CN101827053A - Method for restraining intercell interference - Google Patents

Abstract

The present invention relates to a method for suppressing inter-cell interference. The method includes the steps: user equipment detects the reference signal strength of adjacent base stations at a set period, determines the interfering cell and notifies the base station of the access cell; the base station of the access cell according to the set period The data transmission situation of the interfering cell, vacate the time-frequency resource block position corresponding to the base station reference signal of the interfering cell, and send data to the user equipment; the user equipment detects the reference signal of the interfering cell base station, and estimates the interfering with channel state information between the base station of the cell and the user equipment; according to the channel state information, using an interference suppression algorithm to suppress inter-cell interference. Using the method of the present invention can easily obtain the channel state information from the interfering base station to the user equipment when the interfering signal is unknown, so that the interference suppression algorithm can be used to improve the quality of the received signal at the cell edge, reduce the influence of adjacent cell interference, and improve the data at the cell edge. efficiency, thereby improving system performance.

Description

Methods of suppressing inter-cell interference

technical field

The invention relates to the technical field of communication signal processing, in particular to a method for suppressing inter-cell interference.

Background technique

In November 2004, 3GPP passed the project establishment work on UTRA Long Term Evolution (LTE, Long Term Evolution). The goals of LTE are: higher data rate, lower delay, improved system capacity and coverage, and lower cost. LTE adopts a new core transmission technology, that is, OFDM (Orthogonal Frequency Division Multiplexing, Orthogonal Frequency Division Multiplexing) technology, so large-scale innovation is required both at the system and terminal levels.

In the LTE system, frequencies used by users in a cell are orthogonal to each other. The cyclic prefix (CP) of each OFDM symbol is generally greater than the multipath delay, so the intersymbol interference (ISI) can be basically eliminated. Subcarriers of different users have guard intervals, so inter-subcarrier interference can also be suppressed. Coupled with the use of technologies such as diversity and coding, we can consider that the intra-cell interference of the LTE system is very small. The interference that affects the performance of the LTE system is mainly Inter-Cell Interference (ICI).

In order to achieve high spectral efficiency, the frequency reuse factor should be as close to 1 as possible when deploying the network. In order to provide satisfactory services, it is necessary to ensure the QoS of users, especially cell edge users. The physical layer technology of the LTE system does not have an inter-cell interference suppression mechanism. If the frequency reuse factor is 1, the inter-cell interference level will increase, especially the performance of users located at the edge of the cell will be greatly lost.

In an OFDM system with a frequency reuse factor of 1, all cells in the entire system use the same frequency resources to provide services for users in the cell, and resource allocation in one cell will affect the system capacity and edge user performance of other cells , so coordination between multiple cells is required. Inter-cell coordination has a great impact on inter-cell interference in LTE. This is a feature of radio resource allocation in the LTE system.

At present, the methods for mitigating inter-cell interference discussed in 3GPP are divided into three categories: inter-cell interference coordination/avoidance, inter-cell interference randomization, and inter-cell interference deletion. In addition, using beamforming antennas at the base station is a common way to mitigate inter-cell interference. Among them, the interference randomization uses the statistical characteristics of the interference to suppress the interference, and the error is relatively large. Interference cancellation technology has better performance, but it is not suitable for services with small bandwidth. Interference coordination/avoidance technology classifies and limits the frequency of the entire cell, and trades the total throughput for cell edge performance, but the algorithm and hardware implementation are relatively complicated, and the scheduling requirements are relatively high.

As a technology that can effectively improve spectrum efficiency, resist and suppress various interferences, multi-antenna technology has received extensive attention. LTE supports multi-antenna technology to meet the requirements of high data rate and high system capacity. In the Release 8 protocol, a mode with up to 4 antennas is defined. In LTE-Advanced, the mode of 8 antennas will be supported.

Under multi-antenna reception, a series of algorithms for effectively suppressing interference can be used. For example, IRC (Interference Rejection Combining, interference suppression combination) is a relatively advanced interference suppression algorithm. In GSM, the IRC can obtain a C/I gain of up to 11dB.

