WO2009067841A1

WO2009067841A1 - A downlink transmission system of borrowing frequency spectrum and channel resource of adjacent cells and a method and a terminal thereof

Info

Publication number: WO2009067841A1
Application number: PCT/CN2007/003344
Authority: WO
Inventors: Xinxi Diao
Original assignee: Zte Corporation
Priority date: 2007-11-27
Filing date: 2007-11-27
Publication date: 2009-06-04
Also published as: JP2011505087A; CN101828414B; JP5204240B2; CN101828414A

Abstract

A downlink transmission system of borrowing frequency spectrum and channel of adjacent cells and a method and a terminal thereof are disclosed in the present invention. In the downlink transmission system, the radio node of the cell that the terminal locates uses its transmitting channel and part or whole resource block in its transmitting frequency band, and several radio nodes of the cells adjacent to the cell that the terminal locates use their transmitting channels respectively, and use part or whole resource block in their transmitting frequency bands respectively, so as to send service data to the terminal together in multi-stream mode. With the present invention, it can overcome the problem that frequency borrowing is restricted by multiple cells, and can improve the region of terminal accepting common service of multiple cells in the precondition of maintaining the pattern of frequency space reuse and that interferences of the adjacent cells are controlled, so as to enhance the transmission rate of the terminal in the border area of cell.

Description

Borrowing the frequency of neighboring cells and the downlink of channel resources

