coefficient according to channel information of the uplink data signal, downlink interference channel information received by the uplink data signal, and the uplink interference noise statistical information of the neighboring cell;
and the processing unit is used for processing the uplink signal received by the uplink base station by adopting the equalization coefficient.
With reference to the second aspect of the present embodiment, in a first implementation manner of the second aspect of the present embodiment, the uplink base station further includes:
a fourth calculating unit, configured to calculate a difference between signal-to-interference-plus-noise ratios before and after the cross slot conversion according to a least square estimation value of the uplink channel information of the uplink reference signal from the user equipment and an estimation value of the uplink channel information of the uplink reference signal from the user equipment;
the third calculating unit is specifically configured to calculate, when a difference between signal-to-interference-plus-noise ratios of the uplink base station before and after the cross timeslot conversion is greater than a threshold value, uplink interference noise statistical information of a neighboring cell according to a least square estimation value of uplink channel information of the uplink reference signal, an estimation value of uplink channel information of the uplink reference signal, and an estimation value of downlink channel information of the uplink reference signal;
and when the difference value of the signal to interference plus noise ratios of the uplink base station before and after the cross time slot conversion is less than or equal to a preset value, calculating the statistical information of the uplink interference noise of the adjacent region according to the least square estimation value of the uplink channel information of the uplink reference signal and the estimation value of the uplink channel information of the uplink reference signal.
With reference to the first implementation manner of the second aspect of the present invention, in the second implementation manner of the second aspect of the present invention, when the downlink reference signal from the neighboring cell is a downlink reference signal sent by the neighboring cell in a MIMO mode of TM3, TM4, or TM6, the obtaining unit is further configured to obtain a precoding matrix;
the second calculating unit is further configured to multiply the precoding matrix and the downlink interference channel information received by the uplink reference signal to calculate equivalent downlink interference channel information received by the uplink reference signal, and further multiply the precoding matrix and the downlink interference channel information received by the uplink data signal to calculate equivalent downlink interference channel information received by the uplink data signal;
and when the third calculation unit calculates the statistics information and the balance coefficient of the uplink interference noise of the adjacent region respectively, the third calculation unit adopts the equivalent downlink interference channel information received by the uplink reference signal to replace the downlink interference channel information received by the uplink reference signal, and adopts the equivalent downlink interference channel information received by the uplink data signal to replace the downlink interference channel information received by the uplink data signal.
With reference to the second aspect of the embodiment of the present invention, in a third implementation manner of the second aspect of the embodiment of the present invention, when the downlink reference signal from the neighboring cell is a downlink reference signal sent by the neighboring cell in a MIMO mode of TM2,
the acquiring unit is further configured to acquire the Cell ID and the port information of the neighboring Cell, and generate the local downlink reference signal of the neighboring Cell according to the Cell ID and the port information of the neighboring Cell.
With reference to the second aspect of the present invention, in a fourth implementation manner of the second aspect of the present invention, the obtaining unit is further configured to obtain downlink information at a cross timeslot, and generate the downlink reference signal local to the neighboring cell according to the downlink information.
According to the technical scheme, the embodiment of the invention has the following advantages:
in the embodiment of the invention, the uplink interference noise statistical information of the adjacent region is calculated, and the equalization coefficient is calculated according to the uplink interference noise statistical information of the adjacent region, the channel information of the uplink data signal and the downlink interference channel information received by the uplink data signal, so that a more accurate equalization coefficient can be obtained, and the equalization coefficient can be further adopted to process the uplink signal received by the uplink base station, so as to achieve approximately ideal MMSE-IRC equalization performance exceeding the conventional MMSE-IRC.
Drawings
Fig. 1 is a flowchart of an embodiment of a method of suppressing TD-LTE cross slot interference according to the present invention;
fig. 2 is a flowchart of another embodiment of a method of suppressing TD-LTE cross-slot interference according to the present invention;
fig. 3 is a schematic structural diagram of an uplink base station according to an embodiment of the present invention.
Detailed Description
The embodiment of the invention provides a method for inhibiting TD-LTE cross time slot interference and an uplink base station, which are used for reducing the cross time slot interference.
In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The terms "comprises" and "comprising," and any variations thereof, in the description and claims of this invention and the above-described drawings, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, system, article, or apparatus.
For clarity, channel information H in this context refers to the fading coefficient of the transmitted signal after propagation, and is Rx*TxMatrix of dimensions, wherein RxIs the number of receiving antennas, TxIs the number of transmit antennas.
The method for suppressing TD-LTE cross slot interference according to the present invention is described in detail below.
