GSM-R(GSM-Railway)__第7章-無線測量課件

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1、單擊以編輯母版標(biāo)題樣式,單擊以編輯母版文本樣式,第二級,第三級,第四級,第五級,無線測量,第7章,無線測量第7章,內(nèi)容提要,無線測量的基本原理,不連續(xù)傳輸,DTX,無線測量的處理方法,算術(shù)平均,加權(quán)平均,標(biāo)準(zhǔn)處理與快速處理,測量數(shù)據(jù)的丟失處理,內(nèi)容提要無線測量的基本原理,距離,質(zhì)量,測量,判決:越區(qū)切換,功率控制,呼叫清除,處理,信號強(qiáng)度,一、移動通信中對無線測量的要求,距離質(zhì)量測量判決:越區(qū)切換,功率控制,呼叫清除處理信,判決過程與參數(shù),判決過程與參數(shù),處理優(yōu)先級,處理優(yōu)先級,二、無線測量的流程,無線測量的結(jié)果是判決越區(qū)切換和功率控制的準(zhǔn)則。移動臺測量下行鏈路的信號強(qiáng)度和信號質(zhì)量，基站測量上

2、行鏈路的信號強(qiáng)度和信號質(zhì)量。,移動臺在,測量報告,中包含的測量數(shù)據(jù)：,下行鏈路接收的信號電平：,RXLEV_DL,下行鏈路接收的信號質(zhì)量，即誤比特率（,BER）：RXQUAL_DL,下行鏈路相鄰小區(qū)的信號電平：,RXLEV_NCELL(n),Layer 1 Header,消息中傳輸?shù)臏y量數(shù)據(jù)：,移動臺與基站的距離,移動臺當(dāng)前使用的功率：,MS_TXPWR,和,MS_TXPWR_CONF,基站計(jì)算的測量數(shù)據(jù),上行鏈路接收的信號電平：,RXLEV_UL,上行鏈路接收的信號質(zhì)量：,RXQUAL_UL,基站當(dāng)前使用的功率：,BS_TXPWR,二、無線測量的流程 無線測量的結(jié)果是判決越區(qū)切換和,無線測量

3、過程描述,無線測量過程描述,無線測量的報告消息,Mobile Measurements,Decision of Mobile Power Control,Call Clearing Indication,Handover Indication,L1M:Layer One Management,BSC,L1M,BTS,TRAFFIC,MANAGEMENT,無線測量的報告消息Mobile MeasurementsDe,D0,D1,D2,D3,D4,D5,D6,D7,A0,A1,A2,A3,-,-,-,D0,D1,D2,D3,D4,D5,D6,D7,A4,A5,A6,A7,-,-,-,A5,A6,A

4、7,D0,D1,D2,D3,D4,D5,D6,D7,A0,-,A1,A2,A3,D0,D1,D2,D3,D4,D5,D6,D7,A4,-,-,-,-,-,-,-,SDCCH/8,(downlink),SDCCH/8,(uplink),235,ms,On SDCCH,1,SACCH message block consists of 4 SACCH TS.,A complete measurement report is sent every 2 x 235=470 ms.,Di:data conveyed on sub-channel i,Ai:SACCH block associated w

5、ith block Di,三、無線測量的報告周期,D0D1D2D3D4D5D6D7A0A1A2A3-D0D,TCH,TCH,TCH,TCH,SACCH,Idle,On TCH,120,ms,1,SACCH message block consists of 4 SACCH TS.,A complete measurement report is sent every 4 x 120=480 ms.,12,TCH,12,TCH,.,.,無線測量報告周期,TCHTCHTCHTCHSACCHIdleOn TCH120,無線測量數(shù)據(jù)處理方法的三要素(對象、算法、時間),:,需要對功率電平、通信質(zhì)量、鄰

6、小區(qū)評估、距離,進(jìn)行平均處理；,兩種平均算法：算術(shù)平均(標(biāo)準(zhǔn))和加權(quán)平均；,規(guī)定每一次平均運(yùn)算的周期。,無線測量的三要素,無線測量數(shù)據(jù)處理方法的三要素(對象、算法、時間):無線測量的,RXLEV,RXLEV:Received signal level averaged over a complete SACCH block period and,coded onto 6 bits(0-63),RXLEV in dBm=-110+RXLEV=RXLEV ranges between-110 and-47 dBm,四、無線測量的數(shù)據(jù)類型,1、RXLEV(,信號電平),RXLEVRXLEV:Rece

7、ived signal l,RXQUAL,表示的是一個測量報告周期內(nèi)接收的信號質(zhì)量的平均值，長度為3比特，范圍從0到7,。,2、,無線通信質(zhì)量的測量,RXQUAL,與誤比特率的對應(yīng)關(guān)系,RXQUAL,誤比特率,平均值,0,12.8%,18.10%,誤比特率與,RXQUAL,（,i,）,的換算公式為：,平均誤比特率,=2,1/2,2,i,0.1%,RXQUAL表示的是一個測量報告周期內(nèi)接收的信號質(zhì)量的平均值,TS1,3,TS,Timing Advance,d=,2 x,t,TDMA Frame,F,The compensation of the propagation delay is by t

8、he advancing MS transmission time of,d.,The BTS continuously measures time offset between the burst schedule and the received burst.,TS1,TS1,TS1,Without TA,TS expected,by the BTS,3,TS-,d,TS2,Overlapping,TS2,TS2,TS2,Anticipation of,the MS transmission,t,3、無線傳播時延和定時提前量的測試,TS13 TSTiming Advance d=2 x,處