As shown in Figure 1, assuming that the signal sent by the target base station is s, and the interference signal of the adjacent base station is sI, after passing through the non-frequency selective fading channel, the received signal should be:

$\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; r</span>}}<span\; class="notranslate">\; =</span>\left(\begin{array}{c}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="r"\; filenames="DEST\_PATH\_RE-HSB00000170515900011.png,HSA00000073823600021.png"\; state="\{\{state\}\}">r</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\\ \text{<span class="notranslate"> \&Center Dot;</span>}\\ <span\; class="notranslate">\; \&CenterDot;</span>\\ <span\; class="notranslate">\; \&Center\; Dot;</span>\\ {{\mathrm{<span\; class="notranslate">\; r</span>}}_{\mathrm{<span\; class="notranslate">\; N</span>}}}_{\mathrm{<span\; class="notranslate">\; R</span>}}\end{array}\right)<span\; class="notranslate">\; =</span>\left(\begin{array}{c}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="h"\; filenames="DEST\_PATH\_RE-HSB00000170515900011.png,HSA00000073823600021.png"\; state="\{\{state\}\}">h</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\\ <span\; class="notranslate">\; \&Center\; Dot;</span>\\ <span\; class="notranslate">\; \&Center\; Dot;</span>\\ <span\; class="notranslate">\; \&Center\; Dot;</span>\\ {{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; N</span>}}}_{\mathrm{<span\; class="notranslate">\; R</span>}}\end{array}\right)<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; +</span>\left(\begin{array}{c}{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; I</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}\\ <span\; class="notranslate">\; \&CenterDot;</span>\\ <span\; class="notranslate">\; \&Center\; Dot;</span>\\ <span\; class="notranslate">\; \&Center\; Dot;</span>\\ {\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; I</span>}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; R</span>}}}\end{array}\right)<span\; class="notranslate">\; \&Center\; Dot;</span>{\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; I</span>}}<span\; class="notranslate">\; +</span>\left(\begin{array}{c}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="no"\; filenames="DEST\_PATH\_RE-HSB00000170515900011.png,HSA00000073823600021.png"\; state="\{\{state\}\}">no</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\\ <span\; class="notranslate">\; \&Center\; Dot;</span>\\ <span\; class="notranslate">\; \&Center\; Dot;</span>\\ <span\; class="notranslate">\; \&Center\; Dot;</span>\\ {{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; N</span>}}}_{\mathrm{<span\; class="notranslate">\; R</span>}}\end{array}\right)<span\; class="notranslate">\; =</span>\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; h</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; +</span>{\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; h</span>}}}_{\mathrm{<span\; class="notranslate">\; I</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>{\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; I</span>}}<span\; class="notranslate">\; +</span>\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; no</span>}}$

Using the receiver filter, the coefficient is w, then the filter output:

$\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; =</span>{\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; w</span>}}}^{\mathrm{<span\; class="notranslate">\; h</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; r</span>}}<span\; class="notranslate">\; =</span>{\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; w</span>}}}^{\mathrm{<span\; class="notranslate">\; h</span>}}<span\; class="notranslate">\; (</span>\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; h</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>}\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; +</span>{\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; h</span>}}}_{\mathrm{<span\; class="notranslate">\; I</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>{\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; I</span>}}<span\; class="notranslate">\; +</span>\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; no</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>{\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; w</span>}}}^{\mathrm{<span\; class="notranslate">\; h</span>}}\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; h</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; +</span>{\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; w</span>}}}^{\mathrm{<span\; class="notranslate">\; h</span>}}{\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; h</span>}}}_{\mathrm{<span\; class="notranslate">\; I</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>{\mathrm{<span\; class="notranslate">\; the\; s</span>}}_{\mathrm{<span\; class="notranslate">\; I</span>}}<span\; class="notranslate">\; +</span>{\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; w</span>}}}^{\mathrm{<span\; class="notranslate">\; h</span>}}\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; no</span>}}$

If filter coefficients are chosen such that:

${\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; w</span>}}}^{\mathrm{<span\; class="notranslate">\; h</span>}}{\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; h</span>}}}_{\mathrm{<span\; class="notranslate">\; I</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}$

interference can be completely suppressed.