Referring to fig. 1, a method for suppressing TD-LTE cross slot interference in an embodiment of the present invention includes:
101. an uplink base station acquires an uplink reference signal from UE and a local uplink reference signal of the UE.
The UE sends the local uplink reference signal to the uplink base station, and since the uplink reference signal will experience a certain fading in the sending process, the uplink reference signal received by the uplink base station is different from the uplink reference signal in the local UE. For convenience of description, the uplink reference signal received by the uplink base station is referred to as an uplink reference signal from the UE. Specifically, in this embodiment, the uplink reference signal is a Demodulation reference signal (DMRS). Of course, the above is merely exemplary and not limiting.
102. And the uplink base station calculates an estimated value of uplink channel information of the uplink reference signal and an estimated value of channel information of an uplink data signal according to the uplink reference signal from the UE and the local uplink reference signal of the UE.
Specifically, DMRS is taken as an example. The uplink base station firstly calculates the Least Square (LS) estimation value H of the uplink channel information of the DMRSLS,ul. In particular, the method comprises the following steps of,wherein Y isul,RSIs DMRS, S from UEulIs a DMRS that is local to the UE,is SulConjugation of (1).
Obtaining LS estimation value H of uplink channel information of DMRSLS,ulThen, the uplink base station pair HLS,ulThe estimation value of the uplink channel information of the DMRS can be obtained by carrying out noise reduction filteringIn particular, the method comprises the following steps of,wherein QulIs the up-link noise reduction filter coefficient.
Obtaining an estimation value of uplink channel information of DMRSThen, the uplink base station can utilize methods such as linear interpolation or wiener filtering and the likeCalculating an estimate of channel information of an upstream data signalThe specific calculation method is a known technique and will not be described herein.
103. The uplink base station acquires a downlink reference signal from a neighboring cell and a local downlink reference signal of the neighboring cell.
The neighboring cell in this embodiment is a cell that has cross slot interference with the uplink base station. The neighbor cell sends the local downlink reference signal to the uplink base station, and because the downlink reference signal will experience a certain fading in the sending process, the downlink reference signal received by the uplink base station is different from the downlink reference signal when the neighbor cell is local. For convenience of description, the downlink reference signal received by the uplink base station is referred to as a downlink reference signal from a neighboring cell. Specifically, in the embodiment, the downlink reference signal is a cell-specific reference signal (CRS). The neighbor cell transmits downlink reference signals in a MIMO mode of TM 2. Of course, the above is merely exemplary and not limiting.
There are various methods for the uplink base station to obtain the local downlink reference signal of the neighboring cell. Specifically, for example, the uplink base station may obtain a Cell identification (Cell ID) and port (english: port) information of the neighboring Cell through an information interaction interface X2 between the base stations, and then generate a local CRS of the neighboring Cell according to the Cell ID and the port information of the neighboring Cell.
104. And the uplink base station calculates downlink interference channel information received by the uplink reference signal and downlink interference channel information received by the uplink data signal in the cross time slot according to the downlink reference signal from the adjacent cell and the local downlink reference signal of the adjacent cell.
Specifically, DMRS and CRS are taken as examples. The uplink base station firstly calculates an LS estimation value H of downlink channel information of CRSLS,dl. In particular, the method comprises the following steps of,wherein Y isdl,RSIs CRS, S from a neighbouring celldlIs a CRS that is local to the neighbor cell,is the conjugate of the CRS local to the neighbor.
To obtain HLS,dlThen, the uplink base station pair HLS,dlThe estimation value of the downlink channel information of the CRS can be obtained by carrying out noise reduction filteringIn particular, the method comprises the following steps of,wherein QdlIs the downlink noise reduction filter coefficient.
To obtainThen, the uplink base station can utilize methods such as linear interpolation or wiener filtering and the likeCalculating downlink interference channel information received by uplink DMRS (demodulation reference signal) in cross time slotAnd an estimated value of downlink interference channel information received by the uplink data signalThe specific calculation method is a known technique and will not be described herein.
105. And the uplink base station calculates the SINR difference before and after the conversion of the cross time slot.
By way of specific example, obtaining HLS,ulAndthen, the uplink base station can measure the signal to interference plus noise ratio (SINR) of each Resource Block (RB) of each Transmission Time Interval (TTI):
wherein,is HLS,ul2 norm of (d).
After calculating the SINR of each RB in each TTI, two SINRs of the RB before and after the cross slot transition can be found, and the two SINRs are subtracted from each other to obtain an SINR difference before and after the cross slot transition.
