Apparatus and method for transmitting and receiving signals in a mobile communications system
Patent Information
- Application Number
- ES2020217095T
- Authority / Receiving Office
- ES · ES
- Patent Type
- Patents
- Current Assignee / Owner
- Priority Date
- 2011-08-10
- Filing Date
- 2011-08-10
- Publication Date
- 2026-08-31
- Estimated Expiration
- 2031-08-10
Smart Images
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Abstract
Description
Apparatus and method for transmitting and receiving signals in a mobile communications system Technical field The present invention relates to a mobile communication system. More particularly, the present invention relates to an apparatus and a method for transmitting and receiving signals in a mobile communication system. Technical background The rapid increase in the number of smartphone subscribers has resulted in a corresponding increase in traffic demand from those subscribers. Despite being in the commercialization process, a mobile communications system based on Orthogonal Frequency Division Multiple Access (OFDMA), which has relatively high frequency efficiency, such as a 3GPP Long-Term Evolution (LTE) mobile communications system, will likely not have sufficient capacity to meet the growing traffic demand. Therefore, there is a trend toward adopting a microcell system and a repeater system to increase the overall system capacity. A microcell system configuration will now be described with reference to Figure 1. Figure 1 schematically illustrates a microcell system configuration according to the related technique. With reference to Figure 1, the microcell system includes a plurality of, for example, four microcells: 111-1, 113-1, 115-1, and 117-1. Microcell 111-1 is a service coverage area where an evolved micro Node B (eNB) 111-2 provides services. Microcell 113-1 is a service coverage area where an eNB 113-2 provides services. Microcell 115-1 is a service coverage area where an eNB 115-2 provides services. Microcell 117-1 is a service coverage area where an eNB 117-2 provides services. It will be assumed that the four microcells 111-1, 113-1, 115-1, and 117-1 have the same coverage area as the service coverage area where a macro eNB (not shown) provides services. As described earlier, in the microcell system, eNBs are deployed more densely to increase system capacity, thereby decreasing the spatial coverage or size of the split cells. While the smaller size of the split cells can contribute to increased average throughput for users, at inter-cell boundaries, data throughput can decrease due to interference between data channels, and the likelihood of outages can increase due to interference between control channels. Furthermore, the smaller the cell size, the more frequently User Equipment (UE) devices can experience handovers caused by movement, thus increasing overhead and destabilizing the communication environment. The following will describe a repeater system configuration with reference to Figure 2. Figure 2 schematically illustrates a repeater system configuration according to the related technique. With reference to Figure 2, the repeater system includes a plurality of, for example, four Radio Units (RUs) 211, 213, 215, and 217 within a cell. The four RUs 211, 213, 215, and 217 transmit and receive the same signals. Therefore, at the boundaries between RUs 211, 213, 215, and 217, the signals undergo macrocombination, which contributes to an improvement in the capacity of the UEs located in the boundary areas between RUs 211, 213, 215, and 217, and a reduction in the probability of interruption. Furthermore, when moving between UK 211, 213, 215, and 217, EUs are not required to make a handover. WO2010087031 A1 relates to a wireless communication system, comprising a plurality of base stations, each of which includes a plurality of cells, and a terminal that communicates with the base stations. Each base station is equipped with one or more antennas. The base stations transmit first reference signals that do not overlap with those of at least the neighboring base stations and are unique to the antennas. The terminal receives the first reference signals, estimates the receive power of the first reference signals transmitted from the respective antennas, selects, based on the receive power estimation results, a plurality of antennas suitable for communication, and transmits the antenna selection results to the base stations.Base stations refer to the antenna selection results transmitted from the terminal to assign the antennas belonging to different cells to the terminal and notify the terminal of the antenna assignment results. Description Technical problem The repeater system is primarily used to expand service coverage areas and fill coverage gaps, as it expands areas of strong electric field using multiple spatially separated repeater units (RUs). However, unlike a microcell system, the repeater system can experience reduced resource efficiency and system capacity because multiple RUs transmit and receive the same signals. In summary, the microcell system and the repeater system can be adopted to increase the overall capacity of the system and may have the following drawbacks. First, in the case of the microcell system, the capabilities of the UEs located at the intercellular boundaries are limited, and their probability of disruption is relatively high. The UEs can perform the handover more frequently, increasing the overload and destabilizing the communication environment. Second, the repeater system can improve the capabilities of UEs located at intercellular boundaries because multiple RUs transmit and receive