[0001]    This application claims priority to Chinese Patent Application No. 201110452537.8, filed with the State Intellectual Property Office of China on Dec. 29, 2011 and entitled “Method and device for feedback information transmission based on enhanced PHICH”, which is hereby incorporated by reference in its entirety. 
       FIELD OF THE INVENTION 
       [0002]    The present invention relates to the field of communication and particularly to a method and a device for feedback information transmission based on an enhanced PHICH. 
       BACKGROUND OF THE INVENTION 
       [0003]    At present a Physical Hybrid Automatic Repeat Request (HARQ) Indicator Channel (PHICH) in a Long Term Evolution (LTE) Release 10 (Rel-10) system is relevantly defined as follows: 
         [0004]    A PHICH is configured to carry Acknowledgement/Non-Acknowledgement (ACK/NACK) feedback information of an uplink service. A resource location of the PHICH is typically indicated by a parameter pair (n PHICH   group , n PHICH   seq ) wherein n PHICH   group  represents the serial number of a PHICH group, and n PHICH   seq  represents the index of an orthogonal sequence. 
         [0005]    The PHICH group conceptually refers to a set of Resource Elements (REs) in which 8 PHICHs can be transmitted and the PHICHs are respectively distinguished from each other by orthogonal sequences. There are 8 orthogonal sequences in case of normal Cyclic Prefix (CP), and then there are 8 PHICHs in one PHICH group; and there are 4 orthogonal sequences in case of extended Cyclic Prefix (CP), and then there are 4 PHICHs in one PHICH group. 
         [0006]    Typically the number of PHICH groups in the LTE Rel-10 system can be determined as follows: 
         [0007]    In a Frequency Division Duplexing (FDD) system, the number of PHICH groups is fixed in all of sub-frames and determined by Formula 1 below: 
         [0000]    
       
         
           
             
               
                 
                   
                     N 
                     PHICH 
                     group 
                   
                   = 
                   
                     { 
                     
                       
                         
                           
                             ⌈ 
                             
                               
                                 N 
                                 g 
                               
                                
                               
                                 ( 
                                 
                                   
                                     N 
                                     RB 
                                     DL 
                                   
                                    
                                   
                                     / 
                                   
                                    
                                   8 
                                 
                                 ) 
                               
                             
                             ⌉ 
                           
                         
                         
                           
                             for 
                              
                             
                                 
                             
                              
                             normal 
                              
                             
                                 
                             
                              
                             cyclic 
                              
                             
                                 
                             
                              
                             prefix 
                           
                         
                       
                       
                         
                           
                             2 
                             ⋆ 
                             
                               ⌈ 
                               
                                 
                                   N 
                                   g 
                                 
                                  
                                 
                                   ( 
                                   
                                     
                                       N 
                                       RB 
                                       DL 
                                     
                                      
                                     
                                       / 
                                     
                                      
                                     8 
                                   
                                   ) 
                                 
                               
                               ⌉ 
                             
                           
                         
                         
                           
                             for 
                              
                             
                                 
                             
                              
                             extended 
                              
                             
                                 
                             
                              
                             cyclic 
                              
                             
                                 
                             
                              
                             prefix 
                           
                         
                       
                     
                   
                 
               
               
                 
                   Formula 
                    
                   
                       
                   
                    
                   1 
                 
               
             
           
         
       
     
         [0008]    Wherein n PHICH   group  represents the total number of PHICH groups, N g ε{1/6,1/2,1,2} is configured by a high layer, N RB   DL  represents a system bandwidth, and the serial number of the index n PHICH   group  ranges from 0 to n PHICH   group −1. 
         [0009]    In a Time Division Duplexing (TDD) system, the number of PHICH groups may vary in respective downlink sub-frames and be given by m i ·n PHICH   group , wherein m i  is determined by configuration information as depicted in Table 1, n PHICH   group  is calculated by the above Formula 1, and the serial number of the index n PHICH   group  ranges from 0 to m i ·n PHICH   group −1. 
         [0000]    
       
         
               
             
               
               
             
               
               
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 1 
               
             
             
               
                   
               
               
                 (A definition of factor m i ) 
               
             
          
           
               
                 Uplink- 
                   
               
               
                 downlink 
                 Sub-frame number i 
               
             
          
           
               
                 configuration 
                 0 
                 1 
                 2 
                 3 
                 4 
                 5 
                 6 
                 7 
                 8 
               
               
                   
               
               
                 0 
                 2 
                 1 
                 — 
                 — 
                 — 
                 2 
                 1 
                 — 
                 — 
               
               
                 1 
                 0 
                 1 
                 — 
                 — 
                 1 
                 0 
                 1 
                 — 
                 — 
               
               
                 2 
                 0 
                 0 
                 — 
                 1 
                 0 
                 0 
                 0 
                 — 
                 1 
               
               
                 3 
                 1 
                 0 
                 — 
                 — 
                 — 
                 0 
                 0 
                 0 
                 1 
               
               
                 4 
                 0 
                 0 
                 — 
                 — 
                 0 
                 0 
                 0 
                 0 
                 1 
               
               
                 5 
                 0 
                 0 
                 — 
                 0 
                 0 
                 0 
                 0 
                 0 
                 1 
               
               
                 6 
                 1 
                 1 
                 — 
                 — 
                 — 
                 1 
                 1 
                 — 
                 — 
               
               
                   
               
             
          
         
       
     
         [0010]    Typically network side maps PHICHs onto Resource Element Group (REG) in a control region where Physical Downlink Control Channel (PDCCH) is located, and the REG is unused by Physical Control Format Indicator Channel (PCFICH) and Cell-Specific Reference Signal (CRS), a duration time of the mapping in time domain can be configured and broadcast by the system. Referring to  FIG. 1 , in a case of a normal PHICH time domain resource configuration (i.e., a Normal PHICH Duration), PHICHs are mapped onto a first Orthogonal Frequency Division Multiplexing (OFDM) symbol of a downlink sub-frame to support a scenario with a smaller number of users and a small coverage; while in a case of an extended PHICH time domain resource configuration, each PHICH group can be mapped onto the first 3 OFDM symbols of a downlink sub-frame; and in an especial case, each PHICH group can be mapped onto the first 2 OFDM symbols in a Multimedia Broadcast multicast service Single Frequency Network (MBSFN) sub-frame and TD-SCDMA Long Term Evolution (TD-LTE) sub-frames 1 and 6 to support a scenario with a larger coverage radius or a larger number of users. Furthermore, the number of PHICH groups in a cell can also be configured at 4 different levels (i.e., N g ε{1/6,1/2,1, 2}), and the configuration situations are broadcast by the system to support various user capacities. 
         [0011]    3 REGs occupied in the control region by one PHICH group are distributed differently in time and frequency domains for the purpose of maximizing time and frequency diversity gains. As illustrated in  FIG. 1 ,  FIG. 1  illustrates a schematic diagram of mapping resources of one PHICH group and shows that time-frequency resources occupied by one PHICH group are related to the number of REGs, a cell ID, the serial number of the PHICH group, specific serial numbers of OFDM symbols, etc. 
         [0012]    Correspondingly, for a User Equipment (UE), when the UE transmits uplink data based on Physical Uplink Shared Channel (PUSCH), ACK/NACK feedback information corresponding to the uplink data is transmitted by the network side to the UE based on a PHICH in a downlink sub-frame, wherein considering a PUSCH transmitted in a sub-frame n, the UE receives a corresponding PHICH in a sub-frame n+k PHICH , and for a FDD system, k PHICH =4, and for the TDD system, k PHICH  is determined through configuration information depicted in Table 2: 
         [0000]    
       
