WO2014201875A1

WO2014201875A1 - Method for eliminating cross-slot interference, and terminal

Info

Publication number: WO2014201875A1
Application number: PCT/CN2014/072433
Authority: WO
Inventors: 张连波; 李云波; 张佳胤
Original assignee: 华为技术有限公司
Priority date: 2013-06-21
Filing date: 2014-02-24
Publication date: 2014-12-24
Also published as: CN104244261A; CN104244261B

Abstract

Provided are a method for eliminating cross-slot interference, and a terminal. The method comprises: a first terminal adopting the device-to-device (D2D) technique to create an interference set of the first terminal, wherein the interference set comprises at least one second terminal in a neighbouring cell of a cell in which the first terminal is located; if the first terminal is in a downlink receiving state and the second terminal is in an uplink sending state, then the first terminal reconstructing the cross-slot interference of the second terminal in the uplink sending state to the first terminal; and the first terminal removing the cross-slot interference from received downlink information to obtain the downlink information from which the cross-slot interference has been eliminated. The method can eliminate cross-slot interference between terminals in the prior art.

Description

Cross-slot interference cancellation method and terminal

The present invention relates to the field of communications, and in particular, to a method and a terminal for eliminating cross-slot interference. Background technique

Duplex is defined as the way information can be sent simultaneously in two directions between two points. In wireless communication, the commonly used duplex mode is sometimes divided into duplex (Time Division Duplex, TDD for short), Frequency Division Duplex (FDD), and Hybrid Division Duplex (HDD). In the TDD mode, if the uplink and downlink switching points (Switch Point) in the frame structure remain unchanged while the wireless communication system is running, it is called static TDD; if the uplink and downlink switching points (Switch Point) in the frame structure are When the system is running, it changes in a small time scale (for example, less than 100ms), so it is called dynamic TDD.

In static TDD, since the position of the uplink and downlink switching points remains unchanged, the uplink and downlink subframe (symbol) ratio is constant. In dynamic TDD, the position of the uplink and downlink switching points can be dynamically changed in a small time scale, and the uplink and downlink subframe (symbol) ratio also changes. Therefore, dynamic TDD can better adapt to transient changes in the service, thereby reducing the queue delay of the service, improving system throughput and spectrum efficiency. This feature has obvious advantages in scenarios where the uplink and downlink traffic volume fluctuates frequently. Due to the above advantages of dynamic TDD systems, attention has been paid to the subsequent evolution of Long Term Evolution (LTE) systems and Wireless LANs (WLANs).

In a static TDD system, since the switching point is fixed in position and the whole network is the same, the downlink interference comes from the neighboring base station (or Access Point (AP), LTE base station (eNodeB), etc.) to the target mobile station. (or the interference of the terminal (STA), User Equipment (UE), etc.); the uplink interference comes from the neighboring mobile station (or STA, UE, etc.) to the target base station (or AP, eNodeB, etc.) interference. As shown in Figure 1. In a dynamic TDD system, if the uplink and downlink switching points between the neighboring cells are not aligned, and the uplink and downlink frames have mutually interleaved portions, in addition to the interference in FIG. 1, there is also cross-slot interference. as shown in picture 2. The shaded portion of the frame on the right side of Figure 2 indicates the overlap between the two cell frames, that is, the uplink and downlink switch points of the two cells are not aligned. Therefore, the uplink reception of the base station (BS) k is interfered by the downlink of the neighboring area BS0; and the downlink reception of the mobile station (MS) 0 is interfered by the neighboring area MSk.

Due to the existence of cross-slot interference, in order to exert the advantage that the dynamic TDD system can adapt to the instantaneous fluctuation of the service, it is necessary to eliminate the cross-slot interference between the STA and the STA. Summary of the invention

In view of this, the embodiments of the present invention provide a method and a terminal for eliminating cross-slot interference, which are used to eliminate cross-slot interference between STAs and terminals in the prior art.

In a first aspect, the embodiment of the present invention provides a method for eliminating cross-slot interference, including: if the first terminal is in a downlink receiving state, and the second terminal is in an uplink sending state, the first terminal reconstructs the second Inter-slot interference caused by the terminal to the first terminal; the second terminal is a terminal in the interference set of the first terminal;

The first terminal removes the cross-slot interference in the received downlink information, and obtains downlink information after the cross-slot interference is eliminated.

With reference to the first aspect, in a first possible implementation manner, before the resolving, by the first terminal, the cross-slot interference caused by the second terminal to the first terminal, the method further includes:

The first terminal creates an interference set of the first terminal, where the interference set includes at least one second terminal in a neighboring cell of the cell where the first terminal is located.

With reference to the first aspect and the first possible implementation manner, in a second possible implementation manner, the first terminal, where the first terminal creates an interference set of the first terminal, includes:

The first terminal sends the search information to all the second terminals in the preset range, and receives the response information fed back by the second terminal according to the search information;

The first terminal creates a device-to-device D2D set of the first terminal according to the response information, where the D2D set includes information of the second terminal corresponding to the response information;

The first terminal measures the received power of the local area of the access point of the cell where the first terminal is located, and measures the received power of the neighboring area of the access point in the neighboring cell of the cell where the first terminal is located; And if the absolute value of the difference between the received power of the local area and the received power of the neighboring area is less than a preset threshold, the second terminal served by the access point corresponding to the received power of the neighboring area in the D2D set is interfered with set.