TECHNICAL FIELD The present invention relates to the field of communications, and in particular, to a downlink transmission system, method, and terminal for borrowing spectrum resources and channel resources of a neighboring cell, where the downlink transmission system and method are used for a transmission system using a neighboring cell Transmitting data to the terminal of the own cell on the spectrum of the borrowed neighboring cell. BACKGROUND The core problem of Inter-cell Interference Coordination (ICIC) is to coordinate the use of radio resources among multiple cells, and in particular, the cell border requires special attention. ICIC coordinates spatial, temporal, and frequency channel resources and power across multiple cells to reduce interference between neighboring cells. The time-frequency domain coordination techniques can be divided into static, semi-static and dynamic time-frequency or resource coordination. The static mode is mainly determined by inter-cell planning when performing cell planning. The coordination of resources can be modified according to changes in load and service characteristics between cells, but the time period of such changes is generally longer. For semi-static methods, the period of resource allocation is higher than the static mode. For dynamic coordination, resource allocation is performed at a high frequency. The dynamic method can obtain the highest gain, but the required measurement and information reporting overhead is large, and frequent real-time communication between multiple cells is required. One basic solution to inter-cell interference is "soft frequency reuse" or "partial frequency reuse." The technology divides all subcarriers of an OFDM (Orthogonal Frequency Division Multiple Access) system into m groups, and different neighboring cells select different subcarriers as the primary subcarrier of the current cell, and other subcarriers serve as the local cell. The secondary subcarriers, and then set different transmit power thresholds for the primary subcarriers and the secondary subcarriers of each cell, and the transmit power threshold of the primary subcarrier is higher than the transmit power threshold of the secondary subcarrier, and the cell boundary is determined by the coverage of the primary subcarrier. . The primary subcarrier is allocated from the center of the cell to the cell edge, which can cover the entire cell range; the blank area is allocated a secondary subcarrier, which covers only the interior of the cell. In this way, for the intra-cell, the lower-power sub-subcarrier is mainly used to transmit data. Because the base station is relatively close to the base station, the terminal can receive the clear signal of the local cell, and because the sub-subcarrier power is small, the adjacent cells are The interference is also relatively small; and the high-power primary carrier transmits data in the edge region of each neighboring cell, which is in the edge region. The terminal mainly receives the primary subcarriers of different neighboring cells. Since the primary subcarriers of different neighboring cells do not overlap and are orthogonal, mutual interference is greatly reduced. A patented technology related to "soft frequency reuse" or "partial frequency reuse" has a Chinese patent application entitled "Method for Coordinating Inter-Cell Interference Through Power Planning for OFDM Mobile Communication Systems", entitled "Single Frequency" Chinese Patent Application No. CN200610087983, which is based on the uplink method of "1⁄2 coordinated method, base station, terminal and network" in the network. This method is currently being discussed in the third-generation mobile communication long-term evolution system standard. The frequency resources at the cell edge are limited, and it is difficult to support a large number of users and high data rates. In order to alleviate the problem that the frequency resources of the cell edge existing in the "soft frequency reuse" are limited, a basic idea is to increase the frequency of the cell edge. The reuse factor, that is, the fixed taking factor of the edge area, such as the limit of 1/3. Technical proposal: 3GPP l-051059 (Inter-cell interference mitigation for EUTRA . Texas Instruments , 3 GPP RAN WG1 #42bis, San Diego, California, US, October 2005) A clue is: When the load of the neighboring cell is light, borrow a small neighbor Frequency of the edge to improve the transmission rate of the edge terminal of the cell, Figure 1 shows a schematic diagram of the method. In the R1-051059 scheme, all the frequency bands are used for power reduction within the cell, but the cell edge is no longer fixed 1/3 However, it is adjusted according to the difference of edge load between neighboring cells. When there are fewer edge users in a cell, the available frequency will be less than 1/3, and when the neighboring cell edge load is heavy, the edge of the neighboring cell The available frequency will exceed 1/3. If all cell edge users are heavily loaded, the available frequencies at the edge of each cell are 1/3. Referring to Figure 1, the frequency soft multiplexing used by the inter-cell edge given by the R1-051059 scheme The method is as follows: Assume that at the first moment, the edge load of cell 1 is heavier, and the edge load of the neighboring cells 2, 4, and 6 is lighter, and the edge load of cells of 3, 5, and 7 is general. 3, 5, 7 The cell edge still occupies 1/3 frequency band, and the 2, 4, and 6 cells save a part of the frequency for the edge user of the cell 1. At this time, the edge user of the cell 1 occupies more than 1/3 of the frequency band. At this moment, the edge load of cell 1 is general, and the edge load of its neighboring 2, 4, and 6 cells is heavier, and the edge load of 3, 5, and 7 cells is lighter. One cell edge allocates the original 1/3 available frequency band, while the 3, 5, and 7 cells save a part of the frequency for the 2, 4, and 6 cell edge users. At this time, the available frequencies of the 2, 4, and 6 cell edge users exceed The original 1/3 available frequency. In the above method of using the transmitting system of the local cell to transmit data to the terminal of the local cell in the spectrum of the borrowed neighboring cell, the precondition for borrowing the frequency used by the edge from other cells is: It must be adjacent to all the edges of the cell using the frequency. It can be borrowed if it is lighter. For example, in Figure 1, at the last moment, even if the edge loads of cells 3 and 5 are extremely light, and there are more edge users in the cell, at this time, It is impossible to borrow frequencies from 3, 5, and 7 communities. Fig. 1 shows only the case of the structure of seven neighboring cells, and the same problem exists for the networking mode in which the frequency reuse coefficient is 1/3. When the spectrum is borrowed between three neighboring cells whose working frequencies are fl, f2, and f3, for example, when the cell with the operating frequency of fl is borrowed by £2, two cells adjacent to the cell with the working frequency of fl need to be borrowed. If there is a very light load, it can be borrowed. In other words, when some or all resource blocks of frequency f2 are used for the edge terminal of the cell with the working frequency fl, two neighboring cells of the cell with the working frequency of fl may be interfered. . SUMMARY OF THE INVENTION In view of the related art, a transmitting system using a local cell transmits data to a terminal of a local cell in a spectrum of a borrowed neighboring cell, and the frequency of the cell is restricted by multiple cells, and the neighboring cell of the cell may be interfered. The present invention has been made in view of the problem. Accordingly, the present invention is directed to a technique for transmitting data to a terminal of a cell in a spectrum of a borrowed neighboring cell using a transmitting system of a neighboring cell. According to an aspect of the present invention, a downlink transmission system that borrows spectrum resources and channel resources of a neighboring cell is provided. The downlink transmission system includes a plurality of adjacent or adjacent wireless nodes and at least one terminal, and the plurality of adjacent wireless nodes use the same or different transmission frequency bands to provide services to terminals of the service areas according to the requirements of frequency reuse, and are adjacent to each other. There is an overlap in the area covered by the transmitted signal of the wireless node. The wireless node of the cell where the terminal is located uses its transmitting channel, part or all of the resource blocks in its transmitting frequency band, and the wireless nodes of the neighboring cells of the cell in which the terminal is located use respective transmitting channels and some or all resource blocks in the respective transmitting frequency bands. And jointly sending the service data to the terminal in a multi-stream manner. The multi-flow mode described above means that, in the process of transmitting service data to the terminal, the resource blocks of the wireless node of the neighboring cell and the resource blocks of the wireless node of the cell where the terminal is located respectively carry data belonging to different transport block sets. Preferably, in the process of transmitting the service data to the terminal, the wireless node of the neighboring cell and the wireless