the same signals, but may suffer a reduction in overall system capacity due to their low resource efficiency. Technical solution Aspects of the present invention address the problems and / or disadvantages mentioned above and provide at least the advantages described below. The invention is defined by the appended claims, and further embodiments are described in the dependent claims. A method for transmitting a signal using an evolved Node B (eNB) in a mobile communications system is described. The method includes transmitting the same control channel signal to each of a plurality of radio units (RUs) and transmitting a different data channel signal to each of the plurality of RUs. The data channel signal transmitted to each of the plurality of RUs can be determined by considering at least one location of a user equipment (UE) that will receive the data channel signal and load balancing. An electronic base station (eNB) in a mobile communications system is described. The eNB includes a digital unit for transmitting the same control channel signal to each of a plurality of reference units (RUs) and for transmitting a different data channel signal to each of the plurality of RUs. The data channel signal transmitted to each of the plurality of RUs can be determined by considering at least one location of a receiving unit (UE) that will receive the data channel signal and load balancing. A method is described for transmitting and receiving a signal using a RU in a mobile communications system. The method includes receiving a control channel signal and a data channel signal from an eNB. The control channel signal may be the same as the control channel signals that the eNB transmits to a plurality of RUs, except for the RU itself. The data channel signal may be different from the data channel signals that the eNB transmits to the plurality of RUs, except for the RU itself. The data channel signal transmitted to both each of the RUs and the plurality of RUs may be determined by considering at least one UE location that will receive the data channel signal and load balancing. A RU in a mobile communications system is also described. The RU includes a receiver for receiving a control channel signal and a data channel signal from an eNB node. The control channel signal may be the same as the control channel signals that the eNB transmits to a plurality of RUs, except for the RU itself. The data channel signal may be different from the data channel signals that the eNB transmits to the plurality of RUs, except for the RU itself. A data channel signal transmitted to each of the RUs and to the plurality of RUs may be determined by considering at least one UE location that will receive the data channel signal and load balancing. A method for receiving a signal by a UE in a mobile communications system is also described. The method includes receiving a control channel signal and a data channel signal from each of a plurality of RUs. The control channel signal received from each of the plurality of RUs can be the same. The data channel signal received from each of the plurality of RUs can be different. The data channel signal received from each of the plurality of RUs can be determined by considering at least one UE location and load balancing. A UE in a mobile communications system is also described. The UE includes a receiver for receiving a control channel signal and a data channel signal from each of a plurality of RUs. The control channel signal received from each of the plurality of RUs may be the same. The data channel signal received from each of the plurality of RUs may be different. The data channel signal received from each of the plurality of RUs may be determined by considering at least one UE location and load balancing. Other aspects, advantages, and outstanding features of the invention will become evident to those skilled in the art from the following detailed description, which, taken together with the accompanying drawings, describes exemplary embodiments of the invention. Advantageous effects As is evident from the above description, exemplary embodiments of the present invention allow multiple RUs to transmit control channel signals in the same manner, and transmit data channel signals independently, thereby contributing to an increase in the capacity of the UEs and a reduction in the probability of interruption, and avoiding overload due to frequent UE handover. Brief description of the drawings The above and other aspects, features, and advantages of certain exemplary embodiments of the present invention will become more evident from the following description taken in conjunction with the accompanying drawings, in which: Figure 1 is a diagram that schematically illustrates a configuration of a microcell system according to the related technique; Figure 2 is a diagram that schematically illustrates a repeater system configuration according to the related technique; Figure 3 is a diagram that schematically illustrates a configuration of a 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) mobile communications system; Figure 4 is a diagram that schematically illustrates a method of managing control channels and data channels by the evolved Node B (eNB) 311 in Figure 3; Figure 5 is a diagram illustrating an internal structure of the eNB 311 in Figure 3; Figure 6 is a diagram illustrating an internal structure of the control channel manager 513 in Figure 5; Figure 7 is a diagram illustrating an internal structure of the data channel manager 515 in Figure 5; Figure 8 is a diagram illustrating an internal structure of the channel meter 711 in Figure 7; Figure 9 is a