With reference to the first aspect and the second possible implementation manner, in a third possible implementation, the first terminal sends the search information to all the second terminals in the preset range, including:

The first terminal broadcasts a search to all second terminals in the preset range by using a broadcast polling manner.

In combination with the first aspect and the second possible implementation manner, in a fourth possible implementation manner, the method further includes:

The first terminal periodically updates the interference set.

With reference to the first aspect and the first to fourth possible implementation manners, in a fifth possible implementation manner, after the step of the first terminal to create the interference set of the first terminal, the method further includes: The first terminal sends the interference set to the access point of the cell where the first terminal is located, so that the access point of the cell where the first terminal is located sets the interference set and the neighboring cell of the cell where the first terminal is located The access point is shared.

With reference to the first aspect, and any one of the foregoing possible implementation manners, in a sixth possible implementation, the first terminal reconfiguring the cross-slot interference caused by the second terminal to the first terminal includes: The first terminal acquires channel state information between the first terminal and the second terminal

CSI;

Reconstructing the cross-slot interference caused by the second terminal to the first terminal according to the CSI. With reference to the first aspect and the sixth possible implementation manner, in a seventh possible implementation manner, the acquiring, by the first terminal, the CSI between the first terminal and the second terminal includes:

The first terminal acquires uplink measurement pilot information of the second terminal by using a D2D technology; the first terminal measures an uplink pilot signal of the second terminal according to the uplink measurement pilot information, to obtain the CSI between a terminal and the second terminal.

With reference to the first aspect, the sixth and the seventh possible implementation manner, in an eighth possible implementation, the cross-slot interference caused by the second terminal to the first terminal is reconstructed according to the CSI, Includes:

The first terminal receives the data sent by the second terminal by using the D2D technology, and obtains a channel between the first terminal and the second terminal according to the CSI corresponding to the second terminal; And reconstructing, according to the channel and the data, cross-slot interference caused by the second terminal to the first terminal.

In a second aspect, an embodiment of the present invention provides a terminal, including:

a cross-slot interference reconstruction unit, configured to: when the terminal is in a downlink receiving state, and when the second terminal is in an uplink sending state, reconstructing, by the second terminal, the cross-slot interference caused by the second terminal; a terminal in the interference set of the terminal;

a cross-slot interference removal unit, configured to remove the cross-slot interference in the received downlink information after the cross-slot interference reconstruction unit reconstructs the cross-slot interference, and obtain the cross-slot interference cancellation Downstream information.

With reference to the second aspect, in a first possible implementation manner, the terminal further includes: a creating unit, configured to create the terminal before the cross-slot interference reconstruction unit reconstructs the cross-slot interference The interference set includes at least one second terminal in a neighboring cell of the cell where the terminal is located.

With reference to the second aspect and the first possible implementation manner, in a second possible implementation manner, the creating unit is specifically configured to be used

Sending the search information to all the second terminals in the preset range, and receiving the response information fed back by the second terminal according to the search information;

Creating a device-to-device D2D set of the terminal according to the response information, where the D2D set includes information of the second terminal corresponding to the response information;

Measure the received power of the local area of the access point of the cell in which the terminal is located, and measure the received power of the neighboring area of the access point in the neighboring cell of the cell in which the terminal is located;

And if the absolute value of the difference between the received power of the local area and the received power of the neighboring area is less than a preset threshold, the second terminal served by the access point corresponding to the received power of the neighboring area in the D2D set is interfered with set.

With reference to the second aspect and the foregoing possible implementation manner, in a third possible implementation manner, the terminal further includes: a sharing unit;

The sharing unit is configured to: after the creating unit creates the interference set, send the interference set to an access point of a cell where the terminal is located, so that an access point of a cell where the terminal is located: the interference The set is shared with an access point in a neighboring cell of the cell in which the terminal is located.

In combination with the second aspect and the first to third possible implementations, in a fourth possible implementation Wherein the cross-slot interference reconstruction unit is specifically used for

When the terminal is in the downlink receiving state, and the second terminal is in the uplink sending state, acquiring channel state information CSI between the terminal and the second terminal in the uplink sending state;

Reconstructing the cross-slot interference caused by the second terminal to the terminal according to the CSI.

With reference to the second aspect and the fourth possible implementation manner, in a fifth possible implementation manner, the cross-slot interference reconstruction unit is specifically used to

When the terminal is in the downlink receiving state, and the second terminal is in the uplink sending state, the D2D technology is used to obtain the uplink measurement pilot information of the second terminal in the uplink sending state;

And measuring an uplink pilot signal of the second terminal according to the uplink measurement pilot information, to obtain a CSI between the terminal and the second terminal in an uplink sending state;

With reference to the second aspect and the fourth and fifth possible implementation manners, in a sixth possible implementation manner, the cross-slot interference reconstruction unit is specifically used for

When the terminal is in the downlink receiving state, and the second terminal is in the uplink sending state, acquiring channel state information CSI between the terminal and the second terminal;

Receiving data sent by the second terminal by using the D2D technology, and obtaining a channel between the terminal and the second terminal according to a CSI corresponding to the second terminal;

And reconstructing cross-slot interference caused by the second terminal to the terminal according to the channel and the data.

