TWI508487B - Method of handling interference mitigation in heterogeneous network by channel measurement and related communication device - Google Patents

Description

Method for processing interference suppression in heterogeneous network using channel measurement and communication device thereof

The invention relates to a method for a wireless communication system and a communication device thereof, in particular to a method for processing interference suppression by performing channel measurement in a heterogeneous network and a communication device thereof.

The 3rd Generation Partnership Project (3GPP) has developed a Long Term Evolution (LTE) system with better performance in order to improve the Universal Mobile Telecommunications System (UMTS). Support for the Third Generation Partnership Project 8th Edition (3GPP Rel-8) standard and/or 3rd Generation Partnership Project 9th Edition (3GPP Rel-9) standard to meet the increasing needs of users. The Long Term Evolution (LTE) system is considered to provide a new wireless interface and wireless network architecture that provides high data transfer rates, low latency, packet optimization, and improved system capacity and coverage, including a number of evolved base stations (evolved Nodes). -Evolved Universal Terrestrial Radio Access Network (E-UTRAN) consisting of -Bs, eNBs), which communicate with the UE on the one hand and the non-access layer on the other hand ( The core network controlled by Non Access Stratum (NAS) communicates, and the core network includes entities such as a servo gateway and a Mobility Management Entity (MME).

The Advanced Long Term Evolution (LTE-Avanced, LTE-A) system is an advanced version of the Long Term Evolution (LTE) system, which includes carrier aggregation, coordinated multipoint transmission/reception (CoMP), and multiple inputs. Advanced technologies such as multi-input multi-output (MIMO) to extend bandwidth, provide fast switching power states, and improve cell edge performance. In order for the UEs and the evolved base stations (eNBs) in the advanced long-term evolution system to communicate with each other, the client and the evolved base station (eNB) must be able to support the standards established for the advanced long-term evolution system, such as the third-generation cooperation. The partner plans a tenth version (3GPP Rel-10) standard or a newer version of the standard.

In addition to the advanced techniques described above, the most effective way to improve the quality of received signals is to shorten the distance between the transmitting and receiving ends of the wireless communication system. The concept of a heterogeneous network in which multi-layer cells are deployed in a wireless communication system has therefore been proposed to shorten the distance between the transmitting end and the receiving end. For example, a heterogeneous network consists of three kinds of cells and a relay node. According to the size of the cells, macrocells, picocells, and femtocells are respectively large to small. It is managed by a large cell base station, a small cell base station, and a micro cell base station. Unlike traditional networks that contain only large cells, heterogeneous networks contain not only large cells, but also large cells. Also included is at least one small cell, at least one microcell, and at least one relay station for improving the output of the client in the heterogeneous network. In this case, a user located in the coverage of a large cell may also be located in the coverage of small cells or micro cells. If the user terminal is far away from the large cell base station of the large cell, but is close to the small cell base station of the small cell or the micro cell base station of the micro cell, the user terminal can communicate with the small cell base station or the micro cell base station. In order to use a lower transmission power, access services such as the Internet, TV broadcasting, and the like. Even if the client is not covered by small cells or microcells, the client can communicate with the large cell base station through a nearby relay station. That is to say, the relay station can be regarded as a bridge between the user terminal and the large cell base station, and is used to forward signals transmitted between the user terminal and the large cell base station. In other words, the client and the large cell base station do not need to increase the transmit power when communicating. Therefore, by using a small cell base station, a micro cell base station or a relay station, the power consumption of the user terminal and the large cell base station can be reduced. Further, since the distance between the UE and the small cell base station, the micro cell base station or the relay station is short, the quality of the signal transmitted and received by the user terminal can be improved, thereby increasing the output of the user terminal.

However, even if the heterogeneous network can reduce the power consumption of the client and the large cell base station, large cells can be transmitted and received at the same time and overlapping bandwidth in small cell base stations, micro cell base stations, and relay stations. The interference in the same period has also increased. Further, the orthogonal frequency-division multiplexing (OFDM) and the orthogonal frequency-division multiple access (OFDMA) system used in the long term evolution system and the advanced long term evolution system are used. Broadband technology, the signal will be transmitted and received through any part of the frequency band, that is, small cell base stations, micro cell base stations and relay stations will use any part of any frequency band to transmit and receive signals at the same time. It is very likely that the signal will be transmitted at the same time in the same part of the frequency band, that is, the same resource block, so that the signals interfere with each other. Therefore, interference problems in large cells become more serious in long-term evolution systems and advanced long-term evolution systems, and the benefits of heterogeneous networks cannot be effectively realized. That is to say, the increased output that the UE can increase is limited by the interference. Therefore, before configuring resources for the user, it is necessary to consider the interference generated by the heterogeneous network to effectively increase the output of the client.