node of the cell where the terminal is located adjust the transmission power of the specific resource block according to the channel quality indication reported by the terminal. Preferably, in the foregoing downlink transmission system, for a wireless node, the method includes: an independent base station, a remote radio unit of the distributed base station; the antenna of the wireless node includes: antennas arranged at different sites, and arranged at the same site An antenna covering different areas; for a terminal, it is capable of demodulating a plurality of transport block sets transmitted in parallel on different spectrums from signals transmitted by a plurality of adjacent wireless nodes Hehe. The terminal in the downlink transmission system according to the present invention mainly refers to a terminal located in an edge region of a cell. In addition, the foregoing resource block may be any one of the following: 1) a piece of spectrum corresponding to a specific time interval; 2) a subcarrier group corresponding to a specific time interval in orthogonal frequency multiplexing. According to another aspect of the present invention, a terminal is provided. A terminal according to the present invention includes a receiving channel, a transmitting channel, and a baseband processing unit. The bandwidth of the receiving channel covers part or all of the working frequency band of the cell where the terminal is located and the neighboring cell, and the bandwidth of the transmitting channel covers part or all of the working frequency band of the cell where the terminal is located and the neighboring cell. The baseband processing unit described above is capable of demodulating a plurality of transport block sets transmitted in parallel on different frequency spectrums from signals transmitted by a plurality of adjacent wireless nodes. Preferably, the foregoing baseband processing unit is further capable of requesting the network side to resend some/some of the transport block set if it detects that there is an error in a certain/some transport block set; and is also capable of transmitting to the network side. The channel quality indication information includes channel quality indication information on the working frequency transmission of the radio node of the cell where the terminal is located, and channel quality indication information on the working spectrum of the neighboring cell wireless node. According to still another aspect of the present invention, a downlink transmission method for borrowing a neighboring cell frequency-potential resource and channel resource is provided. The downlink transmission method includes the following processing: determining a pre-selected neighboring cell wireless node that can participate in multi-stream transmission And selecting one or more working wireless nodes participating in the multi-stream transmission from the set of the pre-selected neighboring cell radio nodes; and transmitting the service data that needs to be transmitted to the terminal to the multi-stream transmission radio node, where the multi-stream transmission radio node includes: One or more working wireless nodes, the wireless nodes of the cell where the terminal is located; the multi-streaming wireless node transmits the service data to the terminal in a multi-stream manner. Preferably, the operation of determining the pre-selected neighboring cell wireless node set is specifically: a set of neighboring cell identifiers, wherein the probe set specifies a signal transmitted by a specific neighboring cell wireless node; the terminal reports a measurement result of the signal specified by the probe set; and the network side determines the corresponding cell according to the measurement result reported by the terminal Whether the signal quality reaches the threshold and will The wireless node of the cell whose quality is at a threshold value is a pre-selected neighboring cell wireless node that can participate in multi-stream transmission. Preferably, the operation of selecting the multiple working wireless nodes is specifically: determining, for the neighboring cells corresponding to the pre-selected neighboring cell radio nodes, whether there is resource remaining according to the overload indication information; and acquiring resources for each neighboring cell with the remaining resources Remaining amount, and obtaining the application resource borrowing amount of the neighboring cell for it; for the neighboring cell whose remaining resource amount after the borrowing resource is removed, the wireless node is regarded as the working wireless node. Preferably, the foregoing operation of transmitting the service data to the multi-stream transmission wireless node comprises: allocating data in different transport block sets for the resource blocks of the multi-stream transmission wireless node. Further preferably, the foregoing operation of transmitting the service data in the multi-stream manner comprises: the plurality of working wireless nodes respectively transmitting the service data on different orthogonal subcarrier resource blocks in an OFDM modulation manner. At least one of the foregoing technical solutions of the present invention may achieve the following beneficial effects: by using a transmitting system (transmitting channel) of a neighboring cell to transmit data to a terminal of the cell in the spectrum of the borrowed neighboring cell, the related art may be overcome. The frequency transmission borrowing is restricted by multiple cells. In addition, by dynamically adjusting the areas covered by the neighboring cells in combination with the power control measures, the frequency space multiplexing pattern can be kept unchanged and the neighboring cell interference is controlled. The area where the terminal accepts the multi-cell frequency band common service is improved, thereby improving the transmission rate of the terminal in the cell edge area. Other features and advantages of the invention will be set forth in the description which follows, and The objectives and other advantages of the invention will be realized and attained by the <RTI The drawings are intended to provide a further understanding of the invention, and are intended to be a part of the description of the invention. In the drawings: FIG. 1 is a schematic diagram of an inter-cell frequency borrowing method according to the related art; FIG. 2 is a schematic diagram of a downlink transmission system according to an embodiment of the present invention; FIG. 3 is a multi-stream transmission service according to an embodiment of the present invention; FIG. 4 is a schematic diagram of a terminal according to an embodiment of the present invention; FIG. ⁵ is a schematic diagram of a downlink transmission method according to an embodiment of the present invention; FIG. 6 is a schematic diagram of an example of downlink service transmission in which a neighboring cell spectrum is borrowed between internal nodes of a distributed base station according to an embodiment of the present invention; A schematic diagram of a downlink service data transmission instance in which a spectrum of a neighboring cell is borrowed between distributed base stations in an embodiment. DETAILED DESCRIPTION OF THE INVENTION As described above, in view of the problem that the transmission system using the own cell in the related art has a constraint on spectrum borrowing when transmitting data to the terminal of the own cell on the frequency of the borrowed neighboring cell, the present invention gives a problem. A scheme for transmitting data to a terminal of a local cell in a spectrum of a borrowed neighboring cell by using a transmitting system (transmitting channel) of a neighboring cell. In other words, in the technical solution provided by the present invention, the cell not only borrows a neighboring cell The spectrum resource also borrows the transmission channel of the neighboring cell. The terminal mentioned in the present invention mainly refers to a terminal located at the edge of the cell, but is not limited thereto, and the resource block mentioned in the present invention may be but not limited to any one of the following: 1) corresponding to a specific time interval a piece of spectrum; 2) orthogonal frequency multiplexing corresponding to a subcarrier group within a specific time interval. The preferred embodiments of the present invention are described in the following with reference to the accompanying drawings, which are intended to illustrate and illustrate the invention. Embodiment 1 According to an embodiment of the present invention, a downlink transmission system that borrows spectrum resources and channel resources of a neighboring cell is first provided. The downlink transmission system can also be more visually referred to as a downlink multi-stream transmission system, as described in detail below. 