According to the foregoing technical solution, the method and the terminal for eliminating the cross-slot interference in the embodiment of the present invention can reconstruct the cross-slot interference caused by the second terminal to the first terminal when the first terminal and the second terminal are simultaneously scheduled, so that The first terminal removes the cross-slot interference in the received downlink information, and obtains the downlink information after the cross-slot interference is eliminated, thereby achieving the purpose of eliminating the cross-slot interference between the STAs/terminals in the prior art. DRAWINGS

In order to more clearly illustrate the technical solution of the present invention, a brief description of the drawings to be used in the embodiments will be briefly made. The following drawings are only drawings of some embodiments of the present invention, which are common in the art. For the skilled person, other drawings which can also realize the technical solution of the present invention can also be obtained according to the drawings without any creative labor. 1 is a schematic diagram of neighboring interference in a static TDD system in the prior art; FIG. 2 is a schematic diagram of cross-slot interference in a dynamic TDD system in the prior art; FIG. 3 is a schematic diagram of isolation of clusters in the prior art. ;

4 is a schematic diagram of dynamic TDD based on resource allocation and power control in the prior art; FIG. 5 is a schematic diagram of HDD frequency resource allocation in the prior art;

6 is a schematic diagram of cross-slot interference cancellation of an HDD in the prior art;

7A-7D are schematic flowcharts of a method for eliminating cross-slot interference according to an embodiment of the present invention;

FIG. 8 is a schematic structural diagram of a method for eliminating cross-slot interference according to an embodiment of the present invention; FIG. 8B is a schematic flowchart of a method for eliminating cross-slot interference according to another embodiment of the present invention;

9A and FIG. 9B are schematic diagrams showing the structure of a terminal according to an embodiment of the present invention;

FIG. 10 is a schematic structural diagram of a terminal according to another embodiment of the present invention. detailed description

The technical solutions of the present invention will be clearly and completely described in the following with reference to the drawings in the embodiments of the present invention. It will be apparent that the various embodiments described below are merely exemplary embodiments of the invention. Based on the following various embodiments of the present invention, those skilled in the art can obtain other technical features that can solve the technical problems of the present invention and achieve the technical effects of the present invention by equivalently transforming some or even all of the technical features without creative work. The various embodiments of the invention are apparent from the scope of the invention as disclosed.

In order to facilitate the understanding of the present invention, a cross-slot interference between STAs is shown in the prior art. In the prior art, the first method for reducing cross-slot interference is to divide the BSs into the same cluster if the large-scale fading between the BSs (or APs, eNodeBs, etc.) is lower than a certain threshold. (Cluster). Static TDD is used for all cells in the same cluster, and the switching points of the uplink and downlink frames are aligned. However, for different clusters, the switching points of the uplink and downlink frames between each other do not need to be aligned. As shown in Figure 3.

However, although the above technical solution can achieve dynamic TDD between clusters, it cannot be done in clusters. Dynamic TDD also reduces the flexibility of dynamic TDD. For seamless coverage scenarios, the interference problem at the edge of the cluster is still unresolved. In particular, if the cluster is too large and contains too many BSs, the meaning of dynamic TDD will be lost.

To this end, the second method for reducing cross-slot interference is provided in the prior art, specifically: first, the MS (or STA, UE, etc.) in the cell is divided into inner rings according to signal reception quality or signal reception strength (inner) And the outer circle (outer); Secondly, by the resource allocation method, the resources close to the switching point are preferentially assigned to the inner circle MS (the time slot near the switching point is more likely to be interfered). Since the inner ring MS needs lower downlink (DL) and uplink (UL) power to meet the performance requirements, the interference power between the MS-MSs is reduced. As shown in Figure 4.

In practical applications, the technical solution of the prior art 2 does reduce the cross-slot interference power between the BSs, but since the UL transmit power of the inner ring MS is also reduced, the UL signal to interference and noise ratio of the inner ring MS (Signal) To Interference plus Noise Ratio (SINR) is not necessarily improved.

In addition, in the prior art, a third method for reducing cross-slot interference is provided, which is specifically: dividing an MS (or STA, UE, etc.) in a cell into an inner circle (inner) and an outer according to signal reception quality or signal reception strength. Outer. And two duplex modes (FDD and TDD, hybrid duplex mode HDD) are used at the same time, and the two duplex modes work on separate frequency bands (or carriers). For the uplink of the outer ring MS, the FDD mode is adopted; for the uplink and downlink of the inner ring MS and the downlink of the outer ring MS, the TDD mode is adopted, as shown in FIG. 5.

Among them, since the uplink of the outer ring MS adopts the independent frequency band (carrier) FDD mode, the downlink cross-slot interference generated by it is completely eliminated. As shown in Figure 6.

However, the disadvantage of adopting HDD in the third technical solution is that the system complexity is high, and the two duplex modes are adopted, and the wireless communication system is difficult to implement. In addition, because the outer circle users separately occupy the uplink FDD—an independent frequency band (carrier), it is inconsistent with the dynamic adaptability of dynamic TDD to resources. At the same time, the complexity of system resource scheduling is also high.

In the dynamic TDD system, if the uplink and downlink switching points between the neighboring cells are not aligned, and the uplink and downlink frames have mutually interleaved portions, in addition to the interference in FIG. 1, there is also cross-slot interference between the MSs. as shown in picture 2. The shaded portion of the frame on the right side of Figure 2 indicates the overlap between the two cell frames, that is, the uplink and downlink switch points of the two cells are not aligned. Therefore, for the uplink reception of the BSk, the downlink interference of the neighboring area BS0 is received; for the downlink reception of the MS0, the neighboring area MSk is received. Interference. To this end, the embodiments of the present invention provide a technical solution for eliminating interference between STAs and STAs.