106. Judging whether the SINR difference value is larger than a threshold value; if yes, go to step 107, otherwise go to step 108.
The threshold value is preset by the uplink base station. Specifically, the threshold value may be preset in the uplink base station according to experience or actual measurement results in network planning. The threshold value may be modified during the network operation according to the change of the environment and the service.
107. And the uplink base station calculates the statistical information of the uplink interference noise of the adjacent region according to the LS estimation value of the uplink channel information of the uplink reference signal, the estimation value of the uplink channel information of the uplink reference signal and the estimation value of the downlink interference channel information received by the uplink reference signal.
In this embodiment, the uplink interference noise statistic information of the neighboring cell may include interference of the neighboring cell UE, interference of the downlink base station at the cross timeslot that is lower than the interference noise threshold, white noise, and the like.
There are various methods for calculating the uplink interference noise statistical information of the neighboring cell. For example, the uplink base station may obtain the neighbor uplink interference noise statistical information R by averaging over K subcarriersuu,ul：
Where k is the subcarrier number. In practice, K generally takes the length of one RB, i.e., 12. Of course, in practice, Ruu,ulThe calculation may be performed by other formulas, which are not limited herein.
108. The uplink base station calculates the statistical information R of the uplink interference noise of the adjacent region according to the LS estimation value of the uplink channel information of the uplink reference signal and the estimation value of the uplink channel information of the uplink reference signaluu,ul。
In this embodiment, the uplink interference noise statistic information of the neighboring cell may include interference of the neighboring cell UE, interference of the downlink base station at the cross timeslot that is lower than the interference noise threshold, white noise, and the like.
There are various methods for calculating the uplink interference noise statistical information of the neighboring cell. For example, the uplink base station may obtain R by averaging over K subcarriersuu,ul：
Where k is the subcarrier number. In practice, K generally takes the length of one RB, i.e., 12. Of course, in practice, Ruu,ulThe calculation may be performed by other formulas, which are not limited herein.
109. And the uplink base station calculates an equalization coefficient according to the channel information of the uplink data signal, the downlink interference channel information suffered by the uplink data signal and the uplink interference noise statistical information of the adjacent region, and processes the uplink signal received by the uplink base station by adopting the equalization coefficient.
The uplink base station calculates the balance coefficientSpecifically, the method comprises the following steps:
wherein,is thatThe conjugate transpose of (a) is performed,is thatThe conjugate transpose of (c).
The uplink base station is based on the equalization coefficientAnd an uplink reference signal Y from the UEulEstimating UE uplink transmission dataIn particular, the method comprises the following steps of,
in the embodiment, the uplink interference noise statistical information of the adjacent region is calculated, and the equalization coefficient is calculated according to the uplink interference noise statistical information of the adjacent region, the channel information of the uplink data signal and the downlink interference channel information received by the uplink data signal, so that a more accurate equalization coefficient can be obtained, and the equalization coefficient can be further adopted to process the uplink signal received by the uplink base station, so as to achieve approximately ideal MMSE-IRC equalization performance exceeding conventional MMSE-IRC; and because the downlink base station at the cross time slot sends signals in the MIMO mode of TM2, it can be compatible with the existing protocol without adding extra signaling overhead.
In this embodiment, before calculating the uplink interference noise statistical information of the neighboring cell, the uplink base station first determines whether the SINR difference before and after the cross timeslot conversion is greater than a threshold, and calculates the uplink interference noise statistical information of the neighboring cell by using different methods in two cases of being greater than the threshold and being less than or equal to the threshold, so that the calculated uplink interference noise statistical information of the neighboring cell is more accurate. Of course, in practical application, the uplink base station may also use a method to calculate the uplink interference noise statistical information of the neighboring cell without determining whether the SINR difference before and after the cross timeslot conversion is greater than the threshold, and this is not limited herein.
In the above embodiment, the MIMO mode of the downlink base station at the crossing time slot is limited. In practical application, the MIMO mode of the downlink base station at the cross timeslot may not be limited, referring to fig. 2, another embodiment of the method for suppressing TD-LTE cross timeslot interference in the present invention includes:
201. an uplink base station acquires an uplink reference signal from UE and a local uplink reference signal of the UE.
For a detailed description, refer to the description of step 101 in the embodiment shown in FIG. 1.
202. And the uplink base station calculates an estimated value of uplink channel information of the uplink reference signal and an estimated value of channel information of an uplink data signal according to the uplink reference signal from the UE and the local uplink reference signal of the UE.
