lte概述-資料下載頁(yè)
2025-07-22 09:47本頁(yè)面
【正文】 in HSPA but better performance in OFDM solution Due to orthogonality ? 3GPP R7 brings equalizer and MIMO also to HSPA Voice evolution in LTE/SAE Potential voice evolution steps in LTE LTE used for high speed packet data access only – Operator voice service provided over CS work Fallback to CS voice – LTE work is used for data only – Terminal is simultaneously registered to both LTE and 2G/3G CS work – Voice calls are initiated and received over CS work Single radio Voice Call Continuity (VCC) – Operator provides VoIP over LTE – IMS acts as control machinery – Voice calls can be handed over to CS work AllIP work – Operator provides VoIP over LTE – IMS acts as control machinery – Voice calls can be handed over to other packet switched works Single Radio Voice Call Continuity (SRVCC) LTE primary VoIP service provided via IMS/NVS AllIP work LTE voice evolution Fallback to CS when primary voice needed In ter 3G HSP A w orkLT E ra di o w orkS A E G WOp er atorIP w o rkIMSLT E PS /VoIPcap able MMESGSN/G GSNOpe ra t o r VoI P c on t r ol m ac hine ryVo IPVo IPLTE used for high speed packet data access only Primary voice service provided over CS work Inter 2G/3G radio work LTE radio work MME SAE GW Laptop with LTE data card 2G/3G terminal MSC Server System CS voice Data Operator IP work Optionally: Complementary VoIP via IMS/NVS and PCclient IMS/ NVS Operator VoIP plementary VoIP service + PCclient (NCS) (pl. VoIP) Optionally: Complementary VoIP via IMS/NVS Inter 2G/3G CS work LTE radio work MME SAE GW LTE ps with capable MSC Server System CS voice Data Operator IP work SGs IMS/ NVS Operator VoIP plementary VoIP service (pl. VoIP) O pera to rIP ne t w orkIn terne t2G /3 G CS w orkLT E r adi o w orkS A E G WSVIMS /NVSLTE PS /VoIPc apabl e MMEMS C Ser v er S y s temI M S c en t r aliz ed c o nt rol o f Vo I P and C S v oic e s e rv ic esCS v oi c eVoIPQ amp。 A Backup Comparing OFDM and SCFDMA QPSK example using N=4 subcarriers The following graphs show how this sequence of QPSK symbols is represented in frequency and time 1, 1 1,1 1, 1 1, 1 1, 1 1,1 1, 1 1, 1 15 kHz Frequency fc V CP OFDMA Data symbols occupy 15 kHz for one OFDMA symbol period SCFDMA Data symbols occupy N*15 kHz for 1/N SCFDMA symbol periods 60 kHz Frequency fc V CP
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