2 shows a schematic diagram of a downlink transmission system in accordance with an embodiment of the present invention. As shown in FIG. 2, the downlink transmission system includes a plurality of adjacent or adjacent wireless nodes (seven wireless nodes 201a-201g are shown in FIG. 2) and at least one terminal (shown in FIG. 2 at the wireless node 201a). a user equipment (UE) 202 of the cell in which the neighboring wireless nodes provide services to terminals of the service area using the same or different transmission frequency bands according to the requirements of frequency multiplexing, and the transmitting of the adjacent wireless nodes There is an overlap in the area covered by the signal, where 203 represents the traffic channel of the terminal, which is composed of the resource block (SRB) of the serving cell and the resource block of other cells borrowed. (BRBl-BRBn) composition. The provision of services by multiple neighboring wireless nodes to terminals of their service areas using different or the same transmission frequency bands according to the requirements of frequency reuse means: 1) For the internal terminals of the cell covered by the wireless node, the wireless node uses the multiplexing factor 1 Frequency multiplexing is implemented between the cells adjacent to it, in which case each wireless node can use the same frequency spectrum for its internal terminal; 2) in the edge area of the coverage area of the wireless node, in the geographical location Interference will occur between wireless terminals that are adjacent but adjacent to different cell edge areas. One way to avoid such interference is: Each cell uses a different frequency in its edge area. Although this method can avoid the gap between the edge terminals of the neighboring cells, the available spectrum bandwidth of the terminal in the edge region of each cell is significantly reduced. The basic method for solving the problem in the present invention is: increasing the available bandwidth of the edge terminal by sharing the frequency and transmission channels between the neighboring cells, and the shared bandwidth can be performed between the orthogonal (mutually exclusive) frequency bands used in the cell edge region. It can also be performed within the available frequency band of the entire system, depending on the actual load conditions of each cell. The wireless node of the cell where the terminal 202 is located (for example, the wireless node 201a shown in FIG. 2) uses some or all of the resource blocks in the transmission channel and the transmission band, and the wireless nodes of the neighboring cells of the cell where the terminal is located (for example) The wireless nodes 201b, 201g, and 201f shown in FIG. 2 use the respective transmission channels and some or all of the resource blocks (Resource Blocks, RBs) in the transmission band to jointly transmit the service data to the terminal in a multi-stream manner. . The above multi-flow mode refers to: in the process of transmitting service data to the terminal 202, the resource block of the wireless node of the cell where the terminal is located (for example, the wireless node 201a shown in FIG. 2) and the wireless node of the neighboring cell of the cell where the terminal is located The resource blocks (for example, the wireless nodes 201b, 201g, 201f shown in FIG. 2) and the upper ones respectively carry data belonging to different transport block sets. In the existing soft handover process, although the wireless nodes of the neighboring cells simultaneously provide data to the terminal, different wireless nodes provide the same data; and in the current MIMO (Multiple-Input Multiple-Output, In the input majority technique, although different antennas or wireless nodes provide different data to the terminal in a spatially multiplexed manner, the same frequency or frequency band is used. Specifically, FIG. 3 shows a schematic diagram of transmitting service data in a multi-stream manner. As shown in FIG. 3, the serving cell (or the own cell, for example, the cell where the wireless node 201a is located) uploads the data in the transport block set 0 in its resource block SBR; the neighbor cell 1 (for example, the cell where the wireless node 201b is located) The resource block BRB1 carries the data in the transport block set 1; the neighbor cell 2 (for example, the cell where the wireless node 201g is located) carries the data in the transport block set 2 on its resource block BRB2; and so on, the neighbor cell n is in its resource The data in the transport block set n is carried on the block BRBn. Among them, service The resource block (SRB) of the cell and the BRB1, BRB2, and BRBn may be synchronously transmitted (the time difference between the resource blocks on different antennas reaching the terminal receiving antenna is smaller than the cyclic prefix in the OFDM symbol:), or asynchronous transmission (different The time difference between the resource block on the antenna and the terminal connected to >1 under-the-antenna is an arbitrary value, or the time difference of reaching the receiving antenna of the terminal is an integer multiple of the length of the OFDM symbol). Preferably, in the process of transmitting the service data to the terminal, the wireless node of the neighboring cell and the wireless node of the cell where the terminal is located adjust the channel quality indication (CQI) of the terminal on the specific resource block according to the channel quality indication (CQI) of the terminal. Transmit power. Preferably, in the downlink transmission system, the wireless node may be an independent base station (a conventional base station including radio frequency and baseband processing;), or may be a remote radio unit (RRU) of the distributed base station; The antennas of the wireless nodes may be antennas arranged at different sites, or antennas covering different areas (sectors) arranged at the same site. For a terminal in the downlink transmission system, it is capable of demodulating a plurality of transport block sets transmitted in parallel on different frequency spectrums from signals transmitted by a plurality of adjacent wireless nodes, and preferably demodulating the plurality of transmission blocks The block sets are merged into a data stream. Embodiment 2 According to an embodiment of the present invention, a terminal is provided. Fig. 4 shows an exemplary structure of a terminal according to the present invention. As shown in FIG. 4, the terminal according to the present invention includes a receiving channel 402, a transmitting channel 404, and a baseband processing unit 406. The bandwidth of the receiving channel covers both the cell (the current cell) and the working frequency band of the neighboring cell, and can receive signals from the local cell and the neighboring cell at the same time; the bandwidth of the transmitting channel covers the cell where the terminal is located and the neighboring cell. Or all working bands. The above-mentioned baseband processing unit is capable of demodulating a plurality of transport block sets transmitted in parallel on different frequency terms from signals transmitted by a plurality of adjacent wireless nodes, and further capable of demodulating the plurality of transport blocks. The block sets are merged into a data stream. Preferably, the foregoing baseband processing unit is further capable of requesting the network side to retransmit a certain/some transmission block set if it detects that there is an error in a certain/some transmission block set; and can also report the channel quality to the network side. The indication information not only reports the channel quality indication information on the working spectrum of the radio node of the cell where the terminal is located, but also reports the channel quality indication information on the working spectrum of the neighboring cell radio node. Embodiment 3 According to an embodiment of the present invention, a downlink transmission method for borrowing a neighboring cell frequency resource and a channel resource is provided. As shown in FIG. 5, the downlink transmission method may include the following processes: Step S502: Determine a set of pre-selected neighboring cell radio nodes that can participate in multi-stream transmission; Step S504, select to participate in multi-stream transmission from a set of pre-selected neighboring cell radio nodes. One or more working wireless nodes; Step S506, transmitting service data that needs to be transmitted to the terminal to the multi-stream transmission wireless node, where the multi-stream transmission wireless node comprises: one or more working wireless nodes of the above-mentioned a wireless node; Step S508, the multi-stream transmission wireless node transmits the service data to the terminal in a multi-stream manner. The various processing steps described above will be described in further detail below. (―) Step S502 First, the base station transmits, to the terminal, a sounding set consisting of a set of neighboring cell identification symbol identifiers, wherein the sounding set specifies a signal transmitted by a specific neighboring cell wireless node, such as a pilot signal or a characteristic parameter of the synchronization signal ( For example, the frequency point, the coding mode, the measurement window, etc.; the terminal reports the measurement result of the signal specified by the detection set; the network side determines whether the signal quality of the corresponding cell reaches (including or exceeds) the threshold according to the measurement result reported by the terminal, and The wireless node of the cell whose signal quality reaches the threshold is a potential pre-selected neighboring cell wireless node that can participate in multi-stream transmission. It can also be identified by measuring the Reference Signal Received Power (RSRP) for handover of the local cell and the neighboring cell; the faint neighboring cell wireless node that can participate in the multi-stream transmission.