flowchart illustrating an operation of programmer 713 in Figure 7; Figure 10 is a diagram illustrating an internal structure of the 717 data channel generator in Figure 7; and Figure 11 is a diagram illustrating an internal structure of the Multiplexing Unit (MUX) 517 and connection in Figure 5. Throughout the drawings, it will be understood that the same drawing reference numbers refer to the same elements, features, and structures. Best way The following description, with reference to the accompanying drawings, is provided to aid in a comprehensive understanding of exemplary embodiments of the invention as defined by the claims and their equivalents. It includes various specific details to aid in that understanding, but these should be considered merely as examples. Accordingly, those skilled in the art will recognize that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the invention. Furthermore, descriptions of well-known functions and constructions are omitted for the sake of clarity and conciseness. The terms and words used in the following description and claims are not limited to their bibliographic meanings, but are used simply by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be evident to those skilled in the art that the following description of exemplary embodiments of the present invention is provided for illustrative purposes only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents. It should be understood that the singular forms "a", "one", "an", and "the" include several referents unless the context clearly dictates otherwise. Thus, for example, the reference to "a component surface" includes the reference to one or more such surfaces. Exemplary embodiments of the present invention provide an apparatus and method for transmitting and receiving signals in a mobile communications system. Furthermore, exemplary embodiments of the present invention provide an apparatus and method for enabling multiple Radio Units (RUs) to transmit / receive control channel signals in a shared manner and to transmit / receive data channel signals independently in a mobile communications system. It will be assumed herein that the mobile communications system is a Long Term Evolution (LTE) mobile communications system of the 3rd Generation Partnership Project (3GPP).However, it shall be understood by ordinary persons skilled in the art that the apparatus and method of signal transmission / reception proposed by the exemplary embodiments of the present invention may be used not only in the 3GPP LTE mobile communications system, but also in any other mobile communications system, such as an Institute of Electrical and Electronics Engineers (IEEE) 802.16m communications system. Figure 3 schematically illustrates a configuration of a 3GPP LTE mobile communications system according to an exemplary embodiment of the present invention. With reference to Figure 3, the 3GPP LTE mobile communications system includes an evolved Node B (eNB) 311, at least one, for example, of four RUs 313, 315, 317, and 319, and at least one User Equipment (UE, not shown). The eNB 311 manages the control channels and data channels in different ways, thereby increasing the overall capacity of the system and making it possible to reduce the overhead caused by frequent UE handovers. A method for managing control channels and data channels by the eNB 311 will be described below in Figure 3 with reference to Figure 4. Figure 4 schematically illustrates a method of managing control channels and data channels by the eNB 311 in Figure 3 according to an exemplary embodiment of the present invention. With reference to Figure 4, the eNB 311 controls RU 313, 315, 317, and 319. RU 313, 315, 317, and 319 transmit the same control channel signals in a shared manner under the control of the eNB 311, but transmit data channel signals individually under the control of the eNB 311. The following will describe in detail a method for controlling the transmission of control channel signals and data channel signals from RU 313, 315, 317, and 319 by the eNB 311. First, a method for controlling the transmission of control channel signals from RU 313, 315, 317, and 319 by the eNB 311 will be described below. The eNB 311 controls RU 313, 315, 317, and 319 to transmit the same control channel signals so that a specific UE can acquire a macro-combination gain when receiving the control channel signals. When RU 313, 315, 317, and 319 transmit the same control channel signals in this way, interference between control channels can be avoided, allowing the specific UE to acquire a macro-combination gain. Second, a method for controlling the transmission of data channel signals from RU 313, 315, 317, and 319 by the eNB 311 will be described below. The eNB 311 enables RUs 313, 315, 317, and 319 to transmit data channel signals independently. In other words, the eNB 311 controls each of RUs 313, 315, 317, and 319 to transmit data channel signals only to the UE that the RU itself has selected, thus making it possible to multiplex data channel signals destined for different UEs during transmission using the same frequency resources. The eNB 311 can determine the UE to which each of RUs 313, 315, 317, and 319 will transmit data channel signals, taking into account at least one of several parameters, such as UE locations and load balancing. For example, the eNB 311 can control each of the RU 313, 315, 317, and 319 to transmit data channel signals to the UE located at the shortest distance. Because RU 313, 315, 317, and 319 can multiplex data channel signals destined for different UEs during transmission using the same frequency