For a detailed description, refer to the description of step 102 in the embodiment of FIG. 1.
203. The uplink base station acquires a downlink reference signal from a neighboring cell and a local downlink reference signal of the neighboring cell.
In this embodiment, the uplink base station may directly interact with the local downlink reference signal and the precoding codebook of the neighboring cell through an S1 port or an X2 port. Or, the uplink base station may also obtain the downlink information at the cross timeslot first, and then generate the local downlink reference signal and the precoding codebook of the neighboring cell according to the downlink information.
There are various kinds of downlink information. For example, the downlink information may include RB location information, MIMO mode of the downlink base station, rank value, Precoding Matrix Index (PMI), DMRS sequence information, CSI-RS location information, and the like. Note that when the MIMO mode of the downlink base station is TM3, TM4, TM6, or TM9, the PMI needs to be replaced with a precoding codebook. When the MIMO mode of the downlink base station is TM7 or TM8, the downlink information may further include Radio Network Temporary Identity (RNTI), user equipment ID, port, and other information.
If the MIMO mode of the downlink base station is TM2, TM3, TM4, TM6, or TM9, the uplink base station may generate the local CRS using the port information. When the MIMO mode of the downlink base station is TM3, the uplink base station further needs to select a large cyclic delay matrix and a precoding codebook according to a rank value and RB location information; when the MIMO mode of the downlink base station is TM4, TM6, or TM9, the uplink base station further needs to select a precoding codebook according to the rank value and the PMI value.
If the MIMO mode of the downlink base station is TM7 or TM8, the uplink base station may generate a local DMRS using information such as CellID, RNTI, RB location, Port, and the like.
After obtaining the precoding codebook, the uplink base station can obtain the precoding matrix from the precoding codebook.
204. And the uplink base station calculates downlink interference channel information received by the uplink reference signal and downlink interference channel information received by the uplink data signal in the cross time slot according to the downlink reference signal from the adjacent cell and the local downlink reference signal of the adjacent cell.
In this embodiment, if the MIMO mode of the downlink base station is TM2, the estimated value of the downlink channel information of the downlink reference signalAnd the estimated value of the channel information of the downlink interference channel information received by the uplink data signal at the cross time slotThe calculation method of (c) is the same as that in step 106 in the embodiment shown in fig. 1.
If the MIMO mode of the downlink base station is TM3, the uplink base station adopts the following calculation method.
The uplink base station firstly utilizes the local CRS of the adjacent region to calculate the estimated value H of the downlink channel information of the CRSLS,dl. In particular, the method comprises the following steps of,wherein, Ydl,RSIs CRS, S from a neighbouring celldlIs a CRS that is local to the neighbor cell,is the conjugate of the CRS local to the neighbor.
Obtaining an estimated value H of downlink channel information of CRSLS,dlThen, the uplink base station pair HLS,dlThe estimation value of the downlink channel information of the CRS can be obtained by carrying out noise reduction filteringIn particular, the method comprises the following steps of,wherein QdlIs the downlink noise reduction filter coefficient.
Obtaining an estimated value of downlink channel information of CRSThen, the uplink base station can utilize methods such as linear interpolation or wiener filtering and the likeCalculating downlink interference channel information received by uplink DMRS (demodulation reference signal) in cross time slotAnd an estimated value of downlink interference channel information received by the uplink data signal
Then the uplink base station willMultiplying the corresponding precoding matrix to obtain an equivalent channel estimation valueOr will beMultiplying corresponding cyclic large time delay matrix to obtain estimation value of equivalent channel information
If the MIMO mode of the downlink base station is TM4 or TM6, the uplink base station calculates the estimated value of the downlink interference channel information received by the uplink DMRS in the cross time slotAnd an estimated value of downlink interference channel information received by the uplink data signalThen, the uplink base station willMultiplying the corresponding precoding matrix to obtain an equivalent channel estimation value of downlink interference channel information received by the DMRSOr will beMultiplying the corresponding precoding matrix to obtain an equivalent channel estimation value of downlink interference channel information suffered by the uplink data signal
If the MIMO mode of the downlink base station is TM7, TM8 or TM9, the uplink base station adopts the estimated value of the downlink interference channel information received by the uplink DMRS in the cross time slot calculated by the method in TM3Is already containing a precoding matrixEquivalent channel estimation valueThe estimated value of the downlink interference channel information received by the uplink data signal is obtained by calculationIs an equivalent channel estimation value already containing a precoding matrix
205. And the uplink base station calculates the SINR difference before and after the conversion of the cross time slot.
For a detailed description, refer to the description of step 105 in the embodiment of FIG. 1.