Accordingly, it is a primary object of the present invention to provide a method and communication device therefor for use in a heterogeneous network for processing interference suppression by performing channel measurements to solve the above problems.

The invention discloses a method for processing a resource arrangement, which is used for a first base station of a wireless communication system, and the method comprises: a measurement station, a relay station of the wireless communication system (relay node) Or the second base station of the wireless communication system obtains channel information corresponding to one of the resource blocks, wherein the resource block is identified by a time interval and a bandwidth; and according to the The channel information of the channel is configured to be a mobile device of the wireless communication system.

The present invention further discloses a method for processing channel measurement, which is used in a relay node of a wireless communication system, the method comprising receiving a measurement request transmitted by a base station of the wireless communication system. And the measurement request indicates a channel and a backhaul resource; measuring the channel to obtain channel information of the channel, or using the channel information stored in the relay station; and transmitting the channel information to the base through the backhaul resource station.

Please refer to FIG. 1. FIG. 1 is a schematic diagram of a wireless communication system 10 according to an embodiment of the present invention, which is composed of three macrocells MCEL1 MCMC3. The wireless communication system 10 is preferably a Universal Mobile Telecommunications System (UMTS) using Wideband Code Division Multiple Access (WCDMA). Alternatively, the wireless communication system 10 may be a long term evolution (orthogonal frequency-division multiplexing (OFDM) and/or orthogonal frequency-division multiple access (OFDMA). Evolution, LTE) system and Advanced Long Term Evolution (LTE-A) system. The large cells MCEL1 to MCEL3 are managed by large cell base stations MBS1 to MBS3, respectively. Further, the large cell MCEL1 includes a user equipment (UE) UE1 and relay nodes (RNs) RN1 to RN2; the large cell MCEL2 includes a user terminal UE2 and a femtocell FCEL micro cell base station FBS. The large cell MCEL3 includes a client cell UE3 to UE4, a small cell base station PBS of a small cell (picocell) PCEL, and a relay station RN3. Thus, the wireless communication system 10 can be viewed as a heterogeneous network containing multiple layers of cells.

In general, small cells, microcells, and relay stations are deployed in hot spots, offices, and communities in a large cell to complement the coverage of powerful cells to provide better quality services. To the user and reduce the power consumption of large cell base stations and users. When a client in a large cell is located in the coverage of small cells, microcells, and relay stations, the user terminal will not communicate with large cell base stations of large cells, but will be small cell base stations and micro cells with small cells. The microcell base station and the relay station communicate to access the service.

For example, as shown in FIG. 1, since the UE1 is not close to a relay station and is not in the coverage of small cells and micro cells, the large cell base station MBS1 directly communicates with the UE UE1 to provide a service. User terminal UE1. Conversely, the UE UE4 is closer to the relay station RN3 and farther away from the large cell base station MBS3, and the large cell base station MBS3 communicates through the relay station RN3. On the other hand, since the UE2 is located in the coverage of the microcell FCEL, the UE UE2 can communicate with the microcell base station FBS to access the service without communicating with the large cell base station MBS2 which is far away. Similarly, the UE UE3 can communicate with the small cell base station PBS to access the service without communicating with the large cell base station MBS3 that is far away. Therefore, as long as the client is close to the relay station or located in the coverage of small cells or micro cells, the client and the large base station can communicate without increasing the transmission power.