The basic idea of the embodiment of the present invention is: If the strong interference can be separated by resources through centralized scheduling, the scheduling can be used for interference coordination. It should be noted that even if centralized scheduling is used for interference coordination, it is necessary to know the interference set of the STA. When centralized scheduling does not work, for example, STA pairs that interfere with each other require large bandwidth, or time is required due to carrier switch (similar to Radio Resource Control (RRC) signaling in LTE. Interacting) If there is no time to stagger the carrier, the interference cancellation method is used. In order to eliminate the cross-slot interference between the STA-STA, the STA may be considered to have an uplink measurement function, reconstruct the cross-slot interference signal, and then downlink the receiver in the STA. Eliminate upstream interference. At the same time, the STAs are required to send data through the Device to Device (D2D) technology.

It should be noted that, in the embodiment of the present invention, a terminal may be referred to as a UE, a mobile station (Mobile Station, referred to as "MS"), a mobile terminal (Mobile Terminal) STA, etc., for example, the terminal may be a mobile phone ( Or a "cellular" telephone, a computer with a mobile terminal, etc., for example, the terminal can also be a portable, pocket, handheld, computer built-in or in-vehicle mobile device.

FIG. 7A is a schematic flowchart showing a method for eliminating cross-slot interference according to an embodiment of the present invention. As shown in FIG. 7A, the method for eliminating cross-slot interference in this embodiment is as follows.

101. If the first terminal is in the downlink receiving state, and the second terminal is in the uplink sending state, the first terminal reconstructs the cross-slot interference caused by the second terminal to the first terminal; A terminal in the interference set of the first terminal.

102. The first terminal removes the cross-slot interference in the received downlink information, and obtains downlink information after the cross-slot interference is removed.

For example, the interference set of the first terminal may be the interference set created by the first terminal by using the D2D technology, or the interference set of the first terminal may also share the interference set of the first terminal by other terminals, which is not performed in this embodiment. limited.

The cross-slot interference cancellation method in this embodiment may reconfigure the cross-slot interference caused by the second terminal to the first terminal when the first terminal and the second terminal are simultaneously scheduled, so that the first terminal is in the received downlink information. The cross-slot interference is removed, and the downlink information after the cross-slot interference cancellation is obtained, thereby achieving the purpose of eliminating the cross-slot interference between the STAs in the prior art. Optionally, as shown in FIG. 7B, based on the method for eliminating cross-slot interference shown in FIG. 7A, the foregoing method further includes the following step 100:

100. The first terminal creates an interference set of the first terminal, where the interference set includes at least one second terminal in a neighboring cell of the cell where the first terminal is located.

For example, the first terminal may create a interference set of the first terminal by using D2D technology. The cross-slot interference cancellation method of the embodiment, the interference set is created by the first terminal, and the cross-slot interference caused by the second terminal to the first terminal can be reconstructed when the first terminal and the second terminal are simultaneously scheduled, so that The first terminal removes the cross-slot interference in the received downlink information, and obtains the downlink information after the cross-slot interference is eliminated, thereby eliminating the cross-slot interference between the STAs in the prior art.

In an optional implementation scenario, based on the method for eliminating cross-slot interference shown in FIG. 7B, the foregoing step 100 may include sub-steps 1001 to sub-steps not shown in the following figure. 1004:

The first terminal sends the search information to all the second terminals in the preset range, and receives the response information fed back by the second terminal according to the search information.

For example, the first terminal broadcasts the search information to all the second terminals in the preset range by using a Broadcast Poll.

1002: The first terminal creates a D2D set of the first terminal according to the response information, where the D2D set includes information about a second terminal corresponding to the response information;

1003. The first terminal measures the received power of the local area of the access point of the cell where the first terminal is located, and measures the received power of the neighboring area of the access point in the neighboring cell of the cell where the first terminal is located.

For example, the local area receiving power PI of the access point API of the cell where the first terminal is located, and the neighboring area receiving power of the access point ΑΡι in the neighboring cell of the first terminal are Ρι.

1004. If the absolute value of the difference between the received power of the local area and the received power of the neighboring cell is less than a preset threshold, the second terminal served by the access point corresponding to the received power of the neighboring cell in the D2D set is used. Compose the interference set.

That is, if the absolute value of the difference between the local area received power P1 and the neighboring received power Pi is less than a preset threshold, the access point corresponding to the neighboring received power Pi in the D2D set is ΑΡι The second terminal served constitutes a set of interference.

It should be understood that the access point 邻ι in the neighboring cell of the cell where the first terminal is located refers to the access point AP in the first neighboring cell of the cell where the first terminal is located. The range of 1 is a positive integer greater than 1, and less than or equal to the total number of neighbors plus one. If the total number of neighboring cells in the cell where the first terminal is located is five, the value of i is 2 to 6.

Optionally, the first terminal may periodically update the interference set. That is to say, in the actual application, since the first terminal has mobility, the interference set of the first terminal needs to be periodically updated.

In another optional implementation scenario, based on the method for eliminating cross-slot interference shown in FIG. 7B, after the foregoing step 100, the method further includes a step not shown in the following figure. 100a:

100a: The first terminal sends the interference set to an access point of a cell where the first terminal is located, so that an access point of a cell where the first terminal is located, the interference set, and a cell where the first terminal is located Access points in the neighboring area are shared.

The foregoing step 100a may be located before any of the foregoing steps 101, 102, or after any step, which is not limited in this embodiment.

