【正文】 le delay for Radio Link Control (RLC) and Medium Access Control (MAC) buffering, scheduling and detection should be strictly lower than 150 ms. Hence, assuming that both end users are LTE users, tolerable delay for buffering and scheduling is lower than 80 ms. A delay bound of 50 ms (for delay from eNB to UE) has been chosen for the 3GPP performance evaluations to better account for variability in network endtoend delays. Evolved UTRAN is targeted to support a high number of VoIP users. The maximal VoIP capacity for LTE is limited by the outage limit defined in TR [10] and updated in contribution R1070674 ([10]). Thus, we define the system VoIP capacity according to the following clauses: ? The system capacity is defined as the number of users in the cell when more than 95 % of the users are satisfied ? A VoIP user is satisfied if more than 98 % of its speech frames are delivered successfully within 50 ms (air interface delay). B. Physical downlink control channel Physical Downlink Control Channel carries the DL and UL scheduling grants. Information fields in the grant can be divided into distinct categories as follows ? Resoure allocation information, such as PRBs and assignment duration ? Transport format information, such as multiantenna information, modulation scheme and payload size ? HARQ information, such as process number and redundancy version PDCCH must be reliable enough to get the transmissions through without the need for HARQ, also in the cell edge area. The BLER target for PDCCH has been set to 1 %. To achieve the performance target, both power control and link adaptation as been defined for PDCCH. QPSK modulation with 4 different coding rates can be used based on reported wideband CQI information and 1 % BLER target SINRs 1 for each coding rate. Outer Loop Link Adaptation may be utilized to pensate the CQI measurement errors, delays and other inaccuracies. Transmission power for each control channel can be either increased or decreased within certain limits depending on wideband CQI and 1 % BLER target SINR. Each scheduling grant is defined based on fixed size Control Channel Elements (CCE) which are bined in a predetermined manner using a tree structure to achieve different coding rate. The coding rates of QPSK2/3, QPSK1/3, QPSK1/6 and QPSK1/12 stand for 1, 2, 4, 8 bined CCEs, respectively. Each CCE is prised of ResourceElements (REs) which are distributed throughout time (to three symbols) and frequency (the whole system bandwidth). The number of CCEs available for control channel assignment depends on . carrier bandwidth, number of transmits antennas, number of OFDM symbols used for PDCCH in each subframe, and the CCE size. A CCE size depends on the Downlink Control Information (DCI) format and the system bandwidth resulting a fixed size in REs. Since both the amount of REs and transmit power is limited per TTI,the amount of schedulable UEs in UL and DL is determined by the channel conditions of scheduled UEs. In PDCCH reception the SINR is calculated and the BLER acquired using Exponential Effective SIR Mapping (EESM) linktosystem level tables. If PDCCH is not decoded, the PDU will not be decoded and the HARQ willnot be able to gain from the transmission. More detailed PDCCH analysis is presented . in [8] and [11].C. Channel quality indicator Channel Quality Indicator (CQI) is measured by every UE and reported in PUCCH periodically or on request to the serving BS. Note, that in this article we concentrate on the DL performance, thus CQI reports are assumed to be sent either in PUCCH or Physical Uplink Shared Channel (PUSCH) and no CQI transmission errors are assumed. CQI information is used for both PDCCH and Physical DownlinkShared Channel (PDSCH) resource allocation by the serving BS. CQI measurement model consists of three basic steps: measuring SINR for each all individual PRBs from reference symbols, processing the ideal SINR values into discrete CQIvalues and finally reporting CQI values. CQI is measured at parameterized time intervals and reported with a parameter defined define two parallel CQI mechanisms: wideband and fullband CQI. Wideband CQI is produced by averaging all the ideal SINR values from the whole bandwidth, adding measurement error and finally quantifying into a certain parameter defined resolution. Thus, wideband CQI provides information on the propagationconditions of a certain UE. On the other hand, fullband CQI provides frequency dependent channel quality information to be used by . frequency domain packet scheduler and link adaptation. Fullband CQI is produced by averaging the idealCQI values based on the CQI subband size and then adding measurement error and quantifying each CQI subband. . in this study we utilize the 2 PRBs subband size. More details on the CQI modelling can be found from [12].譯文：控制信道限制對LTE的影響VoIP的容量UTRAN的長期演進（LTE）（也被稱為演進型UTRAN）8版規(guī)范被敲定在3GPP。LTE旨在雄心勃勃下行100Mbps的例如峰值數據速率的目標（DL）和50Mbps的上行鏈路（UL），提高小區(qū)邊緣用戶的吞吐量， MHz到20 MHz。[ 1 ]。語音IP（VoIP）力LTE必須有UMTS電路交換語音性能。然而，很明顯，LTE的應該是至少一樣好高速分組接入（HSPA）也在語音演變的軌跡。這些目標應滿足高達5公里的細胞范圍可達30公里應在輕微的降解能力的支持。LTE是分組數據傳輸和核心網絡的優(yōu)化純粹的分組交換，因此語音與VoIP純粹的傳播協議。LTE將支持的VoIP用戶數很高的服務質量（QoS）的VoIP是確定的最大端到端時延和數據包丟失。這些事實的VoIP用戶設置的挑戰(zhàn)設備（UE）的資源分配：分組調度（PS），鏈接適應（LA）和物理下行控制信道（PDCCH）。動態(tài)的詩被指定為默認的調度機制版本8。這意味著配置可以改變傳輸時間間隔（TTI）到另一個允許在基站中的調度器（BS）的基礎上進行優(yōu)化調度和鏈路適配的決定例如，信道質量指示（CQI）信息。多用戶和頻率頻域（FD）調度的收益是可以實現的VoIP應用與也；一定程度上由于小數據包大小和嚴格的延遲界限。然而，在用戶的動態(tài)調度的靈活性的高度處獲得高控制信令開銷。首先，BS需要頻率選擇性的CQI報告將在物理上行控制信道（PUCCH）由每個UE。然而，由于PUCCH的能力是有限的，只有非頻率選擇性寬帶CQI可能是可行的，特別是對于VoIP活躍用戶的數量。其次，作為數據信道是共享的，BS需要在PDCCH用戶信號被安排每TTI。該信令信息包括物理資源塊（PRBS），的調制和編碼方案（MCS）和相關的混合ARQ（HARQ）每個UE安排在UL或DL信息。同時PDCCH能力是有限的限制多個用戶每TTI量。為LTEVoIP的容量要求高，PUCCH和PDCCH消費/限制可能成為網絡性能的瓶頸。因此，一個半持續(xù)調度（SPS）方案，VoIP已經3GPP版本8對控制信道約束指定的戰(zhàn)斗。3G LTEVoIP服務進行了研究，例如在[ 2 ]，[ 3 ]，[ 4 ]，[ 5 ]和[ 6 ]。然而，VoIP容量沒有現實的PDCCH研究，盡管它明顯的VoIP性能的關鍵作用。影響CQI壓縮和報告對VoIP容量的機理進行了研究在[ 7 ]。然而，現實的PDCCH和semipersistentPS未納入帳戶。在[ 8 ]的PDCCH及其對分組調度性能研究。然而，研究認為，只有充分緩沖區(qū)的交通模型和頻域分組的影響調度性能。但是，在PDCCH限制的效果多個用戶每TTI大概是更高的VoIP流量由于小數據包大小和嚴格的延遲界限。本文的目的是研究帶有現實