It should be noted that the cells, base stations and user terminals described above are used to briefly describe the architecture of the wireless communication system 10. In fact, the large cell base stations MBS1 to MBS3 can be base stations (Node-Bs, NBs) of the Universal Terrestrial Radio Access Network (UTRAN) in the universal mobile telecommunication system, or are long-term evolution systems. The evolved base stations (evolved NBs, eNBs) of the Evolved-URAN (E-UTRAN) in the advanced long-term evolution system are not limited thereto. The small cell base station PBS and the micro cell base station FBS can be a small base station (NBs) or an evolved base station (eNBs), or a newly built base station with partial or complete base stations (NBs). ) or the functionality of evolved base stations (eNBs). The client can be a device such as a mobile phone, a notebook computer, a tablet computer, an e-book, and a portable computer system. In addition, depending on the transmission direction, a station (such as a large cell base, a small cell base, a micro cell base station or a relay station) and a client can be regarded as a transmitting end or a receiving end, respectively. For example, for an uplink (UL), the UE is the transmitting end and the station is the receiving end; for the downlink (DL), the station is the transmitting end and the user end is the receiving end.

Please refer to FIG. 2, which is a schematic diagram of a communication device 20 according to an embodiment of the present invention. The communication device 20 can be a client, a base station or a relay station in FIG. 1 , and includes a processing device 200 , a storage unit 210 , and a communication interface unit 220 . Processing device 200 can be a microprocessor or an application-specific integrated circuit (ASIC). The storage unit 210 can be any data storage device for storing a code 214 and reading and executing the code 214 through the processing device 200. For example, the storage unit 210 can be a subscriber identity module (SIM), a read-only memory (ROM), a random access memory (RAM), a compact disc. A read-only memory (CD-ROM/DVD-ROM), a magnetic tape, a hard disk, and an optical data storage device are not limited thereto. The communication interface unit 220 can be a wireless transceiver for transmitting and receiving wireless signals according to the processing result of the processing device 200.

Please refer to FIG. 3, which is a flowchart of a process 30 according to an embodiment of the present invention. The flow 30 is used for processing the resource allocation in the wireless communication system 10 in the large cell base stations MBS1 to MBS3, the small cell base station PBS, the micro cell base station FBS, and the relay stations RN1 to RN3 in Fig. 1 . Flow 30 can be compiled into code 214, which includes the following steps:

Step 300: Start.

Step 302: A first base station obtains channel information corresponding to a channel of a resource block from a measurement, a relay station of the wireless communication system 10, or a second base station of the wireless communication system 10. The resource block is identified by a time interval and a bandwidth.

Step 304: The first base station configures the resource block to one of the wireless communication systems 10 according to the channel information of the channel.

Step 306: End.

According to the process 30, before the first base station configures the resource block to the user, the first base station obtains channel information corresponding to the channel of the resource block from the measurement, the relay station or the second base station, where the resource area The block is identified by a time period and a frequency bandwidth. Then, the first base station configures the resource block to the UE according to the channel information of the channel. In other words, since the interference (like co-channel interference) exists in the wireless communication system 10, the first base station does not arbitrarily configure the resource block to the user, but according to the first base station or the user end. Transmitting the channel information of the channel used by the resource block, and configuring the resource block to the user end. In addition, the first base station can obtain channel information by self-measuring the channel or through the relay station and the second base station, and is not limited thereto. Therefore, the interference suffered by the transmission between the first base station and the user terminal can be alleviated or eliminated, so as to effectively realize the high output and low power consumption provided by the heterogeneous network.

It should be noted that the spirit of the process 30 is that the base station configures the resource block to the user according to the channel information of the channel used by the base station or the client to transmit the resource block, and configures the resource block and obtains the channel information. There are no restrictions. For example, referring to Fig. 1, an embodiment of the present invention will be described below with the operation of large cell MCEL1. The large cell base station MBS1 prepares to allocate a resource block to the UE1, so the large cell base station MBS1 or the UE1 needs to transmit the channel information of the channel used by the resource block. Since the relay stations RN1 to RN2 are located in the large cell MCEL1 and are managed by the large cell base station MBS1, the large cell base station MBS1 can obtain the channel information through the relay stations RN1 to RN2. In detail, the large cell base station MBS1 first determines the backhaul resources used by the relay station RN1 to return the channel information. Next, the large cell base station MBS1 transmits a measurement request to the relay station RN1 to instruct the relay station RN1 to measure the channel and transmit back channel information through the backhaul resource. After receiving the measurement request, the relay station RN1 measures the channel to obtain channel information, and returns the channel information to the large cell base station MBS1 through the backhaul resource. Alternatively, the channel information is stored in the relay station RN1, and the relay station RN1 can immediately return the channel information through the backhaul resource without measuring the channel. On the other hand, the large cell base station MBS1 can also obtain channel information from the relay station RN2 as described above, and is not limited thereto. After receiving the channel information, the large cell base station MBS1 can allocate the resource block to the UE1 according to the channel information. The foregoing may also be implemented in the large cell base station MBS3, which manages the relay station RN3, and can communicate with the user terminal UE4 through the relay station RN3 according to the channel information, and details thereof are not described herein.