是时变的，通常采用最小均方误差(MMSE)准则计算，选择w以最小化均方误差

In practice,

is time-varying and is usually calculated using the minimum mean square error (MMSE) criterion, w is chosen to minimize the mean square error

The most important prerequisite for the above interference suppression algorithms is that the channel transmission matrix is known.

In an existing LTE-Advanced system, by sending and demodulating a reference signal (pilot), a channel matrix from a serving base station to a UE (User Equipment, user equipment) can be obtained. However, under the existing system, the interference signal is unknown, and it is difficult to obtain the channel state information from the interfering base station to the UE.

Contents of the invention

(1) Technical problems to be solved

The technical problem to be solved by the present invention is to make it easy to obtain the channel state information from the interfering base station to the user equipment when the interfering signal is unknown, thereby using the interference suppression algorithm to improve the quality of the received signal at the edge of the cell, reduce the influence of adjacent cell interference, and improve Data efficiency at the edge of the cell, thereby improving system performance.

(2) Technical solution

In order to achieve the above object, the present invention adopts the following technical solutions.

The present invention provides a method for suppressing inter-cell interference, the method comprising steps:

S1. The user equipment detects the reference signal strength of the adjacent base station at a set period, determines the interfering cell and notifies the base station of the access cell according to the comparison result of the reference signal strength and the set strength;

S2. According to the data transmission situation of the interfering cell, the base station of the access cell vacates the time-frequency resource block position corresponding to the reference signal of the base station of the interfering cell, and sends data to the user equipment;

S3. The user equipment detects a reference signal of the interfering cell base station, and estimates channel state information between the interfering cell base station and the user equipment;

S4. Using an interference suppression algorithm to suppress inter-cell interference according to the channel state information.

Preferably, in step S1, the base station of the access cell does not transmit data at the position of the time-frequency resource block corresponding to the reference signal of each neighboring cell at the time of detection.

Preferably, the step S1 further includes:

S1.1 If the detected reference signal strengths are all lower than the set strength, then the base station of the access cell directly sends data to the user equipment without performing the subsequent steps, otherwise, perform step S1.2;

S1.2 Obtain the corresponding cell ID from the base station whose reference signal strength exceeds the set strength the most, and determine the interfering cell;

S1.3 Notify the access cell base station of the ID of the interfering cell.

Preferably, in step S1.3, when the user equipment waits for the current subframe to have an uplink shared channel, it uses the uplink shared channel to notify the access cell base station of the ID of the interfering cell.

Preferably, step S2 further includes:

S2.1 The base station of the access cell sends a request for obtaining data transmission status to the base station of the interfering cell;

S2.2 The base station of the interfering cell responds to the request of the base station of the access cell, and notifies the base station of the access cell of its data transmission status on the time-frequency resource block corresponding to the user equipment;

S2.3 If there is no data transmission by the base station of the interfering cell on the time-frequency resource block corresponding to the user equipment, then the base station of the access cell directly sends data to the user equipment without performing other steps, otherwise, The base station of the access cell vacates the position of the time-frequency resource block corresponding to the reference signal of the base station of the interfering cell, and sends data to the user equipment.

Preferably, in step S3, the user equipment further detects a reference signal of the base station of the access cell, and estimates channel state information between the base station of the access cell and the user equipment.

Preferably, the interference suppression algorithm is an interference cancellation algorithm.

