MITIGATION OF LOST RESOURCE ALLOCATION SYNCHRONIZATION BETWEEN A USER EQUIPMENT (UE) AND AN EVOLVED NODE B (eNodeB)

Abstract

A method for mitigation of lost resource allocation synchronization between a user equipment (UE) and an evolved Node B (eNodeB) during a Hybrid Automatic Repeat Request (HARQ) transmission and/or retransmission process is described. The method includes determining whether resource allocation is out of synchronization between a user equipment (UE) and an evolved Node B (eNodeB) during a hybrid automatic repeat request (HARQ) transmission and/or retransmission process. The method further includes mitigating a loss of resource allocation synchronization between the UE and the eNodeB during the HARQ transmission and/or retransmission process.

What is claimed is: 
     
         1 . A method of wireless communication, comprising:
 determining a loss of resource allocation synchronization between a user equipment (UE) and an evolved Node B (eNodeB) during a hybrid automatic repeat request (HARQ) transmission and/or retransmission process; and   mitigating the loss of resource allocation synchronization between the UE and the eNodeB during the HARQ transmission and/or retransmission process by at least increasing a power level and/or an aggregation level of a physical downlink control channel (PDCCH).   
     
     
         2 . The method of  claim 1 , in which determining the loss of resource allocation synchronization comprises:
 detecting an energy level on a physical uplink shared channel (PUSCH); and   determining that an uplink grant was not received by the UE when the energy level detected on the PUSCH is below a predetermined threshold.   
     
     
         3 . The method of  claim 1 , in which mitigating the loss of resource allocation synchronization between the UE and the eNodeB further comprises discarding physical uplink shared channel (PUSCH) data when it is determined that an uplink grant was not received by the UE due to the loss of resource allocation synchronization between the UE and the eNodeB. 
     
     
         4 . The method of  claim 1 , in which mitigating the loss of resource allocation synchronization between the UE and the eNodeB comprises not transmitting a physical HARQ indicator channel (PHICH) when an uplink grant is transmitted over the physical downlink control channel (PDCCH). 
     
     
         5 . The method of  claim 1 , in which determining the loss of resource allocation synchronization comprises:
 blindly decoding a physical uplink shared channel (PUSCH) and a physical uplink control channel (PUCCH); and   determining that an uplink grant was not received by the UE when a successfully decoded PUCCH includes uplink control information (UCI) due to the loss resource allocation synchronization between the UE and the eNodeB.   
     
     
         6 . The method of  claim 1 , in which determining the loss of resource allocation synchronization comprises:
 detecting a number of consecutive retransmission decode failures of uplink control information (UCI) over a physical uplink shared channel (PUSCH) and PUSCH data; and   determining that an initial uplink grant was not received by the UE over the PUSCH when the number of consecutive retransmission decode failures of the UCI over the PUSCH and the PUSCH data exceeds a predetermined value due to the loss resource allocation synchronization between the UE and the eNodeB.   
     
     
         7 . The method of  claim 1 , in which mitigating the loss of resource allocation synchronization between the UE and the eNodeB comprises:
 decoding received physical uplink shared channel (PUSCH) data and uplink control information (UCI) according to a previous uplink grant; and   decoding the received PUSCH data and the UCI according to an initial uplink grant.   
     
     
         8 . The method of  claim 1 , in which mitigating the loss of resource allocation synchronization between the UE and the eNodeB comprises:
 transmitting a subsequent uplink grant through the physical downlink control channel (PDCCH) according to a number of physical uplink shared channel (PUSCH) resource blocks (RBs) and presence or absence of a sounding reference signal (SRS) provided with an initial uplink grant to ensure a same number of resource elements (REs) are calculated for uplink control information (UCI).   
     
     
         9 . The method of  claim 1 , in which mitigating the loss of resource allocation synchronization between the UE and the eNodeB comprises:
 transmitting a subsequent uplink grant through the physical downlink control channel (PDCCH) data according a number of resource blocks of a physical uplink shared channel (PUSCH) provided with an initial uplink grant;   decoding received PUSCH data assuming presence of a sounding reference signal (SRS);   decoding the received PUSCH data assuming absence of the SRS; and   selecting successfully decoded PUSCH data.   
     
     
         10 . The method of  claim 1 , in which determining the loss of resource allocation synchronization comprises:
 determining an uplink grant was not received by the UE over a physical uplink shared channel (PUSCH) when an accumulated energy of received PUSCH data does not increase over a number of consecutive retransmission decode failures.   
     
     
         11 . The method of  claim 1 , in which mitigating the loss of resource allocation synchronization between the UE and the eNodeB comprises:
 transmitting a physical HARQ indicator channel (PHICH) negative acknowledgement (NAK) to the UE; and   transmitting a new, initial transmission uplink grant to the UE according to a previous initial uplink grant.   
     
     
         12 . The method of  claim 1 , in which mitigating the loss of resource allocation synchronization between the UE and the eNodeB comprises synchronizing a redundancy version (RV) in response to receiving a HARQ retransmission by synchronizing a number of transmissions by discounting a lost uplink grant or using an adaptive physical uplink shared channel (PUSCH) retransmission uplink grant to prevent loss of RV synchronization between the UE and the eNodeB. 
     
     
         13 . An apparatus configured for operation in a wireless communication network, the apparatus comprising:
 a memory; and   at least one processor coupled to the memory, the at least one processor being configured:   to determine a loss of resource allocation synchronization between a user equipment (UE) and an evolved Node B (eNodeB) during a hybrid automatic repeat request (HARQ) transmission and/or retransmission process; and   to mitigate the loss of resource allocation synchronization between the UE and the eNodeB during the HARQ transmission and/or retransmission process by at least increasing a power level and/or an aggregation level of a physical downlink control channel (PDCCH).   
     