206. Judging whether the SINR difference value is larger than a threshold value; if yes, go to step 207, otherwise go to step 208.
For a detailed description, refer to the description of step 106 in the embodiment of FIG. 1.
207. And the uplink base station calculates the statistical information of the uplink interference noise of the adjacent region according to the LS estimation value of the uplink channel information of the uplink reference signal, the estimation value of the uplink channel information of the uplink reference signal and the equivalent channel estimation value of the downlink interference channel information received by the uplink reference signal.
In this embodiment, the uplink interference noise statistic information of the neighboring cell may include interference of the neighboring cell UE, interference of the downlink base station at the cross timeslot that is lower than the interference noise threshold, white noise, and the like.
There are various methods for calculating the uplink interference noise statistical information of the neighboring cell. For example, the uplink base station may obtain the neighbor uplink interference noise statistical information R by averaging over K subcarriersuu,ul：
Where k is the subcarrier number. In practice, K generally takes the length of one RB, i.e., 12. Of course, in practice, Ruu,ulThe calculation may be performed by other formulas, which are not limited herein.
208. And the uplink base station calculates the statistical information of the uplink interference noise of the adjacent region according to the LS estimation value of the uplink channel information of the uplink reference signal and the estimation value of the uplink channel information of the uplink reference signal.
In this embodiment, the uplink interference noise statistic information of the neighboring cell may include interference of the neighboring cell UE, interference of the downlink base station at the cross timeslot that is lower than the interference noise threshold, white noise, and the like.
There are various methods for calculating the uplink interference noise statistical information of the neighboring cell. For example, the uplink base station may obtain the neighbor uplink interference noise statistical information R by averaging over K subcarriersuu,ul：
Where k is the subcarrier number. In practice, K generally takes the length of one RB, i.e., 12. Of course, in practice, Ruu,ulThe calculation may be performed by other formulas, which are not limited herein.
209. And the uplink base station calculates an equalization coefficient according to the channel information of the uplink data signal, the downlink interference channel information suffered by the uplink data signal and the uplink interference noise statistical information of the adjacent region, and processes the uplink signal received by the uplink base station by adopting the equalization coefficient.
The uplink base station calculates the balance coefficientSpecifically, the method comprises the following steps:
the uplink base station is based on the equalization coefficientAnd an uplink reference signal Y from the UEulEstimating UE uplink transmission dataIn particular, the method comprises the following steps of,
in this embodiment, the uplink base station acquires instantaneous channel information of cross interference by monitoring the downlink reference signal of the neighboring cell at the cross timeslot, thereby obtaining approximately ideal MMSE-IRC equalization performance.
In the above description of the method for suppressing TD-LTE cross timeslot interference in the embodiment of the present invention, an uplink base station in the embodiment of the present invention is described below with reference to fig. 3, where the uplink base station 300 in the embodiment of the present invention includes:
an obtaining unit 301, configured to obtain an uplink reference signal from a user equipment and the uplink reference signal local to the user equipment, and a downlink reference signal from a neighboring cell and the downlink reference signal local to the neighboring cell at a cross timeslot;
a first calculating unit 302, configured to estimate uplink channel information of an uplink reference signal and channel information of an uplink data signal according to the uplink reference signal from the user equipment and the uplink reference signal local to the user equipment;
a second calculating unit 303, configured to estimate, according to the downlink reference signal from the neighboring cell and the downlink reference signal local to the neighboring cell, downlink interference channel information suffered by the uplink reference signal and downlink interference channel information suffered by the uplink data signal on a cross timeslot;
a third calculating unit 304, configured to calculate uplink interference noise statistical information of a neighboring cell according to the obtained data, and further calculate an equalization coefficient according to channel information of the uplink data signal, downlink interference channel information received by the uplink data signal, and the uplink interference noise statistical information of the neighboring cell;
a processing unit 305, configured to process the uplink signal received by the uplink base station by using the equalization coefficient.
In the embodiment, the uplink interference noise statistical information of the adjacent region is calculated, and the equalization coefficient is calculated according to the uplink interference noise statistical information of the adjacent region, the channel information of the uplink data signal and the downlink interference channel information received by the uplink data signal, so that more accurate interference channel information can be obtained, and the equalization coefficient can be further adopted to process the uplink signal received by the uplink base station, so as to achieve approximately ideal MMSE-IRC equalization performance exceeding conventional MMSE-IRC; and because the downlink base station at the cross time slot sends signals in the MIMO mode of TM2, it can be compatible with the existing protocol without adding extra signaling overhead.
