968-NB-IOT 中針對(duì)非錨點(diǎn)接入的Msg3上報(bào)質(zhì)量報(bào)告

1、UEDL carrier AMsg3 retransmissionDL carrier B圖1:網(wǎng)絡(luò)物聯(lián)網(wǎng)的Non-EDT隨機(jī)接入相關(guān)流程N(yùn)B-IOT中針對(duì)非錨點(diǎn)接入的Msg3上報(bào)質(zhì)量報(bào)告在Rei-16中，針對(duì)NB-IOT有較多增強(qiáng)，其中一項(xiàng)就是支持支持非錨點(diǎn)的Msg3質(zhì)量報(bào)告。對(duì)于Msg3中關(guān)于非錨點(diǎn)接入的信道質(zhì)量報(bào)告，信道質(zhì)量由UE解碼假設(shè)NPDCCH （BLER為1%） 所需的重復(fù)次數(shù)表示來(lái)定義。對(duì)于Msg3中關(guān)于非錨點(diǎn)接入的信道質(zhì)量報(bào)告，UE在其監(jiān)測(cè)的載波上執(zhí)行信道質(zhì)量測(cè)量，以接收Msg2 （即RAR）錨點(diǎn)接入的NPDCCH參數(shù)在表1中指定。對(duì)于非錨點(diǎn)接入，可以重用相同的參數(shù)。表1:下

2、行質(zhì)量報(bào)告的NPDCCH傳輸參數(shù)eNB參數(shù)值DCI formatFormat N1Number of information bits (excluding CRC)23bitsSystem bandwidth200kHzAntenna configuration2x1Aggregation level2DRXOFF SIB2-NB (RACH conflguration in UL anchor carrier)SIB22-NB(RACH configuration in UL non-anchor carrier(s) Msgl(Associated with DL carrier A)N

3、PDCCH for Msg2Msg2Msg3NPDCCH for Msg3 retransmission-NB-IoT中的non-EDT隨機(jī)接入過(guò)程如圖1所示。在Rei-14 NB-IoT增強(qiáng)中，非錨載波可用于 尋呼和隨機(jī)接入。UE從SIB22-NB獲取上行非錨載波中的RACH配置。對(duì)于非錨點(diǎn)接入，Msgl 的NPRACH資源與下行載波A相關(guān)聯(lián)，下行載波A在SIB22-NB中配置。在發(fā)送Msgl之后，RACH 過(guò)程中的下行鏈路接收在下行載波A中完成，包括Msg2、用于Msg3重傳的NPDCCH、用于Msg4 的NPDCCH和Msg4接收。如果UE在下行載波A上執(zhí)行信道質(zhì)量測(cè)量并在Msg3中報(bào)告

4、信道質(zhì)量，那么有利于使NPDCCH的 傳輸適應(yīng)RACH過(guò)程的后續(xù)步驟。然而，對(duì)于non-EDT情況，網(wǎng)絡(luò)可以將Msg4中的下行載波B 配置為單播接收。如果下行載波B與下行載波A不同，那么下行載波A中的測(cè)量和報(bào)告對(duì)于下 行載波B中的單播接收無(wú)效。如果UE可以在下行載波B上執(zhí)行測(cè)量并報(bào)告其信道質(zhì)量，那么有 利于適應(yīng)下行載波B中的單播傳輸。TS 36.211第節(jié)規(guī)定了NRS的存在，相應(yīng)的文本摘錄如下。在除尋呼、RACH和SC-PTM 之外的空閑模式下，NRS存在于subframes#0、#1、#3、#4、#9中，以及用于獨(dú)立和保護(hù)帶 部署模式的NBToT卜行子幀中。對(duì)于帶內(nèi)部署模式,NRS存在于su

5、bframes#0、#4、#/l3NBToT 下行子幀中。所以NRS總是存在于一組指定的子幀中。因此，UE可以通過(guò)在Msg2接收的載 波以外的其他載波上使用這些NRS子幀來(lái)執(zhí)行信道質(zhì)量測(cè)量。Extracted from section 1026 ofTS 36.211On an NB-IoT carrier for which DL-CarrierConfigCommon-NB is present and no inbandCarrierlnfo is present.An NB-IoT UE may assume NRSs are transmitted in NB-IoT DL subf

6、rames that are used forType 1A-NPDCCH common search space, and Type2A-NPDCCH common search space, as well as 10 NB-IoT DL subframes prior and 4 NB-IoT DL subframes after each Typel A-NPDCCH common search space and Type2A-NPDCCH common search space. A UE may assume NRSs are transmitted in NB-IoT DL s

7、ubframes carrying NPDSCH scheduled by DCICRC scrambled by G-RNTI or SC-RNTI as well as 4 NB-IoT DL subframes prior and after the scheduled NPDSCH.In other cases, if frame structure typl is used, the UE may assume NRSs are transmitted in subframes #0, #1, #3, #4, #9, and in NB-IoT downlink subframes