(3) Beneficial effects

According to the method of the present invention, the data transmission at some positions is exchanged for intercepting and estimating the channel state information of the interference channel, thereby using the interference suppression algorithm to improve the quality of the received signal at the edge of the cell, reduce the influence of adjacent cell interference, and improve the quality of the cell. Data efficiency at the edge, thereby improving system performance. Compared with the existing method for alleviating inter-cell interference, the method of the present invention fully utilizes the pilot frequency and data structure of the LTE-Advanced system, and the process of detecting the interfering base station is exactly the same as detecting the original serving base station, and the realization of the receiving algorithm is similar to that of the original serving base station The multi-antenna MIMO algorithm also has great similarities, which can make full use of existing hardware without adding new complexity.

Description of drawings

FIG. 1 is a schematic diagram of an LTE system;

FIG. 2 is a flowchart of a method for suppressing inter-cell interference according to an embodiment of the present invention;

FIG. 3(a)-FIG. 3(b) are schematic diagrams showing reference signal locations during reference signal detection in a method for suppressing inter-cell interference according to an embodiment of the present invention;

Figure 4(a)-Figure 4(b) is a schematic diagram of reference signal mapping when the downlink uses 2 antenna ports for transmission in a method for suppressing inter-cell interference according to an embodiment of the present invention;

4(c)-4(d) are schematic diagrams of reference signal mapping when 4 antenna ports are used for downlink transmission in a method for suppressing inter-cell interference according to an embodiment of the present invention.

Detailed ways

The heavy-duty vehicle exhaust monitoring system proposed by the present invention is described in detail as follows in conjunction with the accompanying drawings and embodiments.

The present invention is mainly proposed for the LTE-ADVANCED system, and is also applicable to other transmission systems. It relates to the downlink data time-frequency structure of the LTE-ADVANCED system, and is especially suitable for cell edge users with relatively large interference from adjacent cells. For fully understanding the present invention, it is necessary to carry out following description:

There are three kinds of reference signals (pilots) supported by LTE-ADVANCED: cell-specific reference signal (Cell-Specific RS), MBSFN reference signal (Multicast Broadcast Single Frequency Network RS, multicast/broadcast single frequency network reference signal), user equipment specific Reference signal (UE-Specific RS).

All downlink subframes that support non-MBSFN transmission need to transmit Cell-SpecificRS. Cell-Specifc RS is transmitted over the entire frequency band.

Downlink single-port transmission supports UE-Specific RS. UE-Specific RS is optional and is transmitted on the downlink data resource block corresponding to the UE.

The mapping position of the reference signal is related to the cell ID. The Cell-Specific RS allows 6 cell signals to be orthogonal, and the UE-Specific RS allows 3 cell signals to be orthogonal.

The initial sequence value of the Cell-Specific RS is only related to the cell ID. Based on this, the UE distinguishes cells.

The initial value of the UE-Specific RS sequence is related to the cell ID and RNTI, and the UE can be distinguished according to the RNTI (16 bits).

For signals with serious interference, especially the signals at the edge of the cell, the bit error and transmission efficiency mainly depend on the interference of adjacent cells. Simulation shows that in most cases, there is a main interfering cell. So recording its interference characteristics can play a key role.

For the signal at the edge of the cell with severe interference, the bit error and transmission efficiency mainly depend on the interference of adjacent cells. Simulation shows that in most cases, there is a main interfering cell. Therefore, recording its interference characteristics can play a key role. Therefore, the method of the present invention judges the strength of the reference signal of the base station of the neighboring cell in the user equipment, selects the interfering cell whose signal is second only to the access cell, and uses the interference suppression algorithm , to improve reception performance while also keeping track of other base stations.

As shown in Figure 2, according to a method for suppressing inter-cell interference in an embodiment of the present invention, the method includes steps:

S1. The UE detects the reference signal strength of neighboring base stations at a set period. Since the cell configuration is fixed, it can obtain the ID of the corresponding cell from the base station, and distinguish the reference signals from different cells according to different cell IDs, thereby Determine the interfering cell BS ₂ , and notify the access cell base station BS ₁ ;

S2. The base station BS ₁ of the access cell vacates the position of the time-frequency resource block corresponding to the reference signal of the interfering cell base station BS ₂ to the UE, and sends data to the UE;

S3. The UE detects the UE-SpecificRS of the access base station BS ₁ and the interfering cell base station BS ₂ , respectively estimates the channel state information between the access cell base station BS ₁ and the UE and the interfering cell base station BS ₂ and the UE, and obtains the channel matrix (BS ₁ , UE)(BS ₂ , UE);

S4. According to the channel matrix (BS ₂ , UE) obtained by estimating the channel state information, the inter-cell interference is suppressed through an interference suppression algorithm to obtain a higher quality signal.