         
               
             
               
               
             
               
               
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 2 
               
             
             
               
                   
               
               
                 (A k PHICH  configuration of a TDD system) 
               
             
          
           
               
                 TDD 
                   
               
               
                 UL/DL 
                 UL sub-frame index n 
               
             
          
           
               
                 Configuration 
                 0 
                 1 
                 2 
                 3 
                 4 
                 5 
                 6 
                 7 
                 8 
                 9 
               
               
                   
               
             
          
           
               
                 0 
                   
                 4 
                 7 
                 6 
                   
                 4 
                 7 
                 6 
               
               
                 1 
                   
                 4 
                 6 
                   
                   
                 4 
                 6 
               
               
                 2 
                   
                 6 
                   
                   
                   
                 6 
               
               
                 3 
                   
                 6 
                 6 
                 6 
               
               
                 4 
                   
                 6 
                 6 
               
               
                 5 
                   
                 6 
               
               
                 6 
                   
                 4 
                 6 
                 6 
                   
                 4 
                 7 
               
               
                   
               
             
          
         
       
     
         [0013]    A specific location of a time-frequency resource occupied in a downlink sub-frame by a PHICH is decided jointly by a lowest PRB serial number among PHICH resources indicated by scheduling signaling carried in Downlink Control Information (DCI) transmitted in the format 0 on PDCCH and a De-Modulation Reference Signal (DMRS) indicated by 3 bits in a PUSCH transmission grant indicating a lowest Physical Resource Block (PRB) serial number among resources allocated in rows and a cyclic shift of an uplink DMRS indicated by 3 bits. 
         [0014]    A specific location of a time-frequency resource occupied by a PHICH is identified by a pair of parameters (n PHICH   group , n PHICH   seq ) wherein n PHICH   group  represents the serial number of a PHICH group; and n PHICH   seq  represents the serial number of an orthogonal sequence in the PHICH group, particularly calculated by Formula 2: 
         [0000]        n   PHICH   group =( I   PRB     —     RA   +n   DMRS )mod  n   PHICH   group   +I   PHICH   n   PHICH   group    
         [0000]        n   PHICH   seq =(└ I   PRB     —     RA   /n   PHICH   group   ┘+n   DMRS )mod 2 N   SF   PHICH   Formula 2
 
         [0015]    Wherein n DMRS  represents the value of a cyclic shift of a DMRS used in PUSCH corresponding to a PHICH and indicated by cyclic shift information in a DMRS field in the DCI format 0 (i.e., DCI in the format 0), and the specific mapping relationship is illustrated in Table 3. 
         [0000]    
       
         
               
             
               
               
               
             
           
               
                 TABLE 3 
               
             
             
               
                   
               
               
                 (Mapping relationship between n DMRS  and a cyclic 
               
               
                 shift for a DMRS field in the DCI format 0) 
               
             
          
           
               
                   
                 Cyclic Shift for DMRS Field in 
                   
               
               
                   
                 DCI format 0 in [4] 
                 n DMRS   
               
               
                   
                   
               
               
                   
                 000 
                 0 
               
               
                   
                 001 
                 1 
               
               
                   
                 010 
                 2 
               
               
                   
                 011 
                 3 
               
               
                   
                 100 
                 4 
               
               
                   
                 101 
                 5 
               
               
                   
                 110 
                 6 
               
               
                   
                 111 
                 7 
               
               
                   
                   
               
             
          
         
       
     
         [0016]    Referring to a PUSCH transmitted in a sub-frame n, if there is no corresponding uplink scheduling instruction in the DCI format 0 or transmission of the PUSCH is scheduled by a random access response, n DMRS  is set to 0; 
         [0017]    N SF   PHICH  represents the size of a spreading factor for modulation of a PHICH defined in the standard 36.221; 
         [0000]    
       
         
           
             
               I 
               PRB_RA 
             
             = 
             
               { 
               
                 
                   
                     
                       I 
                       PRB_RA 
                       lowest_index 
                     
                   
                   
                     
                       
                         
                           
                             
                               
                                 
                                   
                                     
                                       
                                         
                                           
                                             
                                               
                                                 
                                                   
                                                     
                                                       in 
                                                        
                                                       
                                                           
                                                       
                                                        
                                                       a 
                                                        
                                                       
                                                           
                                                       
                                                        
                                                       case 
                                                        
                                                       
                                                           
                                                       
                                                        
                                                       that 
                                                        
                                                       
                                                           
                                                       
                                                        
                                                       a 
                                                        
                                                       
                                                           
                                                       
                                                        
                                                       PDCCH 
                                                        
                                                       
                                                           
                                                       
                                                        
                                                       indicates 
                                                        
                                                       
                                                           
                                                       
                                                        
                                                       to 
                                                        
                                                       
                                                           
                                                       
                                                        
                                                       schedule 
                                                     
                                                      
                                                     
                                                         
                                                     
                                                   
                                                 
                                               
                                               
                                                 
                                                   
                                                     
                                                         
                                                     
                                                      
                                                     
                                                       
                                                         a 
                                                          
                                                         
                                                             
                                                         
                                                          
                                                         first 
                                                          
                                                         
                                                             
                                                         
                                                          
                                                         transmission 
                                                          
                                                         
                                                             
                                                         
                                                          
                                                         block 
                                                          
                                                         
                                                             
                                                         
                                                          
                                                         in 
                                                          
                                                         
                                                             
                                                         
                                                          
                                                         a 
                                                          
                                                         
                                                             
                                                         
                                                          
                                                         PUSCH 
                                                       
                                                       , 
                                                       
                                                         or 
                                                          
                                                         
                                                             
                                                         
                                                          
                                                         there 
                                                       
                                                     
                                                   
                                                 
                                               
                                             
                                           
                                         
                                         
                                           
                                             
                                               
                                                   
                                               
                                                
                                               
                                                 is 
                                                  
                                                 
                                                     
                                                 
                                                  
                                                 no 
                                                  
                                                 
                                                     
                                                 
                                                  
                                                 corresponding 
                                                  
                                                 
                                                     
                                                 
                                                  
                                                 PDCCH 
                                                  
                                                 
                                                     
                                                 
                                                  
                                                 and 
                                                  
                                                 
                                                   
                                                       
                                                   
                                                    
                                                   
                                                       
                                                   
                                                 
                                                  
                                                 the 
                                                  
                                                 
                                                     
                                                 
                                                  
                                                 number 
                                                  
                                                 
                                                     
                                                 
                                                  
                                                 of 
                                               
                                             
                                           
                                         
                                       
                                     
                                   
                                   
                                     
                                       
                                         received 
                                          
                                         
                                             
                                         
                                          
                                         NACKs 
                                          
                                         
                                             
                                         
                                          