Further, as shown in FIG. 7C, based on the method for eliminating cross-slot interference shown in FIG. 7A, the aforementioned step 101 may include the following sub-step 1011 and sub-step 1012:

If the first terminal is in the downlink receiving state and the second terminal is in the uplink sending state, the first terminal acquires channel state information between the first terminal and the second terminal.

State Information, CSI).

For example, the acquiring, by the first terminal, the CSI between the first terminal and the second terminal includes: the first terminal may obtain the uplink measurement pilot information of the second terminal in an uplink sending state by using the D2D technology; And measuring an uplink pilot signal of the second terminal according to the uplink measurement pilot information, to obtain CSI between the first terminal and the second terminal in an uplink sending state.

1012. Reconfigure, according to the CSI, cross-slot interference caused by the second terminal to the first terminal.

For example, the first terminal receives the data sent by the second terminal by using the D2D technology, and obtains a channel between the first terminal and the second terminal according to the CSI corresponding to the second terminal; The channel and the data reconstruct cross-slot interference caused by the second terminal to the first terminal.

The method for eliminating cross-slot interference in the above embodiment can eliminate cross-slot interference between STAs in the prior art.

FIG. 7D is a schematic flowchart of a method for eliminating cross-slot interference according to an embodiment of the present invention. As shown in FIG. 7D, the method for eliminating cross-slot interference in this embodiment is as follows. The first terminal uses the D2D technology to create the interference set of the first terminal, where the interference set includes at least one second terminal in the neighboring cell of the cell where the first terminal is located.

202. The first terminal acquires CSI between the first terminal and each second terminal in the interference set.

For example, CSI may refer to a channel matrix H between a first terminal and a second terminal (referred to as a channel)

H) o

203. When the first terminal is in a downlink receiving state, and the target second terminal is in an uplink sending state, the first terminal reconstructs the target second terminal according to the CSI corresponding to the target second terminal. Inter-slot interference caused by the first terminal.

The target second terminal is a general term of one or more second terminals in the uplink transmission state in the interference set.

204. The first terminal removes the cross-slot interference in the received downlink information, and obtains downlink information after the cross-slot interference is eliminated.

The method for eliminating cross-slot interference in the foregoing embodiment, the interference set is created by the first terminal, and the CSI between the first terminal and the second terminal in the interference set is obtained, and then the first terminal and the target second terminal are simultaneously During the scheduling, the cross-slot interference information caused by the second terminal to the first terminal may be reconstructed, so that the first terminal removes the cross-slot interference information in the received downlink information, and obtains the downlink information after the cross-slot interference is eliminated, and further Eliminating cross-slot interference between STAs in the prior art.

Optionally, the foregoing step 202 may include sub-steps 2021 through 2022 of not shown in the following figures:

2021: The first terminal acquires uplink measurement pilot information of each second terminal in the interference set by using a D2D technology.

The first terminal is configured to measure, according to the uplink measurement pilot information, an uplink pilot signal of the second terminal that is corresponding to the uplink measurement pilot information, to obtain that the first terminal corresponds to the uplink measurement pilot information. CSI between the second terminals.

In an alternative implementation scenario, the aforementioned step 203 can include sub-steps 2031 through 2032, which are not shown in the following figures:

The first terminal receives the data 发送ι transmitted by the target second terminal by using the D2D technology, and obtains the channel Hli between the first terminal and the target second terminal according to the CSI corresponding to the target second terminal. ; 2032. The first terminal reconstructs, according to the channel Hli and the data Xi, a cross-slot interference Η1ιΧι caused by the target second terminal to the first terminal.

It should be noted that Xi in step 2031 refers to data X transmitted by the second terminal in the first neighboring cell of the cell where the first terminal is located, and Dli in step 2032 refers to the first terminal. a channel H between the second terminal and the first terminal in the first neighboring cell of the cell in which the cell is located. Where i ranges from a positive integer greater than one.

8A is a block diagram showing a method for eliminating cross-slot interference cancellation according to an embodiment of the present invention, and FIG. 8B is a schematic flowchart showing a method for eliminating cross-slot interference according to another embodiment of the present invention. As shown in and 8B, the cross-slot interference cancellation method in this embodiment is as follows.

In a dynamic TDD system, in order to eliminate cross-slot interference between STAs (or MSs, etc.), the STA needs to have an uplink measurement function, reconstruct cross-slot interference, and then eliminate uplink interference in the STA downlink receiver.

301. STA1 creates an interference set of the STA1.

3011. STA1 knows which STAs are in the surrounding (ie, preset range) through D2D technology.

For example, the STA1 can use the broadcast polling method to send the search information to the second terminal in the preset range. The STA2 (ie, the second terminal) around the STA1 can feedback its existence according to the search information, and the feedback manner can be time-divided. , frequency division or code division.

The preset range is usually less than or equal to the coverage of the base station corresponding to STA1 or the coverage of the access point API of the local area.

3012. The STA2 of the feedback response information around the STA1 may have the STA1 in the local area or the STA2 in the neighboring area, and all the STA2s that feedback the response information constitute the D2D set of the STA1.

For example, the response information may include information such as STA2's Media Access Control (MAC) address, or STA2 identifier.

3013. STA1 measures the received power of the API in the local area and the neighboring area APi. It is assumed that the received power P1 of the local area and the received power Pi of a neighboring area. If the absolute value abs(Pl-Pi) < threshold (preset threshold) is taken, STA1 will The STA2 of the APi service in the D2D group is placed in the interference set of STA1.

