Abstract:
The present invention provides a method and apparatus used for enhanced uplink data transmission, comprising the steps of: monitoring the communication status of a plurality of UEs (user equipment) which conduct uplink data transmission in the RAN; receiving the data transmitted on at least one dedicated uplink channel from at least one of the plurality of UEs; according to the communication status of the plurality of UEs, dynamically allocating the number of dedicated uplink channels for at least one UE of the plurality of UEs. Utilization of the present invention can enable mobile terminal to conduct more efficient uplink transmission.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates generally to TDD CDMA communication system, and more particularly, to a method and apparatus for enhanced uplink data transmission in TDD CDMA communication system. 
       BACKGROUND OF THE INVENTION 
       [0002]    In recent years, in order to satisfy the diverse demands of mobile subscribers, not only higher downlink transmission data rate, but also higher uplink transmission data rate is required in 3G communication system. HSDPA (High Speed Downlink Packet Access) is packet-based data service, which enhances downlink transmission of mobile data. For the downlink channel (5 MHz bandwidth) in WCDMA system, the maximum transmission data rate supported by HSDPA can be up to 10 Mbps. The key technologies which HSDPA adopts are Adaptive Modulation and Coding (AMC) and Hybrid Automatic Repeat Request (HARQ). EUL (Enhanced Uplink) technology is proposed to improve uplink transmission data rate under the support of E-DCH (Enhanced-Dedicated Channel) technology. Nevertheless, in existing TDD specifications, there is no detailed definition for the physical layer architecture of E-DCH. 
         [0003]    In addition, during traditional uplink data transmission, one issue is that the uplink channel is not allowed to be dynamically changed any more, once allocated. However, there would be considerable imbalance for traffic rate of uplink data, for instance, during communication process, when huge volume of data is needed to be transmitted, the capacity of the allocated channel can not satisfy the demands for transmitting such large amount of data, and when small volume of data transmission is needed, the spare channel resource will be wasted. 
         [0004]    Therefore, a complete solution of method and apparatus for enhanced uplink data transmission is needed, which enables mobile terminal to conduct efficient uplink transmission. 
       SUMMARY OF THE INVENTION 
       [0005]    The object of the present invention is to provide a method and apparatus for enhanced uplink data transmission, which can dynamically allocate uplink channel, so as to enable mobile terminal to conduct more efficient uplink data transmission. 
         [0006]    According to the present invention, a method used for enhanced uplink data transmission in radio access networks (RAN) is provided, wherein the method comprises the steps of: monitoring the communication status of a plurality of user equipments (UEs) which are conducting uplink data transmission in the RAN; receiving the data transmitted on at least one dedicated uplink channel from at least one of the plurality of UEs; allocating dynamically the number of dedicated uplink channels for at least one UE of the plurality of UEs, according to communication status of the plurality of UEs. 
         [0007]    According to the present invention, it is provided a method used for enhanced uplink data transmission in user equipment (UE), comprising the steps of: acquiring at least one dedicated uplink channel, which is allocated by the radio access network (RAN) according to communication status of the UE; performing uplink data transmission on the dedicated uplink channel; according to allocation information of the RAN and communication status of the UE, dynamically adjusting the number of the dedicated uplink channels to enable the UE to conduct uplink data transmission on the adjusted dedicated uplink channels. 
         [0008]    According to the present invention, it is provided a UE comprising: a data transmission apparatus, for conducting uplink data transmission to a RAN on at least one dedicated uplink channel; an adjusting apparatus, for adjusting the number of dedicated uplink channels according to allocation information relating to the UE sent from the RAN, so as to enable the transmission apparatus to conduct uplink data transmission on adjusted dedicated uplink channels. 
         [0009]    According to the present invention, it is provided a RAN used to enable a plurality of UEs to conduct uplink data transmission on at least one dedicated uplink channel. The RAN comprises: a monitoring apparatus, for monitoring communication status of the plurality of UEs; a receiving apparatus, for receiving data by enhanced uplink transmission from the plurality of UEs; an allocation apparatus, for dynamically allocating the number of dedicated uplink channels for at least one UE according to the communication status of the plurality of UEs. 
         [0010]    As described above, the method and apparatus for uplink data transmission according to the present invention, enables UE to conduct more efficient uplink data transmission, and also optimizes the corresponding E-DCH resource allocation and makes it more reasonable. 