resources, interference between data channels can occur at the boundaries between RU 313, 315, 317, and 319. Therefore, an exemplary embodiment of the present invention minimizes interference between data channels at the boundaries between RU 313, 315, 317, and 319 by using an interference control procedure, thereby increasing the capabilities of the UEs located at the boundaries between RU 313, 315, 317, and 319. As described above, because RU 313, 315, 317, and 319 can multiplex data channel signals directed to different UEs during their transmission using the same frequency resources, their resource efficiency and system capacity are higher than those of the repeater system of the related technique. An internal structure of the eNB 311 will now be described in Figure 3 with reference to Figure 5. Figure 5 illustrates an internal structure of the eNB 311 in Figure 3 according to an exemplary embodiment of the present invention. With reference to Figure 5, the eNB 311 includes a Digital Unit (DU) 511, which comprises a control channel manager 513, a data channel manager 515, and a Multiplexing (MUX) and Connection unit 517. The control channel manager 513 generates Downlink (DL) control channel signals. The control channel manager 513 receives programming information from the data channel manager 515 and generates DL control channel signals based on that programming information. Data channel manager 515 performs a programming operation, generates programming information corresponding to the results of the programming operation, and transmits the programming information to control channel manager 513. Data channel manager 515 generates DL data channel signals based on the programming information. The MUX and connection unit 517 multiplexes the DL control channel signals generated by the control channel manager 513 and the DL data channel signals generated by the data channel manager 515, and transmits them to RUs 313, 315, 317, and 319. Although RUs 313, 315, 317, and 319 are considered to be connected to the MUX and connection unit 517 in the case of Figure 5 from the 3GPP LTE mobile communications system configuration described in Figure 3, it will be understood by those skilled in the art that the MUX and connection unit 517 can be connected to all RUs in the coverage area served by the eNB 311. The MUX and connection unit 517 transmits Uplink (UL) data channel signals received from RU 313, 315, 317, and 319 to the data channel manager 515. Units 313, 315, 317, and 319 perform Radio Frequency (RF) processing on the DL control channel signals and DL data channel signals transmitted by the MUX and Link unit 517, and transmit them to their associated UEs. Units 313, 315, 317, and 319 are connected to the eNB 311 via, for example, an optical fiber, and exchange signals with the eNB 311 using, for example, a Common Public Radio Interface (CPRI). Preferably, the RU 313, 315, 317, and 319 can be installed to contribute to the formation of strong electric fields in spatially distinct areas. In other words, the RU 313, 315, 317, and 319 can be installed spatially separated, as illustrated in Figure 3, if they have, for example, omnidirectional antennas. On the other hand, if the RU 313, 315, 317, and 319 have directional antennas, they can be installed in the same location. In this latter case, the areas of strong electric field can be expanded by establishing different bore sights for the directional antennas. The internal structure of the 513 control channel manager will now be described in Figure 5 with reference to Figure 6. Figure 6 illustrates an internal structure of the control channel manager 513 in Figure 5 according to an exemplary embodiment of the present invention. With reference to Figure 6, the control channel manager 513 includes a control channel reference signal generator 611, a control channel signal generator 613, and a MUX 615. The control channel signal generator 613 generates control channel signals based on programming information received from the data channel manager 515. Control channels may include, for example, a Physical Broadcast Channel (PBCH), a Physical Downlink Control Channel (PDCCH), a Physical Control Format Indicator Channel (PCFICH), etc. The 611 control channel reference signal generator generates control channel reference signals used to demodulate the control channel signals for the UEs. The control channel reference signals can include, for example, cell-specific reference signals. MUX 615 multiplexes the control channel reference signals generated by the control channel reference signal generator 611 and the control channel signals generated by the control channel signal generator 613, and outputs them to the MUX and connection unit 517. The internal structure of the 515 data channel manager will now be described in Figure 5 with reference to Figure 7. Figure 7 illustrates an internal structure of the 515 data channel manager in Figure 5 according to an exemplary embodiment of the present invention. With reference to figure 7, the data channel manager 515 includes a channel meter 711, a programmer 713, a channel quality receiver 715, a data channel generator 717, a data channel reference signal generator 719, and a MUX 721. The 515 data channel manager enables multiple RUs to transmit data channel signals to different UEs independently. In other words, the 515 data channel manager allows the eNB 311 to transmit different data channel signals to multiple UEs by reusing the same frequency resources. The 515 data channel manager determines which UEs, if possible, are spatially separated and transmit data channel signals using the same frequency