The neighboring cell in this embodiment generally refers to a cell having radio signals overlapping each other.

3014. The STA1 reports the interference set to the API, and the API shares the interference set information with the neighboring area APi through the backhaul (backhaul line).

In practical applications, because the STA has mobility, the interference set of STA1 needs to be more cyclical. New. If the STA is in a scene with a relatively fast mobility, the period may be shorter; in a scenario where the STA is slower, the period may be longer. The period of the place is set according to actual needs.

302. STA1 acquires CSI between the STA1 and each STA2 in the interference set.

3021, STA1 and its neighboring cell in the interference set STA2 exchanges respective uplink measurement sounding information such as time period, frequency domain position, sounding power, etc. through D2D;

3022: The STA1 measures the uplink measurement pilot (sounding by the STA) of the STA2 in the interference symbol set in the corresponding symbol/slot to obtain the CSI between the STA2 and the STA2 in the interference set.

It should be noted that STA1 is the symbol/time slot of the uplink measurement pilot information that STA2 sends to STA1 in the interference set.

Optionally, in other embodiments, STA1 measures the CSI between the interference set STA2 and the interference set STA2 through the UL pilot signal when receiving the cross-slot interference. Gp, in the downlink receiver of STA1, it will receive the cross-slot interference signal (actually the uplink transmission signal of STA2 in the neighbor interference set, the uplink transmission signal includes the uplink demodulation pilot signal, which can be based on the uplink solution The pilot signal estimates the uplink channel of the interference signal, which in turn results in CSI with STA2 in the interference set.

303. When STA1 is in the downlink receiving state and the target STA2 is in the uplink sending state, STA1 reconstructs the cross-slot interference information caused by the target STA2 to the STA1 according to the CSI corresponding to the target STA2.

The target STA2 is any STA2 in the uplink transmission state in the interference set. In a specific application, the target STA2 may also be a collective name of multiple STA2s in the uplink transmission state in the interference set.

Specifically, 3031, if STA1 and one STA2 of its interference set (referred to as target STA2) are simultaneously scheduled, and STA1 is in a downlink receiving state, and target STA2 is in an uplink sending state, target STA2 needs to share its sending data to STA1 through D2D. (eg Xi);

3032. The STA1 reconstructs the cross-slot interference HliXi of the target STA2 to the STA1 by using the estimated channel Hli between the STA1 and the target STA2 and the transmission data Xi of the shared target STA2.

304. STA1 subtracts the cross-slot interference HliXi of the target STA2 in its downlink information Y1, and obtains downlink information 消除1-Η1ιΧι for eliminating cross-slot interference between STAs.

It should be noted that, if a wireless communication system does not use dynamic TDD, wherein the uplink and downlink switching points of each cell radio frame are fixed, but are not aligned with each other, the foregoing steps 301 to 304 may be used. The method performs the elimination of cross-slot interference between MSs.

The method for eliminating cross-slot interference in this embodiment can effectively eliminate the dynamic TDD The cross-slot interference between the STAs enables the dynamic TDD to effectively adapt to the advantages of the instantaneous volatility service, and improves the throughput and spectrum efficiency of the system.

FIG. 9A is a schematic structural diagram of a terminal according to an embodiment of the present invention. As shown in FIG. 9A, the terminal in this embodiment includes: a cross-slot interference reconstruction unit 41 and a cross-slot interference removal unit 42;

The cross-slot interference reconstruction unit 41 is configured to: when the terminal is in the downlink receiving state, and when the second terminal is in the uplink sending state, reconstruct the cross-slot interference caused by the second terminal to the terminal; The terminal is a terminal in the interference set of the terminal;

The cross-slot interference removal unit 42 is configured to remove the cross-slot interference in the received downlink information after the cross-slot interference reconstruction unit 41 reconstructs the cross-slot interference, to obtain cross-slot interference cancellation. After the downlink information.

For example, the cross-slot interference reconstruction unit 41 may be specifically used for

In an optional implementation scenario, the cross-slot interference reconstruction unit 41 is specifically configured to

In another optional implementation scenario, the cross-slot interference reconstruction unit 41 is specifically configured to

Receiving data sent by the second terminal by using the D2D technology, and according to the second terminal

The CSI obtains a channel between the terminal and the second terminal;

And reconstructing cross-slot interference caused by the second terminal to the terminal according to the channel and the data. ,

In the above embodiment, the terminal reconstructs the cross-slot interference caused by the second terminal to the terminal by using the cross-slot interference reconstruction unit, so that the cross-slot interference removal unit removes the cross in the received downlink information. The time slot interference is obtained, and the downlink information after the cross-slot interference is eliminated is obtained, thereby eliminating the prior art.

Cross-slot interference between STAs.

Optionally, as shown in FIG. 9B, the terminal shown in FIG. 9B may further include: a creating unit 40;

The creating unit 40 is configured to create an interference set of the terminal before the cross-slot interference reconstruction unit 41 reconstructs the cross-slot interference, where the interference set includes a neighboring cell in a cell where the terminal is located At least one second terminal.