(2) Step S504: For the neighboring cell corresponding to the pre-selected neighboring cell radio node, determine whether there is resource remaining according to the overload indication information (Overload Indication, OI); for the OI, there is no resource remaining, that is, the neighboring cell that has been overloaded, give up The frequency is borrowed, and for each neighboring cell with the remaining resources, the remaining amount of the resource is obtained, and the application resource borrowing amount of the neighboring cell is obtained, and the data can be obtained through the X2 interface between the base station and the base station; For removal The neighboring cell whose remaining resources after the resource is borrowed still reaches the threshold is used as the working wireless node.

(3) Step S506 The operation of transmitting the service data to the multi-stream transmission wireless node may be specifically as follows: respectively, the resource blocks in the different transport block sets are allocated to the resource blocks of the multi-stream transmission wireless node. Preferably, the network side is located at each wireless node participating in the transmission, which may be referred to as a resource remaining ratio of the multi-stream transmission wireless node (including the local cell wireless node and the one or more working wireless nodes described above), and needs to be transmitted to the terminal. Service data is sent to each multi-stream transmission wireless node (or base station). The method in which the network side transmits the service data to each cell (or base station) participating in the multi-stream transmission is similar to the transmission mode in the handover between the conventional base stations, and will not be described too much here. Further, in order to save the traffic of the service data transmitted between the cells, the service data to be transmitted to the wireless terminal may be split into the respective multi-stream transmission wireless nodes according to a certain ratio. The split service data is transmitted to each multi-stream transmission wireless node through the X2 interface, and each multi-stream transmission wireless node determines the transmission mode of the data stream transmitted by itself according to the channel quality CQI information, including the size of the nitrate transmission block set. , coding format, power control mode, ARQ mode, etc.

