Method and apparatus for data-splitting transmission from multiple sites

Abstract

Methods and apparatus for changing cell range coverage are disclosed. The coverage may be changed on a per-sub-frame basis. An antenna beam elevation tilting angle may be adjusted to provide different effective downlink (DL) coverage. For example, a subframe may be a small tilt subframe or a large tilt subframe. A network or evolved NodeB (eNB) may determine data channel transmission power to adjust cell range per subframe. Low Power Subframe (LPS) may be used alone or with Almost Blank Subframe (ABS) to transmit data. Timing Advance (TA) handling for uplink (UL) transmissions is described. A common TA (CTA) may be determined for multi-site UL signaling. UL power control may be determined for UL transmission to multiple sites. Radio Link Monitoring (RLM) may be performed for multiple sites on a carrier frequency. A wireless transmit/receive unit (WTRU) may maintain synchronization in selected subframes for multiple cells.

1 .- 18 . (canceled) 
     
     
         19 . A method for use in an evolved NodeB (eNB), the method comprising:
 receiving load indication information from at least one other eNB;   transmitting a set of power boosting parameters to a wireless transmit/receive unit (WTRU), wherein the set of power boosting parameters includes a power ratio between a low power subframe (LPS) and a non-LPS;   
       receiving channel quality information from the WTRU during a first subframe, wherein the channel quality information is based at least on the power ratio, and wherein the WTRU is located at a cell-edge of the eNB and the at least one other eNB; and
 transmitting data to the WTRU at a predetermined transmission power during a second subframe, wherein the transmitting is based at least on the load indication information and the received channel quality information such that the transmission at the predetermined transmission power is coordinated with the at least one other eNB to not interfere with transmissions from the at least one other eNB to the WTRU. 
 
     
     
         20 . The method of  claim 19 , further comprising transmitting a power transmission pattern to the WTRU that includes a Physical Downlink Shared Channel (PDSCH) power allocation per subframe. 
     
     
         21 . The method of  claim 19 , further comprising transmitting a power ratio between a Physical Downlink Shared Channel (PDSCH) resource element (RE) and reference symbol RE to the WTRU. 
     
     
         22 . The method of  claim 19 , wherein the channel quality information is channel state information (CSI) feedback. 
     
     
         23 . The method of  claim 22 , further comprising adjusting, at the eNB, the predetermined transmission power based on the received CSI feedback. 
     
     
         24 . An evolved NodeB (eNB) comprising:
 a receiver configured to receive load indication information from at least one other eNB;   a transmitter configured to transmit a set of power boosting parameters to a wireless transmit/receive unit (WTRU), wherein the set of power boosting parameters includes a power ratio between a low power subframe (LPS) and a non-LPS;   
       the receiver further configured to receive channel quality information from the WTRU during a first subframe, wherein the channel quality information is based at least on the power ratio, and wherein the WTRU is located at a cell-edge of the eNB and the at least one other eNB; and
 the transmitter further configured to transmit data to the WTRU at a predetermined transmission power during a second subframe, wherein the transmitting is based at least on the load indication information and the received channel quality information such that the transmission at the predetermined transmission power is coordinated with the at least one eNB to not interfere with transmissions from the at least one other eNB to the WTRU. 
 
     
     
         25 . The eNB of  claim 24 , wherein the transmitter is further configured to transmit a power transmission pattern to the WTRU that includes a Physical Downlink Shared Channel (PDSCH) power allocation per subframe. 
     
     
         26 . The eNB of  claim 24 , wherein the transmitter is further configured to transmit a power ratio between a Physical Downlink Shared Channel (PDSCH) resource element (RE) and reference symbol RE to the WTRU. 
     
     
         27 . The eNB of  claim 24 , wherein the channel quality information is channel state information (CSI) feedback. 
     
     
         28 . The eNB of  claim 27 , further comprising a processor configured to adjust, at the eNB, the predetermined transmission power based on the received CSI feedback. 
     
     
         29 . A method for use in a wireless transmit/receive unit (WTRU), the method comprising:
 receiving a set of power boosting parameters from an evolved NodeB (eNB), wherein the set of power boosting parameters includes a power ratio between a low power subframe (LPS) and a non-LPS;   
       transmitting channel quality information to the eNB during a first subframe, wherein the channel quality information is based at least on the power ratio, and wherein the WTRU is located at a cell-edge of the eNB and at least one other eNB; and
 receiving data from the eNB at a predetermined transmission power during a second subframe, wherein the receiving is based at least on load indication information received by the eNB from at least one other eNB and the received channel quality information such that the reception at the predetermined transmission power is coordinated with the at least one other eNB to not interfere with transmissions from the at least one other eNB to the WTRU. 
 
     
     
         30 . The method of  claim 29 , further comprising receiving a power transmission pattern from the eNB that includes a Physical Downlink Shared Channel (PDSCH) power allocation per subframe. 
     
     
         31 . The method of  claim 29 , further comprising receiving a power ratio between a Physical Downlink Shared Channel (PDSCH) resource element (RE) and reference symbol RE from the eNB. 
     
     
         32 . The method of  claim 29 , wherein the channel quality information is channel state information (CSI) feedback. 
     
     
         33 . The method of  claim 32 , wherein transmitting the CSI feedback information to the eNB enables the eNB to adjust the predetermined transmission power based on the received CSI feedback.