Preferably, the uplink base station further includes:
a fourth calculating unit (not shown) configured to calculate a difference between signal-to-interference-plus-noise ratios before and after the cross slot conversion according to a least square estimation value of the uplink channel information of the uplink reference signal from the ue and an estimation value of the uplink channel information of the uplink reference signal from the ue;
the third calculating unit 304 is specifically configured to calculate, when a difference between signal-to-interference-plus-noise ratios of the uplink base station before and after the cross timeslot conversion is greater than a preset value, uplink interference noise statistical information of a neighboring cell according to a least square estimation value of uplink channel information of the uplink reference signal, an estimation value of uplink channel information of the uplink reference signal, and an estimation value of downlink channel information of the uplink reference signal;
and when the difference value of the signal to interference plus noise ratios of the uplink base station before and after the cross time slot conversion is less than or equal to a preset value, calculating the statistical information of the uplink interference noise of the adjacent region according to the least square estimation value of the uplink channel information of the uplink reference signal and the estimation value of the uplink channel information of the uplink reference signal.
Preferably, when the downlink reference signal from the neighboring cell is a downlink reference signal sent by the neighboring cell in a MIMO mode of TM3, TM4, or TM6, the obtaining unit is further configured to obtain a precoding matrix;
the second calculating unit 303 is further configured to multiply the precoding matrix and the downlink interference channel information received by the uplink reference signal to calculate equivalent downlink interference channel information received by the uplink reference signal, and further multiply the precoding matrix and the downlink interference channel information received by the uplink data signal to calculate equivalent downlink interference channel information received by the uplink data signal;
when the third calculating unit 304 calculates the statistics information of the uplink interference noise of the neighboring cell and the equalization coefficient, the equivalent downlink interference channel information received by the uplink reference signal is used to replace the downlink interference channel information received by the uplink reference signal, and the equivalent downlink interference channel information received by the uplink data signal is used to replace the downlink interference channel information received by the uplink data signal.
Preferably, when the downlink reference signal from the neighboring Cell is a downlink reference signal sent by the neighboring Cell in the MIMO mode of TM2, the obtaining unit 301 is further configured to obtain a Cell ID and port information of the neighboring Cell, and generate the local downlink reference signal of the neighboring Cell according to the Cell ID and port information of the neighboring Cell.
Preferably, the obtaining unit 301 is further configured to obtain downlink information at a cross timeslot, and generate the local downlink reference signal of the neighboring cell according to the downlink information.
It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.
In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other manners. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.
The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.
In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.
The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.
The above-mentioned embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (10)
1. A method for suppressing TD-LTE cross-slot interference, comprising:
an uplink base station acquires an uplink reference signal from user equipment and the uplink reference signal local to the user equipment, and a downlink reference signal from a neighboring cell and a downlink reference signal local to the neighboring cell at a cross time slot;
the uplink base station estimates uplink channel information of the uplink reference signal and channel information of an uplink data signal according to the uplink reference signal from the user equipment and the uplink reference signal local to the user equipment, wherein an LS estimation value of the uplink channel information of the uplink reference signal is obtained according to the uplink reference signal of the user equipment and the uplink reference signal local to the user equipment, and the LS estimation value is subjected to noise reduction filtering to obtain an estimation value of the uplink channel information of the uplink reference signal;
the uplink base station estimates downlink interference channel information received by the uplink reference signal and downlink interference channel information received by the uplink data signal in a cross time slot according to the downlink reference signal from the adjacent cell and the downlink reference signal local to the adjacent cell, wherein an LS estimation value of the downlink channel information of the downlink reference signal is calculated according to the downlink reference signal from the adjacent cell and the local downlink reference signal of the adjacent cell, and the LS estimation value is subjected to noise reduction filtering to obtain an estimation value of the downlink channel information of the downlink reference signal;
the uplink base station calculates the statistical information of the uplink interference noise of the adjacent cell;
the uplink base station calculates an equalization coefficient according to the channel information of the uplink data signal, the downlink interference channel information suffered by the uplink data signal and the neighbor uplink interference noise statistical information;
the uplink base station processes the uplink signal received by the uplink base station by adopting the equalization coefficient;
the uplink base station calculates an equalization coefficient according to the channel information of the uplink data signal, the downlink interference channel information suffered by the uplink data signal and the neighbor uplink interference noise statistical information, and the method comprises the following steps:
wherein,is thatConjugate transpose of，Is thatThe conjugate transpose of (a) is performed,in order to equalize the coefficients,is an estimated value of channel information of the uplink data signal,is an estimate of the downlink interference channel information, R, experienced by the uplink data signaluu,ulIs the statistical information of the uplink interference noise of the adjacent region.
