E-TFC Selection Procedure in TD-HSUPA.docx

E-TFC Selection Procedure in TD-HSUPA1. Outline of E-TFC selection procedure In TD-HSUPA system, E-TFC selection should be subject to absolute grant power in E-AGCH which is determined by scheduler algorithm. A general description for E-TFC selection is as follows:1) The absolute grant power is determined according to the following factors: The restrictions of scheduling information (SI) sent on E-RUCCH or E-PUCH including UPH (User Power Headroom) and SNPL (Serving and Neighbour cell Pathloss). System scheduler requirements. Take ROT-based scheduler for example, the final absolute grant power will be determined by scheduler to maintain system ROT.2) The final E-TFC is selected by UE according to some kind of interpolation method which can make full use of available power resource of UE.2. E-TFC selection procedure In TD-HSUPA system, scheduler will generate absolute grant power which can be determined according to SI (Scheduling Information) in E-RUCCH or E-PUCH (SI including UPH and SNPL information). It should be note that the SNPL will be used for maintaining the interference to other cells contributing from this UE under control. This procedure will not be elaborated due to it is relevant to specific scheduling algorithm. Once the absolute grant power is determined, the scheduler will send AG command in E-AGCH to UE to inform UE the maximum grant power. Then the UE will select the final E-TFC based on the maximum grant power. The transmit power of the E-PUCH is calculated in the UE as follows: where: Pe-base is a closed-loop quantity maintained by the UE and which is incremented or decremented by a value e-base upon each receipt of a TPC command on E-AGCH. On receipt of a TPC “up” command, Pe-base is incremented by e-base. On receipt of a TPC “down” command, Pe-base is decremented by e-base. The TPC step size e-base is configured by higher layers. L is a pathloss term derived by higher layers from beacon function physical channel measurements. It may comprise a weighted sum of the instantaneous (LPCCPCH) and filtered (L0) pathloss measurements. be is the gain factor derived for the selected E-TFC transport block size, E-PUCH physical resource size, E-PUCH modulation type and HARQ offset. KE-PUCH is the E-PUCH constant value signalled by higher layers. Higher layers in the UE shall use the current calculated E-PUCH power in conjunction with the current absolute grant power in order to determine the set of E-TFCs available. That is, the E-TFC selection procedure aim to select a maximum transport block size in the case that P E-PUCH is smaller than or equal to the maximum grant power. The E-TFC selection procedure is actually the procedure of determining be because Pe-base, L and KE-PUCH are not related to E-TFC. Higher layers shall provide a set of reference points defining the relationship between the coderate of E-DCH transmission (le) and the relative reference power per resource unit (bl dB). ). A set of reference points is provided separately for each of QPSK and 16-QAM modulation. An example reference E-TFCI set is listed in Table 1 and Table 2 for QPSK and 16QAM with SF being 1 respectively. Based on the Transport Block Size (TBS), which is listed in Table 3 and Table 4 for QPSK and 16QAM respectively, the be of the particular E-TFCI can be determined according to the following procedure. The coderate of E-DCH transmission le for the selected E-TFC, physical resource allocation and modulation type is defined as:in which Se is the transport block size of the selected E-TFC and Re is the number of physical channel bits output from the physical channel mapping stage of E-DCH transport channel processing. The maximum and minimum values of l signalled by higher layers for the appropriate modulation type are denoted lmax and lmin respectively. For a given le there exists a l0 and a l1 such that: If lminlele Elseo If lelmin.o If lelmax then l0 is the largest signalled l for which llmax and l1 = lmax Associated with l0 and l1 are the corresponding bl0 and bl1 which define the reference points signalled by higher layers. The normalised (per-resource-unit) beta value for the selected E-TFC and E-PUCH resource set is denoted b0,e and is: is a logarithmic value set as a function of the E-PUCH spreading factor (SFE-PUCH) according to Table 5.be is then derived asharq is set by higher layers. Based on the introduction above, the E-TFC selection procedure can be sum up below:1. Scheduler generate absolute grant and send AG command to UE in E-AGCH according to the UPH, SNPL and relevant scheduling algorithm.2. Starting with the maximum E-TFC, UE calculate PE-PUCH according to the method mentioned above. If PE-PUCH is greater than the maximun grant power, then select the smaller E-TFC and try again.3. The maximum E-TFC which can make PE-PUCH be equal to or smaller than the maximun grant power is the final selected E-TFC. Table 1 An example of the relationship between le and bl (dB) (QPSK)Coderate of E-DCH Transmission (le)Relative Reference Power per Resource Unit (bl dB)0.3063-20.3813-0.50.52831.50.71794 Table 2 An example of the relationship between le and bl (dB) (16QAM)Coderate of E-DCH Transmission (le)Relative Reference Power per Resource Unit (bl dB)0.503370.7245100.870118Table 3 Transport Block Size (TBS) (QPSK SF = 1)E-TFCI TB Size Coderate (bits) (le) E-TFCI TB Size Coderate (bits) (le) 0 295 0.2808 13 539 0.4426 1 309 0.2931 14 564 0.4623 2 324 0.3063 15 591 0.4835 3 339 0.3103 16 619 0.5055 4 355 0.3239 17 648 0.5283 5 372 0.3385 18 679 0.5383 6 390 0.3439 19 711 0.5628 7 408 0.3588 20 745 0.5888 8 427 0.3746 21 780 0.6156