GSM-R(GSM-Railway)__第7章-無線測量課件

單擊以編輯母版標題樣式,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,算術平均,加權平均,標準處理與快速處理,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,質量,測量,判決:越區(qū)切換,功率控制,呼叫清除,處理,信號強度,一、移動通信中對無線測量的要求,距離質量測量判決: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,無線測量的結果是判決越區(qū)切換和功率控制的準則。移動臺測量下行鏈路的信號強度和信號質量，基站測量上行鏈路的信號強度和信號質量。,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,移動臺當前使用的功率：,MS_TXPWR,和,MS_TXPWR_CONF,基站計算的測量數(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量：,RXQUAL_UL,基站當前使用的功率：,BS_TXPWR,二、無線測量的流程 無線測量的結果是判決越區(qū)切換和,無線測量過程描述,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,A7,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 with 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、通信質量、鄰小區(qū)評估、距離,進行平均處理；,兩種平均算法：算術平均(標準)和加權平均；,規(guī)定每一次平均運算的周期。,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:Received signal l,RXQUAL,表示的是一個測量報告周期內(nèi)接收的信號質量的平均值，長度為3比特，范圍從0到7,。,2、,無線通信質量的測量,RXQUAL,與誤比特率的對應關系,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 the 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 bit 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 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_CONF are,空閑,空閑,TC25,TC24,復幀,i,復幀,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復幀 i復幀 i+1臨近BTSTS,減少干擾,延長手機電池工作時間,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_SERVING_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,設置,DTX,標志,DTX_USED,或,DTX_NOT USED,MS,測量,RxLevDL_SUB,RxLevDL_FULL,RxQualDL_SUB,RxQualDL_FULL,MS,設置,DTX,標志,DTX_USED,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、標準平均,七、標準平均,算術平均,算術平均是對最新的,XXHreqave,個數(shù)據(jù)(,L1M,收到的測量結果中的數(shù)據(jù))進行計算，并在收到每個新的測量報告時就計算一次，即使目前并不需要這些值，也需要計算。,算術平均 算術平均是對最新的XXHreqave個數(shù)據(jù)(L,加權平均,加權平均是對,XXHreqt,個數(shù)據(jù)(測量值或算術平均值)進行計算，并且只有當需要的時候才會計算一次，即只有當距離、質量或電平的平均值需要與判決門限進行比較時才會計算它們的加權平均值。每當,runCallClear,、,runPwrControl,或,runHandOver,出現(xiàn)時，才會計算加權平均。,加權平均 加權平均是對XXHreqt個數(shù)據(jù)(測量值或算術,算術平均和加權平均相結合,算術平均和加權平均相結合,八、短平均(快速處理),八、短平均(快速處理),TIME,權重,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,PRESENT OVER PAST MEASUREMENTS,標準處理,PRESENT,PAST,No handover decision before Hreqave*Hreqt Level and Quality measurements and rxNCellHreqave neighboring cells measurements.,TIME權重舉例:XXHreqave=4253045P,標準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