resources, thereby minimizing interference between data channels. Because data channel signals, unlike control channel signals, are not transmitted equally by all RUs, if a UE receives data channel signals based solely on channel estimates for reference signals transmitted equally by all RUs—for example, for control channel reference signals—its reception success rate may be poor. Therefore, it is preferable for each RU to transmit a data channel reference signal to an individual UE. The RU will then transmit data channel signals to the UE in such a way that the UE can receive the data channel signals based on a channel estimate for the data channel reference signal, or can estimate a channel for the data channel signals based on both the control channel reference signal and beamforming weight information.For convenience, it will be assumed in this document that RUs transmit data channel reference signals independently, and UEs receive data channel signals based on these reference signals. Data channel reference signals may include, for example, dedicated reference signals. The 3GPP LTE mobile communications system can transmit dedicated reference signals according to Transmission Mode 7 when using Version 8, and can transmit dedicated reference signals according to either Transmission Mode 7 or Transmission Mode 8 when using Version 9. Channel quality receiver 715 receives channel quality information that each UE has measured and transmitted via MUX unit 517 and connection, and transmits the received channel quality information to programmer 713. The following will describe an internal structure of the 711 channel meter in Figure 7 with reference to Figure 8. Figure 8 illustrates an internal structure of the 711 channel meter in Figure 7 according to an exemplary embodiment of the present invention. With reference to figure 8, the 711 channel meter includes a plurality of, for example, 4 UE signal detectors 811-1, 811-2, 811-3, and 811-4, and a plurality of, for example, 4 channel information meters 813-1, 813-2, 813-3, and 813-4. Signals received from the RUs via the MUX and connection unit 517—that is, signals transmitted by UEs—are supplied to their associated UE signal detectors. For example, a signal received from RU 313 is supplied to UE signal detector 811-1. A signal received from RU 315 is supplied to UE signal detector 811-2. A signal received from RU 317 is supplied to UE signal detector 811-3. A signal received from RU 319 is supplied to UE signal detector 811-4. UE signal detectors 811-1, 811-2, 811-3, and 811-4 detect their associated UE signals from the signals received from the MUX and Connection unit 517 and output the detected UE signals to their associated connected channel information meters 813-1, 813-2, 813-3, and 813-4. In other words, UE signal detector 811-1 outputs its detected UE signal to channel information meter 813-1. UE signal detector 811-2 outputs its detected UE signal to channel information meter 813-2. UE signal detector 811-3 outputs its detected UE signal to channel information meter 813-3. The UE signal detector 811-4 sends its detected UE signal to the channel information meter 813-4. Channel information meters 813-1, 813-2, 813-3, and 813-4 measure channel information between associated UEs and RUs based on UE signals detected by UE signal detectors 811-1, 811-2, 811-3, and 811-4, respectively, and output the measured channel information to programmer 713. The channel information may include channel powers and channel coefficients between the associated UEs and RUs. A more detailed description of the operation of channel meter 711 follows. The signals received from the RUs via the MUX unit 517 and connection are sent to their associated UE signal detectors. The UE signal detectors, which receive Survey Reference Signals (SRS) transmitted by the UEs on a UL, can detect their associated UE signals based on the SRS transmitted by the UEs and send the detected UE signals to their associated channel information meters. The channel information meters measure channel information based on the UE signals detected by the UE signal detectors. An operation of the programmer 713 in Figure 7 will now be described with reference to Figure 9. Figure 9 illustrates an operation of the programmer 713 in Figure 7 according to an exemplary embodiment of the present invention. With reference to Figure 9, in step 911, scheduler 713 calculates a scheduling metric for each unit resource based on the UE's channel qualities. The unit resource may include, for example, a sub-band. In step 913, scheduler 713 determines a UE that has the maximum scheduling metric for each unit resource. In step 915, scheduler 713 calculates a scheduling metric when, in addition to the UE with the maximum scheduling metric, another UE, determined based on channel quality information, is assigned to a unit resource using channel information between the UEs and the RUs. In step 917, scheduler 713 further determines a UE with the maximum scheduling metric for each unit resource. In step 919, scheduler 713 determines whether the scheduling metric increases due to the additional determination of a UE. If the scheduling metric does not increase, scheduler 713 finally determines the UEs designated as UEs to which it will transmit data signals using the unit resource in step 921, thereby completing the scheduling operation. However, if it is determined in step 919 that the scheduling metric increases, scheduler 713 determines the specified UEs as the UEs to which it will transmit data signals using the unit resource in step 923, and then returns to step 915. With reference to Figure 9, Scheduler 