In a specific implementation process, the creating unit 40 is specifically used to

For example, the creating unit 40 is specifically used to

Sending the search information to all the second terminals in the preset range by using the broadcast polling manner, and receiving the response information fed back by the second terminal according to the search information;

Creating a D2D set of the terminal according to the response information, where the D2D set includes information of the second terminal corresponding to the response information;

Measure the local receiving power P1 of the access point API of the cell where the terminal is located, and measure the neighboring receiving power Pi of the access point ΑΡι in the neighboring cell of the cell where the terminal is located;

If the absolute value of the difference between the received power P1 of the local area and the received power Pi of the neighboring area is less than a preset threshold, the second access service of the access point corresponding to the neighboring received power Pi in the D2D set is served. The terminal constitutes a set of interference.

In a specific application, the creating unit 40 is further configured to periodically update the interference set after the interference set is created.

In another optional implementation scenario, the terminal shown in FIG. 9B may further include: a sharing unit, where the sharing unit is configured to: after the creating unit 40 creates the interference set, The access point of the cell where the terminal is located sends the interference set, so that the access point of the cell where the terminal is located shares the interference set with the access point in the neighboring cell of the cell where the terminal is located.

In the above embodiment, the terminal creates an interference set by creating a unit, and then reconstructs the cross-slot interference caused by the second terminal to the terminal by using the cross-slot interference reconstruction unit, so that the cross-slot interference removal unit removes the cross in the received downlink information. The time slot interference is obtained, and the downlink information after the cross-slot interference cancellation is obtained, thereby eliminating the cross-slot interference between the terminals in the prior art.

FIG. 10 is a schematic structural diagram of a terminal according to another embodiment of the present invention. As shown in FIG. 10, the terminal in this embodiment includes: a processor 0101, a memory 0201, and a bus 0301, between the processor 0101 and the memory 0201. The processor 0201 is configured to store an instruction, and the processor 0101 executes the instruction, which specifically includes:

If the terminal is in the downlink receiving state, and the second terminal is in the uplink sending state, reconstructing the cross-slot interference caused by the second terminal to the terminal; the second terminal is the terminal in the interference set of the terminal;

The cross-slot interference is removed from the received downlink information, and downlink information after cross-slot interference cancellation is obtained.

Or, in an optional embodiment, the processor 0101 executes the instruction, where the method includes: creating, by using a D2D technology, an interference set of the terminal, where the interference set includes a neighboring cell in a cell where the terminal is located At least one second terminal;

If the terminal is in the downlink receiving state, and the second terminal is in the uplink sending state, reconfiguring the cross-slot interference caused by the second terminal in the uplink sending state to the terminal;

For example, the processor 0101 creates the interference set of the terminal by using the D2D technology, and may include: sending the search information to all the second terminals in the preset range, and receiving the response of the second terminal according to the search information. Information

Measure the received power of the local area of the access point of the cell where the first terminal is located, and measure the received power of the neighboring area of the access point in the neighboring cell of the terminal where the terminal is located;

If the absolute value of the difference between the received power of the local area and the received power of the neighboring cell is less than a preset threshold, the second terminal group served by the access point corresponding to the received power of the neighboring cell in the D2D set is used. Into the interference set.

Optionally, the foregoing processor is further configured to: after the interference set of the terminal is created by using a D2D technology, send the interference set to an access point of a cell where the terminal is located, so as to enable access of a cell where the terminal is located. Pointing the interference set to be shared with an access point in a neighboring cell of the cell in which the terminal is located

In an optional implementation scenario, the processor is specifically configured to: create, by using a D2D technology, a interference set of the terminal, where the interference set includes at least one second terminal in a neighboring cell of the cell where the terminal is located;

If the terminal is in a downlink receiving state, the second terminal is in an uplink sending state, and acquires a CSI between the terminal and the second terminal in an uplink sending state;

For example, the processor 0101 acquires uplink measurement pilot information of the second terminal in an uplink transmission state by using a D2D technology, and measures an uplink pilot signal of the second terminal according to the uplink measurement pilot information, to obtain a location. The CSI between the first terminal and the second terminal in an uplink transmitting state.

Optionally, the processor 0101 receives data sent by the second terminal by using the D2D technology, and obtains a channel between the first terminal and the second terminal according to CSI corresponding to the second terminal; And the data reconstructing cross-slot interference caused by the second terminal to the first terminal.

The above processor 0101 can perform any of the foregoing methods, and this embodiment is merely an example.

The terminal in the above embodiment can eliminate cross-slot interference between STAs in the prior art. One of ordinary skill in the art will appreciate that all or a portion of the steps of implementing the various method embodiments described above can be accomplished by hardware associated with the program instructions. The aforementioned program can be stored in a computer readable storage medium. The program, when executed, performs the steps including the foregoing method embodiments; and the foregoing storage medium includes: a medium that can store program codes, such as a ROM, a RAM, a magnetic disk, or an optical disk.

Finally, it should be noted that the above embodiments are only for explaining the technical solutions of the present invention, and are not intended to be limiting thereof; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that The technical solutions described in the foregoing embodiments may be modified, or some or all of the technical features may be equivalently replaced; and the modifications or substitutions do not deviate from the technical solutions of the embodiments of the present invention. range.

Claims

claims

1. A method for eliminating cross-slot interference, which is characterized by including:

If the first terminal is in the downlink receiving state and the second terminal is in the uplink transmitting state, the first terminal reconstructs the cross-slot interference caused by the second terminal to the first terminal; the second terminal is the terminals in the interference set of the first terminal;

The first terminal removes the cross-slot interference from the received downlink information to obtain downlink information after the cross-slot interference is eliminated.