                                         is 
                                          
                                         
                                             
                                         
                                          
                                         unequal 
                                          
                                         
                                             
                                         
                                          
                                         to 
                                          
                                         
                                             
                                         
                                          
                                         the 
                                          
                                         
                                             
                                         
                                          
                                         number 
                                          
                                         
                                             
                                         
                                          
                                         of 
                                       
                                     
                                   
                                 
                               
                             
                             
                               
                                 
                                   transmission 
                                    
                                   
                                       
                                   
                                    
                                   blocks 
                                    
                                   
                                       
                                   
                                    
                                   in 
                                    
                                   
                                       
                                   
                                    
                                   a 
                                    
                                   
                                       
                                   
                                    
                                   PUSCH 
                                    
                                   
                                       
                                   
                                    
                                   recently 
                                    
                                   
                                       
                                   
                                    
                                   scheduled 
                                 
                               
                             
                           
                         
                       
                       
                         
                           
                             by 
                              
                             
                                 
                             
                              
                             a 
                              
                             
                                 
                             
                              
                             PDCCH 
                           
                         
                       
                     
                   
                 
                 
                   
                     
                       
                         I 
                         PRB_RA 
                         lowest_index 
                       
                       + 
                       1 
                     
                   
                   
                     
                       
                         
                           
                             
                               
                                 in 
                                  
                                 
                                     
                                 
                                  
                                 a 
                                  
                                 
                                     
                                 
                                  
                                 case 
                                  
                                 
                                     
                                 
                                  
                                 that 
                                  
                                 
                                     
                                 
                                  
                                 a 
                                  
                                 
                                     
                                 
                                  
                                 PDCCH 
                                  
                                 
                                     
                                 
                                  
                                 indicates 
                                  
                                 
                                     
                                 
                                  
                                 to 
                                  
                                 
                                     
                                 
                                  
                                 schedule 
                               
                                
                               
                                   
                               
                             
                           
                         
                         
                           
                             
                               
                                   
                               
                                
                               
                                 a 
                                  
                                 
                                     
                                 
                                  
                                 second 
                                  
                                 
                                     
                                 
                                  
                                 transmission 
                                  
                                 
                                     
                                 
                                  
                                 block 
                                  
                                 
                                     
                                 
                                  
                                 in 
                                  
                                 
                                     
                                 
                                  
                                 a 
                                  
                                 
                                     
                                 
                                  
                                 PUSCH 
                               
                             
                           
                         
                       
                        
                       
                           
                       
                     
                   
                 
               
             
           
         
       
     
         [0018]    I PRB     —     RA   lowest     —     index  represents a lowest PRB serial number allocated by a first timeslot in transmission of a corresponding PUSCH: 
         [0019]    n PHICH   group  represents the number of PHICH groups, configured by high-layer signaling; and 
         [0000]    
       
         
           
             
               I 
               PHICH 
             
             = 
             
               { 
               
                 
                   
                     1 
                   
                   
                     
                       
                         
                           
                             
                               when 
                                
                               
                                   
                               
                                
                               TDD 
                                
                               
                                   
                               
                                
                               UL 
                                
                               
                                 / 
                               
                                
                               DL 
                                
                               
                                   
                               
                                
                               is 
                                
                               
                                   
                               
                                
                               configured 
                                
                               
                                   
                               
                                
                               to 
                                
                               
                                   
                               
                                
                               be 
                                
                               
                                   
                               
                                
                               0 
                             
                             , 
                             and 
                           
                         
                       
                       
                         
                           
                             
                               a 
                                
                               
                                   
                               
                                
                               PUSCH 
                                
                               
                                   
                               
                                
                               is 
                                
                               
                                   
                               
                                
                               in 
                                
                               
                                   
                               
                                
                               a 
                                
                               
                                   
                               
                                
                               sub 
                                
                               
                                 - 
                               
                                
                               frame 
                                
                               
                                   
                               
                                
                               of 
                                
                               
                                   
                               
                                
                               n 
                             
                             = 
                             
                               
                                 4 
                                  
                                 
                                     
                                 
                                  
                                 or 
                                  
                                 
                                     
                                 
                                  
                                 n 
                               
                               = 
                               9 
                             
                           
                         
                       
                     
                   
                 
                 
                   
                     0 
                   
                   
                     
                       under 
                        
                       
                           
                       
                        
                       other 
                        
                       
                           
                       
                        
                       conditions 
                     
                   
                 
               
             
           
         
       
     