         [0011]    Other objects and attainments together with a fuller understanding of the invention will become apparent and appreciated by referring to the following description and claims taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a schematic diagram illustrating physical channel configuration of enhanced uplink data transmission according to an embodiment of the present invention; 
           [0013]      FIG. 2  is a flowchart illustrating enhanced uplink data transmission according to an embodiment of the present invention; 
           [0014]      FIG. 3  is a flowchart illustrating dynamical E-PUDCH resource allocation according to an embodiment of the present invention; 
           [0015]      FIG. 4  is a schematic diagram illustrating the timeslot of enhanced uplink data transmission according to an embodiment of the present invention; 
           [0016]      FIG. 5  is a schematic diagram illustrating dynamically allocating E-PUDCH resources according to an embodiment of the present invention; 
           [0017]      FIG. 6  is a block diagram of an apparatus used for enhanced uplink data transmission according to an embodiment of the present invention; 
           [0018]      FIG. 7  is a block diagram of an apparatus used for enhanced uplink data transmission according to another embodiment of the present invention; 
       
    
    
       [0019]    Throughout all the above drawings, like reference numerals will be understood to refer to like, similar or corresponding features or functions. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0020]    Detailed descriptions will be given below to the present invention in conjunction with specific embodiments and accompanying drawings. 
         [0021]      FIG. 1  shows a schematic diagram illustrating physical channel configuration of enhanced uplink data transmission according to an embodiment of the present invention. UE (User Equipment) transmits uplink data on at least one enhanced uplink dedicated physical channel, which is called E-PUDCH (Enhanced Physical Uplink Dedicated Channel) in the present invention and is used for transmitting uplink data to RAN (Radio Access Network), in the meanwhile, E-PUDCH can also be used for sending uplink feedback information to RAN, and the relevant feedback information includes transmission control signal. Alternatively, UE can also send uplink feedback information to RAN on enhanced share information channel, which is called E-SICH (Enhanced Shared Information Channel) in the present invention. E-SICH is an uplink channel, used for sending feedback information from UE to RAN, wherein the relevant feedback information includes: transmission type, the size of transmission block, HARQ related information including HARQ process identifier, new data indicator and incremental redundancy version number. Since E-PUDCH can not only transmit uplink data, but also send uplink feedback information, E-SICH is therefore an optional channel. RAN send control information to UE through enhanced share control channel, which is called E-SCCH (Enhanced Shared Control Channel) in the present invention. E-SCCH is a downlink channel, which is used for RAN (Radio Access Network) to send control information to UE. The relevant control information includes: UE identifier, ACK/NAK (Acknowledgement/Not-Acknowledgement) and TPC (Transmit Power Control). In addition, an EUL-associated uplink DPCH (Dedicated Physical Channel) is used for sending synchronization request and power control request from UE to RAN, and an EUL-associated downlink DPCH is used for sending SS (Synchronization Shift) TPC information from RAN to UE. 
         [0022]    Through E-PUDCH provided according to an embodiment of the present invention, UE is enabled to perform enhanced uplink data transmission to RAN, and in the meanwhile, the number of E-PUDCHs could be dynamically allocated and adjusted according to UE&#39;s communication status after the number is allocated, which makes UE implement more efficient uplink data transmission. The detailed implementation is described with the conjunction of  FIG. 2  and  FIG. 3 . 
         [0023]      FIG. 2  shows a flowchart illustrating enhanced uplink data transmission according to an embodiment of the present invention. Firstly, UE establishes RRC (Radio Resource Control) connection with RAN (step S 110 ), wherein RRC connection is a kind of bidirectional point-to-point connection between RRC protocol layer of UE and RAN. For a communicating UE, there is one RRC connection at most. RRC connection transmits the wireless network signaling between UE and RAN, e.g., allocation of wireless resource and the like. RRC connection is established when call is initially established and released after the communication is ended, between which the RRC connection needs to be maintained. 
         [0024]    UE monitors E-SCCH to obtain E-PUDCH resource allocation information (step S 120 ); then judges if E-PUDCH is allocated to UE (step S 140 ); if not, UE maintains SS and TPC through EUL-associated DPCH (step S 145 ). 
         [0025]    If yes, UE executes EUL data transmission, which is described in detail as following: first, UE (or RAN) chooses AMC (Adaptive Modulation and Coding) transmission mode (step S 150 ); then, UE transmits data on E-PUDCH (step S 160 ) and transmits uplink control information on E-PUDCH or E-SICH (step S 170 ); after receiving the data from UE, RAN sends TPC and SS (Synchronization Shift) through E-SCCH (step S 180 ), then, according to the communication status of the UE performing uplink data transmission, RAN dynamically allocates E-PUDCH resources (step S 190 ); According to RAN&#39;s E-PUDCH allocation information, UE dynamically adjusts the number of E-PUDCHs (step S 195 ); Eventually, UE judges if the data transmission is completed (step S 200 ), if yes, relating wireless resources will be released (step S 210 ), if no, UE returns to step S 140 , and judges if E-PUDCH has been allocated to itself. 