With continued reference to Figure 1, the following is a description of another embodiment of the present invention with the operation of a microcell FCEL. The micro cell base station FBS prepares to allocate a resource block to the UE UE2, so the micro cell base station FBS or the UE UE2 needs to transmit the channel information of the channel used by the resource block. Since the micro cell base station FBS does not manage any relay station, the micro cell base station FBS can measure the channel by itself to obtain channel information. Alternatively, the microcell base station FBS can obtain channel information from neighboring base stations (such as large cell base stations MBS1 to MBS2 and small cell base station PBS). In detail, the micro cell base station FBS will first transmit an exchange request to a base station in the adjacent base station (such as the large cell base station MBS2) for requesting channel information. If the large cell base station MBS2 accepts the exchange request (for example, when the large cell base station MBS2 has the channel information), the large cell base station MBS2 will return the channel information to the micro cell base station FBS. On the other hand, the micro cell base station FBS can also request channel information from the large cell base station MBS1 or the small cell base station PBS according to the above, and is not limited thereto. After receiving the channel information, the micro cell base station FBS can allocate the resource block to the UE2 according to the channel information. The above can also be implemented in the small cell base station PBS, which does not manage any relay station, and can communicate with the UE UE3 according to the channel information, and details thereof are not described herein.

It should be noted that, according to the channel information of the channel used in the transmission resource block, the manner (or behavior) of the base station configuring the resource block to the user end is not limited. For example, when the quality of the channel is in a good state, for example, when the quality of the channel is higher than a predetermined level, the base station configures the resource block to the user. Conversely, when the channel is subjected to severe interference, for example, when the quality of the channel is lower than the preset level, the base station stops configuring the resource block to the UE. Preferably, the preset level is defined by the operator of the base station and stored in the base station. Further, when the base station prepares to allocate the resource block to the UE, the modulation scheme and the coding rate used in the resource block may be adjusted according to the channel information to flexibly configure the resource region. Block to the client.

In addition, the channel information can include any channel related information that helps to configure resource blocks, and is not limited to this. For example, the channel information may include a raw value of the interference power received on the channel, which may generate a larger amount of redundancy (ie, occupy more backhaul resources), or channel information. One of the quantized values of the interference power received on the channel may be included, which will result in a smaller amount of redundancy (ie, less backhaul resources). Further, the channel information may include a binary value, which generates a minimum amount of redundancy, and is used to indicate whether the channel is occupied according to the amount of interference power received on the channel (eg, bit "0") Indicates that the channel is not occupied, and the bit "1" indicates that the channel is occupied). When the channel information is obtained from another base station (such as a large cell base station, a small cell base station or a micro cell base station), the channel information may include the configuration performed by the other base station on the resource block, according to which The accuracy of the channel information obtained by the method is higher than the accuracy of the channel information obtained by the measurement. For example, when the large cell base station MBS1 requests channel information from the small cell base station PBS and the large cell base station MBS2, the small cell base station PBS and the large cell base station MBS2 can return whether the channel has been channeled. Configured in the transfer resource block.

On the other hand, the channel described above can be an uplink channel or a downlink channel. In addition, since a resource block is identified or marked by using a time interval and a bandwidth, the time interval and bandwidth can be further defined according to system requirements. For example, the time interval can be used to indicate the length of time occupied by the resource block, or to accurately indicate the start time and end time of the time interval of the resource block. Similarly, the bandwidth can be used to indicate the frequency width occupied by the resource block, or to accurately indicate the start frequency and end frequency of the bandwidth of the resource block. Preferably, the base station can exchange channel information through the X2 interface defined in the third generation partner project standard, without being limited thereto.

The steps of all the foregoing processes (including the suggested steps) can be implemented by means of a device, which can be hardware and firmware (for the combination of hardware devices and computer instructions and data, and computer instructions and data are read-only on the hardware device). Software) or electronic system. The hardware can be an analog microcomputer circuit, a digital microcomputer circuit, a hybrid microcomputer circuit, a microcomputer chip or a germanium chip. The electronic system can be a system on chip (SOC), a system in package (SiP), a computer on module (COM), and a communication device 20.