(4) Step S508 A method for transmitting a multi-streaming wireless node is that the multi-stream transmission wireless node participating in the multi-stream transmission transmits the service data on different orthogonal sub-carrier resource blocks in an OFDM modulation manner, and the data is wireless. The linear superimposed signal generated by the multi-stream in the time domain is generated on the receiving channel of the terminal, and the wireless terminal performs Fourier transform on the linear superimposed signal according to the linear superposition principle shown in the following formula, and the transmission is performed on each wireless node. The transport block or transport block set, after merging the transport block sets, obtains the total traffic data stream that the network transmits to the wireless terminal.

(0 + a ₂ (t) => A, (ω) + A ₂ F ₂ (ω) When multi-stream transmission wireless nodes participating in multi-stream transmission are different from the same distributed base station

In the RRU (Remote Radio Unit), the BBU (Base Band Unit) directly converts the data corresponding to the RRU after orthogonal transform (inverse Fourier transform, IFFT) (can be I/Q two baseband data) ) is sent to the RRU. The invention will be further described below by way of specific examples. Example -: downlink multi-stream service data transmission between adjacent nodes of distributed base station borrowing neighboring cell frequency and channel resources. FIG. 6 is a radio access network composed of distributed base stations, in which each site is located in the radio access network. Three RRUs are arranged on the radio node 201, each RRU covers a different cell (sector), and each RRU uses a different frequency band or a different orthogonal subcarrier group in the same frequency band: U1 uses the frequency band fl, Covering cell 1; RRU2 uses frequency band f2 to cover cell 2; RRU3 uses band Ω to cover cell 3. A BBU control processes a total of nine RRUs on the above three sites, and each of the RUs is networked in a 1/3 frequency multiplexing manner. In the area i or within the coverage of such a distributed base station, there are radio terminals UE1 202a and UE2 202b, wherein UE1 is covered by three RRUs: RRU1 501a; RRU2 501b; RRU3 501c, R U1 501a is control of the wireless terminal 202a The node, R U1 501a, transmits control commands required for implementing multi-stream transmission between the control channel and the wireless terminal between the wireless terminal and the wireless terminal. The BBU 502 implements multi-stream transmission between the network and the wireless terminal by using the downlink transmission method given in the foregoing embodiment. Specifically, first, the BBU 502 receives the reference signal of the RRU around the wireless terminal 202a. The measured quantity of power (Reference Symbol received power, RSRP) determines that RRU2 501b. RRU3 501c is a potential node participating in multi-stream transmission (ie, the above-mentioned pre-selected neighboring cell radio node); then, BBU 502 is based on RRU2 501b, RRU3 There is no such thing as a terminal using a resource in a cell covered by 501c (for example, OI indicates that the cell load is 0; in the case of implementing multiple streams between cells in a distributed base station, the BBU stores each RRU of the subordinate The load situation, without the external interface of the BBU to obtain the load status of each RRU under its jurisdiction), further determines RRU2 501b, RRU3 501c as a multi-streaming working node to the terminal; second, the BBU 502 is based on RRU2 501b, RRU3 The rate at which 501c may be carried, and considering the role of power control factors, determine RRU2 501a, RRU2 501b, RRU3 501c (ie, the above Streaming partitioned between wireless node) transmission rate; Finally, BBU 502 using RRU2 501a, RRU2 501b, RRU3 501c transmit channel And spectrum, three different sets of transport blocks are transmitted to the wireless terminal on RRU2 501a, RRU2 501b RRU3 501c, respectively. The wireless terminal demodulates and decodes the transport block set on each wireless node according to the multi-flow indication information sent by the control node RRU2 501a, the transport format indication information of the transport block set on each wireless node, and the like. The wireless terminal demodulates and decodes the transport block sets on each wireless node separately, and then merges them into one service data stream. Example 2: Downstream multi-stream service data transmission between neighboring cell spectrum and channel between distributed base stations FIG. 7 is a radio access network composed of three distributed base stations (each of which is composed of FIG. 1). Within the radio access network, there is a radio terminal UE2 202b, which is covered by three RRUs: R U1 601a, RRU2 601b, RRU3 601 c, R U2 501b is a control node of the radio terminal 202b through which the RRU2 501b communicates with the radio terminal The control commands required to implement multi-stream transmission are transmitted between the control channel and the wireless terminal.