         [0020]    The foregoing relevant definition of a PHICH is currently applicable only to the LTE-Rel-10 system. A traditional method of providing an access with use of the single-layer coverage by a macro base station has failed to satisfy a user demand along with an increasingly growing data rate and demand for service load. Thus it is typical at present to address the foregoing issue by a hierarchical coverage, for example, some low-power base stations, e.g., a Home eNodeB/a pico base station/a femto base station/a relay base station, etc., are deployed in a hotspot area or indoors. Such a low-power base station is a base station device applied in a home indoor environment, an office environment or other hotspot small-coverage environment to enable an operator to provide an appealing service at a higher data rate and a lower cost. However the femto base station limits the accessing member users to a certain degree and is inaccessible to a non-member user, and if the non-member user enters the coverage area of the base station, then it may enter a coverage hole due to a stronger signal of the low-power base station and consequentially cannot operate. Moreover the pico base station at the same frequency as the macro base station may also generate strong interference and consequentially cannot operate. In order to address such interference, an existing practice is to set an Almost Blank Subframe (ABS), so that the base station transmits signals less frequently in the ABS so as to reduce interference to an adjacent cell, to perform Inter-Cell Interference Coordination (ICIC) through Time Division Multiple (TDM). 
         [0021]    However in the existing TDM ICIC mechanism, the interfering base station configured with the ABS will not transmit any control information in the ABS in order to avoid interferences, so transmission of a PHICH in the control region may be limited due to the introduced ABS mechanism. 
         [0022]    On the other hand, the definition of an extended carrier may be introduced to the LTE Rel-11 system, that is, a PDCCH control region supported in the LTE Rel-10 system is not included in an extended carrier, but a PUSCH can be scheduled in an extended carrier, and thus other compatible component carriers are scheduled through cross-carrier scheduling on one hand, and transmission of an enhanced PDCCH can be newly defined over an extended carrier on the other hand, wherein a PDSCH transmission region is occupied for transmission of an enhanced PDCCH. Thus limited transmission of a PHICH in the control region may also arise in the latter case. 
         [0023]    In the prior art, a method to address the issue of limited transmission of a PHICH is to adopt scheduling signaling in the DCI format 0 for the system instead of a PHICH to notify the UE whether to retransmit a PUSCH, but this method may result in an extra overhead of system signaling and a consequential increase in operation load of the system, thus degrading the performance of the system. 
       SUMMARY OF THE INVENTION 
       [0024]    Embodiments of the present invention provide a method and a device for feedback information transmission based on PHICH so as to address the issue of limited transmission of PHICHs without any increase in the overhead of system signaling. 
         [0025]    Specific technical solutions provided by the embodiments of the present invention are as follows: 
         [0026]    A method for feedback information transmission based on an enhanced PHICH, which includes: 
         [0027]    determining time-frequency resources occupied by the enhanced PHICH configured in a PDSCH region by a network side; 
         [0028]    notifying a user equipment of the determined time-frequency resources occupied by the enhanced PHICH; 
         [0029]    determining groups of enhanced PHICH resources for carrying ACK/NACK feedback information among the time-frequency resources occupied by the enhanced PHICH according to a scheduling condition of the user equipment; and 
         [0030]    mapping the ACK/NACK feedback information to be transmitted onto the groups of enhanced PHICH resources and transmitting the ACK/NACK feedback information to the user equipment. 
         [0031]    A method for feedback information transmission based on an enhanced PHICH, which includes: 
         [0032]    determining time-frequency resources occupied by the enhanced PHICH configured in a PDSCH region by a network side based on a notification of a base station; 
         [0033]    determining groups of enhanced PHICH resources for carrying ACK/NACK feedback information among the time-frequency resources occupied by the enhanced PHICH according to scheduling signaling of the base station; and 
         [0034]    receiving the ACK/NACK feedback information transmitted from the base station based on the determined groups of enhanced PHICH resources. 
         [0035]    A device for feedback information transmission based on an enhanced PHICH, which includes: 
         [0036]    a first processing component configured to determine time-frequency resources occupied by the enhanced PHICH configured in a Physical Downlink Shared Channel (PDSCH) region by a network side and to notify a user equipment of the determined time-frequency resources occupied by the enhanced PHICH; 
         [0037]    a second processing component configured to determine groups of enhanced PHICH resources for carrying ACK/NACK feedback information among the time-frequency resources occupied by the enhanced PHICH according to a scheduling condition of the user equipment; and 
         [0038]    a communication component configured to map the ACK/NACK feedback information to be transmitted onto the groups of enhanced PHICH resources and to transmit the ACK/NACK feedback information to the user equipment. 
         [0039]    A device for feedback information transmission based on an enhanced PHICH, which includes: 
         [0040]    a first control component configured to determine time-frequency resources occupied by the enhanced PHICH configured in a Physical Downlink Shared Channel (PDSCH) region by a network side based on a notification of a base station; 
         [0041]    a second control component configured to determine groups of enhanced PHICH resources for carrying ACK/NACK feedback information among the time-frequency resources occupied by the enhanced PHICH according to scheduling signaling of the base station; and 
         [0042]    a communication component configured to receive the ACK/NACK feedback information transmitted from the base station based on the determined groups of enhanced PHICH resources. 
         [0043]    In the embodiments of the present invention, a novel method for E-PHICH transmission based upon FDM is proposed, that is, ACK/NACK feedback information is carried over E-PHICH resources configured in a PDSCH region, so that on one hand, the issue of unavailable transmission of PHICHs in some scenarios, e.g., in an ABS sub-frame of eICIC and an extended carrier to be possibly defined subsequently, can be addressed; and on the other hand, the overhead of signaling can be saved and the utilization ratio of resources can be improved, for example, retransmission of a PUSCH scheduled by the system in the DCI format 0 is avoided, to achieve the effects of improving a capacity of PHICHs and addressing a legacy PHICH resource confliction. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0044]      FIG. 1  is a schematic diagram of resources occupied in a legacy PDCCH region by PHICHs in the prior art; 
           [0045]      FIG. 2A  and  FIG. 2B  are schematic diagrams of E-PHICH transmission method according to embodiments of the invention; 
           [0046]      FIG. 3  is a flow chart of a base station transmitting ACK/NACK feedback information based on E-PHICH according to an embodiment of the invention; 
           [0047]      FIG. 4A  and  FIG. 4B  are schematic diagrams of E-PHICH resource occupying methods according to embodiments of the invention; 
           [0048]      FIG. 5  to  FIG. 11  are schematic diagrams of division into E-PHICH groups according to embodiments of the invention; 
           [0049]      FIG. 12  is a flow chart of a user equipment receiving ACK/NACK feedback information based on E-PHICH according to an embodiment of the invention; 
           [0050]      FIG. 13  is a schematic functional structural diagram of a base station according to an embodiment of the invention; and 
           [0051]      FIG. 14  is a schematic functional structural diagram of a user equipment according to an embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0052]    In order to address the issue of limited transmission of PHICHs without any increase in overhead of system signaling, in an embodiment of the present invention, a transmission region of PHICHs is transferred from a legacy Physical Downlink Control Channel (PDCCH) region (also referred to as a control region) to a Physical Downlink Shared Channel (PDSCH) region, and ACK/NACK feedback information is transmitted based on enhanced PHICH resources (denoted as E-PHICH) configured in the PDSCH region. 