     
         14 . The apparatus of  claim 13 , in which the at least one processor is further configured to determine the loss of resource allocation synchronization by:
 detecting an energy level on a physical uplink shared channel (PUSCH); and   determining that an uplink grant was not received by the UE when the energy level detected on the PUSCH is below a predetermined threshold.   
     
     
         15 . The apparatus of  claim 13 , in which the at least one processor is further configured to mitigate the loss of resource allocation synchronization between the UE and the eNodeB by discarding physical uplink shared channel (PUSCH) data when it is determined that an uplink grant was not received by the UE due to the loss of resource allocation synchronization between the UE and the eNodeB. 
     
     
         16 . The apparatus of  claim 13 , in which the at least one processor is further configured to mitigate the loss of resource allocation synchronization between the UE and the eNodeB by not transmitting a physical HARQ indicator channel (PHICH) when an uplink grant is transmitted over the physical downlink control channel (PDCCH). 
     
     
         17 . The apparatus of  claim 13 , in which the at least one processor is further configured to determine the loss of resource allocation synchronization by:
 blindly decoding a physical uplink shared channel (PUSCH) and a physical uplink control channel (PUCCH); and   determining that an uplink grant was not received by the UE when a successfully decoded PUCCH includes uplink control information (UCI) due to the loss resource allocation synchronization between the UE and the eNodeB.   
     
     
         18 . The apparatus of  claim 13 , in which the at least one processor is further configured to determine whether resource allocation is out of synchronization by:
 detecting a number of consecutive retransmission decode failures of uplink control information (UCI) over a physical uplink shared channel (PUSCH) and PUSCH data; and   determining that an initial uplink grant was not received by the UE over the PUSCH when the number of consecutive retransmission decode failures of the UCI over the PUSCH and the PUSCH data exceeds a predetermined value due to the loss resource allocation synchronization between the UE and the eNodeB.   
     
     
         19 . The apparatus of  claim 13 , in which the at least one processor is further configured to mitigate the loss of resource allocation synchronization between the UE and the eNodeB by:
 decoding received physical uplink shared channel (PUSCH) data and uplink control information (UCI) according to a previous uplink grant; and   decoding the received PUSCH data and the UCI according to an initial uplink grant.   
     
     
         20 . The apparatus of  claim 13 , in which the at least one processor is further configured to mitigate the loss of resource allocation synchronization between the UE and the eNodeB by:
 transmitting a subsequent uplink grant through the physical downlink control channel (PDCCH) according to a number of physical uplink shared channel (PUSCH) resource blocks (RBs) and presence or absence of a sounding reference signal (SRS) provided with an initial uplink grant to ensure a same number of resource elements (REs) are calculated for uplink control information (UCI).   
     
     
         21 . The apparatus of  claim 13 , in which the at least one processor is further configured to mitigate the loss of resource allocation synchronization between the UE and the eNodeB by:
 transmitting a subsequent uplink grant through the physical downlink control channel (PDCCH) data according a number of resource blocks of a physical uplink shared channel (PUSCH) provided with an initial uplink grant;   decoding received PUSCH data assuming presence of a sounding reference signal (SRS);   decoding the received PUSCH data assuming absence of the SRS; and selecting successfully decoded PUSCH data.   
     
     
         22 . The apparatus of  claim 13 , in which the at least one processor is further configured to determine the loss of resource allocation synchronization by:
 determining an uplink grant was not received by the UE over a physical uplink shared channel (PUSCH) when an accumulated energy of received PUSCH data does not increase over a number of consecutive retransmission decode failures.   
     
     
         23 . The apparatus of  claim 13 , in which the at least one processor is further configured to mitigate the loss of resource allocation synchronization between the UE and the eNodeB by:
 transmitting a physical HARQ indicator channel (PHICH) negative acknowledgement (NAK) to the UE; and   transmitting a new, initial transmission uplink grant to the UE according to a previous initial uplink grant.   
     
     
         24 . The apparatus of  claim 13 , in which the at least one processor is further configured to mitigate the loss of resource allocation synchronization between the UE and the eNodeB by synchronizing a redundancy version (RV) in response to receiving a HARQ retransmission by synchronizing a number of transmissions by discounting a lost uplink grant or using an adaptive physical uplink shared channel (PUSCH)
 retransmission uplink grant to prevent loss of RV synchronization between the UE and the eNodeB.   
     
     
         25 . A computer program product configured for wireless communication, the computer program product comprising:
 a computer-readable medium having non-transitory program code recorded thereon, the program code comprising:   program code to determine a loss of resource allocation synchronization between a user equipment (UE) and an evolved Node B (eNodeB) during a hybrid automatic repeat request (HARQ) transmission and/or retransmission process; and   program code to mitigate the loss of resource allocation synchronization between the UE and the eNodeB during the HARQ transmission and/or retransmission process by at least increasing a power level and/or an aggregation level of a physical downlink control channel (PDCCH).   
     
     
         26 . An apparatus operable in a wireless communication system, the apparatus comprising:
 means for determining a loss of resource allocation synchronization between a user equipment (UE) and an evolved Node B (eNodeB) during a hybrid automatic repeat request (HARQ) transmission and/or retransmission process; and   means for mitigating the loss of resource allocation synchronization between the UE and the eNodeB during the HARQ transmission and/or retransmission process by at least increasing a power level and/or an aggregation level of a physical downlink control channel (PDCCH).