The BBU3 602c implements the multi-stream downlink transmission between the network and the wireless terminal by using the downlink transmission method in the foregoing embodiment. First, the BBU3 602c receives the under-power according to the reference signal of the RRUs reported by the wireless terminal 202b. Received power, RSRP), determines that RRU1 601a R U3 601c is a potential node participating in multi-stream transmission; then, BBU3 602c according to the load indication of the cell covered by RRU1 601a, RRU3 601c (for example, from BBU2 through X2 interface) The incoming OI indication) and the RRU1 601a, RRU3 601c resources are requested to be borrowed (the BBU2 sends an indication to the BBU3 that the resource is requested to be borrowed through the X2 interface), and further determines the RRU1 601a and the RRU3 601c as the multi-streaming operation to the terminal. Next, the BBU3 602c determines the possible rate of the resource according to the remaining condition of the RRU1 601a. RRU3 601c, and considers the role of the power control factor to determine the R U1 601a, the RRU2 601b, and the RRU3 601c (ie, the multi-stream described above). The transmission rate required for the wireless terminal is allocated between the transmission working nodes), and then the BBU3 602c sets the RRU1 601a and the RRU3 601c To bear the transmission rate and the assigned transmission resources to the BBU2 via the X2 interface, and the need RRU3 601c RRU1 601a and service data transmission sent via the X2 interface to the BBU2. Finally, under the control of the BBU 2, the RRU1 601a, the RRU3 601c, and the RRU2 501b respectively transmit data to the wireless terminal in respective frequency terms in mutually independent transport block sets. The wireless terminal demodulates the transport block set on each wireless node according to the multi-flow indication information sent by the control node RRU2 501b, the transmission format indication information of the transport block set on each wireless node, the access slot, and the like. , decoding. The wireless terminal demodulates and decodes the transport block sets on each wireless node separately, and then merges them into one service data stream. With the above technical solution of the present invention, by using the transmitting system (transmitting channel) of the neighboring cell to transmit data to the terminal of the local cell on the frequency i ridge of the borrowed neighboring cell, the frequency borrowing and borrowing existing in the related art can be overcome. Multiple cells restrict this problem. In addition, by dynamically adjusting the areas covered by neighboring cells in combination with power control measures, it is possible to improve the terminal acceptance while keeping the frequency space multiplexing pattern unchanged and the neighboring cell interference controlled. The area in which the cell bands are commonly served, thereby increasing the transmission rate of the terminals in the area edge area. The above description is only for the preferred embodiment of the present invention, and is not intended to be used for the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Claims

Claim

A downlink transmission system for borrowing spectrum resources and channel resources of a neighboring cell, comprising a plurality of adjacent or adjacent wireless nodes and at least one terminal, wherein the plurality of wireless nodes use the same or different transmissions according to the requirements of frequency reuse The frequency band provides services to terminals in its service area, and the areas covered by the transmitted signals of adjacent wireless nodes overlap, and are characterized by:

The wireless node of the cell where the terminal is located uses some or all of the resource blocks in the transmit channel and the transmit frequency band, and the wireless nodes of the neighboring cells of the cell in which the terminal is located use the respective transmit channel, part or all of the resource blocks in the transmit band, and Transmitting service data to the terminal in a multi-stream manner.