         [0053]    Referring to  FIG. 2A  and  FIG. 2B , for example, a system can transmit ACK/NACK feedback information through E-PHICH resource blocks configured in a PDSCH region over compatible carriers and only transmit PCFICH in the PDCCH region; or the system can transmit ACK/NACK feedback information through E-PHICH resource blocks configured in a PDSCH region over extended carriers. 
         [0054]    ACK/NACK feedback information can be transmitted based on E-PHICH resources through multiplexed transmission including one or any combination of Time Division Multiplexing (TDM). Frequency Division Multiplexing (FDM) and Code Division Multiplexing (CDM). 
         [0055]    Preferred embodiments of the present invention will be detailed below with reference to the drawings. 
         [0056]    Referring to  FIG. 3 , a detailed flow in which a base station transmits ACK/NACK feedback information based on E-PHICH according to an embodiment of the present invention is as follows: 
         [0057]    Step  300 : A base station determines time-frequency resources occupied by E-PHICH configured in a PDSCH region by the network side. 
         [0058]    The time-frequency resources occupied by the E-PHICH may be some combinations of transmission resources discontinuous in time domain or/and frequency domain. Referring to  FIG. 2A  and  FIG. 2B , for example, the time-frequency resources occupied by the E-PHICH are an E-PHICH resource block  1 , an E-PHICH resource block  2 , an E-PHICH resource block  3  and an E-PHICH resource block  4  in the PDSCH region, where the size of each E-PHICH resource block may be one sub-carrier or a combination of a plurality of continuous sub-carriers or a plurality of PRB pairs or a combination of a plurality of REs. 
         [0059]    Step  301 : The base station notifies a user equipment of the determined time-frequency resources occupied by the E-PHICH. 
         [0060]    The step  310  may be performed in the following two implementations but will not be limited thereto: 
         [0061]    In a first implementation, the user equipment is notified of the determined time-frequency resources occupied by the E-PHICH via dedicated signaling. 
         [0062]    For example, the user equipment is notified of specific locations of PRB pairs occupied by the E-PHICH via Radio Resource Control (RRC) signaling or a system broadcast message. 
         [0063]    In another example, the user equipment is notified of a starting location of PRB pairs occupied by the E-PHICH and the number of occupied PRB pairs via RRC signaling or a broadcast message, wherein the PRB pairs occupied by the E-PHICH are distributed uniformly throughout a downlink system bandwidth as a plurality of resource blocks, particularly as follows: 
         [0064]    1. The user equipment is directly notified of the a starting location of the PRB pairs occupied by the E-PHICH and the number of occupied PRB pairs via RRC signaling or a system broadcast message. 
         [0065]    2. The user equipment is notified of the starting location of the PRB pairs occupied by the E-PHICH, and the use equipment is instructed to determine the number of PRB pairs occupied by the E-PHICH as agreed on with the network side, via RRC signaling or a system broadcast message, wherein an association relationship between the number of PRB pairs occupied by the E-PHICH and the downlink system bandwidth may be agreed on. 
         [0066]    3. The user equipment is instructed to calculate the starting location of the PRB pairs occupied by the E-PHICH based on a cell identifier (ID) and a system bandwidth, and to determine an agreed-on association relationship between the number of PRB pairs occupied by the E-PHICH and the downlink system bandwidth as agreed on with the network side, via RRC signaling or a system broadcast message. 
         [0067]    In a second implementation, the user equipment is notified of an E-PHICH resource configuration parameter via RRC signaling or a system broadcast message so that the user equipment occupies a part of time-frequency resources in E-PDCCH (enhanced PDCCH) (i.e., PRB pairs) according to the E-PHICH resource configuration parameter. 
         [0068]    Referring to  FIG. 4A  and  FIG. 4B , in a practical application, the E-PDCCH may be transmitted by occupying the time-frequency resources in the PDSCH region, and the E-PHICH may use a part of the time-frequency resources occupied by the E-PDCCH, wherein typically the network side firstly calculates the resources reserved for the E-PHICH, and the remaining time-frequency resources may be used for the transmission of the E-PDCCH. 
         [0069]    In this embodiment, when the E-PHICH uses a part of the time-frequency resources occupied by the E-PDCCH, the time-frequency resources used by the E-PHICH can still be reserved in a similar reservation way as the PHICH resources in the Rel-10, that is, the size of the time-frequency resources reserved for the E-PHICH (including specific locations of PRB pairs, or a starting location and the number of PRB pairs) is determined by an E-PHICH resource configuration related parameter (e.g., a PHICH configuration parameter Ng in the Rel-10), possibly still as done in the Rel-10, wherein the user equipment may be notified of the E-PHICH resource configuration related parameter via RRC signaling or a system broadcast message. 
         [0070]    Step  320 : The base station determines groups of E-PHICH resources, denoted as E-PHICH groups, for carrying ACK/NACK feedback information among the time-frequency resources occupied by the E-PHICH according to a scheduling condition of the user equipment. 
         [0071]    In the step  320 , the base station may determine E-PHICH resources for carrying the ACK/NACK feedback information among the time-frequency resources occupied by the E-PHICH according to a lowest PRB pair serial number and a cyclic shift of an uplink DMRS indicated in a PUSCH transmission grant, and reference can be made to the Rel-10 for relative operations thereof, so a repeated description thereof will be omitted here. 
         [0072]    On the other hand, in the step  320 , the base station may determine the E-PHICH groups for carrying the ACK/NACK feedback information in the following operations: 
         [0073]    Firstly, each PRB pair included in the time-frequency resources occupied by the E-PHICH is determined; 
         [0074]    Referring to  FIG. 5 , for example, given a normal CP, the time-frequency resources occupied by the E-PHICH include 4 PRB pairs (each of which corresponds to an E-PHICH resource block), and a PRB pair is represented as a 14×12 square with the ordinate representing the frequency domain in a unit of a sub-carrier and the abscissa representing the time domain in a unit of an OFDM symbol, wherein legacy Physical Downlink Control Channel (PDCCH) Resource Elements (REs) are carried in first two OFDM symbols. 
         [0075]    Secondly division into the E-PHICH groups may be performed in one of the following three schemes: 
         [0076]    In a first scheme, all of REs included in sub-carriers at a specified location among the respective PRB pairs belong to an E-PHICH group according to a scheduling condition of the user equipment. 
         [0077]    Referring to  FIG. 5 , for example, all of REs included in sub-carriers at the location  1  among the respective PRB pairs belong to an E-PHICH group. 
         [0078]    Furthermore a plurality of E-PHICH groups may be determined as above, and referring to  FIG. 6 , for example, all of REs included in the sub-carriers at the location  1  among the respective PRB pairs may belong to an E-PHICH group  1 , all of REs included in sub-carriers at the location  2  among the respective PRB pairs may belong to an E-PHICH group  2 , and all of REs included in sub-carriers at the location  3  among the respective PRB pairs may belong to an E-PHICH group  3 , wherein a part of the REs in one of the E-PHICH groups may or may not be reserved as reserved resources by way of an example here but without any limitation thereto. 
         [0079]    Preferably the REs for carrying legacy PDCCHs and reference signals need to be excluded from the respective E-PHICH groups above, wherein the so-called reference signals may be a CRS, a DMRS, a Channel State Information-Reference Signal (CSI-RS), etc. 
         [0080]    Naturally all of REs included in sub-carriers at different locations among the respective PRB pairs may belong to an E-PHICH group, for example, all of REs included in a sub-carrier at the location  1  in the first PRB pair, all of REs included in a sub-carrier at the location  2  in the second PRB pair, all of REs included in a sub-carrier at the location  3  in the third PRB pair and all of REs included in a sub-carrier at the location  4  in the fourth PRB pair belong to an E-PHICH group, and this embodiment has been described with reference to  FIG. 5  and  FIG. 6  by way of an example. 