2. The method according to claim 1, characterized in that, before the first terminal reconstructs the cross-slot interference caused by the second terminal to the first terminal, it further includes:

The first terminal creates an interference set of the first terminal, and the interference set includes at least one second terminal in a neighboring cell of the cell where the first terminal is located.

3. The method according to claim 2, wherein the first terminal creates an interference set of the first terminal, including:

The first terminal sends search information to all second terminals within a preset range, and receives response information fed back by the second terminal based on the search information;

The first terminal creates a device-to-device D2D set of the first terminal according to the response information, and the D2D set includes information of the second terminal corresponding to the response information;

The first terminal measures the local received power of the access point in the cell where the first terminal is located, and measures the adjacent cell received power of the access point in the adjacent cell of the cell where the first terminal is located;

If the absolute value of the difference between the received power of the local area and the received power of the neighboring cell is less than the preset threshold, the second terminal served by the access point corresponding to the received power of the neighboring cell in the D2D set will form an interference gather.

4. The method according to claim 3, characterized in that the first terminal sends search information to all second terminals within a preset range, including:

The first terminal uses a broadcast polling method to broadcast to all second terminals within the preset range to search for itself.

5. The method according to claim 3, further comprising:

The first terminal periodically updates the interference set.

6. The method according to any one of claims 2 to 5, characterized in that, after the first terminal creates the interference set of the first terminal, it further includes: The first terminal sends the interference set to the access point of the cell where the first terminal is located, so that the access point of the cell where the first terminal is located combines the interference set with the access point of the cell where the first terminal is located. Access points in neighboring cells are shared.

7. The method according to any one of claims 1 to 6, characterized in that the first terminal reconstructs the cross-slot interference caused by the second terminal to the first terminal, including:

The first terminal obtains channel state information between the first terminal and the second terminal

CSI;

The cross-slot interference caused by the second terminal to the first terminal is reconstructed according to the CSI.

8. The method according to claim 7, wherein the first terminal obtains the CSI between the first terminal and the second terminal, including:

The first terminal uses D2D technology to obtain the uplink measurement pilot information of the second terminal; the first terminal measures the uplink pilot signal of the second terminal according to the uplink measurement pilot information to obtain the third CSI between a terminal and the second terminal.

9. The method according to claim 7 or 8, characterized in that, reconstructing the cross-slot interference caused by the second terminal to the first terminal according to the CSI includes:

The first terminal receives data sent by the second terminal using D2D technology, and obtains a channel between the first terminal and the second terminal according to the CSI corresponding to the second terminal;

Cross-slot interference caused by the second terminal to the first terminal is reconstructed according to the channel and the data.

10. A terminal, characterized in that it includes:

The cross-slot interference reconstruction unit is used to reconstruct the cross-slot interference caused by the second terminal to the terminal when the terminal is in the downlink receiving state and the second terminal is in the uplink transmitting state; the second terminal is Terminals in the interference set of the terminal;

A cross-slot interference removal unit, configured to remove the cross-slot interference from the received downlink information after the cross-slot interference reconstruction unit reconstructs the cross-slot interference, to obtain the cross-slot interference elimination downward information.

11. The terminal according to claim 10, characterized in that, the terminal further includes: a creation unit, configured to create the terminal before the cross-slot interference reconstruction unit reconstructs the cross-slot interference. An interference set, the interference set includes at least one second terminal in a neighboring cell of the cell where the terminal is located.

12. The terminal according to claim 10 or 11, characterized in that the creation unit is specifically used to

Send search information to all second terminals within a preset range, and receive response information fed back by the second terminal based on the search information;

Create a device-to-device D2D set of the terminal according to the response information, where the D2D set includes information about the second terminal corresponding to the response information;

Measuring the local received power of the access point in the cell where the terminal is located, and measuring the adjacent cell received power of the access point in the adjacent cell of the cell where the terminal is located;

13. The terminal according to any one of claims 11 to 12, characterized in that the terminal further includes: a sharing unit;

The sharing unit is configured to, after the creation unit creates the interference set, send the interference set to the access point of the cell where the terminal is located, so that the access point of the cell where the terminal is located The set is shared with access points in neighboring cells of the cell where the terminal is located.

14. The terminal according to any one of claims 10 to 13, characterized in that the cross-slot interference reconstruction unit is specifically used for

When the terminal is in the downlink receiving state and the second terminal is in the uplink transmitting state, obtain the channel state information CSI between the terminal and the second terminal in the uplink transmitting state;

The cross-slot interference caused by the second terminal to the terminal is reconstructed according to the CSI.

15. The terminal according to claim 14, characterized in that the cross-slot interference reconstruction unit is specifically used for

When the terminal is in the downlink receiving state and the second terminal is in the uplink transmitting state, D2D technology is used to obtain the uplink measurement pilot information of the second terminal in the uplink transmitting state;

Measure the uplink pilot signal of the second terminal according to the uplink measurement pilot information to obtain the CSI between the terminal and the second terminal in the uplink transmission state;

16. The terminal according to claim 14 or 15, characterized in that the cross-slot interference reconstruction unit is specifically used for When the terminal is in the downlink receiving state and the second terminal is in the uplink transmitting state, obtain the channel state information CSI between the terminal and the second terminal;

Receive data sent by the second terminal using D2D technology, and obtain the channel between the terminal and the second terminal according to the CSI corresponding to the second terminal;

Cross-slot interference caused by the second terminal to the terminal is reconstructed according to the channel and the data.