Wherein, step S1 further includes:

S1.1 If the detected reference signal strengths are all lower than the set strength, there is no need to select the interfering cell BS ₂ , and the access cell base station BS ₁ directly sends data to the UE without performing the following other steps until the next Cell- Specific RS detection cycle, otherwise execute step S1.2;

S1.2 Obtain the corresponding cell ID from the base station whose reference signal strength exceeds the set strength the most, and determine the interfering cell BS ₂ ;

S1.3 Notify the access cell base station BS ₁ of the ID of the interfering cell BS ₂ .

In this step, the UE uses the uplink shared channel (PUSCH). If there is no PUSCH in the current subframe, it waits for the current subframe to have an uplink shared channel before transmitting. In short, the normal scheduling may not be changed. Such a notification is sent once per Cell-Specific RS detection cycle.

When configuring the base station, it is necessary to ensure that the Cell-Specific RSs of adjacent cells are orthogonal. When performing step S1.1, in order to accurately estimate the strength of the reference signal, the base station of the access cell should be selected not to transmit data at the Cell-Specific RS position of each neighboring cell at the time of detection, as shown in Figure 3(a)-3(b) shown. This detection is performed once after the UE has just connected to BS ₁ and before data transmission. Afterwards, intermittently detect and update the reference signal strength changes of neighboring cell base stations, since the set update period can be relatively long, which hardly affects the transmission overhead.

In addition, step S2 further includes:

S2.1 The base station BS ₁ of the access cell sends a request for knowing the transmission situation to the base station BS ₂ of the interfering cell;

S2.2 The interfering cell base station BS ₂ responds to the request of the access cell base station BS ₁ , and informs the access cell base station BS ₁ of its data transmission on the time-frequency resource block corresponding to the UE, including the configuration of data transmission, such as The number of antenna ports used, etc., are notified to BS ₁ whenever the data transmission situation of BS ₂ changes during the Cell-SpecificRS detection period;

S2.3 If there is no data transmission, BS ₁ sends data directly to the UE without performing all the subsequent steps; otherwise, the access cell base station BS ₁ vacates the interfering cell base station BS ₂ for the UE-Specific RS of the UE position, send data to the UE, and at the same time, BS ₂ sends the corresponding UE-Specific RS to the UE.

In the LTE-ADVANCED protocol, UE-Specific RS is not sent in every subframe, but is controlled by signaling or not. Using this signaling, the UE can be controlled to detect the UE-Specific RS of its own access cell base station, or detect the UE-Specific RS of the interfering cell base station, or both are orthogonal and appear simultaneously. If the UE-Specific RS of the base station of the interfering cell is detected in this subframe, the base station of the accessing cell does not send data at the position of the UE-Specific RS of the base station of the interfering cell.

In step S3, if the UE-Specific RSs of BS ₁ and BS ₂ are orthogonal to the same subframe, the channel matrix is calculated once per subframe; if the UE-Specific RSs of BS ₁ and BS ₂ are sent alternately, the channel matrix is not sent One side uses the channel matrix of the previous frame.

In addition, the data transmission situation information provided by BS ₂ in step S2.2 needs to be used in step S4.

The overhead of pilot slots in the LTE-ADVANCED system using the method of the present invention will be described below.