The downlink transmission system according to claim 1, wherein the multi-stream mode refers to a resource block of a wireless node of the neighboring cell and the method in the process of transmitting service data to the terminal The data blocks belonging to the different transport block sets are respectively carried on the resource blocks of the wireless nodes of the cell where the terminal is located.

The downlink transmission system according to claim 1, wherein in the process of transmitting the service data to the terminal, the wireless node of the neighboring cell and the wireless node of the cell where the terminal is located are reported according to the terminal The channel quality indicator adjusts its transmit power on a particular resource block separately.

The downlink transmission system according to any one of claims 1 to 3, characterized in that:

The wireless node includes: an independent base station, a remote radio unit of the distributed base station; the antenna of the wireless node includes: an antenna disposed at different sites, an antenna covering different areas disposed at the same site; and/or

The terminal is capable of demodulating a plurality of sets of transport blocks transmitted in parallel on different frequency spectrums from signals transmitted by a plurality of neighboring wireless nodes.

The terminal refers to a terminal located in an edge area of a cell.

The resource block is any one of the following: a frequency term of a specific time interval; a subcarrier group corresponding to a specific time interval in orthogonal frequency multiplexing.

7. A terminal, comprising a receiving channel, a transmitting channel, and a baseband processing unit, wherein a bandwidth of the receiving channel covers a part or all working frequency bands of a cell where the terminal is located and a neighboring cell of the cell where the terminal is located, and the bandwidth of the transmitting channel is simultaneously covered. Part or all of the operating frequency bands of the cell in which the terminal is located and the neighboring cell are characterized by:

The processing by the baseband processing unit includes demodulating a plurality of sets of transport blocks transmitted in parallel on different frequency terms from signals transmitted by a plurality of neighboring wireless nodes.

The terminal according to claim 7, wherein the processing performed by the baseband processing unit comprises:

Requesting the network side to resend the certain/some transport block set if it detects that there is an error in a certain/some transport block set;

The channel quality indication information is reported to the network side, and includes channel quality indication information on a working spectrum of the radio node of the cell where the terminal is located, and channel quality indication information on a working spectrum of the neighboring cell radio node.

A downlink transmission method for borrowing spectrum resources and channel resources of a neighboring cell, which is characterized by:

Determining a set of pre-selected neighboring cell radio nodes that can participate in multi-stream transmission; selecting one or more working radio nodes participating in multi-stream transmission from the set of pre-selected neighboring cell radio nodes; transmitting service data that needs to be transmitted to the terminal to a multi-stream transmission wireless node, where the multi-stream transmission wireless node includes: the one or more working wireless nodes, and a wireless node of a cell where the terminal is located;

The multi-stream transmission wireless node transmits the service data to the terminal in a multi-stream manner.

The downlink transmission method according to claim 9, wherein the determining the operation of the pre-selected neighboring cell wireless node set is specifically:

The base station sends, to the terminal, a sounding set consisting of a set of neighboring cell identification symbol identifiers, where the sounding set specifies a signal transmitted by a specific neighboring cell wireless node;

The terminal reports a measurement result of a signal specified by the detection set; The network side determines, according to the measurement result reported by the terminal, whether the quality of the corresponding cell reaches a threshold, and the wireless node of the cell whose signal quality reaches the threshold is a pre-selected neighboring cell wireless node that can participate in the multi-stream transmission.

The downlink transmission method according to claim 9 or 10, wherein the operation of selecting the plurality of working wireless nodes is specifically:

For the neighboring cell corresponding to the pre-selected neighboring cell radio node, determining whether there is resource remaining according to the overload indication information;

For each neighboring cell with the remaining resources, the remaining amount of the resource is separately obtained, and the application resource borrowing amount of the neighboring cell is obtained;

For the neighboring cell whose remaining resource amount after the borrowed resource is removed, the wireless node is regarded as the working wireless node.

12. The downlink transmission method according to claim 9, wherein

Transmitting the service data to the multi-stream transmission wireless node includes: respectively assigning, for the resource blocks of the multi-stream transmission radio node, data belonging to different transport block sets; and/or

The transmitting the service data in a multi-stream manner includes: the multi-stream transmission radio node transmitting the service data on different orthogonal subcarrier resource blocks in an OFDM modulation manner, respectively.