8、and shall not expect NRSs in other downlink subframes.On an NB-IoT carrier for which DL-CarrierConfigCommon-NB is present and inbandCarrierlnfo is present:An NB-IoT UE may assume NRSs are transmitted in NB-IoT DL subframes that are used forType 1 A-NPDCCH common search space, and Type2A-NPDCCH commo

9、n search space, as well as 10 NB-IoT DL subframes prior and 4 NB-IoT DL subframes after each Typel A-NPDCCH common search space and Type2A-NPDCCH common search space. A UE may assume NRSs are transmitted in NB-IoT DL subframes carrying NPDSCH scheduled by DCI CRC scrambled by G-RNTI or SC-RNTI as we

10、ll as 4 NB-IoT DL subframes prior and after the scheduled NPDSCH.In other cases, if frame structure type 1 is used, the UE may assume NRSs are transmitted in subframes #0, #4, #9, and in NB-IoT downlink subframes and shall not expect NRSs in other downlink subframes.錨點(diǎn)接入的測(cè)量周期為T1或T2,其中T1是用于增強(qiáng)覆蓋水平估計(jì)的N

11、RSRP測(cè)量的NPRACH傳輸之前的時(shí)間段。T2是從隨機(jī)接入響應(yīng)開始到用于下行信道質(zhì)量報(bào)告的NPUSCH formatl開始的時(shí)間段。由UE實(shí)現(xiàn)使用T1或T2來(lái)估計(jì)下行信道質(zhì)量。對(duì)于非錨接入，可以使用相同的測(cè)量周期。對(duì)于RelT4中錨點(diǎn)載波的信道質(zhì)量報(bào)告，消息RRCConnectionReastablishmentRequest-NB 中有3個(gè)候選值，其他RRC消息有12個(gè)候選值。3個(gè)候選值如表2所示。12個(gè)候選值如表3所 示。這里Rmax是NPDCCH Type2 CSS的最大重復(fù)次數(shù)，即RAR的搜索空間。表2：當(dāng)支持DL信道質(zhì)量報(bào)告時(shí)，CQI-NPDCCH-Short-NB的下行信道質(zhì)量測(cè)

12、量報(bào)告映射Reported valueNPDCCH repetition levelnoMeasurementsNo measurement reportingcandidateRep-1Rmax/8 (Note 1)candidateRep-2RmaxcandidateRep-34xRmax (Note 2)Note 1: When Rmax is less than 8, set candidateRep-1 to 1.Note 2: When Rmax is more than 512, set candidateRep-3 to 2048.表3:當(dāng)支持下行信道質(zhì)量報(bào)告時(shí)，CQI-NPD

13、CCH-NB的下行信道質(zhì)量測(cè)量報(bào)告映射Reported valueNPDCCH repetition levelnoMeasurementNo measurement reportingcandidateRep-A1candidateRep-B2candidateRep-C4candidateRep-D8candidateRep-E16candidateRep-F32candidateRep-G64candidateRep-H128candidateRep-I256candidateRep-J512candidateRep-K1024candidateRep-L2048由于非錨載波上的eNB傳

14、輸功率可能小于錨點(diǎn)載波，從而導(dǎo)致更大的重復(fù)，因此UE可以為 非錨載波提供更準(zhǔn)確的信道質(zhì)量反應(yīng)以防止浪費(fèi)資源是有益的。對(duì)于3個(gè)候選值的情況，報(bào)告的值基于Rmax。對(duì)于Msgl傳輸之后的測(cè)量周期T2,如果報(bào)告 的值可以包括有關(guān)Msg2實(shí)際解碼方式的信息，那么該值對(duì)eNB調(diào)度器更有用。信道質(zhì)量在Msg3 中報(bào)告。因此，應(yīng)成功解碼Msg2和Msg2的NPDCCH。信息包括NPDCCH調(diào)度Msg2的重復(fù)次數(shù), 其中UE解碼成功，由DCI formatNl的DCI子幀重復(fù)次數(shù)字段指示的重復(fù)次數(shù)，用于Msg2調(diào) 度的重復(fù)次數(shù)，用于UE解碼成功的Msg2的重復(fù)次數(shù)，以及用于Msg2傳輸?shù)闹貜?fù)次數(shù)都是相 關(guān)的。由于信道質(zhì)量定義表示為NPDCCH解碼的重復(fù)次數(shù)，因此更容易從UE成功解碼的 NPDCCH調(diào)度Msg2的重復(fù)次數(shù)和用于Msg2調(diào)度的DCI formatNl的DCI子幀重復(fù)次數(shù)字段指示 的重復(fù)次數(shù)推導(dǎo)。因此，對(duì)于Msg3中關(guān)于非錨點(diǎn)接入的信道質(zhì)量報(bào)告，可以考慮以下信息：Rmax