         [0081]    In a second scheme, a specified part of REs in sub-carriers at a specified location among the respective PRB pairs may belong to an E-PHICH group according to a scheduling condition of the user equipment. 
         [0082]    Referring to  FIG. 7 , for example, REs in the 3 rd , 4 th  and 5 th  OFDM symbols included in sub-carriers at the location  1  among the respective PRB pairs belong to an E-PHICH group. 
         [0083]    Furthermore, a plurality of E-PHICH groups may be determined as above, and referring to  FIG. 8 , for example, REs in the 3 rd , 4 th  and 5 th  OFDM symbols included in the sub-carriers at the location  1  among the respective PRB pairs belong to an E-PHICH group  1 , REs in the 3 rd , 4 th  and 5 th  OFDM symbols included in sub-carriers at the location  2  among the respective PRB pairs belong to an E-PHICH group  2 , REs in the 3 rd , 4 th  and 5 th  OFDM symbols included in sub-carriers at the location  3  among the respective PRB pairs belong to an E-PHICH group  3 , REs in the 8 th , 9 th , 10 th , 11 th  and 12 th  OFDM symbols included in sub-carriers at the location  1  among the respective PRB pairs belong to an E-PHICH group  4 , REs in the 8 th , 9 th , 10 th , 11 th  and 12 th  OFDM symbols included in sub-carriers at the location  2  among the respective PRB pairs belong to an E-PHICH group  5 , and REs in the 8 th , 9 th , 10 th , 11 th  and 12 th  OFDM symbols included in sub-carriers at the location  1  among the respective PRB pairs belong to an E-PHICH group  6 . 
         [0084]    Preferably the REs for carrying legacy PDCCHs and reference signals also need to be excluded from the respective E-PHICH groups above, wherein the so-called reference signals may be a CRS, a DMRS, a CSI-RS, etc. 
         [0085]    Naturally, REs at specified locations included in sub-carriers at different locations among the respective PRB pairs may belong to an E-PHICH group. For example, REs in the 8 th , 9 th , 10 th , 11 th  and 12 th  OFDM symbols included in a sub-carrier at the location  1  in the first PRB pair, REs in the 8 th , 9 th , 10 th , 11 th  and 12 th  OFDM symbols included in a sub-carrier at the location  2  in the second PRB pair, REs in the 8 th , 9 th , 10 th , 11 th  and 12 th  OFDM symbols included in a sub-carrier at the location  3  in the third PRB pair and REs in the 8 th , 9 th , 10 th , 11 th  and 12 th  OFDM symbols included in a sub-carrier at the location  4  in the fourth PRB pair belong to an E-PHICH group, and this embodiment has been described with reference to  FIG. 7  and  FIG. 8  by way of an example. 
         [0086]    In a third implementation, M REs in specified time domain and adjacent in frequency domain in each PRB pair, among the respective PRB pairs, belong to an E-PHICH group, wherein M represents a pre-configured parameter. 
         [0087]    During the division of the E-PHICH groups, OFDM symbols adjacent to a DMRS in time domain may be occupied firstly. For example, if M=4, then referring to  FIG. 9 , REs in the 8 th  OFDM symbols included in sub-carriers at the location  1 , the location  2 , the location  3  and the location  4  among the respective PRB pairs belong to an E-PHICH group. 
         [0088]    Furthermore a plurality of E-PHICH groups may be determined as above, and referring to  FIG. 10 , for example, REs in the 8 th  OFDM symbols included in sub-carriers at the location  1 , the location  2 , the location  3  and the location  4  among the respective PRB pairs may belong to an E-PHICH group  1 , REs in the 8 th  OFDM symbols included in sub-carriers at the location  5 , the location  6 , the location  7  and the location  8  among the respective PRB pairs may belong to an E-PHICH group  2 , and REs in the 8 th  OFDM symbols included in sub-carriers at the location  9 , the location  10 , the location  11  and the location  12  among the respective PRB pairs may belong to an E-PHICH group  3 . 
         [0089]    Preferably, the REs for carrying legacy PDCCHs and reference signals also need to be excluded from the respective E-PHICH groups above, wherein the so-called reference signals may be a CRS, a DMRS, a CSI-RS, etc. Referring to  FIG. 11 , for example,  FIG. 11  illustrates division into E-PHICH groups in the case of two CRS antenna ports. 
         [0090]    Preferably, the REs for carrying legacy PDCCHs and reference signals also need to be excluded from the respective E-PHICH groups above, wherein the so-called reference signals may be a CRS, a DMRS, a CSI-RS, etc. 
         [0091]    Step  330 : The base station maps the ACK/NACK feedback information to be transmitted onto the corresponding E-PHICH groups and transmits the ACK/NACK feedback information to the user equipment. 
         [0092]    Specifically: 
         [0093]    A. The ACK/NACK feedback information to be transmitted is simply encoded. 
         [0094]    For example, 1-bit ACK/NACK feedback information is simply encoded into N bits, possibly through repeated encoding or sequential encoding or in another encoding scheme, wherein N is a pre-configured parameter or may be a parameter as a result of rate matching according to available time-frequency resources. 
         [0095]    Examples of the simply encoded ACK/NACK feedback information are as follows: 
         [0096]    Example 1: ACK: 111 . . . , and NACK: 000 . . . 
         [0097]    Example 2: ACK: 1010 . . . , and NACK: 0101 . . . 
         [0098]    B. The simply encoded ACK/NACK feedback information is Binary Phase Shift Keying (BPSK) modulated into modulation symbols which are orthogonally spread bit by bit, preferably by a spreading factor of 4 and still using an orthogonal spreading sequence of a PHICH in the Rel-10. 
         [0099]    C. The orthogonally spread modulation symbols are mapped respectively into the corresponding E-PHICH groups. 
         [0100]    Referring to  FIG. 5 , for example, the orthogonally spread modulation symbols are grouped in rows, and the respective groups of modulation symbols are mapped respectively onto REs belonging to the same E-PHICH group among the respective PRB pairs, for example, the respective groups of modulation symbols are mapped respectively onto REs included in sub-carriers at the location  1  in the PRB pairs corresponding to the E-PHICH resource block  1 , REs included in sub-carriers at the location  1  in the PRB pairs corresponding to the E-PHICH resource block  2 , REs included in sub-carriers at the location  1  in the PRB pairs corresponding to the E-PHICH resource block  3  and REs included in sub-carriers at the location  1  in the PRB pairs corresponding to the E-PHICH resource block  4 , and naturally these REs do not include REs for carrying legacy PDCCHs and reference signals. 
         [0101]    In another example, referring to  FIG. 7 , the orthogonally spread modulation symbols are grouped in rows, and the respective groups of modulation symbols are mapped respectively onto REs belonging to the same E-PHICH group among the respective PRB pairs, for example, the respective groups of modulation symbols are mapped respectively onto REs in the 3 rd , 4 th  and 5 th  OFDM symbols included in sub-carriers at the location  1  in the PRB pairs corresponding to the E-PHICH resource block  1 , REs in the 3 rd , 4 th  and 5 th  OFDM symbols included in sub-carriers at the location  1  in the PRB pairs corresponding to the E-PHICH resource block  2 , REs in the 3 rd , 4 th  and 5 th  OFDM symbols included in sub-carriers at the location  1  in the PRB pairs corresponding to the E-PHICH resource block  3  and REs in the 3 rd , 4 th  and 5 th  OFDM symbols included in sub-carriers at the location  1  in the PRB pairs corresponding to the E-PHICH resource block  4 , and naturally these REs do not include REs for carrying legacy PDCCHs and reference signals. 
         [0102]    In another example, referring to  FIG. 9 , the orthogonally spread modulation symbols are grouped in columns, and the respective groups of modulation symbols are mapped respectively onto REs belonging to the same E-PHICH group among the respective PRB pairs, for example, the respective groups of modulation symbols are mapped respectively onto REs in the 8 h  OFDM symbols included in sub-carriers at the location  1 , the location  2 , the location  3  and the location  4  in the PRB pairs corresponding to the E-PHICH resource block  1 , REs in the 8 th  OFDM symbols included in sub-carriers at the location  5 , the location  6 , the location  7  and the location  8  in the PRB pairs corresponding to the E-PHICH resource block  2  and REs in the 8 th  OFDM symbols included in sub-carriers at the location  9 , the location  10 , the location  11  and the location  12  in the PRB pairs corresponding to the E-PHICH resource block  3 , and naturally these REs do not include REs for carrying legacy PDCCHs and reference signals. 