         [0026]      FIG. 3  shows a flowchart illustrating dynamical E-PUDCH resource allocation according to an embodiment of the present invention. To be simplicity, firstly some relevant parameters are defined as following: Q denotes real-time communication quality of the channel occupied by the communicating UE; P denotes the UE&#39;s QoS (Quality of Service) level, that is different types of services are queued into different QoS queues, which makes transmission priority for some services (e.g. voice service) higher than other services (e.g. data service), so as to reduce transmission latency and guarantee the real time transmission quality; N denotes the number of all UEs conducting the enhanced uplink transmission in wireless network; S denotes the number of all E-PUDCHs which are allocated by RAN to the UE for conducting enhanced uplink transmission. 
         [0027]    The assignment/re-assignment of the number of E-PUDCHs acquired by each UE will be based on the Q, P, N and S value. The approaches for RAN to acquire these parameters are as follows: RAN measures UEs&#39; uplink channel quality to get P; Q is directly extracted from UE&#39;s QoS level or service type; S is extracted from RRC (Radio Resource Control) information of RAN; N is yielded according to the number of UEs conducting the EUL transmission currently. 
         [0028]    For every UE conducting the enhanced uplink transmission, RAN will allocate/re-allocate the suitable number of E-PUDCHs according to following two basic principles: 
         [0029]    1. If the UE has a higher P*Q value (P*Q is a synthetic parameter used to denote the quality of channel and QoS level), it will be allocated more E-PUDCHs, otherwise it will be allocated less E-PUDCHs. 
         [0030]    2. If the N value is smaller in the cell, that means there are a few UEs conducting EUL transmission, the cell will be allocated more E-PUDCHs, otherwise it will be allocated less E-PUDCHs. 
         [0031]    The following shows the proposed procedure for dynamical allocation of the E-PUDCH resource shown in  FIG. 3 : 
         [0032]    RAN obtains parameter S, P, Q and N (step S 310 ); 
         [0033]    RAN allocates all the E-PUDECH resource units according to the P*Q value and current N value (step S 320 ); 
         [0034]    The UEs conduct the EUL transmission on E-PUDCH (step S 330 ); 
         [0035]    RAN judges if the value of S is changed (step S 340 ); 
         [0036]    If S is changed, the UE judges if S is increased (step S 350 ), i.e. judges if RAN gets new E-PUDCH resources. If yes, the new available E-PUDCH resource in S domain (i.e. inside RAN coverage area) will be re-allocated (step S 370 ); if no, S is decreased, RAN requests the UE with the smallest P*Q value to release E-PUDCH resources and remove these resources from S domain (step S 360 ). If S value is unchanged, then UE judges if N value is changed (step S 380 ), i.e. judges if the number of all UEs conducting EUL transmission in RAN is changed. 
         [0037]    If N value is changed, UE judges if N is increased (step S 390 ), that is judging if the number of UEs conducting EUL transmission is increased; if yes, RAN will request the UE with the smallest P*Q value to release E-PUDCH resources and allocate the released resources to the new accessed UEs (step S 410 ); if not, RAN will reallocate the new released resources (step S 400 ); if N value is unchanged, UE judges if P*Q value is changed. (step S 420 ). 
         [0038]    If P*Q value is changed, that is the synthetic parameter of the channel quality and QoS level parameter changes, RAN will reallocate all the resources in S domain according to currently P*Q value of each UE and the number of UEs conducting EUL transmission (step S 430 ); if P*Q is unchanged, then UE judges if transmission has completed (step S 440 ); if yes, the relevant occupied wireless resources will be released (step S 450 ); if not, then go back to step S 330  and continue EUL transmission on E-PUDCH. 
         [0039]      FIG. 4  shows schematic diagram illustrating the timeslot of enhanced uplink data transmission according to an embodiment of the present invention. In the embodiment, five timeslots (TS) (TS 2 ˜TS 6 ) in one sub-frame are assigned for E-DCH transmission. At most five TSs per sub-frame can be allocated for E-DCH, because one TS must be served for the EUL-associated DPCHs. 
         [0040]      FIG. 5  shows a schematic diagram illustrating dynamical allocation of E-PUDCH resources according to an embodiment of the present invention. As shown in  FIG. 5 , the allocation status of code channels in different sub-frame when E-PUDCH resources are dynamically allocated to one “target” UE is provided (the grey area represents the code channel has been occupied). During sub-frame n and n+1: the target UE has the supposed smallest P*Q value, so the UE is allocated only one code channel; In sub-frame n+2: a new UE requests to conduct enhanced uplink transmission, so the target UE is requested to release its code channel because it has the smallest P*Q value. As a result, the target UE pauses the enhanced uplink transmission due to only one code channel available; In sub-frame n+3: the parameters (S, P, Q, N) keep unvaried; In sub-frame n+4: the target UE&#39;s channel quality gets improved and the target UE has a much higher P*Q value, so it is allocated more E-PUDCH resources. 