2. The method of claim 1, wherein the estimating, by the uplink base station, the uplink channel information of the uplink reference signal and the channel information of the uplink data signal according to the uplink reference signal from the user equipment and the uplink reference signal local to the user equipment further comprises:
the uplink base station calculates a difference value of signal-to-interference-plus-noise ratios before and after the cross time slot conversion according to a least square estimation value of uplink channel information of the uplink reference signal from the user equipment and an estimation value of the uplink channel information of the uplink reference signal from the user equipment;
the calculating, by the uplink base station, the neighbor uplink interference noise statistic information according to the obtained data specifically includes:
judging whether the difference value of the signal to interference plus noise ratios of the uplink base station before and after the cross time slot conversion is larger than a threshold value;
if so, the uplink base station calculates the statistical information of the uplink interference noise of the adjacent region according to the least square estimation value of the uplink channel information of the uplink reference signal, the estimation value of the uplink channel information of the uplink reference signal and the estimation value of the downlink interference channel information received by the uplink reference signal;
and if not, the uplink base station calculates the uplink interference noise statistical information of the adjacent region according to the least square estimation value of the uplink channel information of the uplink reference signal and the estimation value of the uplink channel information of the uplink reference signal.
3. The method of claim 2, wherein the downlink reference signal from the neighbor cell is a downlink reference signal transmitted by the neighbor cell in a MIMO mode of TM3, TM4, or TM 6;
the method further comprises the following steps:
the uplink base station also acquires a precoding matrix;
the uplink base station also multiplies the precoding matrix and downlink interference channel information suffered by the uplink reference signal to calculate equivalent downlink interference channel information suffered by the uplink reference signal;
the uplink base station also multiplies the precoding matrix and downlink interference channel information received by the uplink data signal to calculate equivalent downlink interference channel information received by the uplink data signal;
and when the uplink base station respectively calculates the statistics information and the balance coefficient of the uplink interference noise of the adjacent regions, the uplink base station adopts the equivalent downlink interference channel information received by the uplink reference signal to replace the downlink interference channel information received by the uplink reference signal, and adopts the equivalent downlink interference channel information received by the uplink data signal to replace the downlink interference channel information received by the uplink data signal.
4. The method of claim 1, wherein when the downlink reference signal from the neighbor cell is a downlink reference signal transmitted by the neighbor cell in a MIMO mode of TM2,
the acquiring, by the uplink base station, the local downlink reference signal of the neighboring cell specifically includes:
the uplink base station acquires the Cell ID and the port information of the neighboring Cell;
and the uplink base station generates the local downlink reference signal of the neighbor Cell according to the Cell ID and the port information of the neighbor Cell.
5. The method of suppressing TD-LTE cross-slot interference according to claim 1,
the acquiring, by the uplink base station, the local downlink reference signal of the neighboring cell specifically includes:
the uplink base station acquires downlink information at a cross time slot;
and the uplink base station generates the local downlink reference signal of the adjacent region according to the downlink information.
6. An uplink base station, comprising:
an obtaining unit, configured to obtain an uplink reference signal from a user equipment and the uplink reference signal local to the user equipment, and a downlink reference signal from a neighboring cell and the downlink reference signal local to the neighboring cell at a cross timeslot;
a first calculating unit, configured to estimate uplink channel information of the uplink reference signal and channel information of an uplink data signal according to the uplink reference signal from the user equipment and the uplink reference signal local to the user equipment, where an LS estimation value of the uplink channel information of the uplink reference signal is obtained according to the uplink reference signal of the user equipment and the uplink reference signal local to the user equipment, and the LS estimation value is subjected to noise reduction filtering to obtain an estimation value of the uplink channel information of the uplink reference signal;
a second calculating unit, configured to estimate downlink interference channel information suffered by the uplink reference signal and downlink interference channel information suffered by the uplink data signal on a cross timeslot according to the downlink reference signal from the neighboring cell and the downlink reference signal local to the neighboring cell, where an LS estimation value of the downlink channel information of the downlink reference signal is calculated according to the downlink reference signal from the neighboring cell and the local downlink reference signal of the neighboring cell, and the LS estimation value is subjected to noise reduction filtering to obtain an estimation value of the downlink channel information of the downlink reference signal;
a third calculating unit, configured to calculate uplink interference noise statistical information of a neighboring cell according to the obtained data, and further calculate an equalization coefficient according to channel information of the uplink data signal, downlink interference channel information received by the uplink data signal, and the uplink interference noise statistical information of the neighboring cell;
the processing unit is used for processing the uplink signal received by the uplink base station by adopting the equalization coefficient;
wherein, calculating an equalization coefficient according to the channel information of the uplink data signal, the downlink interference channel information suffered by the uplink data signal and the neighbor uplink interference noise statistical information comprises:
wherein,is thatThe conjugate transpose of (a) is performed,is thatThe conjugate transpose of (a) is performed,in order to equalize the coefficients,is an estimated value of channel information of the uplink data signal,is an estimate of the downlink interference channel information, R, experienced by the uplink data signaluu,ulIs the statistical information of the uplink interference noise of the adjacent region.