         [0103]    Based upon the foregoing embodiments, the base station can transmit the ACK/NACK feedback information in a transmission mode including a DMRS based single-port transmission mode and a DMRS based transmit diversity mode. Specific DMRS ports in use may be agreed on with the user equipment or may be notified to the user equipment via RRC signaling or a system broadcast message. 
         [0104]    In the foregoing embodiments, the REs included in any one of the E-PHICH groups may carry transmission of 8 or 4 E-PHICHs, wherein different E-PHICHs may have the resources of the same E-PHICH group multiplexed through code division, and transmission of the same E-PHICH may be divided into a plurality of parts, different parts among which may occupy different time-frequency resources for transmission to achieve a diversity gain. The respective E-PHICHs are distinguished from each other by orthogonal sequences, so in the step  320 , the base station further needs to determine orthogonal sequences for spreading according to the lowest PRB serial number and the cyclic shift of the uplink DMRS indicated in the PUSCH transmission grant and to notify the user equipment of the orthogonal sequences, and the user equipment determines the E-PHICH for receiving the ACK/NACK feedback information in the corresponding E-PHICH groups according to the obtained orthogonal sequences, particularly as in Formula 1 and Formula 2. This embodiment is focused on determination of the E-PHICH groups, so a description of details concerning the orthogonal sequences will be omitted here. 
         [0105]    In correspondence to the foregoing embodiments, referring to  FIG. 12 , a detailed flow in which a user equipment receives ACK/NACK feedback information based on E-PHICH according to an embodiment of the present invention is as follows: 
         [0106]    Step  1200 : A user equipment determines time-frequency resources occupied by E-PHICH configured in a PDSCH region by the network side based on a notification of a base station. 
         [0107]    Like the step  310 , in the step  800 , the user equipment may determine specific locations of PRB pairs occupied by the E-PHICH, or determine a starting location and the number of PRBs occupied by the E-PHICH, according to RRC signaling or a system broadcast message sent from the base station; or may obtain an E-PHICH resource configuration parameter according to RRC signaling or a system broadcast message sent from the base station and occupy a part of time-frequency resources in E-PDCCH according to the E-PHICH resource configuration parameter. 
         [0108]    Step  1210 : The user equipment determines groups of E-PHICH resources, denoted as E-PHICH groups, for carrying ACK/NACK feedback information among the determined time-frequency resources occupied by the E-PHICH according to scheduling signaling of the base station. 
         [0109]    In the step  810 , the user equipment may determine the E-PHICH resources for carrying the ACK/NACK feedback information among the time-frequency resources occupied by the E-PHICH according to a lowest PRB serial number and a cyclic shift of an uplink DMRS indicated in the scheduling signaling, and reference can be made to the Rel-10 for related operations thereof, so a repeated description thereof will be omitted here. 
         [0110]    On the other hand, the user equipment may perform the following operations in the step  810 : 
         [0111]    Firstly each PRB pair included in the time-frequency resources occupied by the E-PHICH is determined; and 
         [0112]    Secondly, according to the scheduling signaling of the base station, all of Resource Elements (REs) included in sub-carriers at a specified location among the respective PRB pairs belong to an enhanced PHICH group; or a specified part of REs in sub-carriers at a specified location among the respective PRB pairs belong to an enhanced PHICH group; or M REs in specified time domain and adjacent in frequency domain in each PRB pair, among the respective PRB pairs, belong to an enhanced PHICH group. Preferably, when the respective E-PHICH groups are determined, REs for carrying legacy PDCCHs and reference signals are excluded from the respective REs belong to the same E-PHICH group; and reference can be made to  FIG. 5 .  FIG. 7  and  FIG. 9  for details thereof, so a repeated description thereof will be omitted here. 
         [0113]    Step  1220 : The user equipment receives the ACK/NACK feedback information transmitted from the base station based on the determined E-PHICH groups. 
         [0114]    Specifically: 
         [0115]    Firstly, orthogonally spread modulation symbols, for carrying the ACK/NACK feedback information, in the determined E-PHICH groups are de-mapped; 
         [0116]    For example, orthogonally spread modulation symbols, for carrying the ACK/NACK feedback information, in the REs belonging to the same E-PHICH group among the respective PRB pairs are combined, wherein referring to  FIG. 9  to  FIG. 10 , the above orthogonally spread modulation symbols for carrying the ACK/NACK feedback information may be combined in rows or columns. 
         [0117]    Secondly, the orthogonally spread modulation symbols for carrying the ACK/NACK feedback information are de-spread orthogonally and demodulated into simply encoded ACK/NACK feedback information; and 
         [0118]    Finally, the simply encoded ACK/NACK feedback information is decoded into the ACK/NACK feedback information. 
         [0119]    In a practical application, the REs included in any one of the E-PHICH groups may carry transmission of 8 or 4 E-PHICHs, wherein different E-PHICHs may have the resources of the same E-PHICH group multiplexed through code division, and transmission of the same E-PHICH may be divided into a plurality of parts, different parts among which may occupy different time-frequency resources for transmission to achieve a diversity gain. The respective E-PHICHs are distinguished from each other by orthogonal sequences, so in the step  320 , the user equipment further needs to determine orthogonal sequences used by the base station according to the lowest PRB serial number and the cyclic shift of the uplink DMRS indicated in the scheduling signaling and determines the E-PHICH for receiving the ACK/NACK feedback information in the corresponding E-PHICH group according to the determined orthogonal sequences, particularly as in Formula 1 and Formula 2. This embodiment is focused on determination of the E-PHICH groups, so a description of details concerning the orthogonal sequences will be omitted here. 
         [0120]    On the other hand, in this embodiment, the user equipment may receive the ACK/NACK feedback information in a transmission mode including a DMRS based single-port transmission mode and a DMRS based transmit diversity mode. Specific DMRS ports in use may be agreed on with the base station or may be determined according to RRC signaling or a system broadcast message sent from the base station. 
         [0121]    In summary, referring to  FIG. 13  and  FIG. 14 , a device (e.g., a base station) for feedback information transmission based on an enhanced Physical Hybrid Automatic Repeat Request (HARQ) Indicator Channel (PHICH) includes a communication component  130 , a first processing component  131  and a second processing component  132 . 
         [0122]    The first processing component  131  is configured to determine time-frequency resources occupied by an enhanced PHICH configured in a PDSCH region by the network side and to notify a user equipment of the determined time-frequency resources occupied by the E-PHICH; 
         [0123]    The second processing component  132  is configured to determine E-PHICH groups for carrying ACK/NACK feedback information among the time-frequency resources occupied by the E-PHICH according to a scheduling condition of the user equipment; and 
         [0124]    The communication component  130  is configured to map the ACK/NACK feedback information to be transmitted onto the E-PHICH groups and to transmit the ACK/NACK feedback information to the user equipment. 
         [0125]    Furthermore the first processing component  131  configured to notify the user equipment of the determined time-frequency resources occupied by the E-PHICH is further configured to: 
         [0126]    notify the user equipment of specific locations of Physical Resource Block (PRB) pairs occupied by the E-PHICH, or to notify the user equipment of a starting location and the number of PRB pairs occupied by the E-PHICH, via Radio Resource Control (RRC) signaling or a system broadcast message through the communication component  130 ; 
         [0127]    or 
         [0128]    notify the user equipment of an E-PHICH resource configuration parameter via RRC signaling or a system broadcast message through the communication component  130  to instruct the user equipment to occupy a part of time-frequency resources in Enhanced-Physical Downlink Control Channel (E-PDCCH) according to the E-PHICH resource configuration parameter. 