         [0041]      FIG. 6  is a block diagram of an apparatus used for enhanced uplink data transmission according to an embodiment of the present invention. The embodiment describes the functional blocks of UE and RAN with precondition that RAN  2  determines the transmission type. UE  1  comprises data transmission unit  11  and DPCH adjusting unit  12 , in which data transmission unit  11  is used for conducting enhanced uplink transmission on E-PUDCH, and DPCH adjusting unit  12  is used to dynamically adjust E-PUDCH resources accordingly. 
         [0042]    RAN 2  comprises measurement unit  21 , monitoring unit  211 , transmission type selection unit  22 , TFI (Transport Format Information) setting unit  23 , receiving unit  24  and DPCH allocating unit  25 ; in which measurement unit  21  is used to measure the quality of UE 1  uplink channel, monitoring unit  211  is used to monitor the value of Q,P,N and S shown in above  FIG. 3 ; transmission type selection unit  22  is used to select transmission type according to the quality of the UE  1  uplink channel. When channel quality is good with unvaried transmission power, we can select high-order modulation and relating encoding (e.g. 64 QAM, ¾ channel coding), or decrease transmission power when using low-order modulation and relating encoding (e.g. BPSK, ½ channel encoding). TFI setting unit  23  is used to modify the transmission type contained in TFI information according to the selected transmission type. Demodulation unit  24  is used for receiving and demodulating data transmitted by UE 1 &#39;s data transmission unit  11  according to transmission type. DPCH allocating unit  25  is used to dynamically allocate E-PUDCH resource. 
         [0043]    When UE 1  starts to conduct enhanced uplink transmission, measurement unit  21  measures the quality of uplink channels of UE 1 , and according to the quality of the UE 1 &#39;s uplink channel, transmission type selection unit  22  selects appropriate transmission type and informs TFI setting unit  23  to modify the transmission type contained in TFI information, in the meanwhile data transmission unit  11  conducts enhanced uplink transmission according to the transmission type, and the data will be sent to demodulation unit  24  that demodulates the data according to the transmission type. During above enhanced uplink transmission process, based on the parameter value monitored by monitoring unit  211  and the method shown in  FIG. 3 , DPCH allocating unit  25  will dynamically allocate E-PUDCH resources to UE 1 , while DPCH adjusting unit  12  adjusts the number of E-PUDCH used by it own according to E-PUDCH resource allocation information. 
         [0044]      FIG. 7  is a block diagram of an apparatus used for enhanced uplink data transmission according to another embodiment of the present invention. The embodiment describes the functional blocks of UE and RAN with precondition that UE 1 ′ determines the transmission type. UE  1 ′ comprises data transmission unit  11 ′, DPCH adjusting unit  12 ′, measurement unit  21 ′, transmission type selection unit  22 ′ and TFI setting unit  23 ′. RAN 2 ′ comprises monitoring unit  211 ′, receiving unit  24 ′ and DPCH allocating unit  25 ′. Since the functions of the units are same as that in  FIG. 6 , the detail description is omitted. In TDD communication system, uplink and downlink transmission are implemented on same frequencies, so the quality of uplink channel can be acquired by measuring the quality of downlink channels. 
         [0045]    When UE 1  starts to conduct enhanced uplink transmission, measurement unit  21 ′ measures the quality of downlink channels, and according to the quality of the UE 1 &#39;s downlink channel, transmission type selection unit  22 ′ selects appropriate transmission type and inform TFI setting unit  23 ′ to modify the transmission type contained in TFI information, and meanwhile, data transmission unit  11 ′ conducts enhanced uplink transmission according to the transmission type, and the data will be sent to receiving unit  24 ′ that demodulates the data according to the transmission type sent by TFI setting unit  23 ′. During above enhanced uplink transmission process, based on the parameter value monitored by monitoring unit  211 ′ and the method shown in  FIG. 3 , DPCH allocating unit  25 ′ will dynamically allocate E-PUDCH resources to UE 1 ′, while DPCH adjusting unit  12 ′ adjusts the number of E-PUDCH used by it own according to E-PUDCH resource allocation information. 
         [0046]    It is to be understood by those skilled in the art that multicast method and apparatus in P2P-enabled wireless communication networks as disclosed in this invention can be made of various modifications without departing from the spirit and scope of the invention as defined by the appended claims.