In summary, the present invention provides a method for suppressing interference in a heterogeneous network by channel measurement, which can be implemented in a base station and a relay station. The invention can reduce or eliminate the interference suffered by the transmission between the base station and the client end, so as to effectively realize the high output and low power consumption provided by the heterogeneous network.

The above are only the preferred embodiments of the present invention, and all changes and modifications made to the scope of the present invention should be within the scope of the present invention.

10. . . Wireless communication system

20. . . Communication device

200. . . Processing device

210. . . Storage unit

214. . . Code

220‧‧‧Communication interface unit

30‧‧‧Process

300, 302, 304, 306‧‧ steps

MCEL1~MCEL3‧‧‧ Large cells

PCEL‧‧‧Small cells

FCEL‧‧‧microcells

MBS1~MBS3‧‧‧ Large Cell Base Station

PBS‧‧‧Small cell base station

FBS‧‧‧Micro Cell Base Station

UE1~UE4‧‧‧ client

RN1~RN3‧‧‧ relay station

FIG. 1 is a schematic diagram of a wireless communication system according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a communication device according to an embodiment of the present invention.

FIG. 3 is a schematic diagram of a process of an embodiment of the present invention.

30. . . Process

300, 302, 304, 306. . . step

Claims (15)

A method for processing a resource arrangement for a first base station of a wireless communication system, the method comprising: from a measurement, a relay node of the wireless communication system or The second base station of the wireless communication system obtains channel information corresponding to one channel of a resource block, wherein the resource block is identified by a time interval and a bandwidth; when the channel information is used When the quality of the channel is higher than a predetermined level in the first base station, the resource block is allocated to one of the wireless communication systems; and when the quality of the channel is lower than the preset level In the case of a bit, the allocation of the resource block to the mobile device is stopped to eliminate or mitigate the interference experienced by the transmission of the resource block. The method of claim 1, wherein the step of obtaining the channel information corresponding to the channel of the resource block from the measurement comprises: measuring the channel when the first base station does not manage any of the relay stations Get the channel information. The method of claim 1, wherein the step of obtaining the channel information corresponding to the channel of the resource block from the relay station comprises: determining that the relay station returns when the relay station is managed by the first base station a backhaul resource used by the channel information; transmitting a measurement request to the relay station to instruct the relay station to measure the channel and Transmitting the channel information through the backhaul resource; and receiving the channel information transmitted by the relay station through the backhaul resource. The method of claim 1, wherein the step of obtaining the channel information corresponding to the channel of the resource block from the second base station comprises: transmitting an exchange request to the second base station to request the channel Information; and when the second base station grants the exchange request, receiving the channel information transmitted by the second base station. The method of claim 1, wherein when the resource block is allocated to the mobile device, the first base station adjusts a modulation scheme used in the resource block according to the channel information and a The coding rate. The method of claim 1, wherein the channel information includes a raw value of interference power received on the channel, or a quantized value of the received interference power on the channel. . The method of claim 1, wherein the channel information includes a binary value indicating whether the channel is occupied. The method of claim 1, wherein when the first base station obtains the channel information from the second base station, the channel information includes a configuration performed by the second base station on the resource block. The method of claim 1, wherein each of the first base station and the second base station is a macrocell base station, a picocell base station or a femtocell. Base station. A method for processing channel measurement for a relay node of a wireless communication system, the method comprising: Receiving a measurement request transmitted by a base station of the wireless communication system, and the measurement request indicating a channel and a return resource; measuring the channel to obtain channel information of the channel, or storing the information in the channel The channel information of the relay station; and transmitting the channel information to the base station through the backhaul resource, to provide the base station to configure a resource block according to the channel information to a mobile device in the wireless communication system. The method of claim 10, wherein the relay station is managed by the base station. The method of claim 10, wherein the channel information includes a raw value of interference power received on the channel, or a quantized value of the received interference power on the channel. . The method of claim 10, wherein the channel information includes a binary value indicating whether the channel is occupied. The method of claim 10, wherein the base station is a macrocell base station, a picocell base station or a femtocell base station. The method of claim 10, wherein the resource block is identified by a time interval and a bandwidth.