713 determines a UE that has the maximum scheduling metric when transmitting data channel signals using a relevant unit resource, based on the UE's channel characteristics. It then determines whether the scheduling metric increases when transmitting data channel signals to another UE besides the determined UE using a related unit resource, based on channel information between the UEs and the RUs. If the scheduling metric is found to increase, Scheduler 713 determines the identified UEs as the UEs to which it will transmit data channel signals using the unit resource, and again determines whether to assign an additional UE to which it will transmit data channel signals using the unit resource.On the other hand, if the scheduling metric does not increase, scheduler 713 finally determines the specified UEs as the UEs to which it will transmit data channel signals using the unit resource, completing the scheduling operation. After completing the scheduling operation, scheduler 713 broadcasts the scheduling information corresponding to the specified UEs to data channel generator 717 and control channel manager 513. Scheduler 713 can determine only one UE or multiple UEs at the same time for each unit resource. Scheduler 713 can allow a single RU to transmit data channel signals to the UEs, or allow multiple RUs to transmit data channel signals to the UEs together.Scheduler 713 sends channel information to data channel generator 717 so that data channel generator 717 can determine a beamforming weight to apply to the data channels if necessary. The internal structure of the 717 data channel generator will now be described in Figure 7 with reference to Figure 10. Figure 10 illustrates an internal structure of the 717 data channel generator in Figure 7 according to an exemplary embodiment of the present invention. With reference to Figure 10, the 717 data channel generator includes a 1011 beamforming weight calculator, a 1013 encoding / modulation / channeling processor, and a 1015 beamforming processor. Data channel generator 717 receives scheduling information from scheduler 713, and receives traffic data directed to a UE, which is assigned to a related unit resource based on the scheduling information, i.e., to which it will transmit data channel signals using the unit resource. The beamforming weight calculator 1011 generates a beamforming weight to be used for a data channel based on the scheduling information and sends the beamforming weight to the beamforming processor 1015 and the data channel reference signal generator 719. The encoding / modulation / channeling processor 1013 performs the encoding / modulation / channeling of the incoming traffic data and sends the results to the beamforming processor 1015. The 1015 beamforming processor performs beamforming processing on the signals emitted from the 1013 encoding / modulation / channeling processor, and outputs transmission signals for the RUs to the 721 MUX. The data channel reference signal generator 719 generates reference signals for data channels, i.e., data channel reference signals. The data channel reference signal generator 719 performs the same beamforming processing on these data channel reference signals, using the beamforming weights output from the beamforming weight calculator 1011, and outputs them to the MUX and connection unit 517. Instead of generating data channel reference signals as described above, it is also possible to allow a UE to estimate a data channel signal based on control channel reference signals and beamforming weight information. In this case, the data channel reference signal generator 719 is permitted not to generate data channel reference signals. MUX 721 multiplexes the signals emitted from data channel generator 717 and data channel reference signal generator 719, and outputs the results to MUX and connection unit 517. The internal structure of MUX and connection unit 517 is described below in Figure 5 with reference to Figure 11. Figure 11 illustrates an internal structure of the MUX unit 517 and connection in Figure 5 according to an exemplary embodiment. With reference to figure 11, the MUX and connection unit 517 includes a control channel copier 1111 and a MUX 1113. The control channel copier 1111 generates control channel signals for the RUs by copying a control channel signal so that all RUs can transmit the same control channel signals, and then outputs them to the MUX 1113 for the RUs individually. MUX 1113 receives the control channel signals from copier 1111 and the data channel signals generated for the RUs by data channel manager 515, multiplexes them for individual RUs, and transmits the results to the associated RUs. MUX 1113 outputs the signals that the RUs have received from the UEs to data channel manager 515. Although not illustrated in separate drawings, each RU may include a transmitter for transmitting various signals, a receiver for receiving various signals, and a controller for controlling the operation of the transmitter and receiver. The transmitter, receiver, and controller may be implemented as separate units or integrated into a single unit. Similarly, a UE may include a transmitter to transmit various signals, a receiver to receive various signals, a controller to control the operation of the transmitter and receiver, and an estimator to estimate various signals. The transmitter, receiver, controller, and estimator may be implemented as separate units or integrated into a single unit. Although the invention has been shown and described below with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that the invention is defined by the appended claims.