When two antenna ports are used for downlink transmission, and the UE-Specific reference signal of the interfering cell BS ₂ is vacated at the same time, the occupied time-frequency resources are shown in Figure 4(a);

If in the same subframe, there are both UE-Specific RSs of the base station of the access cell to the UE, and UE-Specific RS of the base station of the interfering cell needs to be detected, then the two reference signals are orthogonal, and the time-frequency resources occupied are as follows: As shown in Figure 4(b);

When 4 antenna ports are used for downlink transmission, and the UE-Specific RS of the base station of the interfering cell is vacated at the same time, the occupied time-frequency resources are shown in Figure 4(c);

If in the same subframe, there are both UE-Specific RSs of the base station of the access cell to the UE, and UE-Specific RS of the base station of the interfering cell needs to be detected, then the two reference signals are orthogonal, and the time-frequency resources occupied are as follows: As shown in Figure 4(d):

With 4 antenna ports for transmission, the remaining data bits are reduced, but each data bit can accommodate the data of 4 antenna ports. Theoretically, the capacity is increased, but it is also related to the measurement accuracy of the channel matrix.

It can be seen that the overhead of the method of the present invention is related to the number of antenna ports and the time density of UE-Specific RS. This is also a compromise between transmission capacity and transmission quality. In actual operation, different choices can be made according to conditions and circumstances.

The above embodiments are only used to illustrate the present invention, but not to limit the present invention. Those of ordinary skill in the relevant technical field can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, all Equivalent technical solutions also belong to the category of the present invention, and the scope of patent protection of the present invention should be defined by the claims.

Claims (7)

1. method that suppresses presence of intercell interference, the method comprising the steps of:

S1. subscriber equipment according to described reference signal strength and the comparing result of setting intensity, determines that interfered cell and notice insert cell base station with the reference signal strength of setting cycle detecting neighbor base station;

S2. described access cell base station is vacated the time-frequency resource block position of described interfered cell base station reference signal correspondence according to the transfer of data situation of described interfered cell, sends data to described subscriber equipment;

S3. described subscriber equipment detects the reference signal of described interfered cell base station, estimates the channel condition information between described interfered cell base station and the described subscriber equipment;

S4. according to described channel condition information, adopt interference suppression algorithm to suppress presence of intercell interference.

2. the method for inhibition presence of intercell interference as claimed in claim 1 is characterized in that, in step S1, detecting described access cell base station is not constantly transmitted data in the time-frequency resource block position of each adjacent cell reference signals correspondence.

3. the method for inhibition presence of intercell interference as claimed in claim 2 is characterized in that, described step S1 further comprises:

All less than described setting intensity, then described access cell base station directly sends data to described subscriber equipment to S1.1, does not carry out later step as if the reference signal strength that detects, otherwise execution in step S1.2;

S1.2 exceeds the maximum base station of described setting intensity from reference signal strength and obtains corresponding district ID, determines interfered cell;

S1.3 notifies described access cell base station with the ID of described interfered cell.

4. the method for inhibition presence of intercell interference as claimed in claim 1, it is characterized in that, in step S1.3, subscriber equipment waits for when current subframe has Uplink Shared Channel, uses described Uplink Shared Channel to notify described access cell base station with the ID of described interfered cell.

5. the method for inhibition presence of intercell interference as claimed in claim 1 is characterized in that, step S2 further comprises:

The described access cell base station of S2.1 sends the request of knowing the transfer of data situation to described interfered cell base station;

The request of the described access cell base station of the described interfered cell base station in response of S2.2 is informed described access cell base station with its transfer of data situation on the time corresponding with described subscriber equipment;

If S2.3 is the free of data transmission of described interfered cell base station on the time corresponding with described subscriber equipment, then described access cell base station directly sends data to described subscriber equipment, do not carry out other steps, otherwise, described access cell base station is vacated the time-frequency resource block position of described interfered cell base station reference signal correspondence, sends data to described subscriber equipment.

6. the method for inhibition presence of intercell interference as claimed in claim 1, it is characterized in that, in step S3, described subscriber equipment also detects the reference signal of described access cell base station, estimates the channel condition information between described access cell base station and the described subscriber equipment.

7. the method for inhibition presence of intercell interference as claimed in claim 1 is characterized in that, described interference suppression algorithm is an interference cancellation algorithm.

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