9、于專用模式,The BTS permanently evaluates,Timing Advance TA for Frame Alignment.,TA:0.63,The BTS permanently evaluates MS_BS Distance used as a,criterion for HO and Call Clearing.,MS_BS DISTANCE(m)=TA_TO_M*Timing advance TA,TA_TO_M=T*v/(2*BP),with:,T=Duration of one timeslot(secs)=3/5200,577 s,BP=No.of bi

10、t periods in one timeslot=156.25,v=velocity of light,MS_BS DISTANCE range=0-63,定時提前量和,MS-BS,距離數(shù)據(jù)的描述方法,處于專用模式The BTS permanently eval,MS_TXPWR and MS_TXPWR_CONF are expressed as a power control level from the maximum TXPWR possible in the band:,The Power Control Levels are not converted into dBm for

11、the storage,BS_TXPWR and BS_TXPWR_CONF are expressed as a power control level,in the range 0-15(not in dBm),from the maximum TXPWR allowed for the BTS through,bsTxPwrMax,parameter.,功率控制電平,Power Control Level,Nominal Output Power(900 MHz),0,43.41 dBm,1,41.39 dBm,2,39.37 dBm,.,MS_TXPWR and MS_TXPWR_CO

12、NF are,空閑,空閑,TC25,TC24,復(fù)幀,i,復(fù)幀,i+1,臨近,BTS,TS0,TS0,監(jiān)視窗口,TS0,TS0,TS0,在鄰近小區(qū)的,BCCH,頻率上測量,TC1,處于當(dāng)前小區(qū)的移動臺,TC25,TC24,TC1,五、對鄰小區(qū)的監(jiān)視和測量,下行鏈路,上行鏈路,空閑空閑TC25TC24復(fù)幀 i復(fù)幀 i+1臨近BTSTS,減少干擾,延長手機(jī)電池工作時間,a,a,b,b,小區(qū),b,小區(qū),a,六、不連續(xù)傳輸,減少干擾延長手機(jī)電池工作時間aabb小區(qū) b小區(qū) a六、不連,采用,DTX,不采用,DTX,下行鏈路測量報告,RXLEV_SUB_SERVING_CELL,RXQUAL_SUB_SE

13、RVING_CELL,RXLEV_FULL_SERVING_CELL,RXQUAL_FULL_SERVING_CELL,上行鏈路測量報告,RXLEV_SUB_UP,RXQUAL_SUB_UP,RXLEV_FULL_UP,RXQUAL_FULL_UP,BTS,測量,RxLevUL_SUB,RxLevUL_FULL,RxQualUL_SUB,RxQualUL_FULL,BTS,設(shè)置,DTX,標(biāo)志,DTX_USED,或,DTX_NOT USED,MS,測量,RxLevDL_SUB,RxLevDL_FULL,RxQualDL_SUB,RxQualDL_FULL,MS,設(shè)置,DTX,標(biāo)志,DTX_USE

14、D,或,DTX_NOT USED,不連續(xù)傳輸對無線測量的影響,采用DTX 不采用DTX 下行鏈路測量報告RXLEV_SUB,七、標(biāo)準(zhǔn)平均,七、標(biāo)準(zhǔn)平均,算術(shù)平均,算術(shù)平均是對最新的,XXHreqave,個數(shù)據(jù)(,L1M,收到的測量結(jié)果中的數(shù)據(jù))進(jìn)行計(jì)算，并在收到每個新的測量報告時就計(jì)算一次，即使目前并不需要這些值，也需要計(jì)算。,算術(shù)平均 算術(shù)平均是對最新的XXHreqave個數(shù)據(jù)(L,加權(quán)平均,加權(quán)平均是對,XXHreqt,個數(shù)據(jù)(測量值或算術(shù)平均值)進(jìn)行計(jì)算，并且只有當(dāng)需要的時候才會計(jì)算一次，即只有當(dāng)距離、質(zhì)量或電平的平均值需要與判決門限進(jìn)行比較時才會計(jì)算它們的加權(quán)平均值。每當(dāng),runCal

15、lClear,、,runPwrControl,或,runHandOver,出現(xiàn)時，才會計(jì)算加權(quán)平均。,加權(quán)平均 加權(quán)平均是對XXHreqt個數(shù)據(jù)(測量值或算術(shù),算術(shù)平均和加權(quán)平均相結(jié)合,算術(shù)平均和加權(quán)平均相結(jié)合,八、短平均(快速處理),八、短平均(快速處理),TIME,權(quán)重,舉例,:,XXHreqave,=4,XXHreqt,=3,Weights,=45,30,25,25,30,45,PAST,12 SACCH,塊,6 s,PRESENT,TIME,T0,HREQAVE x HREQT,WEIGHTING IS A WAY OF GIVING MORE IMPORTANCE TO,PRESEN

16、T OVER PAST MEASUREMENTS,標(biāo)準(zhǔn)處理,PRESENT,PAST,No handover decision before Hreqave*Hreqt Level and Quality measurements and rxNCellHreqave neighboring cells measurements.,TIME權(quán)重舉例:XXHreqave=4253045P,標(biāo)準(zhǔn)處理不能滿足特定的需要,HOW?,Arithmetic averaging on less measurements,SHORTER AVERAGES,WHY?,To enable a quicker handover decision,(HO on PBGT only),WHAT?,Level on the current+neighboring cells,WHO?,Fast moving MS,slow reselection process,MS turning at a street corner,MS entering a tunnel,SHORTER AVERAGES ARE USED