7. The uplink base station of claim 6, wherein the uplink base station further comprises:
a fourth calculating unit, configured to calculate a difference between signal-to-interference-plus-noise ratios before and after the cross slot conversion according to a least square estimation value of the uplink channel information of the uplink reference signal from the user equipment and an estimation value of the uplink channel information of the uplink reference signal from the user equipment;
the third calculating unit is specifically configured to calculate, when a difference between signal-to-interference-plus-noise ratios of the uplink base station before and after the cross timeslot conversion is greater than a threshold value, uplink interference noise statistical information of a neighboring cell according to a least square estimation value of uplink channel information of the uplink reference signal, an estimation value of uplink channel information of the uplink reference signal, and an estimation value of downlink channel information of the uplink reference signal;
and when the difference value of the signal to interference plus noise ratio of the uplink base station before and after the cross time slot conversion is less than or equal to a threshold value, calculating the uplink interference noise statistical information of the adjacent region according to the least square estimation value of the uplink channel information of the uplink reference signal and the estimation value of the uplink channel information of the uplink reference signal.
8. The uplink base station according to claim 7, wherein the obtaining unit is further configured to obtain a precoding matrix when the downlink reference signal from the neighbor cell is a downlink reference signal sent by the neighbor cell in a MIMO mode of TM3, TM4, or TM 6;
the second calculating unit is further configured to multiply the precoding matrix and the downlink interference channel information received by the uplink reference signal to calculate equivalent downlink interference channel information received by the uplink reference signal, and further multiply the precoding matrix and the downlink interference channel information received by the uplink data signal to calculate equivalent downlink interference channel information received by the uplink data signal;
and when the third calculation unit calculates the statistics information and the balance coefficient of the uplink interference noise of the adjacent cell respectively, the third calculation unit replaces the downlink interference channel information received by the uplink reference signal with the equivalent downlink interference channel information received by the uplink reference signal, and replaces the downlink interference channel information received by the uplink data signal with the equivalent downlink interference channel information received by the uplink data signal.
9. The uplink base station according to claim 6, wherein when the downlink reference signal from the neighboring cell is a downlink reference signal sent by the neighboring cell in a MIMO mode of TM2,
the acquiring unit is further configured to acquire the Cell ID and the port information of the neighboring Cell, and generate the local downlink reference signal of the neighboring Cell according to the Cell ID and the port information of the neighboring Cell.
10. The uplink base station of claim 6,
the obtaining unit is further configured to obtain downlink information at the cross timeslot, and generate the local downlink reference signal of the neighboring cell according to the downlink information.
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| CN106941464B (en) * | 2016-01-04 | 2020-01-21 | 中国移动通信集团公司 | Interference elimination method, base station and user equipment |
| WO2017190272A1 (en) * | 2016-05-03 | 2017-11-09 | 华为技术有限公司 | Interference elimination method and base station |
| WO2020000317A1 (en) * | 2018-06-28 | 2020-01-02 | Telefonaktiebolaget Lm Ericsson (Publ) | Methods and devices for channel estimation |
| CN113852441B (en) * | 2020-06-28 | 2023-04-14 | 大唐移动通信设备有限公司 | Cross time slot interference processing method, base station, device and medium |
| CN112512077B (en) * | 2020-12-15 | 2023-08-11 | 中国联合网络通信集团有限公司 | Method and device for evaluating uplink rate |
| CN115021858B (en) * | 2021-03-05 | 2024-07-26 | 深圳市运联通通信服务有限公司 | Interference suppression method and related device, base station and storage medium |
| CN115087014B (en) * | 2022-06-20 | 2024-04-12 | 中国联合网络通信集团有限公司 | Uplink signal detection method and device for flexible frame structure simulation system |
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