         [0129]    Furthermore, the second processing component  132  configured to determine the E-PHICH groups for carrying the ACK/NACK feedback information among the time-frequency resources occupied by the E-PHICH according to the scheduling condition of the user equipment is further configured to: 
         [0130]    determine each Physical Resource Block (PRB) pair included in the time-frequency resources occupied by the E-PHICH; and 
         [0131]    attribute all of Resource Elements (REs) included in sub-carriers at a specified location among the respective PRB pairs to an enhanced PHICH group; or to attribute a specified part of REs in sub-carriers at a specified location among the respective PRB pairs to an enhanced PHICH group; or to attribute M REs in specified time domain and adjacent in frequency domain in each PRB pair, among the respective PRB pairs, to an enhanced PHICH group, according to the scheduling condition of the user equipment, wherein M represents a pre-configured parameter. 
         [0132]    Furthermore, when determining the respective E-PHICH groups, the second processing component  132  excludes REs for carrying legacy control information and reference signals from the respective REs belonging to the same E-PHICH group. 
         [0133]    Furthermore the communication component  130  configured to map the ACK/NACK information to be transmitted onto the E-PHICH groups is further configured to: 
         [0134]    simply encode the ACK/NACK information to be transmitted: 
         [0135]    perform binary phase modulation on the simply encoded ACK/NACK information and orthogonally spread obtained modulation symbols; and 
         [0136]    map the orthogonally spread modulation symbols respectively into the E-PHICH groups. 
         [0137]    Furthermore the communication component  130  configured to map the orthogonally spread modulation symbols respectively into the E-PHICH groups is further configured to: 
         [0138]    group the orthogonally spread modulation symbols in rows or columns and map the respective groups of modulation symbols respectively onto the REs, belonging to the same E-PHICH group, among the respective PRB pairs. 
         [0139]    Furthermore, the communication component  130  is configured to transmit the ACK/NACK feedback information in a DMRS based single-port transmission mode or a DMRS based transmit diversity mode. 
         [0140]    A device (e.g., a user equipment) for feedback information transmission based on an enhanced Physical Hybrid Automatic Repeat Request (HARQ) Indicator Channel (PHICH) includes a communication component  140 , a first control component  141  and a second control component  142 . 
         [0141]    The first control component  141  is configured to determine time-frequency resources occupied by E-PHICH configured in a PDSCH region by a network side based on a notification of a base station; 
         [0142]    The second control component  142  is configured to determine E-PHICH groups for carrying ACK/NACK feedback information among the time-frequency resources occupied by the E-PHICH according to scheduling signaling of the base station; and 
         [0143]    The communication component  140  is configured to receive the ACK/NACK feedback information transmitted from the base station based on the determined E-PHICH groups. 
         [0144]    Furthermore, the first control component  141  configured to determine time-frequency resources occupied by E-PHICH configured in the PDSCH region by the network side based on the notification of the base station is further configured to: 
         [0145]    determine specific locations of Physical Resource Block (PRB) pairs occupied by the E-PHICH, or determine a starting location and the number of PRB pairs occupied by the E-PHICH, according to Radio Resource Control (RRC) signaling or a system broadcast message sent from the base station through the communication component  140 ; 
         [0146]    or 
         [0147]    obtain an E-PHICH resource configuration parameter according to RRC signaling or a system broadcast message sent from the base station through the communication component  140  and occupy a part of time-frequency resources in Enhanced-Physical Downlink Control Channel (E-PDCCH) according to the E-PHICH resource configuration parameter. 
         [0148]    Furthermore, the second control component  142  configured to determine the E-PHICH groups for carrying the ACK/NACK feedback information among the time-frequency resources occupied by the E-PHICH according to the scheduling signaling of the base station is further configured to: 
         [0149]    determine each Physical Resource Block (PRB) pair included in the time-frequency resources occupied by the E-PHICH; and 
         [0150]    attribute all of Resource Elements (REs) included in sub-carriers at a specified location among the respective PRB pairs to an enhanced PHICH group; or to attribute a specified part of REs in sub-carriers at a specified location among the respective PRB pairs to an enhanced PHICH group; or to attribute M REs in specified time domain and adjacent in frequency domain in each PRB pair, among the respective PRB pairs, to an enhanced PHICH group, according to the scheduling signaling of the base station, wherein M represents a pre-configured parameter. 
         [0151]    Furthermore, when determining the respective E-PHICH groups, the second control component  142  excludes REs for carrying legacy control information and reference signals from the respective REs belonging to the same E-PHICH group. 
         [0152]    Furthermore the communication component  140  configured to receive the ACK/NACK feedback information transmitted from the base station based on the determined E-PHICH groups is further configured to: 
         [0153]    de-map orthogonally spread modulation symbols, for carrying the ACK/NACK feedback information, in the E-PHICH groups; 
         [0154]    de-spread orthogonally and demodulate the orthogonally spread modulation symbols for carrying the ACK/NACK feedback information into simply encoded ACK/NACK feedback information; and 
         [0155]    decode the simply encoded ACK/NACK feedback information into the ACK/NACK feedback information. 
         [0156]    Furthermore, the orthogonally spread modulation symbols, for carrying the ACK/NACK feedback information, in the E-PHICH groups are de-mapped as follows: 
         [0157]    The orthogonally spread modulation symbols, for carrying the ACK/NACK feedback information, in the REs belonging to the same E-PHICH group among the respective PRB pairs are combined, wherein the orthogonally spread modulation symbols for carrying the ACK/NACK feedback information are combined in rows or columns. 
         [0158]    Furthermore, the communication component  140  is configured to receive the ACK/NACK feedback information in a DMRS based single-port transmission mode or a DMRS based transmit diversity mode. 
         [0159]    In summary, an embodiment of the present invention proposes a novel method for E-PHICH transmission based upon FDM, that is. ACK/NACK feedback information is carried over E-PHICH resources configured in a PDSCH region, so that on one hand, the issue of unavailable transmission of PHICHs in some scenarios, e.g., in an ABS sub-frame of eICIC and an extended carrier to be possibly defined subsequently, can be addressed; and on the other hand, the overhead of signaling can be saved and the utilization ratio of resources can be improved, for example, retransmission of a PUSCH scheduled by the system in the DCI format 0 is avoided, to achieve the effects of improving a capacity of PHICHs and addressing a legacy PHICH resource confliction. 
         [0160]    Evidently those skilled in the art can make various modifications and variations to the invention without departing from the spirit and scope of the invention. Thus the invention is also intended to encompass these modifications and variations thereto so long as the modifications and variations come into the scope of the claims appended to the invention and their equivalents.
The present invention relates to the field of communications. Disclosed are a method and a device for feedback information transmission based on an enhanced PHICH. The method comprises transmitting ACK/NACK feedback information to a terminal through E-PHICH sources configured in a PDSCH area; therefore, on one hand, the problem that the PHICH cannot be transmitted in some scenarios, such as an ABS sub-frame of eICIC and a subsequent possibly-defined extended carrier, is solved; and on the other hand, the signaling overhead can be saved, so that the utilization rate of resources is improved, for example, the scheduling of retransmission of a PUSCH is prevented from being carried out by a system though a DCI format 0, therefore, the effects of improving the capacity of the PHICH and solving the problem of legacy PHICH resource contention are achieved.