Claims
1. A method implemented by a Digital Unit (511), DU, of an evolved Node B (311), eNB, in a mobile communication system, the method comprising: multiplexing a first control channel signal and a first data channel signal into a first multiplexed signal for transmission to a first Radio Unit, RU, from among a plurality of RUs; multiplexing a second control channel signal and a second data channel signal into a second multiplexed signal for transmission to a second RU from among the plurality of RUs; transmitting the first multiplexed signal to the first RU; and transmitting the second multiplexed signal to the second RU, wherein the first and second control channel signals are generated from a control channel signal and are the same for the first and second RUs, and the first data channel signal and the second data channel signal are different for the first and second RUs. 2.A method according to claim 1, further comprising generating the control channel signal and the first and second data channel signals for the first and second RU.
3. A method according to claim 1 or claim 2, further comprising a scheduling operation and generating the first and second data channel signals and the control channel signal based on scheduling information generated therefrom.
4. A method according to claim 3, wherein the scheduling operation calculates a scheduling metric for each resource unit based on channel quality information about the channels between the first and second RU and a plurality of associated user equipment (UE) units, received from the UE units.
5. A method according to claim 4, wherein the scheduling operation determines a UE unit that has the maximum scheduling metric for each resource unit. 6.The method of claim 1, wherein the first and second multiplexed signals further comprise: control channel reference signals; and data channel reference signals.
7. The method of claim 1, wherein the control channel signal includes at least one of the following: a broadcast physical channel signal, a downlink control physical channel signal, and a control format indicator physical channel signal. 8.An evolved Node B, eNB, (311), for use in a mobile communications system, the eNB (311) comprising: a digital unit, DU, (511), for multiplexing a first control channel signal and a first data channel signal into a first multiplexed signal for transmission to a first radio unit, RU, multiplexing a second control channel signal and a second data channel signal into a second multiplexed signal for transmission to a second RU from among a plurality of RUs, transmitting the first multiplexed signal to the first RU, and transmitting the second multiplexed signal to the second RU, wherein the first and second control channel signals are generated from a control channel signal and are the same for the first and second RUs, and the first data channel signal and the second data channel signal are different for the first and second RUs.
9. An eNB (311) according to claim 8, including the plurality of RU. 10.An eNB (311) according to claim 8 or claim 9, wherein the digital unit (511) is arranged to generate the control channel signal and the first and second data channel signals for the first and second RU.
11. An eNB (311) according to any one of claims 8 to 10, wherein the digital unit (511) is arranged to perform a scheduling operation and generates the first and second data channel signals and the control channel signal based on scheduling information generated therefrom.
12. An eNB (311) according to claim 11, wherein the scheduling operation calculates a scheduling metric for each resource unit based on channel quality information about the channels between the first and second RU and a plurality of associated UEs, received from the UEs. 13.An eNB (311) according to claim 12, wherein the scheduling operation determines a UE having the maximum scheduling metric for each unit resource.
14. The eNB (311) of claim 8, wherein the digital unit (511) is arranged to multiplex the control channel signal and the first and second data channel signals with control channel reference signals and data channel reference signals, and transmits the first and second multiplexed signals to the plurality of RUs.
15. An eNB (311) according to claim 8, wherein the control channel signal includes at least one of a broadcast physical channel signal, a downlink control physical channel signal, and a control format indicator physical channel signal.